Merge "libbinder: setMinSchedulerPolicy" am: 3309b5e8f2 am: 026ea3a306 am: 289ef51442 am: 4f7b706b82 am: bc0f8043dc

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/1365301

Change-Id: I637ed9170fe4260d538a88acb2ee0e0380acd2c9
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index e0fb543..6ca3b16 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -24,6 +24,7 @@
 #include <binder/IShellCallback.h>
 #include <binder/Parcel.h>
 
+#include <linux/sched.h>
 #include <stdio.h>
 
 namespace android {
@@ -133,6 +134,8 @@
     // unlocked objects
     bool mRequestingSid = false;
     sp<IBinder> mExtension;
+    int mPolicy = SCHED_NORMAL;
+    int mPriority = 0;
 
     // for below objects
     Mutex mLock;
@@ -279,6 +282,47 @@
     return e->mExtension;
 }
 
+void BBinder::setMinSchedulerPolicy(int policy, int priority) {
+    switch (policy) {
+    case SCHED_NORMAL:
+      LOG_ALWAYS_FATAL_IF(priority < -20 || priority > 19, "Invalid priority for SCHED_NORMAL: %d", priority);
+      break;
+    case SCHED_RR:
+    case SCHED_FIFO:
+      LOG_ALWAYS_FATAL_IF(priority < 1 || priority > 99, "Invalid priority for sched %d: %d", policy, priority);
+      break;
+    default:
+      LOG_ALWAYS_FATAL("Unrecognized scheduling policy: %d", policy);
+    }
+
+    Extras* e = mExtras.load(std::memory_order_acquire);
+
+    if (e == nullptr) {
+        // Avoid allocations if called with default.
+        if (policy == SCHED_NORMAL && priority == 0) {
+            return;
+        }
+
+        e = getOrCreateExtras();
+        if (!e) return; // out of memory
+    }
+
+    e->mPolicy = policy;
+    e->mPriority = priority;
+}
+
+int BBinder::getMinSchedulerPolicy() {
+    Extras* e = mExtras.load(std::memory_order_acquire);
+    if (e == nullptr) return SCHED_NORMAL;
+    return e->mPolicy;
+}
+
+int BBinder::getMinSchedulerPriority() {
+    Extras* e = mExtras.load(std::memory_order_acquire);
+    if (e == nullptr) return 0;
+    return e->mPriority;
+}
+
 pid_t BBinder::getDebugPid() {
     return getpid();
 }
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 5ea56de..8fd59ba 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -20,6 +20,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
+#include <linux/sched.h>
 #include <pthread.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -188,16 +189,18 @@
     return OK;
 }
 
+static constexpr inline int schedPolicyMask(int policy, int priority) {
+    return (priority & FLAT_BINDER_FLAG_PRIORITY_MASK) | ((policy & 3) << FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT);
+}
+
 status_t Parcel::flattenBinder(const sp<IBinder>& binder)
 {
     flat_binder_object obj;
+    obj.flags = FLAT_BINDER_FLAG_ACCEPTS_FDS;
 
-    if (IPCThreadState::self()->backgroundSchedulingDisabled()) {
-        /* minimum priority for all nodes is nice 0 */
-        obj.flags = FLAT_BINDER_FLAG_ACCEPTS_FDS;
-    } else {
-        /* minimum priority for all nodes is MAX_NICE(19) */
-        obj.flags = 0x13 | FLAT_BINDER_FLAG_ACCEPTS_FDS;
+    int schedBits = 0;
+    if (!IPCThreadState::self()->backgroundSchedulingDisabled()) {
+        schedBits = schedPolicyMask(SCHED_NORMAL, 19);
     }
 
     if (binder != nullptr) {
@@ -213,6 +216,13 @@
             obj.handle = handle;
             obj.cookie = 0;
         } else {
+            int policy = local->getMinSchedulerPolicy();
+            int priority = local->getMinSchedulerPriority();
+
+            if (policy != 0 || priority != 0) {
+                // override value, since it is set explicitly
+                schedBits = schedPolicyMask(policy, priority);
+            }
             if (local->isRequestingSid()) {
                 obj.flags |= FLAT_BINDER_FLAG_TXN_SECURITY_CTX;
             }
@@ -226,6 +236,8 @@
         obj.cookie = 0;
     }
 
+    obj.flags |= schedBits;
+
     return finishFlattenBinder(binder, obj);
 }
 
diff --git a/libs/binder/include/binder/Binder.h b/libs/binder/include/binder/Binder.h
index 74e52db..f3fea16 100644
--- a/libs/binder/include/binder/Binder.h
+++ b/libs/binder/include/binder/Binder.h
@@ -72,6 +72,22 @@
     // This must be called before the object is sent to another process. Not thread safe.
     void                setExtension(const sp<IBinder>& extension);
 
+    // This must be called before the object is sent to another process. Not thread safe.
+    //
+    // This function will abort if improper parameters are set. This is like
+    // sched_setscheduler. However, it sets the minimum scheduling policy
+    // only for the duration that this specific binder object is handling the
+    // call in a threadpool. By default, this API is set to SCHED_NORMAL/0. In
+    // this case, the scheduling priority will not actually be modified from
+    // binder defaults. See also IPCThreadState::disableBackgroundScheduling.
+    //
+    // Appropriate values are:
+    // SCHED_NORMAL: -20 <= priority <= 19
+    // SCHED_RR/SCHED_FIFO: 1 <= priority <= 99
+    void                setMinSchedulerPolicy(int policy, int priority);
+    int                 getMinSchedulerPolicy();
+    int                 getMinSchedulerPriority();
+
     pid_t               getDebugPid();
 
 protected:
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index 40de2db..917751e 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -50,6 +50,9 @@
 static char *binderserversuffix;
 static char binderserverarg[] = "--binderserver";
 
+static constexpr int kSchedPolicy = SCHED_RR;
+static constexpr int kSchedPriority = 7;
+
 static String16 binderLibTestServiceName = String16("test.binderLib");
 
 enum BinderLibTestTranscationCode {
@@ -75,6 +78,7 @@
     BINDER_LIB_TEST_GET_PTR_SIZE_TRANSACTION,
     BINDER_LIB_TEST_CREATE_BINDER_TRANSACTION,
     BINDER_LIB_TEST_GET_WORK_SOURCE_TRANSACTION,
+    BINDER_LIB_TEST_GET_SCHEDULING_POLICY,
     BINDER_LIB_TEST_ECHO_VECTOR,
     BINDER_LIB_TEST_REJECT_BUF,
 };
@@ -1015,6 +1019,22 @@
     EXPECT_EQ(NO_ERROR, ret2);
 }
 
+TEST_F(BinderLibTest, SchedPolicySet) {
+    sp<IBinder> server = addServer();
+    ASSERT_TRUE(server != nullptr);
+
+    Parcel data, reply;
+    status_t ret = server->transact(BINDER_LIB_TEST_GET_SCHEDULING_POLICY, data, &reply);
+    EXPECT_EQ(NO_ERROR, ret);
+
+    int policy = reply.readInt32();
+    int priority = reply.readInt32();
+
+    EXPECT_EQ(kSchedPolicy, policy & (~SCHED_RESET_ON_FORK));
+    EXPECT_EQ(kSchedPriority, priority);
+}
+
+
 TEST_F(BinderLibTest, VectorSent) {
     Parcel data, reply;
     sp<IBinder> server = addServer();
@@ -1332,6 +1352,16 @@
                 reply->writeInt32(IPCThreadState::self()->getCallingWorkSourceUid());
                 return NO_ERROR;
             }
+            case BINDER_LIB_TEST_GET_SCHEDULING_POLICY: {
+                int policy = 0;
+                sched_param param;
+                if (0 != pthread_getschedparam(pthread_self(), &policy, &param)) {
+                    return UNKNOWN_ERROR;
+                }
+                reply->writeInt32(policy);
+                reply->writeInt32(param.sched_priority);
+                return NO_ERROR;
+            }
             case BINDER_LIB_TEST_ECHO_VECTOR: {
                 std::vector<uint64_t> vector;
                 auto err = data.readUint64Vector(&vector);
@@ -1368,6 +1398,8 @@
     {
         sp<BinderLibTestService> testService = new BinderLibTestService(index);
 
+        testService->setMinSchedulerPolicy(kSchedPolicy, kSchedPriority);
+
         /*
          * Normally would also contain functionality as well, but we are only
          * testing the extension mechanism.