Merge pull request #16081 from sreecha/rq-threads
Restrict the number of threads in C++ sync server
diff --git a/grpc.def b/grpc.def
index 5b98792..312e916 100644
--- a/grpc.def
+++ b/grpc.def
@@ -68,6 +68,7 @@
grpc_resource_quota_ref
grpc_resource_quota_unref
grpc_resource_quota_resize
+ grpc_resource_quota_set_max_threads
grpc_resource_quota_arg_vtable
grpc_channelz_get_top_channels
grpc_channelz_get_channel
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index f0eb2c0..eb02514 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -450,6 +450,10 @@
GRPCAPI void grpc_resource_quota_resize(grpc_resource_quota* resource_quota,
size_t new_size);
+/** Update the size of the maximum number of threads allowed */
+GRPCAPI void grpc_resource_quota_set_max_threads(
+ grpc_resource_quota* resource_quota, int new_max_threads);
+
/** Fetch a vtable for a grpc_channel_arg that points to a grpc_resource_quota
*/
GRPCAPI const grpc_arg_pointer_vtable* grpc_resource_quota_arg_vtable(void);
diff --git a/include/grpcpp/resource_quota.h b/include/grpcpp/resource_quota.h
index 554437a..50bd1cb 100644
--- a/include/grpcpp/resource_quota.h
+++ b/include/grpcpp/resource_quota.h
@@ -26,10 +26,10 @@
namespace grpc {
-/// ResourceQuota represents a bound on memory usage by the gRPC library.
-/// A ResourceQuota can be attached to a server (via \a ServerBuilder),
+/// ResourceQuota represents a bound on memory and thread usage by the gRPC
+/// library. A ResourceQuota can be attached to a server (via \a ServerBuilder),
/// or a client channel (via \a ChannelArguments).
-/// gRPC will attempt to keep memory used by all attached entities
+/// gRPC will attempt to keep memory and threads used by all attached entities
/// below the ResourceQuota bound.
class ResourceQuota final : private GrpcLibraryCodegen {
public:
@@ -44,6 +44,16 @@
/// No time bound is given for this to occur however.
ResourceQuota& Resize(size_t new_size);
+ /// Set the max number of threads that can be allocated from this
+ /// ResourceQuota object.
+ ///
+ /// If the new_max_threads value is smaller than the current value, no new
+ /// threads are allocated until the number of active threads fall below
+ /// new_max_threads. There is no time bound on when this may happen i.e none
+ /// of the current threads are forcefully destroyed and all threads run their
+ /// normal course.
+ ResourceQuota& SetMaxThreads(int new_max_threads);
+
grpc_resource_quota* c_resource_quota() const { return impl_; }
private:
diff --git a/include/grpcpp/server.h b/include/grpcpp/server.h
index 81c3907..189cf8a 100644
--- a/include/grpcpp/server.h
+++ b/include/grpcpp/server.h
@@ -144,7 +144,8 @@
Server(int max_message_size, ChannelArguments* args,
std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
sync_server_cqs,
- int min_pollers, int max_pollers, int sync_cq_timeout_msec);
+ grpc_resource_quota* server_rq, int min_pollers, int max_pollers,
+ int sync_cq_timeout_msec);
/// Start the server.
///
diff --git a/src/core/lib/iomgr/resource_quota.cc b/src/core/lib/iomgr/resource_quota.cc
index 539bc12..b6fc757 100644
--- a/src/core/lib/iomgr/resource_quota.cc
+++ b/src/core/lib/iomgr/resource_quota.cc
@@ -96,6 +96,9 @@
list, false otherwise */
bool added_to_free_pool;
+ /* The number of threads currently allocated to this resource user */
+ gpr_atm num_threads_allocated;
+
/* Reclaimers: index 0 is the benign reclaimer, 1 is the destructive reclaimer
*/
grpc_closure* reclaimers[2];
@@ -135,12 +138,33 @@
gpr_atm last_size;
+ /* Mutex to protect max_threads and num_threads_allocated */
+ /* Note: We could have used gpr_atm for max_threads and num_threads_allocated
+ * and avoid having this mutex; but in that case, each invocation of the
+ * function grpc_resource_user_allocate_threads() would have had to do at
+ * least two atomic loads (for max_threads and num_threads_allocated) followed
+ * by a CAS (on num_threads_allocated).
+ * Moreover, we expect grpc_resource_user_allocate_threads() to be often
+ * called concurrently thereby increasing the chances of failing the CAS
+ * operation. This additional complexity is not worth the tiny perf gain we
+ * may (or may not) have by using atomics */
+ gpr_mu thread_count_mu;
+
+ /* Max number of threads allowed */
+ int max_threads;
+
+ /* Number of threads currently allocated via this resource_quota object */
+ int num_threads_allocated;
+
/* Has rq_step been scheduled to occur? */
bool step_scheduled;
+
/* Are we currently reclaiming memory */
bool reclaiming;
+
/* Closure around rq_step */
grpc_closure rq_step_closure;
+
/* Closure around rq_reclamation_done */
grpc_closure rq_reclamation_done_closure;
@@ -524,6 +548,11 @@
static void ru_destroy(void* ru, grpc_error* error) {
grpc_resource_user* resource_user = static_cast<grpc_resource_user*>(ru);
GPR_ASSERT(gpr_atm_no_barrier_load(&resource_user->refs) == 0);
+ // Free all the remaining thread quota
+ grpc_resource_user_free_threads(resource_user,
+ static_cast<int>(gpr_atm_no_barrier_load(
+ &resource_user->num_threads_allocated)));
+
for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
rulist_remove(resource_user, static_cast<grpc_rulist>(i));
}
@@ -594,6 +623,9 @@
resource_quota->free_pool = INT64_MAX;
resource_quota->size = INT64_MAX;
gpr_atm_no_barrier_store(&resource_quota->last_size, GPR_ATM_MAX);
+ gpr_mu_init(&resource_quota->thread_count_mu);
+ resource_quota->max_threads = INT_MAX;
+ resource_quota->num_threads_allocated = 0;
resource_quota->step_scheduled = false;
resource_quota->reclaiming = false;
gpr_atm_no_barrier_store(&resource_quota->memory_usage_estimation, 0);
@@ -616,6 +648,8 @@
void grpc_resource_quota_unref_internal(grpc_resource_quota* resource_quota) {
if (gpr_unref(&resource_quota->refs)) {
+ // No outstanding thread quota
+ GPR_ASSERT(resource_quota->num_threads_allocated == 0);
GRPC_COMBINER_UNREF(resource_quota->combiner, "resource_quota");
gpr_free(resource_quota->name);
gpr_free(resource_quota);
@@ -647,6 +681,15 @@
}
/* Public API */
+void grpc_resource_quota_set_max_threads(grpc_resource_quota* resource_quota,
+ int new_max_threads) {
+ GPR_ASSERT(new_max_threads >= 0);
+ gpr_mu_lock(&resource_quota->thread_count_mu);
+ resource_quota->max_threads = new_max_threads;
+ gpr_mu_unlock(&resource_quota->thread_count_mu);
+}
+
+/* Public API */
void grpc_resource_quota_resize(grpc_resource_quota* resource_quota,
size_t size) {
grpc_core::ExecCtx exec_ctx;
@@ -731,6 +774,7 @@
grpc_closure_list_init(&resource_user->on_allocated);
resource_user->allocating = false;
resource_user->added_to_free_pool = false;
+ gpr_atm_no_barrier_store(&resource_user->num_threads_allocated, 0);
resource_user->reclaimers[0] = nullptr;
resource_user->reclaimers[1] = nullptr;
resource_user->new_reclaimers[0] = nullptr;
@@ -785,6 +829,40 @@
}
}
+bool grpc_resource_user_allocate_threads(grpc_resource_user* resource_user,
+ int thread_count) {
+ GPR_ASSERT(thread_count >= 0);
+ bool is_success = false;
+ gpr_mu_lock(&resource_user->resource_quota->thread_count_mu);
+ grpc_resource_quota* rq = resource_user->resource_quota;
+ if (rq->num_threads_allocated + thread_count <= rq->max_threads) {
+ rq->num_threads_allocated += thread_count;
+ gpr_atm_no_barrier_fetch_add(&resource_user->num_threads_allocated,
+ thread_count);
+ is_success = true;
+ }
+ gpr_mu_unlock(&resource_user->resource_quota->thread_count_mu);
+ return is_success;
+}
+
+void grpc_resource_user_free_threads(grpc_resource_user* resource_user,
+ int thread_count) {
+ GPR_ASSERT(thread_count >= 0);
+ gpr_mu_lock(&resource_user->resource_quota->thread_count_mu);
+ grpc_resource_quota* rq = resource_user->resource_quota;
+ rq->num_threads_allocated -= thread_count;
+ int old_count = static_cast<int>(gpr_atm_no_barrier_fetch_add(
+ &resource_user->num_threads_allocated, -thread_count));
+ if (old_count < thread_count || rq->num_threads_allocated < 0) {
+ gpr_log(GPR_ERROR,
+ "Releasing more threads (%d) than currently allocated (rq threads: "
+ "%d, ru threads: %d)",
+ thread_count, rq->num_threads_allocated + thread_count, old_count);
+ abort();
+ }
+ gpr_mu_unlock(&resource_user->resource_quota->thread_count_mu);
+}
+
void grpc_resource_user_alloc(grpc_resource_user* resource_user, size_t size,
grpc_closure* optional_on_done) {
gpr_mu_lock(&resource_user->mu);
diff --git a/src/core/lib/iomgr/resource_quota.h b/src/core/lib/iomgr/resource_quota.h
index 937daf8..1d5e95e 100644
--- a/src/core/lib/iomgr/resource_quota.h
+++ b/src/core/lib/iomgr/resource_quota.h
@@ -93,6 +93,22 @@
void grpc_resource_user_unref(grpc_resource_user* resource_user);
void grpc_resource_user_shutdown(grpc_resource_user* resource_user);
+/* Attempts to get quota (from the resource_user) to create 'thd_count' number
+ * of threads. Returns true if successful (i.e the caller is now free to create
+ * 'thd_count' number of threads) or false if quota is not available */
+bool grpc_resource_user_allocate_threads(grpc_resource_user* resource_user,
+ int thd_count);
+/* Releases 'thd_count' worth of quota back to the resource user. The quota
+ * should have been previously obtained successfully by calling
+ * grpc_resource_user_allocate_threads().
+ *
+ * Note: There need not be an exact one-to-one correspondence between
+ * grpc_resource_user_allocate_threads() and grpc_resource_user_free_threads()
+ * calls. The only requirement is that the number of threads allocated should
+ * all be eventually released */
+void grpc_resource_user_free_threads(grpc_resource_user* resource_user,
+ int thd_count);
+
/* Allocate from the resource user (and its quota).
If optional_on_done is NULL, then allocate immediately. This may push the
quota over-limit, at which point reclamation will kick in.
diff --git a/src/cpp/common/resource_quota_cc.cc b/src/cpp/common/resource_quota_cc.cc
index daeb0ba..276e5f7 100644
--- a/src/cpp/common/resource_quota_cc.cc
+++ b/src/cpp/common/resource_quota_cc.cc
@@ -33,4 +33,8 @@
return *this;
}
+ResourceQuota& ResourceQuota::SetMaxThreads(int new_max_threads) {
+ grpc_resource_quota_set_max_threads(impl_, new_max_threads);
+ return *this;
+}
} // namespace grpc
diff --git a/src/cpp/server/server_builder.cc b/src/cpp/server/server_builder.cc
index e0b9b7a..0ab3cd0 100644
--- a/src/cpp/server/server_builder.cc
+++ b/src/cpp/server/server_builder.cc
@@ -261,7 +261,7 @@
}
std::unique_ptr<Server> server(new Server(
- max_receive_message_size_, &args, sync_server_cqs,
+ max_receive_message_size_, &args, sync_server_cqs, resource_quota_,
sync_server_settings_.min_pollers, sync_server_settings_.max_pollers,
sync_server_settings_.cq_timeout_msec));
diff --git a/src/cpp/server/server_cc.cc b/src/cpp/server/server_cc.cc
index 0d77510..472c503 100644
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@@ -47,6 +47,12 @@
namespace grpc {
namespace {
+// The default value for maximum number of threads that can be created in the
+// sync server. This value of 500 is empirically chosen. To increase the max
+// number of threads in a sync server, pass a custom ResourceQuota object (with
+// the desired number of max-threads set) to the server builder
+#define DEFAULT_MAX_SYNC_SERVER_THREADS 500
+
class DefaultGlobalCallbacks final : public Server::GlobalCallbacks {
public:
~DefaultGlobalCallbacks() override {}
@@ -266,9 +272,9 @@
public:
SyncRequestThreadManager(Server* server, CompletionQueue* server_cq,
std::shared_ptr<GlobalCallbacks> global_callbacks,
- int min_pollers, int max_pollers,
- int cq_timeout_msec)
- : ThreadManager(min_pollers, max_pollers),
+ grpc_resource_quota* rq, int min_pollers,
+ int max_pollers, int cq_timeout_msec)
+ : ThreadManager("SyncServer", rq, min_pollers, max_pollers),
server_(server),
server_cq_(server_cq),
cq_timeout_msec_(cq_timeout_msec),
@@ -376,7 +382,8 @@
int max_receive_message_size, ChannelArguments* args,
std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
sync_server_cqs,
- int min_pollers, int max_pollers, int sync_cq_timeout_msec)
+ grpc_resource_quota* server_rq, int min_pollers, int max_pollers,
+ int sync_cq_timeout_msec)
: max_receive_message_size_(max_receive_message_size),
sync_server_cqs_(std::move(sync_server_cqs)),
started_(false),
@@ -392,10 +399,22 @@
global_callbacks_->UpdateArguments(args);
if (sync_server_cqs_ != nullptr) {
+ bool default_rq_created = false;
+ if (server_rq == nullptr) {
+ server_rq = grpc_resource_quota_create("SyncServer-default-rq");
+ grpc_resource_quota_set_max_threads(server_rq,
+ DEFAULT_MAX_SYNC_SERVER_THREADS);
+ default_rq_created = true;
+ }
+
for (const auto& it : *sync_server_cqs_) {
sync_req_mgrs_.emplace_back(new SyncRequestThreadManager(
- this, it.get(), global_callbacks_, min_pollers, max_pollers,
- sync_cq_timeout_msec));
+ this, it.get(), global_callbacks_, server_rq, min_pollers,
+ max_pollers, sync_cq_timeout_msec));
+ }
+
+ if (default_rq_created) {
+ grpc_resource_quota_unref(server_rq);
}
}
diff --git a/src/cpp/thread_manager/thread_manager.cc b/src/cpp/thread_manager/thread_manager.cc
index 02ac56a..fa9eec5 100644
--- a/src/cpp/thread_manager/thread_manager.cc
+++ b/src/cpp/thread_manager/thread_manager.cc
@@ -22,8 +22,8 @@
#include <mutex>
#include <grpc/support/log.h>
-
#include "src/core/lib/gprpp/thd.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
namespace grpc {
@@ -48,12 +48,17 @@
thd_.Join();
}
-ThreadManager::ThreadManager(int min_pollers, int max_pollers)
+ThreadManager::ThreadManager(const char* name,
+ grpc_resource_quota* resource_quota,
+ int min_pollers, int max_pollers)
: shutdown_(false),
num_pollers_(0),
min_pollers_(min_pollers),
max_pollers_(max_pollers == -1 ? INT_MAX : max_pollers),
- num_threads_(0) {}
+ num_threads_(0),
+ max_active_threads_sofar_(0) {
+ resource_user_ = grpc_resource_user_create(resource_quota, name);
+}
ThreadManager::~ThreadManager() {
{
@@ -61,6 +66,8 @@
GPR_ASSERT(num_threads_ == 0);
}
+ grpc_core::ExecCtx exec_ctx; // grpc_resource_user_unref needs an exec_ctx
+ grpc_resource_user_unref(resource_user_);
CleanupCompletedThreads();
}
@@ -81,17 +88,27 @@
return shutdown_;
}
+int ThreadManager::GetMaxActiveThreadsSoFar() {
+ std::lock_guard<std::mutex> list_lock(list_mu_);
+ return max_active_threads_sofar_;
+}
+
void ThreadManager::MarkAsCompleted(WorkerThread* thd) {
{
std::lock_guard<std::mutex> list_lock(list_mu_);
completed_threads_.push_back(thd);
}
- std::lock_guard<std::mutex> lock(mu_);
- num_threads_--;
- if (num_threads_ == 0) {
- shutdown_cv_.notify_one();
+ {
+ std::lock_guard<std::mutex> lock(mu_);
+ num_threads_--;
+ if (num_threads_ == 0) {
+ shutdown_cv_.notify_one();
+ }
}
+
+ // Give a thread back to the resource quota
+ grpc_resource_user_free_threads(resource_user_, 1);
}
void ThreadManager::CleanupCompletedThreads() {
@@ -106,14 +123,22 @@
}
void ThreadManager::Initialize() {
+ if (!grpc_resource_user_allocate_threads(resource_user_, min_pollers_)) {
+ gpr_log(GPR_ERROR,
+ "No thread quota available to even create the minimum required "
+ "polling threads (i.e %d). Unable to start the thread manager",
+ min_pollers_);
+ abort();
+ }
+
{
std::unique_lock<std::mutex> lock(mu_);
num_pollers_ = min_pollers_;
num_threads_ = min_pollers_;
+ max_active_threads_sofar_ = min_pollers_;
}
for (int i = 0; i < min_pollers_; i++) {
- // Create a new thread (which ends up calling the MainWorkLoop() function
new WorkerThread(this);
}
}
@@ -139,11 +164,15 @@
done = true;
break;
case WORK_FOUND:
- // If we got work and there are now insufficient pollers, start a new
- // one
- if (!shutdown_ && num_pollers_ < min_pollers_) {
+ // If we got work and there are now insufficient pollers and there is
+ // quota available to create a new thread, start a new poller thread
+ if (!shutdown_ && num_pollers_ < min_pollers_ &&
+ grpc_resource_user_allocate_threads(resource_user_, 1)) {
num_pollers_++;
num_threads_++;
+ if (num_threads_ > max_active_threads_sofar_) {
+ max_active_threads_sofar_ = num_threads_;
+ }
// Drop lock before spawning thread to avoid contention
lock.unlock();
new WorkerThread(this);
@@ -196,6 +225,8 @@
}
};
+ // This thread is exiting. Do some cleanup work i.e delete already completed
+ // worker threads
CleanupCompletedThreads();
// If we are here, either ThreadManager is shutting down or it already has
diff --git a/src/cpp/thread_manager/thread_manager.h b/src/cpp/thread_manager/thread_manager.h
index 5a40f2d..01043ed 100644
--- a/src/cpp/thread_manager/thread_manager.h
+++ b/src/cpp/thread_manager/thread_manager.h
@@ -27,12 +27,14 @@
#include <grpcpp/support/config.h>
#include "src/core/lib/gprpp/thd.h"
+#include "src/core/lib/iomgr/resource_quota.h"
namespace grpc {
class ThreadManager {
public:
- explicit ThreadManager(int min_pollers, int max_pollers);
+ explicit ThreadManager(const char* name, grpc_resource_quota* resource_quota,
+ int min_pollers, int max_pollers);
virtual ~ThreadManager();
// Initializes and Starts the Rpc Manager threads
@@ -84,6 +86,11 @@
// all the threads have drained all the outstanding work
virtual void Wait();
+ // Max number of concurrent threads that were ever active in this thread
+ // manager so far. This is useful for debugging purposes (and in unit tests)
+ // to check if resource_quota is properly being enforced.
+ int GetMaxActiveThreadsSoFar();
+
private:
// Helper wrapper class around grpc_core::Thread. Takes a ThreadManager object
// and starts a new grpc_core::Thread to calls the Run() function.
@@ -91,6 +98,24 @@
// The Run() function calls ThreadManager::MainWorkLoop() function and once
// that completes, it marks the WorkerThread completed by calling
// ThreadManager::MarkAsCompleted()
+ //
+ // WHY IS THIS NEEDED?:
+ // When a thread terminates, some other thread *must* call Join() on that
+ // thread so that the resources are released. Having a WorkerThread wrapper
+ // will make this easier. Once Run() completes, each thread calls the
+ // following two functions:
+ // ThreadManager::CleanupCompletedThreads()
+ // ThreadManager::MarkAsCompleted()
+ //
+ // - MarkAsCompleted() puts the WorkerThread object in the ThreadManger's
+ // completed_threads_ list
+ // - CleanupCompletedThreads() calls "Join()" on the threads that are already
+ // in the completed_threads_ list (since a thread cannot call Join() on
+ // itself, it calls CleanupCompletedThreads() *before* calling
+ // MarkAsCompleted())
+ //
+ // TODO(sreek): Consider creating the threads 'detached' so that Join() need
+ // not be called (and the need for this WorkerThread class is eliminated)
class WorkerThread {
public:
WorkerThread(ThreadManager* thd_mgr);
@@ -111,13 +136,21 @@
void MarkAsCompleted(WorkerThread* thd);
void CleanupCompletedThreads();
- // Protects shutdown_, num_pollers_ and num_threads_
- // TODO: sreek - Change num_pollers and num_threads_ to atomics
+ // Protects shutdown_, num_pollers_, num_threads_ and
+ // max_active_threads_sofar_
std::mutex mu_;
bool shutdown_;
std::condition_variable shutdown_cv_;
+ // The resource user object to use when requesting quota to create threads
+ //
+ // Note: The user of this ThreadManager object must create grpc_resource_quota
+ // object (that contains the actual max thread quota) and a grpc_resource_user
+ // object through which quota is requested whenver new threads need to be
+ // created
+ grpc_resource_user* resource_user_;
+
// Number of threads doing polling
int num_pollers_;
@@ -125,10 +158,15 @@
int min_pollers_;
int max_pollers_;
- // The total number of threads (includes threads includes the threads that are
- // currently polling i.e num_pollers_)
+ // The total number of threads currently active (includes threads includes the
+ // threads that are currently polling i.e num_pollers_)
int num_threads_;
+ // See GetMaxActiveThreadsSoFar()'s description.
+ // To be more specific, this variable tracks the max value num_threads_ was
+ // ever set so far
+ int max_active_threads_sofar_;
+
std::mutex list_mu_;
std::list<WorkerThread*> completed_threads_;
};
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.c b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
index 2443532..78090af 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.c
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
@@ -91,6 +91,7 @@
grpc_resource_quota_ref_type grpc_resource_quota_ref_import;
grpc_resource_quota_unref_type grpc_resource_quota_unref_import;
grpc_resource_quota_resize_type grpc_resource_quota_resize_import;
+grpc_resource_quota_set_max_threads_type grpc_resource_quota_set_max_threads_import;
grpc_resource_quota_arg_vtable_type grpc_resource_quota_arg_vtable_import;
grpc_channelz_get_top_channels_type grpc_channelz_get_top_channels_import;
grpc_channelz_get_channel_type grpc_channelz_get_channel_import;
@@ -341,6 +342,7 @@
grpc_resource_quota_ref_import = (grpc_resource_quota_ref_type) GetProcAddress(library, "grpc_resource_quota_ref");
grpc_resource_quota_unref_import = (grpc_resource_quota_unref_type) GetProcAddress(library, "grpc_resource_quota_unref");
grpc_resource_quota_resize_import = (grpc_resource_quota_resize_type) GetProcAddress(library, "grpc_resource_quota_resize");
+ grpc_resource_quota_set_max_threads_import = (grpc_resource_quota_set_max_threads_type) GetProcAddress(library, "grpc_resource_quota_set_max_threads");
grpc_resource_quota_arg_vtable_import = (grpc_resource_quota_arg_vtable_type) GetProcAddress(library, "grpc_resource_quota_arg_vtable");
grpc_channelz_get_top_channels_import = (grpc_channelz_get_top_channels_type) GetProcAddress(library, "grpc_channelz_get_top_channels");
grpc_channelz_get_channel_import = (grpc_channelz_get_channel_type) GetProcAddress(library, "grpc_channelz_get_channel");
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index b08a1f9..1807efa 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -248,6 +248,9 @@
typedef void(*grpc_resource_quota_resize_type)(grpc_resource_quota* resource_quota, size_t new_size);
extern grpc_resource_quota_resize_type grpc_resource_quota_resize_import;
#define grpc_resource_quota_resize grpc_resource_quota_resize_import
+typedef void(*grpc_resource_quota_set_max_threads_type)(grpc_resource_quota* resource_quota, int new_max_threads);
+extern grpc_resource_quota_set_max_threads_type grpc_resource_quota_set_max_threads_import;
+#define grpc_resource_quota_set_max_threads grpc_resource_quota_set_max_threads_import
typedef const grpc_arg_pointer_vtable*(*grpc_resource_quota_arg_vtable_type)(void);
extern grpc_resource_quota_arg_vtable_type grpc_resource_quota_arg_vtable_import;
#define grpc_resource_quota_arg_vtable grpc_resource_quota_arg_vtable_import
diff --git a/test/core/iomgr/resource_quota_test.cc b/test/core/iomgr/resource_quota_test.cc
index 059ff7b..f3b35fe 100644
--- a/test/core/iomgr/resource_quota_test.cc
+++ b/test/core/iomgr/resource_quota_test.cc
@@ -798,6 +798,98 @@
}
}
+// Simple test to check resource quota thread limits
+static void test_thread_limit() {
+ grpc_core::ExecCtx exec_ctx;
+
+ grpc_resource_quota* rq = grpc_resource_quota_create("test_thread_limit");
+ grpc_resource_user* ru1 = grpc_resource_user_create(rq, "ru1");
+ grpc_resource_user* ru2 = grpc_resource_user_create(rq, "ru2");
+
+ // Max threads = 100
+ grpc_resource_quota_set_max_threads(rq, 100);
+
+ // Request quota for 100 threads (50 for ru1, 50 for ru2)
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru1, 10));
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 10));
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru1, 40));
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 40));
+
+ // Threads exhausted. Next request must fail
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru2, 20));
+
+ // Free 20 threads from two different users
+ grpc_resource_user_free_threads(ru1, 10);
+ grpc_resource_user_free_threads(ru2, 10);
+
+ // Next request to 20 threads must succeed
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 20));
+
+ // No more thread quota again
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru1, 20));
+
+ // Free 10 more
+ grpc_resource_user_free_threads(ru1, 10);
+
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru1, 5));
+ GPR_ASSERT(
+ !grpc_resource_user_allocate_threads(ru2, 10)); // Only 5 available
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 5));
+
+ // Teardown (ru1 and ru2 release all the quota back to rq)
+ grpc_resource_user_unref(ru1);
+ grpc_resource_user_unref(ru2);
+ grpc_resource_quota_unref(rq);
+}
+
+// Change max quota in either direction dynamically
+static void test_thread_maxquota_change() {
+ grpc_core::ExecCtx exec_ctx;
+
+ grpc_resource_quota* rq =
+ grpc_resource_quota_create("test_thread_maxquota_change");
+ grpc_resource_user* ru1 = grpc_resource_user_create(rq, "ru1");
+ grpc_resource_user* ru2 = grpc_resource_user_create(rq, "ru2");
+
+ // Max threads = 100
+ grpc_resource_quota_set_max_threads(rq, 100);
+
+ // Request quota for 100 threads (50 for ru1, 50 for ru2)
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru1, 50));
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 50));
+
+ // Threads exhausted. Next request must fail
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru2, 20));
+
+ // Increase maxquota and retry
+ // Max threads = 150;
+ grpc_resource_quota_set_max_threads(rq, 150);
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 20)); // ru2=70, ru1=50
+
+ // Decrease maxquota (Note: Quota already given to ru1 and ru2 is unaffected)
+ // Max threads = 10;
+ grpc_resource_quota_set_max_threads(rq, 10);
+
+ // New requests will fail until quota is available
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru1, 10));
+
+ // Make quota available
+ grpc_resource_user_free_threads(ru1, 50); // ru1 now has 0
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru1, 10)); // not enough
+
+ grpc_resource_user_free_threads(ru2, 70); // ru2 now has 0
+
+ // Now we can get quota up-to 10, the current max
+ GPR_ASSERT(grpc_resource_user_allocate_threads(ru2, 10));
+ // No more thread quota again
+ GPR_ASSERT(!grpc_resource_user_allocate_threads(ru1, 10));
+
+ // Teardown (ru1 and ru2 release all the quota back to rq)
+ grpc_resource_user_unref(ru1);
+ grpc_resource_user_unref(ru2);
+ grpc_resource_quota_unref(rq);
+}
+
int main(int argc, char** argv) {
grpc_test_init(argc, argv);
grpc_init();
@@ -827,6 +919,11 @@
test_negative_rq_free_pool();
gpr_mu_destroy(&g_mu);
gpr_cv_destroy(&g_cv);
+
+ // Resource quota thread related
+ test_thread_limit();
+ test_thread_maxquota_change();
+
grpc_shutdown();
return 0;
}
diff --git a/test/core/surface/public_headers_must_be_c89.c b/test/core/surface/public_headers_must_be_c89.c
index 9f4ad2b..497f719 100644
--- a/test/core/surface/public_headers_must_be_c89.c
+++ b/test/core/surface/public_headers_must_be_c89.c
@@ -130,6 +130,7 @@
printf("%lx", (unsigned long) grpc_resource_quota_ref);
printf("%lx", (unsigned long) grpc_resource_quota_unref);
printf("%lx", (unsigned long) grpc_resource_quota_resize);
+ printf("%lx", (unsigned long) grpc_resource_quota_set_max_threads);
printf("%lx", (unsigned long) grpc_resource_quota_arg_vtable);
printf("%lx", (unsigned long) grpc_channelz_get_top_channels);
printf("%lx", (unsigned long) grpc_channelz_get_channel);
diff --git a/test/cpp/thread_manager/thread_manager_test.cc b/test/cpp/thread_manager/thread_manager_test.cc
index 7a95a9f..838f5f7 100644
--- a/test/cpp/thread_manager/thread_manager_test.cc
+++ b/test/cpp/thread_manager/thread_manager_test.cc
@@ -30,30 +30,44 @@
#include "test/cpp/util/test_config.h"
namespace grpc {
+
+struct ThreadManagerTestSettings {
+ // The min number of pollers that SHOULD be active in ThreadManager
+ int min_pollers;
+ // The max number of pollers that could be active in ThreadManager
+ int max_pollers;
+ // The sleep duration in PollForWork() function to simulate "polling"
+ int poll_duration_ms;
+ // The sleep duration in DoWork() function to simulate "work"
+ int work_duration_ms;
+ // Max number of times PollForWork() is called before shutting down
+ int max_poll_calls;
+};
+
class ThreadManagerTest final : public grpc::ThreadManager {
public:
- ThreadManagerTest()
- : ThreadManager(kMinPollers, kMaxPollers),
+ ThreadManagerTest(const char* name, grpc_resource_quota* rq,
+ const ThreadManagerTestSettings& settings)
+ : ThreadManager(name, rq, settings.min_pollers, settings.max_pollers),
+ settings_(settings),
num_do_work_(0),
num_poll_for_work_(0),
num_work_found_(0) {}
grpc::ThreadManager::WorkStatus PollForWork(void** tag, bool* ok) override;
void DoWork(void* tag, bool ok) override;
- void PerformTest();
+
+ // Get number of times PollForWork() returned WORK_FOUND
+ int GetNumWorkFound();
+ // Get number of times DoWork() was called
+ int GetNumDoWork();
private:
void SleepForMs(int sleep_time_ms);
- static const int kMinPollers = 2;
- static const int kMaxPollers = 10;
+ ThreadManagerTestSettings settings_;
- static const int kPollingTimeoutMsec = 10;
- static const int kDoWorkDurationMsec = 1;
-
- // PollForWork will return SHUTDOWN after these many number of invocations
- static const int kMaxNumPollForWork = 50;
-
+ // Counters
gpr_atm num_do_work_; // Number of calls to DoWork
gpr_atm num_poll_for_work_; // Number of calls to PollForWork
gpr_atm num_work_found_; // Number of times WORK_FOUND was returned
@@ -69,54 +83,117 @@
grpc::ThreadManager::WorkStatus ThreadManagerTest::PollForWork(void** tag,
bool* ok) {
int call_num = gpr_atm_no_barrier_fetch_add(&num_poll_for_work_, 1);
-
- if (call_num >= kMaxNumPollForWork) {
+ if (call_num >= settings_.max_poll_calls) {
Shutdown();
return SHUTDOWN;
}
- // Simulate "polling for work" by sleeping for sometime
- SleepForMs(kPollingTimeoutMsec);
-
+ SleepForMs(settings_.poll_duration_ms); // Simulate "polling" duration
*tag = nullptr;
*ok = true;
- // Return timeout roughly 1 out of every 3 calls
+ // Return timeout roughly 1 out of every 3 calls just to make the test a bit
+ // more interesting
if (call_num % 3 == 0) {
return TIMEOUT;
- } else {
- gpr_atm_no_barrier_fetch_add(&num_work_found_, 1);
- return WORK_FOUND;
}
+
+ gpr_atm_no_barrier_fetch_add(&num_work_found_, 1);
+ return WORK_FOUND;
}
void ThreadManagerTest::DoWork(void* tag, bool ok) {
gpr_atm_no_barrier_fetch_add(&num_do_work_, 1);
- SleepForMs(kDoWorkDurationMsec); // Simulate doing work by sleeping
+ SleepForMs(settings_.work_duration_ms); // Simulate work by sleeping
}
-void ThreadManagerTest::PerformTest() {
- // Initialize() starts the ThreadManager
- Initialize();
+int ThreadManagerTest::GetNumWorkFound() {
+ return static_cast<int>(gpr_atm_no_barrier_load(&num_work_found_));
+}
- // Wait for all the threads to gracefully terminate
- Wait();
-
- // The number of times DoWork() was called is equal to the number of times
- // WORK_FOUND was returned
- gpr_log(GPR_DEBUG, "DoWork() called %" PRIdPTR " times",
- gpr_atm_no_barrier_load(&num_do_work_));
- GPR_ASSERT(gpr_atm_no_barrier_load(&num_do_work_) ==
- gpr_atm_no_barrier_load(&num_work_found_));
+int ThreadManagerTest::GetNumDoWork() {
+ return static_cast<int>(gpr_atm_no_barrier_load(&num_do_work_));
}
} // namespace grpc
+// Test that the number of times DoWork() is called is equal to the number of
+// times PollForWork() returned WORK_FOUND
+static void TestPollAndWork() {
+ grpc_resource_quota* rq = grpc_resource_quota_create("Test-poll-and-work");
+ grpc::ThreadManagerTestSettings settings = {
+ 2 /* min_pollers */, 10 /* max_pollers */, 10 /* poll_duration_ms */,
+ 1 /* work_duration_ms */, 50 /* max_poll_calls */};
+
+ grpc::ThreadManagerTest test_thread_mgr("TestThreadManager", rq, settings);
+ grpc_resource_quota_unref(rq);
+
+ test_thread_mgr.Initialize(); // Start the thread manager
+ test_thread_mgr.Wait(); // Wait for all threads to finish
+
+ // Verify that The number of times DoWork() was called is equal to the number
+ // of times WORK_FOUND was returned
+ gpr_log(GPR_DEBUG, "DoWork() called %d times",
+ test_thread_mgr.GetNumDoWork());
+ GPR_ASSERT(test_thread_mgr.GetNumDoWork() ==
+ test_thread_mgr.GetNumWorkFound());
+}
+
+static void TestThreadQuota() {
+ const int kMaxNumThreads = 3;
+ grpc_resource_quota* rq = grpc_resource_quota_create("Test-thread-quota");
+ grpc_resource_quota_set_max_threads(rq, kMaxNumThreads);
+
+ // Set work_duration_ms to be much greater than poll_duration_ms. This way,
+ // the thread manager will be forced to create more 'polling' threads to
+ // honor the min_pollers guarantee
+ grpc::ThreadManagerTestSettings settings = {
+ 1 /* min_pollers */, 1 /* max_pollers */, 1 /* poll_duration_ms */,
+ 10 /* work_duration_ms */, 50 /* max_poll_calls */};
+
+ // Create two thread managers (but with same resource quota). This means
+ // that the max number of active threads across BOTH the thread managers
+ // cannot be greater than kMaxNumthreads
+ grpc::ThreadManagerTest test_thread_mgr_1("TestThreadManager-1", rq,
+ settings);
+ grpc::ThreadManagerTest test_thread_mgr_2("TestThreadManager-2", rq,
+ settings);
+ // It is ok to unref resource quota before starting thread managers.
+ grpc_resource_quota_unref(rq);
+
+ // Start both thread managers
+ test_thread_mgr_1.Initialize();
+ test_thread_mgr_2.Initialize();
+
+ // Wait for both to finish
+ test_thread_mgr_1.Wait();
+ test_thread_mgr_2.Wait();
+
+ // Now verify that the total number of active threads in either thread manager
+ // never exceeds kMaxNumThreads
+ //
+ // NOTE: Actually the total active threads across *both* thread managers at
+ // any point of time never exceeds kMaxNumThreads but unfortunately there is
+ // no easy way to verify it (i.e we can't just do (max1 + max2 <= k))
+ // Its okay to not test this case here. The resource quota c-core tests
+ // provide enough coverage to resource quota object with multiple resource
+ // users
+ int max1 = test_thread_mgr_1.GetMaxActiveThreadsSoFar();
+ int max2 = test_thread_mgr_2.GetMaxActiveThreadsSoFar();
+ gpr_log(
+ GPR_DEBUG,
+ "MaxActiveThreads in TestThreadManager_1: %d, TestThreadManager_2: %d",
+ max1, max2);
+ GPR_ASSERT(max1 <= kMaxNumThreads && max2 <= kMaxNumThreads);
+}
+
int main(int argc, char** argv) {
std::srand(std::time(nullptr));
-
grpc::testing::InitTest(&argc, &argv, true);
- grpc::ThreadManagerTest test_rpc_manager;
- test_rpc_manager.PerformTest();
+ grpc_init();
+ TestPollAndWork();
+ TestThreadQuota();
+
+ grpc_shutdown();
return 0;
}