Merge pull request #9545 from yang-g/fix

Minor fixes
diff --git a/doc/command_line_tool.md b/doc/command_line_tool.md
index 79a131c..77c3d07 100644
--- a/doc/command_line_tool.md
+++ b/doc/command_line_tool.md
@@ -2,8 +2,8 @@
 
 ## Overview
 
-This document describes the command line tool that comes with gRPC repository. It is desireable to have command line
-tools written in other languages to roughly follow the same syntax and flags.
+This document describes the command line tool that comes with gRPC repository. It is desirable to have command line
+tools written in other languages roughly follow the same syntax and flags.
 
 At this point, the tool needs to be built from source, and it should be moved out to grpc-tools repository as a stand
 alone application once it is mature enough.
@@ -30,7 +30,26 @@
 
 ## Code location
 
-To use the tool, you need to get the grpc repository and in the grpc directory execute
+To use the tool, you need to get the grpc repository and make sure your system
+has the prerequisites for building grpc from source, given in the [installation
+instructions](https://github.com/grpc/grpc/blob/master/INSTALL.md).
+
+In order to build the grpc command line tool from a fresh clone of the grpc
+repository, you need to run the following command to update submodules:
+
+```
+git submodule update --init
+```
+
+You also need to have the gflags library installed on your system. On Linux
+systems, gflags can be installed with the following command:
+
+```
+sudo apt-get install libgflags-dev
+```
+
+Once the prerequisites are satisfied, you can build the command line tool with
+the command:
 
 ```
 $ make grpc_cli
diff --git a/doc/environment_variables.md b/doc/environment_variables.md
index 832762a..2c83972 100644
--- a/doc/environment_variables.md
+++ b/doc/environment_variables.md
@@ -35,6 +35,7 @@
   A comma separated list of tracers that provide additional insight into how
   gRPC C core is processing requests via debug logs. Available tracers include:
   - api - traces api calls to the C core
+  - call_error - traces the possible errors contributing to final call status
   - channel - traces operations on the C core channel stack
   - combiner - traces combiner lock state
   - compression - traces compression operations
@@ -55,10 +56,10 @@
   - secure_endpoint - traces bytes flowing through encrypted channels
   - transport_security - traces metadata about secure channel establishment
   - tcp - traces bytes in and out of a channel
-  
+
   'all' can additionally be used to turn all traces on.
   Individual traces can be disabled by prefixing them with '-'.
- 
+
   Example:
   export GRPC_TRACE=all,-pending_tags
 
diff --git a/examples/php/composer.json b/examples/php/composer.json
index 3d1a95d..f0b9977 100644
--- a/examples/php/composer.json
+++ b/examples/php/composer.json
@@ -2,7 +2,11 @@
   "name": "grpc/grpc-demo",
   "description": "gRPC example for PHP",
   "require": {
-    "ext-grpc": "*",
-    "grpc/grpc": "v1.0.0"
+    "grpc/grpc": "v1.1.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "": "route_guide/"
+    }
   }
 }
diff --git a/examples/php/greeter_client.php b/examples/php/greeter_client.php
index a5c0865..986a4bb 100644
--- a/examples/php/greeter_client.php
+++ b/examples/php/greeter_client.php
@@ -33,14 +33,18 @@
  */
 
 require dirname(__FILE__).'/vendor/autoload.php';
-require dirname(__FILE__).'/helloworld.php';
+
+// The following includes are needed when using protobuf 3.1.0
+// and will suppress warnings when using protobuf 3.2.0+
+@include_once dirname(__FILE__).'/helloworld.pb.php';
+@include_once dirname(__FILE__).'/helloworld_grpc_pb.php';
 
 function greet($name)
 {
-    $client = new helloworld\GreeterClient('localhost:50051', [
+    $client = new Helloworld\GreeterClient('localhost:50051', [
         'credentials' => Grpc\ChannelCredentials::createInsecure(),
     ]);
-    $request = new helloworld\HelloRequest();
+    $request = new Helloworld\HelloRequest();
     $request->setName($name);
     list($reply, $status) = $client->SayHello($request)->wait();
     $message = $reply->getMessage();
diff --git a/examples/php/helloworld.pb.php b/examples/php/helloworld.pb.php
new file mode 100644
index 0000000..757a4a5
--- /dev/null
+++ b/examples/php/helloworld.pb.php
@@ -0,0 +1,58 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: helloworld.proto
+
+namespace Helloworld;
+
+use Google\Protobuf\Internal\DescriptorPool;
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+class HelloRequest extends \Google\Protobuf\Internal\Message
+{
+    private $name = '';
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function setName($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->name = $var;
+    }
+
+}
+
+class HelloReply extends \Google\Protobuf\Internal\Message
+{
+    private $message = '';
+
+    public function getMessage()
+    {
+        return $this->message;
+    }
+
+    public function setMessage($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->message = $var;
+    }
+
+}
+
+$pool = DescriptorPool::getGeneratedPool();
+
+$pool->internalAddGeneratedFile(hex2bin(
+    "0ae6010a1068656c6c6f776f726c642e70726f746f120a68656c6c6f776f" .
+    "726c64221c0a0c48656c6c6f52657175657374120c0a046e616d65180120" .
+    "012809221d0a0a48656c6c6f5265706c79120f0a076d6573736167651801" .
+    "2001280932490a0747726565746572123e0a0853617948656c6c6f12182e" .
+    "68656c6c6f776f726c642e48656c6c6f526571756573741a162e68656c6c" .
+    "6f776f726c642e48656c6c6f5265706c79220042360a1b696f2e67727063" .
+    "2e6578616d706c65732e68656c6c6f776f726c64420f48656c6c6f576f72" .
+    "6c6450726f746f5001a20203484c57620670726f746f33"
+));
+
diff --git a/examples/php/helloworld.php b/examples/php/helloworld.php
deleted file mode 100644
index 697f52a..0000000
--- a/examples/php/helloworld.php
+++ /dev/null
@@ -1,168 +0,0 @@
-<?php
-// DO NOT EDIT! Generated by Protobuf-PHP protoc plugin 1.0
-// Source: helloworld.proto
-//   Date: 2015-09-24 20:40:14
-
-namespace helloworld {
-
-  class HelloRequest extends \DrSlump\Protobuf\Message
-  {
-      /**  @var string */
-    public $name = null;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'helloworld.HelloRequest');
-
-      // OPTIONAL STRING name = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'name';
-          $f->type = \DrSlump\Protobuf::TYPE_STRING;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <name> has a value.
-     *
-     * @return bool
-     */
-    public function hasName()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <name> value.
-     *
-     * @return \helloworld\HelloRequest
-     */
-    public function clearName()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <name> value.
-     *
-     * @return string
-     */
-    public function getName()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <name> value.
-     *
-     * @param string $value
-     *
-     * @return \helloworld\HelloRequest
-     */
-    public function setName($value)
-    {
-        return $this->_set(1, $value);
-    }
-  }
-}
-
-namespace helloworld {
-
-  class HelloReply extends \DrSlump\Protobuf\Message
-  {
-      /**  @var string */
-    public $message = null;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'helloworld.HelloReply');
-
-      // OPTIONAL STRING message = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'message';
-          $f->type = \DrSlump\Protobuf::TYPE_STRING;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <message> has a value.
-     *
-     * @return bool
-     */
-    public function hasMessage()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <message> value.
-     *
-     * @return \helloworld\HelloReply
-     */
-    public function clearMessage()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <message> value.
-     *
-     * @return string
-     */
-    public function getMessage()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <message> value.
-     *
-     * @param string $value
-     *
-     * @return \helloworld\HelloReply
-     */
-    public function setMessage($value)
-    {
-        return $this->_set(1, $value);
-    }
-  }
-}
-
-namespace helloworld {
-
-  class GreeterClient extends \Grpc\BaseStub
-  {
-      public function __construct($hostname, $opts)
-      {
-          parent::__construct($hostname, $opts);
-      }
-    /**
-     * @param helloworld\HelloRequest $input
-     */
-    public function SayHello(\helloworld\HelloRequest $argument, $metadata = array(), $options = array())
-    {
-        return $this->_simpleRequest('/helloworld.Greeter/SayHello', $argument, '\helloworld\HelloReply::deserialize', $metadata, $options);
-    }
-  }
-}
diff --git a/examples/php/helloworld.proto b/examples/php/helloworld_grpc_pb.php
similarity index 62%
rename from examples/php/helloworld.proto
rename to examples/php/helloworld_grpc_pb.php
index ad8f7a1..cae48bc 100644
--- a/examples/php/helloworld.proto
+++ b/examples/php/helloworld_grpc_pb.php
@@ -1,3 +1,7 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
 // Copyright 2015, Google Inc.
 // All rights reserved.
 //
@@ -26,25 +30,35 @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+namespace Helloworld {
 
-syntax = "proto2";
+  // The greeting service definition.
+  class GreeterClient extends \Grpc\BaseStub {
 
-option java_package = "ex.grpc";
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+      parent::__construct($hostname, $opts, $channel);
+    }
 
-package helloworld;
+    /**
+     * Sends a greeting
+     * @param \Helloworld\HelloRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function SayHello(\Helloworld\HelloRequest $argument,
+      $metadata = [], $options = []) {
+      return $this->_simpleRequest('/helloworld.Greeter/SayHello',
+      $argument,
+      ['\Helloworld\HelloReply', 'decode'],
+      $metadata, $options);
+    }
 
-// The greeting service definition.
-service Greeter {
-  // Sends a greeting
-  rpc SayHello (HelloRequest) returns (HelloReply) {}
-}
+  }
 
-// The request message containing the user's name.
-message HelloRequest {
-  optional string name = 1;
-}
-
-// The response message containing the greetings
-message HelloReply {
-  optional string message = 1;
 }
diff --git a/examples/php/route_guide/route_guide.pb.php b/examples/php/route_guide/route_guide.pb.php
new file mode 100644
index 0000000..78f3ea6
--- /dev/null
+++ b/examples/php/route_guide/route_guide.pb.php
@@ -0,0 +1,209 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: route_guide.proto
+
+namespace Routeguide;
+
+use Google\Protobuf\Internal\DescriptorPool;
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+class Point extends \Google\Protobuf\Internal\Message
+{
+    private $latitude = 0;
+    private $longitude = 0;
+
+    public function getLatitude()
+    {
+        return $this->latitude;
+    }
+
+    public function setLatitude($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->latitude = $var;
+    }
+
+    public function getLongitude()
+    {
+        return $this->longitude;
+    }
+
+    public function setLongitude($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->longitude = $var;
+    }
+
+}
+
+class Rectangle extends \Google\Protobuf\Internal\Message
+{
+    private $lo = null;
+    private $hi = null;
+
+    public function getLo()
+    {
+        return $this->lo;
+    }
+
+    public function setLo(&$var)
+    {
+        GPBUtil::checkMessage($var, \Routeguide\Point::class);
+        $this->lo = $var;
+    }
+
+    public function getHi()
+    {
+        return $this->hi;
+    }
+
+    public function setHi(&$var)
+    {
+        GPBUtil::checkMessage($var, \Routeguide\Point::class);
+        $this->hi = $var;
+    }
+
+}
+
+class Feature extends \Google\Protobuf\Internal\Message
+{
+    private $name = '';
+    private $location = null;
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function setName($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->name = $var;
+    }
+
+    public function getLocation()
+    {
+        return $this->location;
+    }
+
+    public function setLocation(&$var)
+    {
+        GPBUtil::checkMessage($var, \Routeguide\Point::class);
+        $this->location = $var;
+    }
+
+}
+
+class RouteNote extends \Google\Protobuf\Internal\Message
+{
+    private $location = null;
+    private $message = '';
+
+    public function getLocation()
+    {
+        return $this->location;
+    }
+
+    public function setLocation(&$var)
+    {
+        GPBUtil::checkMessage($var, \Routeguide\Point::class);
+        $this->location = $var;
+    }
+
+    public function getMessage()
+    {
+        return $this->message;
+    }
+
+    public function setMessage($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->message = $var;
+    }
+
+}
+
+class RouteSummary extends \Google\Protobuf\Internal\Message
+{
+    private $point_count = 0;
+    private $feature_count = 0;
+    private $distance = 0;
+    private $elapsed_time = 0;
+
+    public function getPointCount()
+    {
+        return $this->point_count;
+    }
+
+    public function setPointCount($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->point_count = $var;
+    }
+
+    public function getFeatureCount()
+    {
+        return $this->feature_count;
+    }
+
+    public function setFeatureCount($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->feature_count = $var;
+    }
+
+    public function getDistance()
+    {
+        return $this->distance;
+    }
+
+    public function setDistance($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->distance = $var;
+    }
+
+    public function getElapsedTime()
+    {
+        return $this->elapsed_time;
+    }
+
+    public function setElapsedTime($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->elapsed_time = $var;
+    }
+
+}
+
+$pool = DescriptorPool::getGeneratedPool();
+
+$pool->internalAddGeneratedFile(hex2bin(
+    "0ac5050a11726f7574655f67756964652e70726f746f120a726f75746567" .
+    "75696465222c0a05506f696e7412100a086c617469747564651801200128" .
+    "0512110a096c6f6e67697475646518022001280522490a0952656374616e" .
+    "676c65121d0a026c6f18012001280b32112e726f75746567756964652e50" .
+    "6f696e74121d0a02686918022001280b32112e726f75746567756964652e" .
+    "506f696e74223c0a0746656174757265120c0a046e616d65180120012809" .
+    "12230a086c6f636174696f6e18022001280b32112e726f75746567756964" .
+    "652e506f696e7422410a09526f7574654e6f746512230a086c6f63617469" .
+    "6f6e18012001280b32112e726f75746567756964652e506f696e74120f0a" .
+    "076d65737361676518022001280922620a0c526f75746553756d6d617279" .
+    "12130a0b706f696e745f636f756e7418012001280512150a0d6665617475" .
+    "72655f636f756e7418022001280512100a0864697374616e636518032001" .
+    "280512140a0c656c61707365645f74696d651804200128053285020a0a52" .
+    "6f757465477569646512360a0a4765744665617475726512112e726f7574" .
+    "6567756964652e506f696e741a132e726f75746567756964652e46656174" .
+    "7572652200123e0a0c4c697374466561747572657312152e726f75746567" .
+    "756964652e52656374616e676c651a132e726f75746567756964652e4665" .
+    "617475726522003001123e0a0b5265636f7264526f75746512112e726f75" .
+    "746567756964652e506f696e741a182e726f75746567756964652e526f75" .
+    "746553756d6d61727922002801123f0a09526f7574654368617412152e72" .
+    "6f75746567756964652e526f7574654e6f74651a152e726f757465677569" .
+    "64652e526f7574654e6f746522002801300142360a1b696f2e677270632e" .
+    "6578616d706c65732e726f7574656775696465420f526f75746547756964" .
+    "6550726f746f5001a20203525447620670726f746f33"
+));
+
diff --git a/examples/php/route_guide/route_guide.php b/examples/php/route_guide/route_guide.php
deleted file mode 100644
index 65045d0..0000000
--- a/examples/php/route_guide/route_guide.php
+++ /dev/null
@@ -1,789 +0,0 @@
-<?php
-// DO NOT EDIT! Generated by Protobuf-PHP protoc plugin 1.0
-// Source: route_guide.proto
-//   Date: 2015-09-24 21:21:51
-
-namespace routeguide {
-
-  class Point extends \DrSlump\Protobuf\Message
-  {
-      /**  @var int */
-    public $latitude = 0;
-
-    /**  @var int */
-    public $longitude = 0;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'routeguide.Point');
-
-      // OPTIONAL INT32 latitude = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'latitude';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-      // OPTIONAL INT32 longitude = 2
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 2;
-          $f->name = 'longitude';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <latitude> has a value.
-     *
-     * @return bool
-     */
-    public function hasLatitude()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <latitude> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function clearLatitude()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <latitude> value.
-     *
-     * @return int
-     */
-    public function getLatitude()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <latitude> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\Point
-     */
-    public function setLatitude($value)
-    {
-        return $this->_set(1, $value);
-    }
-
-    /**
-     * Check if <longitude> has a value.
-     *
-     * @return bool
-     */
-    public function hasLongitude()
-    {
-        return $this->_has(2);
-    }
-
-    /**
-     * Clear <longitude> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function clearLongitude()
-    {
-        return $this->_clear(2);
-    }
-
-    /**
-     * Get <longitude> value.
-     *
-     * @return int
-     */
-    public function getLongitude()
-    {
-        return $this->_get(2);
-    }
-
-    /**
-     * Set <longitude> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\Point
-     */
-    public function setLongitude($value)
-    {
-        return $this->_set(2, $value);
-    }
-  }
-}
-
-namespace routeguide {
-
-  class Rectangle extends \DrSlump\Protobuf\Message
-  {
-      /**  @var \routeguide\Point */
-    public $lo = null;
-
-    /**  @var \routeguide\Point */
-    public $hi = null;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'routeguide.Rectangle');
-
-      // OPTIONAL MESSAGE lo = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'lo';
-          $f->type = \DrSlump\Protobuf::TYPE_MESSAGE;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->reference = '\routeguide\Point';
-          $descriptor->addField($f);
-
-      // OPTIONAL MESSAGE hi = 2
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 2;
-          $f->name = 'hi';
-          $f->type = \DrSlump\Protobuf::TYPE_MESSAGE;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->reference = '\routeguide\Point';
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <lo> has a value.
-     *
-     * @return bool
-     */
-    public function hasLo()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <lo> value.
-     *
-     * @return \routeguide\Rectangle
-     */
-    public function clearLo()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <lo> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function getLo()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <lo> value.
-     *
-     * @param \routeguide\Point $value
-     *
-     * @return \routeguide\Rectangle
-     */
-    public function setLo(\routeguide\Point $value)
-    {
-        return $this->_set(1, $value);
-    }
-
-    /**
-     * Check if <hi> has a value.
-     *
-     * @return bool
-     */
-    public function hasHi()
-    {
-        return $this->_has(2);
-    }
-
-    /**
-     * Clear <hi> value.
-     *
-     * @return \routeguide\Rectangle
-     */
-    public function clearHi()
-    {
-        return $this->_clear(2);
-    }
-
-    /**
-     * Get <hi> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function getHi()
-    {
-        return $this->_get(2);
-    }
-
-    /**
-     * Set <hi> value.
-     *
-     * @param \routeguide\Point $value
-     *
-     * @return \routeguide\Rectangle
-     */
-    public function setHi(\routeguide\Point $value)
-    {
-        return $this->_set(2, $value);
-    }
-  }
-}
-
-namespace routeguide {
-
-  class Feature extends \DrSlump\Protobuf\Message
-  {
-      /**  @var string */
-    public $name = null;
-
-    /**  @var \routeguide\Point */
-    public $location = null;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'routeguide.Feature');
-
-      // OPTIONAL STRING name = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'name';
-          $f->type = \DrSlump\Protobuf::TYPE_STRING;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $descriptor->addField($f);
-
-      // OPTIONAL MESSAGE location = 2
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 2;
-          $f->name = 'location';
-          $f->type = \DrSlump\Protobuf::TYPE_MESSAGE;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->reference = '\routeguide\Point';
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <name> has a value.
-     *
-     * @return bool
-     */
-    public function hasName()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <name> value.
-     *
-     * @return \routeguide\Feature
-     */
-    public function clearName()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <name> value.
-     *
-     * @return string
-     */
-    public function getName()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <name> value.
-     *
-     * @param string $value
-     *
-     * @return \routeguide\Feature
-     */
-    public function setName($value)
-    {
-        return $this->_set(1, $value);
-    }
-
-    /**
-     * Check if <location> has a value.
-     *
-     * @return bool
-     */
-    public function hasLocation()
-    {
-        return $this->_has(2);
-    }
-
-    /**
-     * Clear <location> value.
-     *
-     * @return \routeguide\Feature
-     */
-    public function clearLocation()
-    {
-        return $this->_clear(2);
-    }
-
-    /**
-     * Get <location> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function getLocation()
-    {
-        return $this->_get(2);
-    }
-
-    /**
-     * Set <location> value.
-     *
-     * @param \routeguide\Point $value
-     *
-     * @return \routeguide\Feature
-     */
-    public function setLocation(\routeguide\Point $value)
-    {
-        return $this->_set(2, $value);
-    }
-  }
-}
-
-namespace routeguide {
-
-  class RouteNote extends \DrSlump\Protobuf\Message
-  {
-      /**  @var \routeguide\Point */
-    public $location = null;
-
-    /**  @var string */
-    public $message = null;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'routeguide.RouteNote');
-
-      // OPTIONAL MESSAGE location = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'location';
-          $f->type = \DrSlump\Protobuf::TYPE_MESSAGE;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->reference = '\routeguide\Point';
-          $descriptor->addField($f);
-
-      // OPTIONAL STRING message = 2
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 2;
-          $f->name = 'message';
-          $f->type = \DrSlump\Protobuf::TYPE_STRING;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <location> has a value.
-     *
-     * @return bool
-     */
-    public function hasLocation()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <location> value.
-     *
-     * @return \routeguide\RouteNote
-     */
-    public function clearLocation()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <location> value.
-     *
-     * @return \routeguide\Point
-     */
-    public function getLocation()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <location> value.
-     *
-     * @param \routeguide\Point $value
-     *
-     * @return \routeguide\RouteNote
-     */
-    public function setLocation(\routeguide\Point $value)
-    {
-        return $this->_set(1, $value);
-    }
-
-    /**
-     * Check if <message> has a value.
-     *
-     * @return bool
-     */
-    public function hasMessage()
-    {
-        return $this->_has(2);
-    }
-
-    /**
-     * Clear <message> value.
-     *
-     * @return \routeguide\RouteNote
-     */
-    public function clearMessage()
-    {
-        return $this->_clear(2);
-    }
-
-    /**
-     * Get <message> value.
-     *
-     * @return string
-     */
-    public function getMessage()
-    {
-        return $this->_get(2);
-    }
-
-    /**
-     * Set <message> value.
-     *
-     * @param string $value
-     *
-     * @return \routeguide\RouteNote
-     */
-    public function setMessage($value)
-    {
-        return $this->_set(2, $value);
-    }
-  }
-}
-
-namespace routeguide {
-
-  class RouteSummary extends \DrSlump\Protobuf\Message
-  {
-      /**  @var int */
-    public $point_count = 0;
-
-    /**  @var int */
-    public $feature_count = 0;
-
-    /**  @var int */
-    public $distance = 0;
-
-    /**  @var int */
-    public $elapsed_time = 0;
-
-    /** @var \Closure[] */
-    protected static $__extensions = array();
-
-      public static function descriptor()
-      {
-          $descriptor = new \DrSlump\Protobuf\Descriptor(__CLASS__, 'routeguide.RouteSummary');
-
-      // OPTIONAL INT32 point_count = 1
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 1;
-          $f->name = 'point_count';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-      // OPTIONAL INT32 feature_count = 2
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 2;
-          $f->name = 'feature_count';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-      // OPTIONAL INT32 distance = 3
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 3;
-          $f->name = 'distance';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-      // OPTIONAL INT32 elapsed_time = 4
-      $f = new \DrSlump\Protobuf\Field();
-          $f->number = 4;
-          $f->name = 'elapsed_time';
-          $f->type = \DrSlump\Protobuf::TYPE_INT32;
-          $f->rule = \DrSlump\Protobuf::RULE_OPTIONAL;
-          $f->default = 0;
-          $descriptor->addField($f);
-
-          foreach (self::$__extensions as $cb) {
-              $descriptor->addField($cb(), true);
-          }
-
-          return $descriptor;
-      }
-
-    /**
-     * Check if <point_count> has a value.
-     *
-     * @return bool
-     */
-    public function hasPointCount()
-    {
-        return $this->_has(1);
-    }
-
-    /**
-     * Clear <point_count> value.
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function clearPointCount()
-    {
-        return $this->_clear(1);
-    }
-
-    /**
-     * Get <point_count> value.
-     *
-     * @return int
-     */
-    public function getPointCount()
-    {
-        return $this->_get(1);
-    }
-
-    /**
-     * Set <point_count> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function setPointCount($value)
-    {
-        return $this->_set(1, $value);
-    }
-
-    /**
-     * Check if <feature_count> has a value.
-     *
-     * @return bool
-     */
-    public function hasFeatureCount()
-    {
-        return $this->_has(2);
-    }
-
-    /**
-     * Clear <feature_count> value.
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function clearFeatureCount()
-    {
-        return $this->_clear(2);
-    }
-
-    /**
-     * Get <feature_count> value.
-     *
-     * @return int
-     */
-    public function getFeatureCount()
-    {
-        return $this->_get(2);
-    }
-
-    /**
-     * Set <feature_count> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function setFeatureCount($value)
-    {
-        return $this->_set(2, $value);
-    }
-
-    /**
-     * Check if <distance> has a value.
-     *
-     * @return bool
-     */
-    public function hasDistance()
-    {
-        return $this->_has(3);
-    }
-
-    /**
-     * Clear <distance> value.
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function clearDistance()
-    {
-        return $this->_clear(3);
-    }
-
-    /**
-     * Get <distance> value.
-     *
-     * @return int
-     */
-    public function getDistance()
-    {
-        return $this->_get(3);
-    }
-
-    /**
-     * Set <distance> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function setDistance($value)
-    {
-        return $this->_set(3, $value);
-    }
-
-    /**
-     * Check if <elapsed_time> has a value.
-     *
-     * @return bool
-     */
-    public function hasElapsedTime()
-    {
-        return $this->_has(4);
-    }
-
-    /**
-     * Clear <elapsed_time> value.
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function clearElapsedTime()
-    {
-        return $this->_clear(4);
-    }
-
-    /**
-     * Get <elapsed_time> value.
-     *
-     * @return int
-     */
-    public function getElapsedTime()
-    {
-        return $this->_get(4);
-    }
-
-    /**
-     * Set <elapsed_time> value.
-     *
-     * @param int $value
-     *
-     * @return \routeguide\RouteSummary
-     */
-    public function setElapsedTime($value)
-    {
-        return $this->_set(4, $value);
-    }
-  }
-}
-
-namespace routeguide {
-
-  class RouteGuideClient extends \Grpc\BaseStub
-  {
-      public function __construct($hostname, $opts)
-      {
-          parent::__construct($hostname, $opts);
-      }
-    /**
-     * @param routeguide\Point $input
-     */
-    public function GetFeature(\routeguide\Point $argument, $metadata = array(), $options = array())
-    {
-        return $this->_simpleRequest('/routeguide.RouteGuide/GetFeature', $argument, '\routeguide\Feature::deserialize', $metadata, $options);
-    }
-    /**
-     * @param routeguide\Rectangle $input
-     */
-    public function ListFeatures($argument, $metadata = array(), $options = array())
-    {
-        return $this->_serverStreamRequest('/routeguide.RouteGuide/ListFeatures', $argument, '\routeguide\Feature::deserialize', $metadata, $options);
-    }
-    /**
-     * @param routeguide\Point $input
-     */
-    public function RecordRoute($metadata = array())
-    {
-        return $this->_clientStreamRequest('/routeguide.RouteGuide/RecordRoute', '\routeguide\RouteSummary::deserialize', $metadata);
-    }
-    /**
-     * @param routeguide\RouteNote $input
-     */
-    public function RouteChat($metadata = array())
-    {
-        return $this->_bidiRequest('/routeguide.RouteGuide/RouteChat', '\routeguide\RouteNote::deserialize', $metadata);
-    }
-  }
-}
diff --git a/examples/php/route_guide/route_guide.proto b/examples/php/route_guide/route_guide.proto
deleted file mode 100644
index d50f8a5..0000000
--- a/examples/php/route_guide/route_guide.proto
+++ /dev/null
@@ -1,120 +0,0 @@
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-syntax = "proto2";
-
-option java_package = "io.grpc.examples";
-
-package routeguide;
-
-// Interface exported by the server.
-service RouteGuide {
-  // A simple RPC.
-  //
-  // Obtains the feature at a given position.
-  rpc GetFeature(Point) returns (Feature) {}
-
-  // A server-to-client streaming RPC.
-  //
-  // Obtains the Features available within the given Rectangle.  Results are
-  // streamed rather than returned at once (e.g. in a response message with a
-  // repeated field), as the rectangle may cover a large area and contain a
-  // huge number of features.
-  rpc ListFeatures(Rectangle) returns (stream Feature) {}
-
-  // A client-to-server streaming RPC.
-  //
-  // Accepts a stream of Points on a route being traversed, returning a
-  // RouteSummary when traversal is completed.
-  rpc RecordRoute(stream Point) returns (RouteSummary) {}
-
-  // A Bidirectional streaming RPC.
-  //
-  // Accepts a stream of RouteNotes sent while a route is being traversed,
-  // while receiving other RouteNotes (e.g. from other users).
-  rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}
-}
-
-// Points are represented as latitude-longitude pairs in the E7 representation
-// (degrees multiplied by 10**7 and rounded to the nearest integer).
-// Latitudes should be in the range +/- 90 degrees and longitude should be in
-// the range +/- 180 degrees (inclusive).
-message Point {
-  optional int32 latitude = 1 [default = 0];
-  optional int32 longitude = 2 [default = 0];
-}
-
-// A latitude-longitude rectangle, represented as two diagonally opposite
-// points "lo" and "hi".
-message Rectangle {
-  // One corner of the rectangle.
-  optional Point lo = 1;
-
-  // The other corner of the rectangle.
-  optional Point hi = 2;
-}
-
-// A feature names something at a given point.
-//
-// If a feature could not be named, the name is empty.
-message Feature {
-  // The name of the feature.
-  optional string name = 1;
-
-  // The point where the feature is detected.
-  optional Point location = 2;
-}
-
-// A RouteNote is a message sent while at a given point.
-message RouteNote {
-  // The location from which the message is sent.
-  optional Point location = 1;
-
-  // The message to be sent.
-  optional string message = 2;
-}
-
-// A RouteSummary is received in response to a RecordRoute rpc.
-//
-// It contains the number of individual points received, the number of
-// detected features, and the total distance covered as the cumulative sum of
-// the distance between each point.
-message RouteSummary {
-  // The number of points received.
-  optional int32 point_count = 1 [default = 0];
-
-  // The number of known features passed while traversing the route.
-  optional int32 feature_count = 2 [default = 0];
-
-  // The distance covered in metres.
-  optional int32 distance = 3 [default = 0];
-
-  // The duration of the traversal in seconds.
-  optional int32 elapsed_time = 4 [default = 0];
-}
diff --git a/examples/php/route_guide/route_guide_client.php b/examples/php/route_guide/route_guide_client.php
index b3cd606..3f38c26 100644
--- a/examples/php/route_guide/route_guide_client.php
+++ b/examples/php/route_guide/route_guide_client.php
@@ -33,11 +33,15 @@
  */
 
 require dirname(__FILE__).'/../vendor/autoload.php';
-require dirname(__FILE__).'/route_guide.php';
+
+// The following includes are needed when using protobuf 3.1.0
+// and will suppress warnings when using protobuf 3.2.0+
+@include_once dirname(__FILE__).'/route_guide.pb.php';
+@include_once dirname(__FILE__).'/route_guide_grpc_pb.php';
 
 define('COORD_FACTOR', 1e7);
 
-$client = new routeguide\RouteGuideClient('localhost:50051', [
+$client = new Routeguide\RouteGuideClient('localhost:50051', [
     'credentials' => Grpc\ChannelCredentials::createInsecure(),
 ]);
 
@@ -63,7 +67,7 @@
     echo "Running GetFeature...\n";
     global $client;
 
-    $point = new routeguide\Point();
+    $point = new Routeguide\Point();
     $points = array(
         array(409146138, -746188906),
         array(0, 0),
@@ -88,15 +92,15 @@
     echo "Running ListFeatures...\n";
     global $client;
 
-    $lo_point = new routeguide\Point();
-    $hi_point = new routeguide\Point();
+    $lo_point = new Routeguide\Point();
+    $hi_point = new Routeguide\Point();
 
     $lo_point->setLatitude(400000000);
     $lo_point->setLongitude(-750000000);
     $hi_point->setLatitude(420000000);
     $hi_point->setLongitude(-730000000);
 
-    $rectangle = new routeguide\Rectangle();
+    $rectangle = new Routeguide\Rectangle();
     $rectangle->setLo($lo_point);
     $rectangle->setHi($hi_point);
 
@@ -126,7 +130,7 @@
     $num_points_in_db = count($db);
     $num_points = 10;
     for ($i = 0; $i < $num_points; ++$i) {
-        $point = new routeguide\Point();
+        $point = new Routeguide\Point();
         $index = rand(0, $num_points_in_db - 1);
         $lat = $db[$index]['location']['latitude'];
         $long = $db[$index]['location']['longitude'];
@@ -169,11 +173,11 @@
     );
 
     foreach ($notes as $n) {
-        $point = new routeguide\Point();
+        $point = new Routeguide\Point();
         $point->setLatitude($lat = $n[0]);
         $point->setLongitude($long = $n[1]);
 
-        $route_note = new routeguide\RouteNote();
+        $route_note = new Routeguide\RouteNote();
         $route_note->setLocation($point);
         $route_note->setMessage($message = $n[2]);
 
diff --git a/examples/php/route_guide/route_guide_grpc_pb.php b/examples/php/route_guide/route_guide_grpc_pb.php
new file mode 100644
index 0000000..fdc55e6
--- /dev/null
+++ b/examples/php/route_guide/route_guide_grpc_pb.php
@@ -0,0 +1,116 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+namespace Routeguide {
+
+  // Interface exported by the server.
+  class RouteGuideClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+      parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * A simple RPC.
+     *
+     * Obtains the feature at a given position.
+     *
+     * A feature with an empty name is returned if there's no feature at the given
+     * position.
+     * @param \Routeguide\Point $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function GetFeature(\Routeguide\Point $argument,
+      $metadata = [], $options = []) {
+      return $this->_simpleRequest('/routeguide.RouteGuide/GetFeature',
+      $argument,
+      ['\Routeguide\Feature', 'decode'],
+      $metadata, $options);
+    }
+
+    /**
+     * A server-to-client streaming RPC.
+     *
+     * Obtains the Features available within the given Rectangle.  Results are
+     * streamed rather than returned at once (e.g. in a response message with a
+     * repeated field), as the rectangle may cover a large area and contain a
+     * huge number of features.
+     * @param \Routeguide\Rectangle $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function ListFeatures(\Routeguide\Rectangle $argument,
+      $metadata = [], $options = []) {
+      return $this->_serverStreamRequest('/routeguide.RouteGuide/ListFeatures',
+      $argument,
+      ['\Routeguide\Feature', 'decode'],
+      $metadata, $options);
+    }
+
+    /**
+     * A client-to-server streaming RPC.
+     *
+     * Accepts a stream of Points on a route being traversed, returning a
+     * RouteSummary when traversal is completed.
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function RecordRoute($metadata = [], $options = []) {
+      return $this->_clientStreamRequest('/routeguide.RouteGuide/RecordRoute',
+      ['\Routeguide\RouteSummary','decode'],
+      $metadata, $options);
+    }
+
+    /**
+     * A Bidirectional streaming RPC.
+     *
+     * Accepts a stream of RouteNotes sent while a route is being traversed,
+     * while receiving other RouteNotes (e.g. from other users).
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function RouteChat($metadata = [], $options = []) {
+      return $this->_bidiRequest('/routeguide.RouteGuide/RouteChat',
+      ['\Routeguide\RouteNote','decode'],
+      $metadata, $options);
+    }
+
+  }
+
+}
diff --git a/src/core/ext/census/gen/trace_context.pb.c b/src/core/ext/census/gen/trace_context.pb.c
index c8aea32..f4126d4 100644
--- a/src/core/ext/census/gen/trace_context.pb.c
+++ b/src/core/ext/census/gen/trace_context.pb.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2016, Google Inc.
+ * Copyright 2017, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,51 +31,24 @@
  *
  */
 /* Automatically generated nanopb constant definitions */
-/* Generated by nanopb-0.3.5-dev */
+/* Generated by nanopb-0.3.7-dev at Fri Jan 20 16:14:22 2017. */
 
 #include "src/core/ext/census/gen/trace_context.pb.h"
 
+/* @@protoc_insertion_point(includes) */
 #if PB_PROTO_HEADER_VERSION != 30
 #error Regenerate this file with the current version of nanopb generator.
 #endif
 
 
 
-const pb_field_t google_trace_TraceId_fields[3] = {
-    PB_FIELD(  1, FIXED64 , OPTIONAL, STATIC  , FIRST, google_trace_TraceId, hi, hi, 0),
-    PB_FIELD(  2, FIXED64 , OPTIONAL, STATIC  , OTHER, google_trace_TraceId, lo, hi, 0),
-    PB_LAST_FIELD
-};
-
-const pb_field_t google_trace_TraceContext_fields[4] = {
-    PB_FIELD(  1, MESSAGE , OPTIONAL, STATIC  , FIRST, google_trace_TraceContext, trace_id, trace_id, &google_trace_TraceId_fields),
-    PB_FIELD(  2, FIXED64 , OPTIONAL, STATIC  , OTHER, google_trace_TraceContext, span_id, trace_id, 0),
-    PB_FIELD(  3, BOOL    , OPTIONAL, STATIC  , OTHER, google_trace_TraceContext, is_sampled, span_id, 0),
+const pb_field_t google_trace_TraceContext_fields[5] = {
+    PB_FIELD(  1, FIXED64 , OPTIONAL, STATIC  , FIRST, google_trace_TraceContext, trace_id_hi, trace_id_hi, 0),
+    PB_FIELD(  2, FIXED64 , OPTIONAL, STATIC  , OTHER, google_trace_TraceContext, trace_id_lo, trace_id_hi, 0),
+    PB_FIELD(  3, FIXED64 , OPTIONAL, STATIC  , OTHER, google_trace_TraceContext, span_id, trace_id_lo, 0),
+    PB_FIELD(  4, FIXED32 , OPTIONAL, STATIC  , OTHER, google_trace_TraceContext, span_options, span_id, 0),
     PB_LAST_FIELD
 };
 
 
-/* Check that field information fits in pb_field_t */
-#if !defined(PB_FIELD_32BIT)
-/* If you get an error here, it means that you need to define PB_FIELD_32BIT
- * compile-time option. You can do that in pb.h or on compiler command line.
- * 
- * The reason you need to do this is that some of your messages contain tag
- * numbers or field sizes that are larger than what can fit in 8 or 16 bit
- * field descriptors.
- */
-PB_STATIC_ASSERT((pb_membersize(google_trace_TraceContext, trace_id) < 65536), YOU_MUST_DEFINE_PB_FIELD_32BIT_FOR_MESSAGES_google_trace_TraceId_google_trace_TraceContext)
-#endif
-
-#if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
-/* If you get an error here, it means that you need to define PB_FIELD_16BIT
- * compile-time option. You can do that in pb.h or on compiler command line.
- * 
- * The reason you need to do this is that some of your messages contain tag
- * numbers or field sizes that are larger than what can fit in the default
- * 8 bit descriptors.
- */
-PB_STATIC_ASSERT((pb_membersize(google_trace_TraceContext, trace_id) < 256), YOU_MUST_DEFINE_PB_FIELD_16BIT_FOR_MESSAGES_google_trace_TraceId_google_trace_TraceContext)
-#endif
-
-
+/* @@protoc_insertion_point(eof) */
diff --git a/src/core/ext/census/gen/trace_context.pb.h b/src/core/ext/census/gen/trace_context.pb.h
index cfb2f04..ea127bf 100644
--- a/src/core/ext/census/gen/trace_context.pb.h
+++ b/src/core/ext/census/gen/trace_context.pb.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2016, Google Inc.
+ * Copyright 2017, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,11 +31,13 @@
  *
  */
 /* Automatically generated nanopb header */
-/* Generated by nanopb-0.3.5-dev */
+/* Generated by nanopb-0.3.7-dev at Fri Jan 20 16:14:22 2017. */
 
 #ifndef GRPC_CORE_EXT_CENSUS_GEN_TRACE_CONTEXT_PB_H
 #define GRPC_CORE_EXT_CENSUS_GEN_TRACE_CONTEXT_PB_H
 #include "third_party/nanopb/pb.h"
+
+/* @@protoc_insertion_point(includes) */
 #if PB_PROTO_HEADER_VERSION != 30
 #error Regenerate this file with the current version of nanopb generator.
 #endif
@@ -45,44 +47,35 @@
 #endif
 
 /* Struct definitions */
-typedef struct _google_trace_TraceId {
-    bool has_hi;
-    uint64_t hi;
-    bool has_lo;
-    uint64_t lo;
-} google_trace_TraceId;
-
 typedef struct _google_trace_TraceContext {
-    bool has_trace_id;
-    google_trace_TraceId trace_id;
+    bool has_trace_id_hi;
+    uint64_t trace_id_hi;
+    bool has_trace_id_lo;
+    uint64_t trace_id_lo;
     bool has_span_id;
     uint64_t span_id;
-    bool has_is_sampled;
-    bool is_sampled;
+    bool has_span_options;
+    uint32_t span_options;
+/* @@protoc_insertion_point(struct:google_trace_TraceContext) */
 } google_trace_TraceContext;
 
 /* Default values for struct fields */
 
 /* Initializer values for message structs */
-#define google_trace_TraceId_init_default        {false, 0, false, 0}
-#define google_trace_TraceContext_init_default   {false, google_trace_TraceId_init_default, false, 0, false, 0}
-#define google_trace_TraceId_init_zero           {false, 0, false, 0}
-#define google_trace_TraceContext_init_zero      {false, google_trace_TraceId_init_zero, false, 0, false, 0}
+#define google_trace_TraceContext_init_default   {false, 0, false, 0, false, 0, false, 0}
+#define google_trace_TraceContext_init_zero      {false, 0, false, 0, false, 0, false, 0}
 
 /* Field tags (for use in manual encoding/decoding) */
-#define google_trace_TraceId_hi_tag              1
-#define google_trace_TraceId_lo_tag              2
-#define google_trace_TraceContext_trace_id_tag   1
-#define google_trace_TraceContext_span_id_tag    2
-#define google_trace_TraceContext_is_sampled_tag 3
+#define google_trace_TraceContext_trace_id_hi_tag 1
+#define google_trace_TraceContext_trace_id_lo_tag 2
+#define google_trace_TraceContext_span_id_tag    3
+#define google_trace_TraceContext_span_options_tag 4
 
 /* Struct field encoding specification for nanopb */
-extern const pb_field_t google_trace_TraceId_fields[3];
-extern const pb_field_t google_trace_TraceContext_fields[4];
+extern const pb_field_t google_trace_TraceContext_fields[5];
 
 /* Maximum encoded size of messages (where known) */
-#define google_trace_TraceId_size                18
-#define google_trace_TraceContext_size           31
+#define google_trace_TraceContext_size           32
 
 /* Message IDs (where set with "msgid" option) */
 #ifdef PB_MSGID
@@ -95,5 +88,6 @@
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
+/* @@protoc_insertion_point(eof) */
 
-#endif /* GRPC_CORE_EXT_CENSUS_GEN_TRACE_CONTEXT_PB_H */
+#endif
diff --git a/src/core/ext/census/trace_context.c b/src/core/ext/census/trace_context.c
index fbb20d3..47d0de1 100644
--- a/src/core/ext/census/trace_context.c
+++ b/src/core/ext/census/trace_context.c
@@ -73,7 +73,7 @@
   }
 
   // check fields
-  if (!ctxt->has_trace_id) {
+  if (!ctxt->has_trace_id_hi || !ctxt->has_trace_id_lo) {
     gpr_log(GPR_DEBUG, "Invalid TraceContext: missing trace_id");
     return false;
   }
diff --git a/src/core/ext/census/trace_context.h b/src/core/ext/census/trace_context.h
index 1cb5e26..f391a1b 100644
--- a/src/core/ext/census/trace_context.h
+++ b/src/core/ext/census/trace_context.h
@@ -38,6 +38,9 @@
 
 #include "src/core/ext/census/gen/trace_context.pb.h"
 
+/* Span option flags. */
+#define SPAN_OPTIONS_IS_SAMPLED 0x01
+
 /* Maximum number of bytes required to encode a TraceContext (31)
 1 byte for trace_id field
 1 byte for trace_id length
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index 27097fa..70bab4c 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -86,8 +86,11 @@
   /* Status came from 'the wire' - or somewhere below the surface
      layer */
   STATUS_FROM_WIRE,
-  /* Status was created by some internal channel stack operation */
+  /* Status was created by some internal channel stack operation: must come via
+     add_batch_error */
   STATUS_FROM_CORE,
+  /* Status was created by some surface error */
+  STATUS_FROM_SURFACE,
   /* Status came from the server sending status */
   STATUS_FROM_SERVER_STATUS,
   STATUS_SOURCE_COUNT
@@ -212,6 +215,8 @@
   void *saved_receiving_stream_ready_bctlp;
 };
 
+int grpc_call_error_trace = 0;
+
 #define CALL_STACK_FROM_CALL(call) ((grpc_call_stack *)((call) + 1))
 #define CALL_FROM_CALL_STACK(call_stack) (((grpc_call *)(call_stack)) - 1)
 #define CALL_ELEM_FROM_CALL(call, idx) \
@@ -221,11 +226,11 @@
 
 static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
                        grpc_transport_stream_op *op);
-static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                                          grpc_status_code status,
-                                          const char *description);
+static void cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                               status_source source, grpc_status_code status,
+                               const char *description);
 static void cancel_with_error(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                              grpc_error *error);
+                              status_source source, grpc_error *error);
 static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
                          grpc_error *error);
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
@@ -312,15 +317,18 @@
     /* TODO(ctiller): This should change to use the appropriate census start_op
      * call. */
     if (args->propagation_mask & GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT) {
-      GPR_ASSERT(args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
+      if (0 == (args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT)) {
+        add_init_error(&error,
+                       GRPC_ERROR_CREATE("Census tracing propagation requested "
+                                         "without Census context propagation"));
+      }
       grpc_call_context_set(
           call, GRPC_CONTEXT_TRACING,
           args->parent_call->context[GRPC_CONTEXT_TRACING].value, NULL);
-    } else if (0 ==
-               (args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT)) {
+    } else if (args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT) {
       add_init_error(&error,
-                     GRPC_ERROR_CREATE("Census tracing propagation requested "
-                                       "without Census context propagation"));
+                     GRPC_ERROR_CREATE("Census context propagation requested "
+                                       "without Census tracing propagation"));
     }
     if (args->propagation_mask & GRPC_PROPAGATE_CANCELLATION) {
       call->cancellation_is_inherited = 1;
@@ -349,7 +357,8 @@
                                               call->start_time, send_deadline,
                                               CALL_STACK_FROM_CALL(call)));
   if (error != GRPC_ERROR_NONE) {
-    cancel_with_error(exec_ctx, call, GRPC_ERROR_REF(error));
+    cancel_with_error(exec_ctx, call, STATUS_FROM_SURFACE,
+                      GRPC_ERROR_REF(error));
   }
   if (args->cq != NULL) {
     GPR_ASSERT(
@@ -524,7 +533,6 @@
                                              grpc_status_code status,
                                              const char *description,
                                              void *reserved) {
-  grpc_call_error r;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   GRPC_API_TRACE(
       "grpc_call_cancel_with_status("
@@ -532,16 +540,16 @@
       4, (c, (int)status, description, reserved));
   GPR_ASSERT(reserved == NULL);
   gpr_mu_lock(&c->mu);
-  r = cancel_with_status(&exec_ctx, c, status, description);
+  cancel_with_status(&exec_ctx, c, STATUS_FROM_API_OVERRIDE, status,
+                     description);
   gpr_mu_unlock(&c->mu);
   grpc_exec_ctx_finish(&exec_ctx);
-  return r;
+  return GRPC_CALL_OK;
 }
 
 typedef struct termination_closure {
   grpc_closure closure;
   grpc_call *call;
-  grpc_error *error;
   grpc_transport_stream_op op;
 } termination_closure;
 
@@ -556,36 +564,27 @@
                              grpc_error *error) {
   termination_closure *tc = tcp;
   memset(&tc->op, 0, sizeof(tc->op));
-  tc->op.cancel_error = tc->error;
+  tc->op.cancel_error = GRPC_ERROR_REF(error);
   /* reuse closure to catch completion */
-  grpc_closure_init(&tc->closure, done_termination, tc,
-                    grpc_schedule_on_exec_ctx);
-  tc->op.on_complete = &tc->closure;
+  tc->op.on_complete = grpc_closure_init(&tc->closure, done_termination, tc,
+                                         grpc_schedule_on_exec_ctx);
   execute_op(exec_ctx, tc->call, &tc->op);
 }
 
-static grpc_call_error terminate_with_status(grpc_exec_ctx *exec_ctx,
-                                             termination_closure *tc) {
-  set_status_from_error(exec_ctx, tc->call, STATUS_FROM_API_OVERRIDE,
-                        GRPC_ERROR_REF(tc->error));
-  grpc_closure_init(&tc->closure, send_termination, tc,
-                    grpc_schedule_on_exec_ctx);
-  GRPC_CALL_INTERNAL_REF(tc->call, "termination");
-  grpc_closure_sched(exec_ctx, &tc->closure, GRPC_ERROR_NONE);
-  return GRPC_CALL_OK;
-}
-
-static grpc_call_error terminate_with_error(grpc_exec_ctx *exec_ctx,
-                                            grpc_call *c, grpc_error *error) {
+static void terminate_with_error(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                 grpc_error *error) {
   termination_closure *tc = gpr_malloc(sizeof(*tc));
   memset(tc, 0, sizeof(*tc));
   tc->call = c;
-  tc->error = error;
-  return terminate_with_status(exec_ctx, tc);
+  GRPC_CALL_INTERNAL_REF(tc->call, "termination");
+  grpc_closure_sched(exec_ctx, grpc_closure_init(&tc->closure, send_termination,
+                                                 tc, grpc_schedule_on_exec_ctx),
+                     error);
 }
 
 static void cancel_with_error(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                              grpc_error *error) {
+                              status_source source, grpc_error *error) {
+  set_status_from_error(exec_ctx, c, source, GRPC_ERROR_REF(error));
   terminate_with_error(exec_ctx, c, error);
 }
 
@@ -597,32 +596,35 @@
       GRPC_ERROR_INT_GRPC_STATUS, status);
 }
 
-static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                                          grpc_status_code status,
-                                          const char *description) {
-  return terminate_with_error(exec_ctx, c,
-                              error_from_status(status, description));
+static void cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                               status_source source, grpc_status_code status,
+                               const char *description) {
+  cancel_with_error(exec_ctx, c, source,
+                    error_from_status(status, description));
 }
 
 /*******************************************************************************
  * FINAL STATUS CODE MANIPULATION
  */
 
-static void get_final_status_from(grpc_call *call, status_source from_source,
-                                  void (*set_value)(grpc_status_code code,
-                                                    void *user_data),
-                                  void *set_value_user_data,
-                                  grpc_slice *details) {
+static bool get_final_status_from(
+    grpc_call *call, status_source from_source, bool allow_ok_status,
+    void (*set_value)(grpc_status_code code, void *user_data),
+    void *set_value_user_data, grpc_slice *details) {
   grpc_status_code code;
   const char *msg = NULL;
   grpc_error_get_status(call->status[from_source].error, call->send_deadline,
                         &code, &msg, NULL);
+  if (code == GRPC_STATUS_OK && !allow_ok_status) {
+    return false;
+  }
 
   set_value(code, set_value_user_data);
   if (details != NULL) {
     *details =
         msg == NULL ? grpc_empty_slice() : grpc_slice_from_copied_string(msg);
   }
+  return true;
 }
 
 static void get_final_status(grpc_call *call,
@@ -630,22 +632,37 @@
                                                void *user_data),
                              void *set_value_user_data, grpc_slice *details) {
   int i;
-  /* search for the best status we can present: ideally the error we use has a
-     clearly defined grpc-status, and we'll prefer that. */
-  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
-    if (call->status[i].is_set &&
-        grpc_error_has_clear_grpc_status(call->status[i].error)) {
-      get_final_status_from(call, (status_source)i, set_value,
-                            set_value_user_data, details);
-      return;
+  if (grpc_call_error_trace) {
+    gpr_log(GPR_DEBUG, "get_final_status %s", call->is_client ? "CLI" : "SVR");
+    for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+      if (call->status[i].is_set) {
+        gpr_log(GPR_DEBUG, "  %d: %s", i,
+                grpc_error_string(call->status[i].error));
+      }
     }
   }
-  /* If no clearly defined status exists, search for 'anything' */
-  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
-    if (call->status[i].is_set) {
-      get_final_status_from(call, (status_source)i, set_value,
-                            set_value_user_data, details);
-      return;
+  /* first search through ignoring "OK" statuses: if something went wrong,
+   * ensure we report it */
+  for (int allow_ok_status = 0; allow_ok_status < 2; allow_ok_status++) {
+    /* search for the best status we can present: ideally the error we use has a
+       clearly defined grpc-status, and we'll prefer that. */
+    for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+      if (call->status[i].is_set &&
+          grpc_error_has_clear_grpc_status(call->status[i].error)) {
+        if (get_final_status_from(call, (status_source)i, allow_ok_status != 0,
+                                  set_value, set_value_user_data, details)) {
+          return;
+        }
+      }
+    }
+    /* If no clearly defined status exists, search for 'anything' */
+    for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+      if (call->status[i].is_set) {
+        if (get_final_status_from(call, (status_source)i, allow_ok_status != 0,
+                                  set_value, set_value_user_data, details)) {
+          return;
+        }
+      }
     }
   }
   /* If nothing exists, set some default */
@@ -1026,11 +1043,6 @@
 
   gpr_mu_lock(&call->mu);
 
-  if (error != GRPC_ERROR_NONE) {
-    set_status_from_error(exec_ctx, call, STATUS_FROM_CORE,
-                          GRPC_ERROR_REF(error));
-  }
-
   if (bctl->send_initial_metadata) {
     grpc_metadata_batch_destroy(
         exec_ctx,
@@ -1173,7 +1185,8 @@
   grpc_call *call = bctl->call;
   gpr_mu_lock(&bctl->call->mu);
   if (error != GRPC_ERROR_NONE) {
-    cancel_with_error(exec_ctx, call, GRPC_ERROR_REF(error));
+    cancel_with_error(exec_ctx, call, STATUS_FROM_SURFACE,
+                      GRPC_ERROR_REF(error));
   }
   if (call->has_initial_md_been_received || error != GRPC_ERROR_NONE ||
       call->receiving_stream == NULL) {
@@ -1200,7 +1213,8 @@
       gpr_asprintf(&error_msg, "Invalid compression algorithm value '%d'.",
                    algo);
       gpr_log(GPR_ERROR, "%s", error_msg);
-      cancel_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
+      cancel_with_status(exec_ctx, call, STATUS_FROM_SURFACE,
+                         GRPC_STATUS_UNIMPLEMENTED, error_msg);
     } else if (grpc_compression_options_is_algorithm_enabled(
                    &compression_options, algo) == 0) {
       /* check if algorithm is supported by current channel config */
@@ -1209,7 +1223,8 @@
       gpr_asprintf(&error_msg, "Compression algorithm '%s' is disabled.",
                    algo_name);
       gpr_log(GPR_ERROR, "%s", error_msg);
-      cancel_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
+      cancel_with_status(exec_ctx, call, STATUS_FROM_SURFACE,
+                         GRPC_STATUS_UNIMPLEMENTED, error_msg);
     } else {
       call->incoming_compression_algorithm = algo;
     }
@@ -1239,7 +1254,10 @@
                             grpc_error *error) {
   if (error == GRPC_ERROR_NONE) return;
   int idx = (int)gpr_atm_no_barrier_fetch_add(&bctl->num_errors, 1);
-  if (idx == 0) cancel_with_error(exec_ctx, bctl->call, GRPC_ERROR_REF(error));
+  if (idx == 0) {
+    cancel_with_error(exec_ctx, bctl->call, STATUS_FROM_CORE,
+                      GRPC_ERROR_REF(error));
+  }
   bctl->errors[idx] = error;
 }
 
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index 8c46a83..b70343d 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -125,6 +125,8 @@
 grpc_compression_algorithm grpc_call_compression_for_level(
     grpc_call *call, grpc_compression_level level);
 
+extern int grpc_call_error_trace;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index cfa1882..787e4d0 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -199,6 +199,7 @@
     grpc_cq_event_timeout_trace = 1;
     grpc_register_tracer("op_failure", &grpc_trace_operation_failures);
     grpc_register_tracer("resource_quota", &grpc_resource_quota_trace);
+    grpc_register_tracer("call_error", &grpc_call_error_trace);
 #ifndef NDEBUG
     grpc_register_tracer("pending_tags", &grpc_trace_pending_tags);
 #endif
diff --git a/src/php/composer.json b/src/php/composer.json
index f352916..746474d 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -13,10 +13,8 @@
   "autoload": {
     "psr-4": {
       "Grpc\\": "lib/Grpc/",
-      "Grpc\\Testing\\": "tests/interop/Grpc/Testing/",
-      "GPBMetadata\\Src\\Proto\\Grpc\\Testing\\": "tests/interop/GPBMetadata/Src/Proto/Grpc/Testing/",
-      "Math\\": "tests/generated_code/Math/",
-      "GPBMetadata\\": "tests/generated_code/GPBMetadata/"
+      "": ["tests/interop/",
+           "tests/generated_code/"]
     }
   }
 }
diff --git a/src/proto/census/trace_context.proto b/src/proto/census/trace_context.proto
index a5d5a95..fc0a54d 100644
--- a/src/proto/census/trace_context.proto
+++ b/src/proto/census/trace_context.proto
@@ -31,18 +31,14 @@
 
 package google.trace;
 
-// A TraceId uniquely represents a single Trace. It is a 128-bit nonce.
-message TraceId {
-  fixed64 hi = 1;
-  fixed64 lo = 2;
-}
-
 // Tracing information that is propagated with RPC's.
 message TraceContext {
-  // Trace identifer. Must be present.
-  TraceId trace_id = 1;
-  // ID of parent (client) span. Must be present.
-  fixed64 span_id = 2;
-  // true if this trace is sampled.
-  bool is_sampled = 3;
+  // A TraceId uniquely represents a single Trace. It is a 128-bit nonce.
+  // The 128-bit ID is split into 2 64-bit chunks. (REQUIRED)
+  fixed64 trace_id_hi = 1;
+  fixed64 trace_id_lo = 2;
+  // ID of parent (client) span. (REQUIRED)
+  fixed64 span_id = 3;
+  // Span option flags. First bit is true if this trace is sampled. (OPTIONAL)
+  fixed32 span_options = 4;
 }
diff --git a/templates/src/php/composer.json.template b/templates/src/php/composer.json.template
index 5223efd..08710d3 100644
--- a/templates/src/php/composer.json.template
+++ b/templates/src/php/composer.json.template
@@ -15,10 +15,8 @@
     "autoload": {
       "psr-4": {
         "Grpc\\": "lib/Grpc/",
-        "Grpc\\Testing\\": "tests/interop/Grpc/Testing/",
-        "GPBMetadata\\Src\\Proto\\Grpc\\Testing\\": "tests/interop/GPBMetadata/Src/Proto/Grpc/Testing/",
-        "Math\\": "tests/generated_code/Math/",
-        "GPBMetadata\\": "tests/generated_code/GPBMetadata/"
+        "": ["tests/interop/",
+             "tests/generated_code/"]
       }
     }
   }
diff --git a/test/core/census/data/context_full.pb b/test/core/census/data/context_full.pb
index 80ebcf2..7b5895c 100644
--- a/test/core/census/data/context_full.pb
+++ b/test/core/census/data/context_full.pb
Binary files differ
diff --git a/test/core/census/data/context_full.txt b/test/core/census/data/context_full.txt
index 7901a10..7d8df37 100644
--- a/test/core/census/data/context_full.txt
+++ b/test/core/census/data/context_full.txt
@@ -1,3 +1,4 @@
-trace_id { hi : 5; lo : 1 }
+trace_id_hi : 5
+trace_id_lo : 1
 span_id : 7
-is_sampled : true
+span_options : 1
diff --git a/test/core/census/data/context_no_sample.pb b/test/core/census/data/context_no_sample.pb
deleted file mode 100644
index ab7ad7d..0000000
--- a/test/core/census/data/context_no_sample.pb
+++ /dev/null
Binary files differ
diff --git a/test/core/census/data/context_no_sample.txt b/test/core/census/data/context_no_sample.txt
deleted file mode 100644
index 1502980..0000000
--- a/test/core/census/data/context_no_sample.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-trace_id { hi : 5; lo : 1 }
-span_id : 7
diff --git a/test/core/census/data/context_no_span_options.pb b/test/core/census/data/context_no_span_options.pb
new file mode 100644
index 0000000..4b3425a
--- /dev/null
+++ b/test/core/census/data/context_no_span_options.pb
Binary files differ
diff --git a/test/core/census/data/context_no_span_options.txt b/test/core/census/data/context_no_span_options.txt
new file mode 100644
index 0000000..4c8398f
--- /dev/null
+++ b/test/core/census/data/context_no_span_options.txt
@@ -0,0 +1,3 @@
+trace_id_hi : 5
+trace_id_lo : 1
+span_id : 7
diff --git a/test/core/census/data/context_span_only.pb b/test/core/census/data/context_span_only.pb
index 2a9527a..a9315be 100644
--- a/test/core/census/data/context_span_only.pb
+++ b/test/core/census/data/context_span_only.pb
Binary files differ
diff --git a/test/core/census/data/context_span_only.txt b/test/core/census/data/context_span_only.txt
index d90de2e..4e473fc 100644
--- a/test/core/census/data/context_span_only.txt
+++ b/test/core/census/data/context_span_only.txt
@@ -1,2 +1,2 @@
 span_id : 7
-is_sampled : true
+span_options : 1
diff --git a/test/core/census/data/context_trace_only.pb b/test/core/census/data/context_trace_only.pb
index 7fdf6f6..aabb325 100644
--- a/test/core/census/data/context_trace_only.pb
+++ b/test/core/census/data/context_trace_only.pb
Binary files differ
diff --git a/test/core/census/data/context_trace_only.txt b/test/core/census/data/context_trace_only.txt
index 9b68a6a..e48a6d7 100644
--- a/test/core/census/data/context_trace_only.txt
+++ b/test/core/census/data/context_trace_only.txt
@@ -1,2 +1,3 @@
-trace_id { hi : 5; lo : 1 }
-is_sampled : true
+trace_id_hi : 5
+trace_id_lo : 1
+span_options : 1
diff --git a/test/core/census/trace_context_test.c b/test/core/census/trace_context_test.c
index ee409e8..5963b1a 100644
--- a/test/core/census/trace_context_test.c
+++ b/test/core/census/trace_context_test.c
@@ -59,7 +59,6 @@
                                     uint8_t *buffer, size_t buf_size) {
   google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
   size_t msg_length;
-  GPR_ASSERT(ctxt1->has_trace_id && ctxt1->has_span_id);
 
   msg_length = encode_trace_context(ctxt1, buffer, buf_size);
   if (msg_length == 0) {
@@ -70,16 +69,17 @@
     return false;
   }
 
-  if (!ctxt2.has_trace_id || !ctxt2.has_span_id) {
+  if (!ctxt2.has_trace_id_hi || !ctxt2.has_trace_id_lo || !ctxt2.has_span_id) {
     return false;
   }
 
-  GPR_ASSERT(
-      ctxt1->trace_id.hi == ctxt2.trace_id.hi &&
-      ctxt1->trace_id.lo == ctxt2.trace_id.lo &&
-      ctxt1->span_id == ctxt2.span_id &&
-      ctxt1->has_is_sampled == ctxt2.has_is_sampled &&
-      (ctxt1->has_is_sampled ? ctxt1->is_sampled == ctxt2.is_sampled : true));
+  GPR_ASSERT(ctxt1->trace_id_hi == ctxt2.trace_id_hi &&
+             ctxt1->trace_id_lo == ctxt2.trace_id_lo &&
+             ctxt1->span_id == ctxt2.span_id &&
+             ctxt1->has_span_options == ctxt2.has_span_options &&
+             (ctxt1->has_span_options
+                  ? ctxt1->span_options == ctxt2.span_options
+                  : true));
 
   return true;
 }
@@ -94,7 +94,7 @@
     return false;
   }
 
-  if (!ctxt->has_trace_id || !ctxt->has_span_id) {
+  if (!ctxt->has_trace_id_hi || !ctxt->has_trace_id_lo || !ctxt->has_span_id) {
     return false;
   }
 
@@ -144,49 +144,48 @@
       &ctxt, "test/core/census/data/context_span_only.pb", false);
 }
 
-// Test proto-buffer without is_sampled value.
-static void test_no_sample() {
+// Test proto-buffer without span_options value.
+static void test_no_span_options() {
   google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
   read_and_validate_context_from_file(
-      &ctxt, "test/core/census/data/context_no_sample.pb", true);
-  GPR_ASSERT(ctxt.has_is_sampled == false && ctxt.is_sampled == false);
+      &ctxt, "test/core/census/data/context_no_span_options.pb", true);
+  GPR_ASSERT(ctxt.has_span_options == false && ctxt.span_options == 0);
 }
 
 static void test_encode_decode() {
   uint8_t buffer[BUF_SIZE] = {0};
 
   google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
-  ctxt1.has_trace_id = true;
-  ctxt1.trace_id.has_hi = true;
-  ctxt1.trace_id.has_lo = true;
-  ctxt1.trace_id.lo = 1;
-  ctxt1.trace_id.hi = 2;
+  ctxt1.has_trace_id_hi = true;
+  ctxt1.has_trace_id_lo = true;
+  ctxt1.trace_id_lo = 1;
+  ctxt1.trace_id_hi = 2;
   ctxt1.has_span_id = true;
   ctxt1.span_id = 3;
   validate_encode_decode_context(&ctxt1, buffer, sizeof(buffer));
 
+  // Missing trace_id. This should fail.
   google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
-  ctxt2.has_trace_id = true;
-  ctxt2.trace_id.has_hi = false;
-  ctxt2.trace_id.has_lo = false;
+  ctxt2.has_trace_id_hi = false;
+  ctxt2.has_trace_id_lo = false;
   ctxt2.has_span_id = true;
   validate_encode_decode_context(&ctxt2, buffer, sizeof(buffer));
 }
 
-// Test a corrupted proto-buffer.
+// Test a corrupted proto-buffer. This should fail.
 static void test_corrupt() {
   uint8_t buffer[BUF_SIZE] = {0};
   google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
   size_t msg_length;
 
-  ctxt1.has_trace_id = true;
-  ctxt1.trace_id.has_hi = true;
-  ctxt1.trace_id.has_lo = true;
-  ctxt1.trace_id.lo = 1;
-  ctxt1.trace_id.hi = 2;
+  ctxt1.has_trace_id_hi = true;
+  ctxt1.has_trace_id_lo = true;
+  ctxt1.trace_id_lo = 1;
+  ctxt1.trace_id_hi = 2;
   ctxt1.has_span_id = true;
   ctxt1.span_id = 3;
-  ctxt1.is_sampled = true;
+  ctxt1.has_span_options = true;
+  ctxt1.span_options = SPAN_OPTIONS_IS_SAMPLED;
   msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));
 
   /* Corrupt some bytes.  255 (0xFF) should be illegal for the first byte of the
@@ -198,19 +197,19 @@
 }
 
 static void test_buffer_size() {
-  // This buffer is too small, so the encode should fail.
+  // This buffer is too small. This should fail.
   uint8_t buffer[16] = {0};
   google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
   size_t msg_length;
 
-  ctxt1.has_trace_id = true;
-  ctxt1.trace_id.has_hi = true;
-  ctxt1.trace_id.has_lo = true;
-  ctxt1.trace_id.lo = 1;
-  ctxt1.trace_id.hi = 2;
+  ctxt1.has_trace_id_hi = true;
+  ctxt1.has_trace_id_lo = true;
+  ctxt1.trace_id_lo = 1;
+  ctxt1.trace_id_hi = 2;
   ctxt1.has_span_id = true;
   ctxt1.span_id = 3;
-  ctxt1.is_sampled = true;
+  ctxt1.has_span_options = true;
+  ctxt1.span_options = SPAN_OPTIONS_IS_SAMPLED;
   msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));
 
   GPR_ASSERT(msg_length == 0);
@@ -224,7 +223,7 @@
   test_span_only();
   test_encode_decode();
   test_corrupt();
-  test_no_sample();
+  test_no_span_options();
   test_buffer_size();
 
   return 0;
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/0a4b84c2a50ba66f06c99e945912972cdcfc96be b/test/core/end2end/fuzzers/api_fuzzer_corpus/0a4b84c2a50ba66f06c99e945912972cdcfc96be
new file mode 100644
index 0000000..d0f43e9
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/0a4b84c2a50ba66f06c99e945912972cdcfc96be
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/22c7bfb3460529c77255e9cb82ef8f7d8381f8f3 b/test/core/end2end/fuzzers/api_fuzzer_corpus/22c7bfb3460529c77255e9cb82ef8f7d8381f8f3
new file mode 100644
index 0000000..b5f6a85
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/22c7bfb3460529c77255e9cb82ef8f7d8381f8f3
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/33f0e1b78dd158df720604cbb4c9a0c90eece435 b/test/core/end2end/fuzzers/api_fuzzer_corpus/33f0e1b78dd158df720604cbb4c9a0c90eece435
new file mode 100644
index 0000000..df5e442
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/33f0e1b78dd158df720604cbb4c9a0c90eece435
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/3cac506501825fadf2e4adf7619d16f72cfd8832 b/test/core/end2end/fuzzers/api_fuzzer_corpus/3cac506501825fadf2e4adf7619d16f72cfd8832
new file mode 100644
index 0000000..62447e4
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/3cac506501825fadf2e4adf7619d16f72cfd8832
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/87a34188d51bc8b43bd7d9097958097e70154960 b/test/core/end2end/fuzzers/api_fuzzer_corpus/87a34188d51bc8b43bd7d9097958097e70154960
new file mode 100644
index 0000000..a90fb52
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/87a34188d51bc8b43bd7d9097958097e70154960
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/939a61533db8868591c514fc41c7dfb4232e3e4f b/test/core/end2end/fuzzers/api_fuzzer_corpus/939a61533db8868591c514fc41c7dfb4232e3e4f
new file mode 100644
index 0000000..c21081b
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/939a61533db8868591c514fc41c7dfb4232e3e4f
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/98a661d328f1ad6277c802604126d91965d6fda8 b/test/core/end2end/fuzzers/api_fuzzer_corpus/98a661d328f1ad6277c802604126d91965d6fda8
new file mode 100644
index 0000000..ee68d20
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/98a661d328f1ad6277c802604126d91965d6fda8
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/9c052499ada417d5038f8cc7da62e6acae9ba9ae b/test/core/end2end/fuzzers/api_fuzzer_corpus/9c052499ada417d5038f8cc7da62e6acae9ba9ae
new file mode 100644
index 0000000..ccee196
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/9c052499ada417d5038f8cc7da62e6acae9ba9ae
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/a881a2dcd16f595644c1543ccf047b7ae5bb7fa4 b/test/core/end2end/fuzzers/api_fuzzer_corpus/a881a2dcd16f595644c1543ccf047b7ae5bb7fa4
new file mode 100644
index 0000000..cd6c17b
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/a881a2dcd16f595644c1543ccf047b7ae5bb7fa4
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/b09e64aa807db006a219bd1b9faf1a2e00dc6d33 b/test/core/end2end/fuzzers/api_fuzzer_corpus/b09e64aa807db006a219bd1b9faf1a2e00dc6d33
new file mode 100644
index 0000000..50548fa
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/b09e64aa807db006a219bd1b9faf1a2e00dc6d33
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-b208a1eb5ef9f229f309492329323f485768fa74 b/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-b208a1eb5ef9f229f309492329323f485768fa74
new file mode 100644
index 0000000..e7a6aed
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-b208a1eb5ef9f229f309492329323f485768fa74
Binary files differ
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/e52ac2e3cad2e544488a01822115cb37d10a76ce b/test/core/end2end/fuzzers/api_fuzzer_corpus/e52ac2e3cad2e544488a01822115cb37d10a76ce
new file mode 100644
index 0000000..b3bb240
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/e52ac2e3cad2e544488a01822115cb37d10a76ce
Binary files differ
diff --git a/test/cpp/qps/gen_build_yaml.py b/test/cpp/qps/gen_build_yaml.py
index 188d619..2f035ab 100755
--- a/test/cpp/qps/gen_build_yaml.py
+++ b/test/cpp/qps/gen_build_yaml.py
@@ -92,7 +92,8 @@
       'defaults': 'boringssl',
       'cpu_cost': guess_cpu(scenario_json, False),
       'exclude_configs': ['tsan', 'asan'],
-      'timeout_seconds': 6*60
+      'timeout_seconds': 6*60,
+      'excluded_poll_engines': scenario_json.get('EXCLUDED_POLL_ENGINES', [])
     }
     for scenario_json in scenario_config.CXXLanguage().scenarios()
     if 'scalable' in scenario_json.get('CATEGORIES', [])
@@ -109,8 +110,9 @@
       'defaults': 'boringssl',
       'cpu_cost': guess_cpu(scenario_json, True),
       'exclude_configs': sorted(c for c in configs_from_yaml if c not in ('tsan', 'asan')),
-      'timeout_seconds': 6*60
-    }
+      'timeout_seconds': 6*60,
+      'excluded_poll_engines': scenario_json.get('EXCLUDED_POLL_ENGINES', [])
+   }
     for scenario_json in scenario_config.CXXLanguage().scenarios()
     if 'scalable' in scenario_json.get('CATEGORIES', [])
   ]
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index c28a68e..fbf2115 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -38342,6 +38342,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38366,6 +38367,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38390,6 +38392,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38402,7 +38405,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -38414,6 +38417,9 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38426,7 +38432,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -38438,6 +38444,9 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38462,6 +38471,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38486,6 +38496,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38510,6 +38521,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38534,6 +38546,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38558,6 +38571,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38582,6 +38596,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38606,6 +38621,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38630,6 +38646,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38654,6 +38671,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38678,6 +38696,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38702,6 +38721,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38726,6 +38746,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38750,6 +38771,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38774,6 +38796,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38798,6 +38821,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38810,7 +38834,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -38822,6 +38846,9 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38834,7 +38861,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -38846,6 +38873,9 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38870,6 +38900,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38894,6 +38925,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38918,6 +38950,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38942,6 +38975,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38966,6 +39000,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -38990,6 +39025,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39014,6 +39050,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39038,6 +39075,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39062,6 +39100,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39086,6 +39125,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39110,6 +39150,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39134,6 +39175,7 @@
       "tsan", 
       "asan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39168,6 +39210,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39202,6 +39245,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39236,6 +39280,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39248,7 +39293,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -39270,6 +39315,9 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39282,7 +39330,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -39304,6 +39352,9 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39338,6 +39389,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39372,6 +39424,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39406,6 +39459,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39440,6 +39494,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39474,6 +39529,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39508,6 +39564,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39542,6 +39599,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39576,6 +39634,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39610,6 +39669,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39644,6 +39704,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39678,6 +39739,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39712,6 +39774,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39746,6 +39809,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39780,6 +39844,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39814,6 +39879,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39826,7 +39892,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -39848,6 +39914,9 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39860,7 +39929,7 @@
   {
     "args": [
       "--scenarios_json", 
-      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
+      "{\"scenarios\": [{\"name\": \"cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 0, \"benchmark_seconds\": 1, \"server_config\": {\"async_server_threads\": 0, \"security_params\": null, \"payload_config\": null, \"server_type\": \"SYNC_SERVER\"}, \"num_servers\": 1, \"num_clients\": 0, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": null, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 10, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}}]}"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -39882,6 +39951,9 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [
+      "poll-cv"
+    ], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39916,6 +39988,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39950,6 +40023,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -39984,6 +40058,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40018,6 +40093,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40052,6 +40128,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40086,6 +40163,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40120,6 +40198,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40154,6 +40233,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40188,6 +40268,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40222,6 +40303,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40256,6 +40338,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -40290,6 +40373,7 @@
       "stapprof", 
       "ubsan"
     ], 
+    "excluded_poll_engines": [], 
     "flaky": false, 
     "language": "c++", 
     "name": "json_run_localhost", 
@@ -42325,6 +42409,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/0a4b84c2a50ba66f06c99e945912972cdcfc96be"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/0a71ae781345f9ee2b08008a81f9055e6c1d5256"
     ], 
     "ci_platforms": [
@@ -46681,6 +46787,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/22c7bfb3460529c77255e9cb82ef8f7d8381f8f3"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/22c9ed2979d9963bce6500997f1e0433988e7e37"
     ], 
     "ci_platforms": [
@@ -50069,6 +50197,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/33f0e1b78dd158df720604cbb4c9a0c90eece435"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/33ff864434b4f0c0e08c00ec2442cb521e9f79ed"
     ], 
     "ci_platforms": [
@@ -51565,6 +51715,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/3cac506501825fadf2e4adf7619d16f72cfd8832"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/3cc56c99c6046f0d66c50c4062d90608064fd742"
     ], 
     "ci_platforms": [
@@ -65645,6 +65817,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/87a34188d51bc8b43bd7d9097958097e70154960"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/87a4605e106399e71e689468a23ba11e7f17de2b"
     ], 
     "ci_platforms": [
@@ -67889,6 +68083,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/939a61533db8868591c514fc41c7dfb4232e3e4f"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/940a622e8995529f6b0455906d8a035902682d2d"
     ], 
     "ci_platforms": [
@@ -68747,6 +68963,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/98a661d328f1ad6277c802604126d91965d6fda8"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/98b88c0751f1d9e5dc3d4751d2cb52ed8f0b008d"
     ], 
     "ci_platforms": [
@@ -69341,6 +69579,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/9c052499ada417d5038f8cc7da62e6acae9ba9ae"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/9c0911c1a4b91f842670082c14af67d1f4b7bb6f"
     ], 
     "ci_platforms": [
@@ -71387,6 +71647,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/a881a2dcd16f595644c1543ccf047b7ae5bb7fa4"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/a89d59f59e43670ca3e8baf454fea723ae295653"
     ], 
     "ci_platforms": [
@@ -72773,6 +73055,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/b09e64aa807db006a219bd1b9faf1a2e00dc6d33"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/b0c9bc430c79f064b61d8cad076b072c9c014804"
     ], 
     "ci_platforms": [
@@ -80495,6 +80799,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/crash-b208a1eb5ef9f229f309492329323f485768fa74"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/crash-b39ce8e62e5c9e046d67e946436609e01f067a53"
     ], 
     "ci_platforms": [
@@ -84983,6 +85309,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/e52ac2e3cad2e544488a01822115cb37d10a76ce"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/e53a201505fe8412278d7444b1a915b353bacb3e"
     ], 
     "ci_platforms": [
diff --git a/tools/run_tests/performance/scenario_config.py b/tools/run_tests/performance/scenario_config.py
index 12ee127..1856093 100644
--- a/tools/run_tests/performance/scenario_config.py
+++ b/tools/run_tests/performance/scenario_config.py
@@ -73,6 +73,7 @@
   scenario.pop('CATEGORIES', None)
   scenario.pop('CLIENT_LANGUAGE', None)
   scenario.pop('SERVER_LANGUAGE', None)
+  scenario.pop('EXCLUDED_POLL_ENGINES', None)
   return scenario
 
 
@@ -109,7 +110,8 @@
                         categories=DEFAULT_CATEGORIES,
                         channels=None,
                         outstanding=None,
-                        resource_quota_size=None):
+                        resource_quota_size=None,
+                        excluded_poll_engines=[]):
   """Creates a basic ping pong scenario."""
   scenario = {
     'name': name,
@@ -169,6 +171,9 @@
     scenario['SERVER_LANGUAGE'] = server_language
   if categories:
     scenario['CATEGORIES'] = categories
+  if len(excluded_poll_engines):
+    # The polling engines for which this scenario is excluded
+    scenario['EXCLUDED_POLL_ENGINES'] = excluded_poll_engines
   return scenario
 
 
@@ -224,7 +229,8 @@
           server_type='SYNC_SERVER',
           unconstrained_client='async',
           secure=secure,
-          categories=smoketest_categories + [SCALABLE])
+          categories=smoketest_categories + [SCALABLE],
+          excluded_poll_engines = ['poll-cv'])
 
       yield _ping_pong_scenario(
           'cpp_protobuf_async_client_sync_server_streaming_qps_unconstrained_%s' % secstr,
@@ -233,7 +239,8 @@
           server_type='SYNC_SERVER',
           unconstrained_client='async',
           secure=secure,
-          categories=smoketest_categories+[SCALABLE])
+          categories=smoketest_categories+[SCALABLE],
+          excluded_poll_engines = ['poll-cv'])
 
       for rpc_type in ['unary', 'streaming']:
         for synchronicity in ['sync', 'async']:
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index c182288..9d76725 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -235,6 +235,9 @@
         if polling_strategy == 'poll-cv':
           timeout_scaling *= 5
 
+        if polling_strategy in target.get('excluded_poll_engines', []):
+          continue
+
         # Scale overall test timeout if running under various sanitizers.
         config = self.args.config
         if ('asan' in config