--- /dev/null
+/*
+ *
+ * Copyright 2015-2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/surface/completion_queue.h"
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/atm.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+
+#include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/spinlock.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/tls.h"
+#include "src/core/lib/gprpp/atomic.h"
+#include "src/core/lib/iomgr/executor.h"
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/event_string.h"
+
+grpc_core::TraceFlag grpc_trace_operation_failures(false, "op_failure");
+grpc_core::DebugOnlyTraceFlag grpc_trace_pending_tags(false, "pending_tags");
+grpc_core::DebugOnlyTraceFlag grpc_trace_cq_refcount(false, "cq_refcount");
+
+namespace {
+
+// Specifies a cq thread local cache.
+// The first event that occurs on a thread
+// with a cq cache will go into that cache, and
+// will only be returned on the thread that initialized the cache.
+// NOTE: Only one event will ever be cached.
+GPR_TLS_DECL(g_cached_event);
+GPR_TLS_DECL(g_cached_cq);
+
+typedef struct {
+ grpc_pollset_worker** worker;
+ void* tag;
+} plucker;
+
+typedef struct {
+ bool can_get_pollset;
+ bool can_listen;
+ size_t (*size)(void);
+ void (*init)(grpc_pollset* pollset, gpr_mu** mu);
+ grpc_error* (*kick)(grpc_pollset* pollset,
+ grpc_pollset_worker* specific_worker);
+ grpc_error* (*work)(grpc_pollset* pollset, grpc_pollset_worker** worker,
+ grpc_millis deadline);
+ void (*shutdown)(grpc_pollset* pollset, grpc_closure* closure);
+ void (*destroy)(grpc_pollset* pollset);
+} cq_poller_vtable;
+
+typedef struct non_polling_worker {
+ gpr_cv cv;
+ bool kicked;
+ struct non_polling_worker* next;
+ struct non_polling_worker* prev;
+} non_polling_worker;
+
+typedef struct {
+ gpr_mu mu;
+ bool kicked_without_poller;
+ non_polling_worker* root;
+ grpc_closure* shutdown;
+} non_polling_poller;
+
+size_t non_polling_poller_size(void) { return sizeof(non_polling_poller); }
+
+void non_polling_poller_init(grpc_pollset* pollset, gpr_mu** mu) {
+ non_polling_poller* npp = reinterpret_cast<non_polling_poller*>(pollset);
+ gpr_mu_init(&npp->mu);
+ *mu = &npp->mu;
+}
+
+void non_polling_poller_destroy(grpc_pollset* pollset) {
+ non_polling_poller* npp = reinterpret_cast<non_polling_poller*>(pollset);
+ gpr_mu_destroy(&npp->mu);
+}
+
+grpc_error* non_polling_poller_work(grpc_pollset* pollset,
+ grpc_pollset_worker** worker,
+ grpc_millis deadline) {
+ non_polling_poller* npp = reinterpret_cast<non_polling_poller*>(pollset);
+ if (npp->shutdown) return GRPC_ERROR_NONE;
+ if (npp->kicked_without_poller) {
+ npp->kicked_without_poller = false;
+ return GRPC_ERROR_NONE;
+ }
+ non_polling_worker w;
+ gpr_cv_init(&w.cv);
+ if (worker != nullptr) *worker = reinterpret_cast<grpc_pollset_worker*>(&w);
+ if (npp->root == nullptr) {
+ npp->root = w.next = w.prev = &w;
+ } else {
+ w.next = npp->root;
+ w.prev = w.next->prev;
+ w.next->prev = w.prev->next = &w;
+ }
+ w.kicked = false;
+ gpr_timespec deadline_ts =
+ grpc_millis_to_timespec(deadline, GPR_CLOCK_MONOTONIC);
+ while (!npp->shutdown && !w.kicked &&
+ !gpr_cv_wait(&w.cv, &npp->mu, deadline_ts))
+ ;
+ grpc_core::ExecCtx::Get()->InvalidateNow();
+ if (&w == npp->root) {
+ npp->root = w.next;
+ if (&w == npp->root) {
+ if (npp->shutdown) {
+ GRPC_CLOSURE_SCHED(npp->shutdown, GRPC_ERROR_NONE);
+ }
+ npp->root = nullptr;
+ }
+ }
+ w.next->prev = w.prev;
+ w.prev->next = w.next;
+ gpr_cv_destroy(&w.cv);
+ if (worker != nullptr) *worker = nullptr;
+ return GRPC_ERROR_NONE;
+}
+
+grpc_error* non_polling_poller_kick(grpc_pollset* pollset,
+ grpc_pollset_worker* specific_worker) {
+ non_polling_poller* p = reinterpret_cast<non_polling_poller*>(pollset);
+ if (specific_worker == nullptr)
+ specific_worker = reinterpret_cast<grpc_pollset_worker*>(p->root);
+ if (specific_worker != nullptr) {
+ non_polling_worker* w =
+ reinterpret_cast<non_polling_worker*>(specific_worker);
+ if (!w->kicked) {
+ w->kicked = true;
+ gpr_cv_signal(&w->cv);
+ }
+ } else {
+ p->kicked_without_poller = true;
+ }
+ return GRPC_ERROR_NONE;
+}
+
+void non_polling_poller_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
+ non_polling_poller* p = reinterpret_cast<non_polling_poller*>(pollset);
+ GPR_ASSERT(closure != nullptr);
+ p->shutdown = closure;
+ if (p->root == nullptr) {
+ GRPC_CLOSURE_SCHED(closure, GRPC_ERROR_NONE);
+ } else {
+ non_polling_worker* w = p->root;
+ do {
+ gpr_cv_signal(&w->cv);
+ w = w->next;
+ } while (w != p->root);
+ }
+}
+
+const cq_poller_vtable g_poller_vtable_by_poller_type[] = {
+ /* GRPC_CQ_DEFAULT_POLLING */
+ {true, true, grpc_pollset_size, grpc_pollset_init, grpc_pollset_kick,
+ grpc_pollset_work, grpc_pollset_shutdown, grpc_pollset_destroy},
+ /* GRPC_CQ_NON_LISTENING */
+ {true, false, grpc_pollset_size, grpc_pollset_init, grpc_pollset_kick,
+ grpc_pollset_work, grpc_pollset_shutdown, grpc_pollset_destroy},
+ /* GRPC_CQ_NON_POLLING */
+ {false, false, non_polling_poller_size, non_polling_poller_init,
+ non_polling_poller_kick, non_polling_poller_work,
+ non_polling_poller_shutdown, non_polling_poller_destroy},
+};
+
+} // namespace
+
+struct cq_vtable {
+ grpc_cq_completion_type cq_completion_type;
+ size_t data_size;
+ void (*init)(void* data,
+ grpc_experimental_completion_queue_functor* shutdown_callback);
+ void (*shutdown)(grpc_completion_queue* cq);
+ void (*destroy)(void* data);
+ bool (*begin_op)(grpc_completion_queue* cq, void* tag);
+ void (*end_op)(grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage),
+ void* done_arg, grpc_cq_completion* storage, bool internal);
+ grpc_event (*next)(grpc_completion_queue* cq, gpr_timespec deadline,
+ void* reserved);
+ grpc_event (*pluck)(grpc_completion_queue* cq, void* tag,
+ gpr_timespec deadline, void* reserved);
+};
+
+namespace {
+
+/* Queue that holds the cq_completion_events. Internally uses gpr_mpscq queue
+ * (a lockfree multiproducer single consumer queue). It uses a queue_lock
+ * to support multiple consumers.
+ * Only used in completion queues whose completion_type is GRPC_CQ_NEXT */
+class CqEventQueue {
+ public:
+ CqEventQueue() { gpr_mpscq_init(&queue_); }
+ ~CqEventQueue() { gpr_mpscq_destroy(&queue_); }
+
+ /* Note: The counter is not incremented/decremented atomically with push/pop.
+ * The count is only eventually consistent */
+ intptr_t num_items() const {
+ return num_queue_items_.Load(grpc_core::MemoryOrder::RELAXED);
+ }
+
+ bool Push(grpc_cq_completion* c);
+ grpc_cq_completion* Pop();
+
+ private:
+ /* Spinlock to serialize consumers i.e pop() operations */
+ gpr_spinlock queue_lock_ = GPR_SPINLOCK_INITIALIZER;
+
+ gpr_mpscq queue_;
+
+ /* A lazy counter of number of items in the queue. This is NOT atomically
+ incremented/decremented along with push/pop operations and hence is only
+ eventually consistent */
+ grpc_core::Atomic<intptr_t> num_queue_items_{0};
+};
+
+struct cq_next_data {
+ ~cq_next_data() { GPR_ASSERT(queue.num_items() == 0); }
+
+ /** Completed events for completion-queues of type GRPC_CQ_NEXT */
+ CqEventQueue queue;
+
+ /** Counter of how many things have ever been queued on this completion queue
+ useful for avoiding locks to check the queue */
+ grpc_core::Atomic<intptr_t> things_queued_ever{0};
+
+ /** Number of outstanding events (+1 if not shut down)
+ Initial count is dropped by grpc_completion_queue_shutdown */
+ grpc_core::Atomic<intptr_t> pending_events{1};
+
+ /** 0 initially. 1 once we initiated shutdown */
+ bool shutdown_called = false;
+};
+
+struct cq_pluck_data {
+ cq_pluck_data() {
+ completed_tail = &completed_head;
+ completed_head.next = reinterpret_cast<uintptr_t>(completed_tail);
+ }
+
+ ~cq_pluck_data() {
+ GPR_ASSERT(completed_head.next ==
+ reinterpret_cast<uintptr_t>(&completed_head));
+ }
+
+ /** Completed events for completion-queues of type GRPC_CQ_PLUCK */
+ grpc_cq_completion completed_head;
+ grpc_cq_completion* completed_tail;
+
+ /** Number of pending events (+1 if we're not shutdown).
+ Initial count is dropped by grpc_completion_queue_shutdown. */
+ grpc_core::Atomic<intptr_t> pending_events{1};
+
+ /** Counter of how many things have ever been queued on this completion queue
+ useful for avoiding locks to check the queue */
+ grpc_core::Atomic<intptr_t> things_queued_ever{0};
+
+ /** 0 initially. 1 once we completed shutting */
+ /* TODO: (sreek) This is not needed since (shutdown == 1) if and only if
+ * (pending_events == 0). So consider removing this in future and use
+ * pending_events */
+ grpc_core::Atomic<bool> shutdown{false};
+
+ /** 0 initially. 1 once we initiated shutdown */
+ bool shutdown_called = false;
+
+ int num_pluckers = 0;
+ plucker pluckers[GRPC_MAX_COMPLETION_QUEUE_PLUCKERS];
+};
+
+struct cq_callback_data {
+ cq_callback_data(
+ grpc_experimental_completion_queue_functor* shutdown_callback)
+ : shutdown_callback(shutdown_callback) {}
+ /** No actual completed events queue, unlike other types */
+
+ /** Number of pending events (+1 if we're not shutdown).
+ Initial count is dropped by grpc_completion_queue_shutdown. */
+ grpc_core::Atomic<intptr_t> pending_events{1};
+
+ /** Counter of how many things have ever been queued on this completion queue
+ useful for avoiding locks to check the queue */
+ grpc_core::Atomic<intptr_t> things_queued_ever{0};
+
+ /** 0 initially. 1 once we initiated shutdown */
+ bool shutdown_called = false;
+
+ /** A callback that gets invoked when the CQ completes shutdown */
+ grpc_experimental_completion_queue_functor* shutdown_callback;
+};
+
+} // namespace
+
+/* Completion queue structure */
+struct grpc_completion_queue {
+ /** Once owning_refs drops to zero, we will destroy the cq */
+ grpc_core::RefCount owning_refs;
+
+ gpr_mu* mu;
+
+ const cq_vtable* vtable;
+ const cq_poller_vtable* poller_vtable;
+
+#ifndef NDEBUG
+ void** outstanding_tags;
+ size_t outstanding_tag_count;
+ size_t outstanding_tag_capacity;
+#endif
+
+ grpc_closure pollset_shutdown_done;
+ int num_polls;
+};
+
+/* Forward declarations */
+static void cq_finish_shutdown_next(grpc_completion_queue* cq);
+static void cq_finish_shutdown_pluck(grpc_completion_queue* cq);
+static void cq_finish_shutdown_callback(grpc_completion_queue* cq);
+static void cq_shutdown_next(grpc_completion_queue* cq);
+static void cq_shutdown_pluck(grpc_completion_queue* cq);
+static void cq_shutdown_callback(grpc_completion_queue* cq);
+
+static bool cq_begin_op_for_next(grpc_completion_queue* cq, void* tag);
+static bool cq_begin_op_for_pluck(grpc_completion_queue* cq, void* tag);
+static bool cq_begin_op_for_callback(grpc_completion_queue* cq, void* tag);
+
+// A cq_end_op function is called when an operation on a given CQ with
+// a given tag has completed. The storage argument is a reference to the
+// space reserved for this completion as it is placed into the corresponding
+// queue. The done argument is a callback that will be invoked when it is
+// safe to free up that storage. The storage MUST NOT be freed until the
+// done callback is invoked.
+static void cq_end_op_for_next(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal);
+
+static void cq_end_op_for_pluck(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal);
+
+static void cq_end_op_for_callback(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal);
+
+static grpc_event cq_next(grpc_completion_queue* cq, gpr_timespec deadline,
+ void* reserved);
+
+static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
+ gpr_timespec deadline, void* reserved);
+
+// Note that cq_init_next and cq_init_pluck do not use the shutdown_callback
+static void cq_init_next(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback);
+static void cq_init_pluck(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback);
+static void cq_init_callback(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback);
+static void cq_destroy_next(void* data);
+static void cq_destroy_pluck(void* data);
+static void cq_destroy_callback(void* data);
+
+/* Completion queue vtables based on the completion-type */
+static const cq_vtable g_cq_vtable[] = {
+ /* GRPC_CQ_NEXT */
+ {GRPC_CQ_NEXT, sizeof(cq_next_data), cq_init_next, cq_shutdown_next,
+ cq_destroy_next, cq_begin_op_for_next, cq_end_op_for_next, cq_next,
+ nullptr},
+ /* GRPC_CQ_PLUCK */
+ {GRPC_CQ_PLUCK, sizeof(cq_pluck_data), cq_init_pluck, cq_shutdown_pluck,
+ cq_destroy_pluck, cq_begin_op_for_pluck, cq_end_op_for_pluck, nullptr,
+ cq_pluck},
+ /* GRPC_CQ_CALLBACK */
+ {GRPC_CQ_CALLBACK, sizeof(cq_callback_data), cq_init_callback,
+ cq_shutdown_callback, cq_destroy_callback, cq_begin_op_for_callback,
+ cq_end_op_for_callback, nullptr, nullptr},
+};
+
+#define DATA_FROM_CQ(cq) ((void*)(cq + 1))
+#define POLLSET_FROM_CQ(cq) \
+ ((grpc_pollset*)(cq->vtable->data_size + (char*)DATA_FROM_CQ(cq)))
+
+grpc_core::TraceFlag grpc_cq_pluck_trace(false, "queue_pluck");
+
+#define GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, event) \
+ do { \
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_api_trace) && \
+ (GRPC_TRACE_FLAG_ENABLED(grpc_cq_pluck_trace) || \
+ (event)->type != GRPC_QUEUE_TIMEOUT)) { \
+ char* _ev = grpc_event_string(event); \
+ gpr_log(GPR_INFO, "RETURN_EVENT[%p]: %s", cq, _ev); \
+ gpr_free(_ev); \
+ } \
+ } while (0)
+
+static void on_pollset_shutdown_done(void* cq, grpc_error* error);
+
+void grpc_cq_global_init() {
+ gpr_tls_init(&g_cached_event);
+ gpr_tls_init(&g_cached_cq);
+}
+
+void grpc_completion_queue_thread_local_cache_init(grpc_completion_queue* cq) {
+ if ((grpc_completion_queue*)gpr_tls_get(&g_cached_cq) == nullptr) {
+ gpr_tls_set(&g_cached_event, (intptr_t)0);
+ gpr_tls_set(&g_cached_cq, (intptr_t)cq);
+ }
+}
+
+int grpc_completion_queue_thread_local_cache_flush(grpc_completion_queue* cq,
+ void** tag, int* ok) {
+ grpc_cq_completion* storage =
+ (grpc_cq_completion*)gpr_tls_get(&g_cached_event);
+ int ret = 0;
+ if (storage != nullptr &&
+ (grpc_completion_queue*)gpr_tls_get(&g_cached_cq) == cq) {
+ *tag = storage->tag;
+ grpc_core::ExecCtx exec_ctx;
+ *ok = (storage->next & static_cast<uintptr_t>(1)) == 1;
+ storage->done(storage->done_arg, storage);
+ ret = 1;
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down");
+ gpr_mu_lock(cq->mu);
+ cq_finish_shutdown_next(cq);
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
+ }
+ }
+ gpr_tls_set(&g_cached_event, (intptr_t)0);
+ gpr_tls_set(&g_cached_cq, (intptr_t)0);
+
+ return ret;
+}
+
+bool CqEventQueue::Push(grpc_cq_completion* c) {
+ gpr_mpscq_push(&queue_, reinterpret_cast<gpr_mpscq_node*>(c));
+ return num_queue_items_.FetchAdd(1, grpc_core::MemoryOrder::RELAXED) == 0;
+}
+
+grpc_cq_completion* CqEventQueue::Pop() {
+ grpc_cq_completion* c = nullptr;
+
+ if (gpr_spinlock_trylock(&queue_lock_)) {
+ GRPC_STATS_INC_CQ_EV_QUEUE_TRYLOCK_SUCCESSES();
+
+ bool is_empty = false;
+ c = reinterpret_cast<grpc_cq_completion*>(
+ gpr_mpscq_pop_and_check_end(&queue_, &is_empty));
+ gpr_spinlock_unlock(&queue_lock_);
+
+ if (c == nullptr && !is_empty) {
+ GRPC_STATS_INC_CQ_EV_QUEUE_TRANSIENT_POP_FAILURES();
+ }
+ } else {
+ GRPC_STATS_INC_CQ_EV_QUEUE_TRYLOCK_FAILURES();
+ }
+
+ if (c) {
+ num_queue_items_.FetchSub(1, grpc_core::MemoryOrder::RELAXED);
+ }
+
+ return c;
+}
+
+grpc_completion_queue* grpc_completion_queue_create_internal(
+ grpc_cq_completion_type completion_type, grpc_cq_polling_type polling_type,
+ grpc_experimental_completion_queue_functor* shutdown_callback) {
+ GPR_TIMER_SCOPE("grpc_completion_queue_create_internal", 0);
+
+ grpc_completion_queue* cq;
+
+ GRPC_API_TRACE(
+ "grpc_completion_queue_create_internal(completion_type=%d, "
+ "polling_type=%d)",
+ 2, (completion_type, polling_type));
+
+ const cq_vtable* vtable = &g_cq_vtable[completion_type];
+ const cq_poller_vtable* poller_vtable =
+ &g_poller_vtable_by_poller_type[polling_type];
+
+ grpc_core::ExecCtx exec_ctx;
+ GRPC_STATS_INC_CQS_CREATED();
+
+ cq = static_cast<grpc_completion_queue*>(
+ gpr_zalloc(sizeof(grpc_completion_queue) + vtable->data_size +
+ poller_vtable->size()));
+
+ cq->vtable = vtable;
+ cq->poller_vtable = poller_vtable;
+
+ /* One for destroy(), one for pollset_shutdown */
+ new (&cq->owning_refs) grpc_core::RefCount(2);
+
+ poller_vtable->init(POLLSET_FROM_CQ(cq), &cq->mu);
+ vtable->init(DATA_FROM_CQ(cq), shutdown_callback);
+
+ GRPC_CLOSURE_INIT(&cq->pollset_shutdown_done, on_pollset_shutdown_done, cq,
+ grpc_schedule_on_exec_ctx);
+ return cq;
+}
+
+static void cq_init_next(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback) {
+ new (data) cq_next_data();
+}
+
+static void cq_destroy_next(void* data) {
+ cq_next_data* cqd = static_cast<cq_next_data*>(data);
+ cqd->~cq_next_data();
+}
+
+static void cq_init_pluck(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback) {
+ new (data) cq_pluck_data();
+}
+
+static void cq_destroy_pluck(void* data) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*>(data);
+ cqd->~cq_pluck_data();
+}
+
+static void cq_init_callback(
+ void* data, grpc_experimental_completion_queue_functor* shutdown_callback) {
+ new (data) cq_callback_data(shutdown_callback);
+}
+
+static void cq_destroy_callback(void* data) {
+ cq_callback_data* cqd = static_cast<cq_callback_data*>(data);
+ cqd->~cq_callback_data();
+}
+
+grpc_cq_completion_type grpc_get_cq_completion_type(grpc_completion_queue* cq) {
+ return cq->vtable->cq_completion_type;
+}
+
+int grpc_get_cq_poll_num(grpc_completion_queue* cq) {
+ int cur_num_polls;
+ gpr_mu_lock(cq->mu);
+ cur_num_polls = cq->num_polls;
+ gpr_mu_unlock(cq->mu);
+ return cur_num_polls;
+}
+
+#ifndef NDEBUG
+void grpc_cq_internal_ref(grpc_completion_queue* cq, const char* reason,
+ const char* file, int line) {
+ grpc_core::DebugLocation debug_location(file, line);
+#else
+void grpc_cq_internal_ref(grpc_completion_queue* cq) {
+ grpc_core::DebugLocation debug_location;
+ const char* reason = nullptr;
+#endif
+ cq->owning_refs.Ref(debug_location, reason);
+}
+
+static void on_pollset_shutdown_done(void* arg, grpc_error* error) {
+ grpc_completion_queue* cq = static_cast<grpc_completion_queue*>(arg);
+ GRPC_CQ_INTERNAL_UNREF(cq, "pollset_destroy");
+}
+
+#ifndef NDEBUG
+void grpc_cq_internal_unref(grpc_completion_queue* cq, const char* reason,
+ const char* file, int line) {
+ grpc_core::DebugLocation debug_location(file, line);
+#else
+void grpc_cq_internal_unref(grpc_completion_queue* cq) {
+ grpc_core::DebugLocation debug_location;
+ const char* reason = nullptr;
+#endif
+ if (GPR_UNLIKELY(cq->owning_refs.Unref(debug_location, reason))) {
+ cq->vtable->destroy(DATA_FROM_CQ(cq));
+ cq->poller_vtable->destroy(POLLSET_FROM_CQ(cq));
+#ifndef NDEBUG
+ gpr_free(cq->outstanding_tags);
+#endif
+ gpr_free(cq);
+ }
+}
+
+#ifndef NDEBUG
+static void cq_check_tag(grpc_completion_queue* cq, void* tag, bool lock_cq) {
+ int found = 0;
+ if (lock_cq) {
+ gpr_mu_lock(cq->mu);
+ }
+
+ for (int i = 0; i < static_cast<int>(cq->outstanding_tag_count); i++) {
+ if (cq->outstanding_tags[i] == tag) {
+ cq->outstanding_tag_count--;
+ GPR_SWAP(void*, cq->outstanding_tags[i],
+ cq->outstanding_tags[cq->outstanding_tag_count]);
+ found = 1;
+ break;
+ }
+ }
+
+ if (lock_cq) {
+ gpr_mu_unlock(cq->mu);
+ }
+
+ GPR_ASSERT(found);
+}
+#else
+static void cq_check_tag(grpc_completion_queue* cq, void* tag, bool lock_cq) {}
+#endif
+
+static bool cq_begin_op_for_next(grpc_completion_queue* cq, void* tag) {
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+ return cqd->pending_events.IncrementIfNonzero();
+}
+
+static bool cq_begin_op_for_pluck(grpc_completion_queue* cq, void* tag) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+ return cqd->pending_events.IncrementIfNonzero();
+}
+
+static bool cq_begin_op_for_callback(grpc_completion_queue* cq, void* tag) {
+ cq_callback_data* cqd = static_cast<cq_callback_data*> DATA_FROM_CQ(cq);
+ return cqd->pending_events.IncrementIfNonzero();
+}
+
+bool grpc_cq_begin_op(grpc_completion_queue* cq, void* tag) {
+#ifndef NDEBUG
+ gpr_mu_lock(cq->mu);
+ if (cq->outstanding_tag_count == cq->outstanding_tag_capacity) {
+ cq->outstanding_tag_capacity = GPR_MAX(4, 2 * cq->outstanding_tag_capacity);
+ cq->outstanding_tags = static_cast<void**>(gpr_realloc(
+ cq->outstanding_tags,
+ sizeof(*cq->outstanding_tags) * cq->outstanding_tag_capacity));
+ }
+ cq->outstanding_tags[cq->outstanding_tag_count++] = tag;
+ gpr_mu_unlock(cq->mu);
+#endif
+ return cq->vtable->begin_op(cq, tag);
+}
+
+/* Queue a GRPC_OP_COMPLETED operation to a completion queue (with a
+ * completion
+ * type of GRPC_CQ_NEXT) */
+static void cq_end_op_for_next(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal) {
+ GPR_TIMER_SCOPE("cq_end_op_for_next", 0);
+
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_api_trace) ||
+ (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE)) {
+ const char* errmsg = grpc_error_string(error);
+ GRPC_API_TRACE(
+ "cq_end_op_for_next(cq=%p, tag=%p, error=%s, "
+ "done=%p, done_arg=%p, storage=%p)",
+ 6, (cq, tag, errmsg, done, done_arg, storage));
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE) {
+ gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
+ }
+ }
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+ int is_success = (error == GRPC_ERROR_NONE);
+
+ storage->tag = tag;
+ storage->done = done;
+ storage->done_arg = done_arg;
+ storage->next = static_cast<uintptr_t>(is_success);
+
+ cq_check_tag(cq, tag, true); /* Used in debug builds only */
+
+ if ((grpc_completion_queue*)gpr_tls_get(&g_cached_cq) == cq &&
+ (grpc_cq_completion*)gpr_tls_get(&g_cached_event) == nullptr) {
+ gpr_tls_set(&g_cached_event, (intptr_t)storage);
+ } else {
+ /* Add the completion to the queue */
+ bool is_first = cqd->queue.Push(storage);
+ cqd->things_queued_ever.FetchAdd(1, grpc_core::MemoryOrder::RELAXED);
+ /* Since we do not hold the cq lock here, it is important to do an 'acquire'
+ load here (instead of a 'no_barrier' load) to match with the release
+ store
+ (done via pending_events.FetchSub(1, ACQ_REL)) in cq_shutdown_next
+ */
+ if (cqd->pending_events.Load(grpc_core::MemoryOrder::ACQUIRE) != 1) {
+ /* Only kick if this is the first item queued */
+ if (is_first) {
+ gpr_mu_lock(cq->mu);
+ grpc_error* kick_error =
+ cq->poller_vtable->kick(POLLSET_FROM_CQ(cq), nullptr);
+ gpr_mu_unlock(cq->mu);
+
+ if (kick_error != GRPC_ERROR_NONE) {
+ const char* msg = grpc_error_string(kick_error);
+ gpr_log(GPR_ERROR, "Kick failed: %s", msg);
+ GRPC_ERROR_UNREF(kick_error);
+ }
+ }
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) ==
+ 1) {
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down");
+ gpr_mu_lock(cq->mu);
+ cq_finish_shutdown_next(cq);
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
+ }
+ } else {
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down");
+ cqd->pending_events.Store(0, grpc_core::MemoryOrder::RELEASE);
+ gpr_mu_lock(cq->mu);
+ cq_finish_shutdown_next(cq);
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
+ }
+ }
+
+ GRPC_ERROR_UNREF(error);
+}
+
+/* Queue a GRPC_OP_COMPLETED operation to a completion queue (with a
+ * completion
+ * type of GRPC_CQ_PLUCK) */
+static void cq_end_op_for_pluck(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal) {
+ GPR_TIMER_SCOPE("cq_end_op_for_pluck", 0);
+
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+ int is_success = (error == GRPC_ERROR_NONE);
+
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_api_trace) ||
+ (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE)) {
+ const char* errmsg = grpc_error_string(error);
+ GRPC_API_TRACE(
+ "cq_end_op_for_pluck(cq=%p, tag=%p, error=%s, "
+ "done=%p, done_arg=%p, storage=%p)",
+ 6, (cq, tag, errmsg, done, done_arg, storage));
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE) {
+ gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
+ }
+ }
+
+ storage->tag = tag;
+ storage->done = done;
+ storage->done_arg = done_arg;
+ storage->next =
+ ((uintptr_t)&cqd->completed_head) | (static_cast<uintptr_t>(is_success));
+
+ gpr_mu_lock(cq->mu);
+ cq_check_tag(cq, tag, false); /* Used in debug builds only */
+
+ /* Add to the list of completions */
+ cqd->things_queued_ever.FetchAdd(1, grpc_core::MemoryOrder::RELAXED);
+ cqd->completed_tail->next =
+ ((uintptr_t)storage) | (1u & cqd->completed_tail->next);
+ cqd->completed_tail = storage;
+
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ cq_finish_shutdown_pluck(cq);
+ gpr_mu_unlock(cq->mu);
+ } else {
+ grpc_pollset_worker* pluck_worker = nullptr;
+ for (int i = 0; i < cqd->num_pluckers; i++) {
+ if (cqd->pluckers[i].tag == tag) {
+ pluck_worker = *cqd->pluckers[i].worker;
+ break;
+ }
+ }
+
+ grpc_error* kick_error =
+ cq->poller_vtable->kick(POLLSET_FROM_CQ(cq), pluck_worker);
+
+ gpr_mu_unlock(cq->mu);
+
+ if (kick_error != GRPC_ERROR_NONE) {
+ const char* msg = grpc_error_string(kick_error);
+ gpr_log(GPR_ERROR, "Kick failed: %s", msg);
+
+ GRPC_ERROR_UNREF(kick_error);
+ }
+ }
+
+ GRPC_ERROR_UNREF(error);
+}
+
+static void functor_callback(void* arg, grpc_error* error) {
+ auto* functor = static_cast<grpc_experimental_completion_queue_functor*>(arg);
+ functor->functor_run(functor, error == GRPC_ERROR_NONE);
+}
+
+/* Complete an event on a completion queue of type GRPC_CQ_CALLBACK */
+static void cq_end_op_for_callback(
+ grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage), void* done_arg,
+ grpc_cq_completion* storage, bool internal) {
+ GPR_TIMER_SCOPE("cq_end_op_for_callback", 0);
+
+ cq_callback_data* cqd = static_cast<cq_callback_data*> DATA_FROM_CQ(cq);
+
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_api_trace) ||
+ (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE)) {
+ const char* errmsg = grpc_error_string(error);
+ GRPC_API_TRACE(
+ "cq_end_op_for_callback(cq=%p, tag=%p, error=%s, "
+ "done=%p, done_arg=%p, storage=%p)",
+ 6, (cq, tag, errmsg, done, done_arg, storage));
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) &&
+ error != GRPC_ERROR_NONE) {
+ gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
+ }
+ }
+
+ // The callback-based CQ isn't really a queue at all and thus has no need
+ // for reserved storage. Invoke the done callback right away to release it.
+ done(done_arg, storage);
+
+ cq_check_tag(cq, tag, true); /* Used in debug builds only */
+
+ cqd->things_queued_ever.FetchAdd(1, grpc_core::MemoryOrder::RELAXED);
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ cq_finish_shutdown_callback(cq);
+ }
+
+ auto* functor = static_cast<grpc_experimental_completion_queue_functor*>(tag);
+ if (internal || grpc_iomgr_is_any_background_poller_thread()) {
+ grpc_core::ApplicationCallbackExecCtx::Enqueue(functor,
+ (error == GRPC_ERROR_NONE));
+ GRPC_ERROR_UNREF(error);
+ return;
+ }
+
+ // Schedule the callback on a closure if not internal or triggered
+ // from a background poller thread.
+ GRPC_CLOSURE_SCHED(
+ GRPC_CLOSURE_CREATE(
+ functor_callback, functor,
+ grpc_core::Executor::Scheduler(grpc_core::ExecutorJobType::SHORT)),
+ error);
+}
+
+void grpc_cq_end_op(grpc_completion_queue* cq, void* tag, grpc_error* error,
+ void (*done)(void* done_arg, grpc_cq_completion* storage),
+ void* done_arg, grpc_cq_completion* storage,
+ bool internal) {
+ cq->vtable->end_op(cq, tag, error, done, done_arg, storage, internal);
+}
+
+typedef struct {
+ gpr_atm last_seen_things_queued_ever;
+ grpc_completion_queue* cq;
+ grpc_millis deadline;
+ grpc_cq_completion* stolen_completion;
+ void* tag; /* for pluck */
+ bool first_loop;
+} cq_is_finished_arg;
+
+class ExecCtxNext : public grpc_core::ExecCtx {
+ public:
+ ExecCtxNext(void* arg) : ExecCtx(0), check_ready_to_finish_arg_(arg) {}
+
+ bool CheckReadyToFinish() override {
+ cq_is_finished_arg* a =
+ static_cast<cq_is_finished_arg*>(check_ready_to_finish_arg_);
+ grpc_completion_queue* cq = a->cq;
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+ GPR_ASSERT(a->stolen_completion == nullptr);
+
+ intptr_t current_last_seen_things_queued_ever =
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED);
+
+ if (current_last_seen_things_queued_ever !=
+ a->last_seen_things_queued_ever) {
+ a->last_seen_things_queued_ever =
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED);
+
+ /* Pop a cq_completion from the queue. Returns NULL if the queue is empty
+ * might return NULL in some cases even if the queue is not empty; but
+ * that
+ * is ok and doesn't affect correctness. Might effect the tail latencies a
+ * bit) */
+ a->stolen_completion = cqd->queue.Pop();
+ if (a->stolen_completion != nullptr) {
+ return true;
+ }
+ }
+ return !a->first_loop && a->deadline < grpc_core::ExecCtx::Get()->Now();
+ }
+
+ private:
+ void* check_ready_to_finish_arg_;
+};
+
+#ifndef NDEBUG
+static void dump_pending_tags(grpc_completion_queue* cq) {
+ if (!GRPC_TRACE_FLAG_ENABLED(grpc_trace_pending_tags)) return;
+
+ gpr_strvec v;
+ gpr_strvec_init(&v);
+ gpr_strvec_add(&v, gpr_strdup("PENDING TAGS:"));
+ gpr_mu_lock(cq->mu);
+ for (size_t i = 0; i < cq->outstanding_tag_count; i++) {
+ char* s;
+ gpr_asprintf(&s, " %p", cq->outstanding_tags[i]);
+ gpr_strvec_add(&v, s);
+ }
+ gpr_mu_unlock(cq->mu);
+ char* out = gpr_strvec_flatten(&v, nullptr);
+ gpr_strvec_destroy(&v);
+ gpr_log(GPR_DEBUG, "%s", out);
+ gpr_free(out);
+}
+#else
+static void dump_pending_tags(grpc_completion_queue* cq) {}
+#endif
+
+static grpc_event cq_next(grpc_completion_queue* cq, gpr_timespec deadline,
+ void* reserved) {
+ GPR_TIMER_SCOPE("grpc_completion_queue_next", 0);
+
+ grpc_event ret;
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+
+ GRPC_API_TRACE(
+ "grpc_completion_queue_next("
+ "cq=%p, "
+ "deadline=gpr_timespec { tv_sec: %" PRId64
+ ", tv_nsec: %d, clock_type: %d }, "
+ "reserved=%p)",
+ 5,
+ (cq, deadline.tv_sec, deadline.tv_nsec, (int)deadline.clock_type,
+ reserved));
+ GPR_ASSERT(!reserved);
+
+ dump_pending_tags(cq);
+
+ GRPC_CQ_INTERNAL_REF(cq, "next");
+
+ grpc_millis deadline_millis = grpc_timespec_to_millis_round_up(deadline);
+ cq_is_finished_arg is_finished_arg = {
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED),
+ cq,
+ deadline_millis,
+ nullptr,
+ nullptr,
+ true};
+ ExecCtxNext exec_ctx(&is_finished_arg);
+ for (;;) {
+ grpc_millis iteration_deadline = deadline_millis;
+
+ if (is_finished_arg.stolen_completion != nullptr) {
+ grpc_cq_completion* c = is_finished_arg.stolen_completion;
+ is_finished_arg.stolen_completion = nullptr;
+ ret.type = GRPC_OP_COMPLETE;
+ ret.success = c->next & 1u;
+ ret.tag = c->tag;
+ c->done(c->done_arg, c);
+ break;
+ }
+
+ grpc_cq_completion* c = cqd->queue.Pop();
+
+ if (c != nullptr) {
+ ret.type = GRPC_OP_COMPLETE;
+ ret.success = c->next & 1u;
+ ret.tag = c->tag;
+ c->done(c->done_arg, c);
+ break;
+ } else {
+ /* If c == NULL it means either the queue is empty OR in an transient
+ inconsistent state. If it is the latter, we shold do a 0-timeout poll
+ so that the thread comes back quickly from poll to make a second
+ attempt at popping. Not doing this can potentially deadlock this
+ thread forever (if the deadline is infinity) */
+ if (cqd->queue.num_items() > 0) {
+ iteration_deadline = 0;
+ }
+ }
+
+ if (cqd->pending_events.Load(grpc_core::MemoryOrder::ACQUIRE) == 0) {
+ /* Before returning, check if the queue has any items left over (since
+ gpr_mpscq_pop() can sometimes return NULL even if the queue is not
+ empty. If so, keep retrying but do not return GRPC_QUEUE_SHUTDOWN */
+ if (cqd->queue.num_items() > 0) {
+ /* Go to the beginning of the loop. No point doing a poll because
+ (cq->shutdown == true) is only possible when there is no pending
+ work (i.e cq->pending_events == 0) and any outstanding completion
+ events should have already been queued on this cq */
+ continue;
+ }
+
+ ret.type = GRPC_QUEUE_SHUTDOWN;
+ ret.success = 0;
+ break;
+ }
+
+ if (!is_finished_arg.first_loop &&
+ grpc_core::ExecCtx::Get()->Now() >= deadline_millis) {
+ ret.type = GRPC_QUEUE_TIMEOUT;
+ ret.success = 0;
+ dump_pending_tags(cq);
+ break;
+ }
+
+ /* The main polling work happens in grpc_pollset_work */
+ gpr_mu_lock(cq->mu);
+ cq->num_polls++;
+ grpc_error* err = cq->poller_vtable->work(POLLSET_FROM_CQ(cq), nullptr,
+ iteration_deadline);
+ gpr_mu_unlock(cq->mu);
+
+ if (err != GRPC_ERROR_NONE) {
+ const char* msg = grpc_error_string(err);
+ gpr_log(GPR_ERROR, "Completion queue next failed: %s", msg);
+
+ GRPC_ERROR_UNREF(err);
+ ret.type = GRPC_QUEUE_TIMEOUT;
+ ret.success = 0;
+ dump_pending_tags(cq);
+ break;
+ }
+ is_finished_arg.first_loop = false;
+ }
+
+ if (cqd->queue.num_items() > 0 &&
+ cqd->pending_events.Load(grpc_core::MemoryOrder::ACQUIRE) > 0) {
+ gpr_mu_lock(cq->mu);
+ cq->poller_vtable->kick(POLLSET_FROM_CQ(cq), nullptr);
+ gpr_mu_unlock(cq->mu);
+ }
+
+ GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, &ret);
+ GRPC_CQ_INTERNAL_UNREF(cq, "next");
+
+ GPR_ASSERT(is_finished_arg.stolen_completion == nullptr);
+
+ return ret;
+}
+
+/* Finishes the completion queue shutdown. This means that there are no more
+ completion events / tags expected from the completion queue
+ - Must be called under completion queue lock
+ - Must be called only once in completion queue's lifetime
+ - grpc_completion_queue_shutdown() MUST have been called before calling
+ this function */
+static void cq_finish_shutdown_next(grpc_completion_queue* cq) {
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+
+ GPR_ASSERT(cqd->shutdown_called);
+ GPR_ASSERT(cqd->pending_events.Load(grpc_core::MemoryOrder::RELAXED) == 0);
+
+ cq->poller_vtable->shutdown(POLLSET_FROM_CQ(cq), &cq->pollset_shutdown_done);
+}
+
+static void cq_shutdown_next(grpc_completion_queue* cq) {
+ cq_next_data* cqd = static_cast<cq_next_data*> DATA_FROM_CQ(cq);
+
+ /* Need an extra ref for cq here because:
+ * We call cq_finish_shutdown_next() below, that would call pollset shutdown.
+ * Pollset shutdown decrements the cq ref count which can potentially destroy
+ * the cq (if that happens to be the last ref).
+ * Creating an extra ref here prevents the cq from getting destroyed while
+ * this function is still active */
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down");
+ gpr_mu_lock(cq->mu);
+ if (cqd->shutdown_called) {
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
+ return;
+ }
+ cqd->shutdown_called = true;
+ /* Doing acq/release FetchSub here to match with
+ * cq_begin_op_for_next and cq_end_op_for_next functions which read/write
+ * on this counter without necessarily holding a lock on cq */
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ cq_finish_shutdown_next(cq);
+ }
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
+}
+
+grpc_event grpc_completion_queue_next(grpc_completion_queue* cq,
+ gpr_timespec deadline, void* reserved) {
+ return cq->vtable->next(cq, deadline, reserved);
+}
+
+static int add_plucker(grpc_completion_queue* cq, void* tag,
+ grpc_pollset_worker** worker) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+ if (cqd->num_pluckers == GRPC_MAX_COMPLETION_QUEUE_PLUCKERS) {
+ return 0;
+ }
+ cqd->pluckers[cqd->num_pluckers].tag = tag;
+ cqd->pluckers[cqd->num_pluckers].worker = worker;
+ cqd->num_pluckers++;
+ return 1;
+}
+
+static void del_plucker(grpc_completion_queue* cq, void* tag,
+ grpc_pollset_worker** worker) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+ for (int i = 0; i < cqd->num_pluckers; i++) {
+ if (cqd->pluckers[i].tag == tag && cqd->pluckers[i].worker == worker) {
+ cqd->num_pluckers--;
+ GPR_SWAP(plucker, cqd->pluckers[i], cqd->pluckers[cqd->num_pluckers]);
+ return;
+ }
+ }
+ GPR_UNREACHABLE_CODE(return );
+}
+
+class ExecCtxPluck : public grpc_core::ExecCtx {
+ public:
+ ExecCtxPluck(void* arg) : ExecCtx(0), check_ready_to_finish_arg_(arg) {}
+
+ bool CheckReadyToFinish() override {
+ cq_is_finished_arg* a =
+ static_cast<cq_is_finished_arg*>(check_ready_to_finish_arg_);
+ grpc_completion_queue* cq = a->cq;
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+
+ GPR_ASSERT(a->stolen_completion == nullptr);
+ gpr_atm current_last_seen_things_queued_ever =
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED);
+ if (current_last_seen_things_queued_ever !=
+ a->last_seen_things_queued_ever) {
+ gpr_mu_lock(cq->mu);
+ a->last_seen_things_queued_ever =
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED);
+ grpc_cq_completion* c;
+ grpc_cq_completion* prev = &cqd->completed_head;
+ while ((c = (grpc_cq_completion*)(prev->next &
+ ~static_cast<uintptr_t>(1))) !=
+ &cqd->completed_head) {
+ if (c->tag == a->tag) {
+ prev->next = (prev->next & static_cast<uintptr_t>(1)) |
+ (c->next & ~static_cast<uintptr_t>(1));
+ if (c == cqd->completed_tail) {
+ cqd->completed_tail = prev;
+ }
+ gpr_mu_unlock(cq->mu);
+ a->stolen_completion = c;
+ return true;
+ }
+ prev = c;
+ }
+ gpr_mu_unlock(cq->mu);
+ }
+ return !a->first_loop && a->deadline < grpc_core::ExecCtx::Get()->Now();
+ }
+
+ private:
+ void* check_ready_to_finish_arg_;
+};
+
+static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
+ gpr_timespec deadline, void* reserved) {
+ GPR_TIMER_SCOPE("grpc_completion_queue_pluck", 0);
+
+ grpc_event ret;
+ grpc_cq_completion* c;
+ grpc_cq_completion* prev;
+ grpc_pollset_worker* worker = nullptr;
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+
+ if (GRPC_TRACE_FLAG_ENABLED(grpc_cq_pluck_trace)) {
+ GRPC_API_TRACE(
+ "grpc_completion_queue_pluck("
+ "cq=%p, tag=%p, "
+ "deadline=gpr_timespec { tv_sec: %" PRId64
+ ", tv_nsec: %d, clock_type: %d }, "
+ "reserved=%p)",
+ 6,
+ (cq, tag, deadline.tv_sec, deadline.tv_nsec, (int)deadline.clock_type,
+ reserved));
+ }
+ GPR_ASSERT(!reserved);
+
+ dump_pending_tags(cq);
+
+ GRPC_CQ_INTERNAL_REF(cq, "pluck");
+ gpr_mu_lock(cq->mu);
+ grpc_millis deadline_millis = grpc_timespec_to_millis_round_up(deadline);
+ cq_is_finished_arg is_finished_arg = {
+ cqd->things_queued_ever.Load(grpc_core::MemoryOrder::RELAXED),
+ cq,
+ deadline_millis,
+ nullptr,
+ tag,
+ true};
+ ExecCtxPluck exec_ctx(&is_finished_arg);
+ for (;;) {
+ if (is_finished_arg.stolen_completion != nullptr) {
+ gpr_mu_unlock(cq->mu);
+ c = is_finished_arg.stolen_completion;
+ is_finished_arg.stolen_completion = nullptr;
+ ret.type = GRPC_OP_COMPLETE;
+ ret.success = c->next & 1u;
+ ret.tag = c->tag;
+ c->done(c->done_arg, c);
+ break;
+ }
+ prev = &cqd->completed_head;
+ while (
+ (c = (grpc_cq_completion*)(prev->next & ~static_cast<uintptr_t>(1))) !=
+ &cqd->completed_head) {
+ if (c->tag == tag) {
+ prev->next = (prev->next & static_cast<uintptr_t>(1)) |
+ (c->next & ~static_cast<uintptr_t>(1));
+ if (c == cqd->completed_tail) {
+ cqd->completed_tail = prev;
+ }
+ gpr_mu_unlock(cq->mu);
+ ret.type = GRPC_OP_COMPLETE;
+ ret.success = c->next & 1u;
+ ret.tag = c->tag;
+ c->done(c->done_arg, c);
+ goto done;
+ }
+ prev = c;
+ }
+ if (cqd->shutdown.Load(grpc_core::MemoryOrder::RELAXED)) {
+ gpr_mu_unlock(cq->mu);
+ ret.type = GRPC_QUEUE_SHUTDOWN;
+ ret.success = 0;
+ break;
+ }
+ if (!add_plucker(cq, tag, &worker)) {
+ gpr_log(GPR_DEBUG,
+ "Too many outstanding grpc_completion_queue_pluck calls: maximum "
+ "is %d",
+ GRPC_MAX_COMPLETION_QUEUE_PLUCKERS);
+ gpr_mu_unlock(cq->mu);
+ /* TODO(ctiller): should we use a different result here */
+ ret.type = GRPC_QUEUE_TIMEOUT;
+ ret.success = 0;
+ dump_pending_tags(cq);
+ break;
+ }
+ if (!is_finished_arg.first_loop &&
+ grpc_core::ExecCtx::Get()->Now() >= deadline_millis) {
+ del_plucker(cq, tag, &worker);
+ gpr_mu_unlock(cq->mu);
+ ret.type = GRPC_QUEUE_TIMEOUT;
+ ret.success = 0;
+ dump_pending_tags(cq);
+ break;
+ }
+ cq->num_polls++;
+ grpc_error* err =
+ cq->poller_vtable->work(POLLSET_FROM_CQ(cq), &worker, deadline_millis);
+ if (err != GRPC_ERROR_NONE) {
+ del_plucker(cq, tag, &worker);
+ gpr_mu_unlock(cq->mu);
+ const char* msg = grpc_error_string(err);
+ gpr_log(GPR_ERROR, "Completion queue pluck failed: %s", msg);
+
+ GRPC_ERROR_UNREF(err);
+ ret.type = GRPC_QUEUE_TIMEOUT;
+ ret.success = 0;
+ dump_pending_tags(cq);
+ break;
+ }
+ is_finished_arg.first_loop = false;
+ del_plucker(cq, tag, &worker);
+ }
+done:
+ GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, &ret);
+ GRPC_CQ_INTERNAL_UNREF(cq, "pluck");
+
+ GPR_ASSERT(is_finished_arg.stolen_completion == nullptr);
+
+ return ret;
+}
+
+grpc_event grpc_completion_queue_pluck(grpc_completion_queue* cq, void* tag,
+ gpr_timespec deadline, void* reserved) {
+ return cq->vtable->pluck(cq, tag, deadline, reserved);
+}
+
+static void cq_finish_shutdown_pluck(grpc_completion_queue* cq) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+
+ GPR_ASSERT(cqd->shutdown_called);
+ GPR_ASSERT(!cqd->shutdown.Load(grpc_core::MemoryOrder::RELAXED));
+ cqd->shutdown.Store(1, grpc_core::MemoryOrder::RELAXED);
+
+ cq->poller_vtable->shutdown(POLLSET_FROM_CQ(cq), &cq->pollset_shutdown_done);
+}
+
+/* NOTE: This function is almost exactly identical to cq_shutdown_next() but
+ * merging them is a bit tricky and probably not worth it */
+static void cq_shutdown_pluck(grpc_completion_queue* cq) {
+ cq_pluck_data* cqd = static_cast<cq_pluck_data*> DATA_FROM_CQ(cq);
+
+ /* Need an extra ref for cq here because:
+ * We call cq_finish_shutdown_pluck() below, that would call pollset shutdown.
+ * Pollset shutdown decrements the cq ref count which can potentially destroy
+ * the cq (if that happens to be the last ref).
+ * Creating an extra ref here prevents the cq from getting destroyed while
+ * this function is still active */
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down (pluck cq)");
+ gpr_mu_lock(cq->mu);
+ if (cqd->shutdown_called) {
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down (pluck cq)");
+ return;
+ }
+ cqd->shutdown_called = true;
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ cq_finish_shutdown_pluck(cq);
+ }
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down (pluck cq)");
+}
+
+static void cq_finish_shutdown_callback(grpc_completion_queue* cq) {
+ cq_callback_data* cqd = static_cast<cq_callback_data*> DATA_FROM_CQ(cq);
+ auto* callback = cqd->shutdown_callback;
+
+ GPR_ASSERT(cqd->shutdown_called);
+
+ cq->poller_vtable->shutdown(POLLSET_FROM_CQ(cq), &cq->pollset_shutdown_done);
+ if (grpc_iomgr_is_any_background_poller_thread()) {
+ grpc_core::ApplicationCallbackExecCtx::Enqueue(callback, true);
+ return;
+ }
+
+ // Schedule the callback on a closure if not internal or triggered
+ // from a background poller thread.
+ GRPC_CLOSURE_SCHED(
+ GRPC_CLOSURE_CREATE(
+ functor_callback, callback,
+ grpc_core::Executor::Scheduler(grpc_core::ExecutorJobType::SHORT)),
+ GRPC_ERROR_NONE);
+}
+
+static void cq_shutdown_callback(grpc_completion_queue* cq) {
+ cq_callback_data* cqd = static_cast<cq_callback_data*> DATA_FROM_CQ(cq);
+
+ /* Need an extra ref for cq here because:
+ * We call cq_finish_shutdown_callback() below, which calls pollset shutdown.
+ * Pollset shutdown decrements the cq ref count which can potentially destroy
+ * the cq (if that happens to be the last ref).
+ * Creating an extra ref here prevents the cq from getting destroyed while
+ * this function is still active */
+ GRPC_CQ_INTERNAL_REF(cq, "shutting_down (callback cq)");
+ gpr_mu_lock(cq->mu);
+ if (cqd->shutdown_called) {
+ gpr_mu_unlock(cq->mu);
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down (callback cq)");
+ return;
+ }
+ cqd->shutdown_called = true;
+ if (cqd->pending_events.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1) {
+ gpr_mu_unlock(cq->mu);
+ cq_finish_shutdown_callback(cq);
+ } else {
+ gpr_mu_unlock(cq->mu);
+ }
+ GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down (callback cq)");
+}
+
+/* Shutdown simply drops a ref that we reserved at creation time; if we drop
+ to zero here, then enter shutdown mode and wake up any waiters */
+void grpc_completion_queue_shutdown(grpc_completion_queue* cq) {
+ GPR_TIMER_SCOPE("grpc_completion_queue_shutdown", 0);
+ grpc_core::ApplicationCallbackExecCtx callback_exec_ctx;
+ grpc_core::ExecCtx exec_ctx;
+ GRPC_API_TRACE("grpc_completion_queue_shutdown(cq=%p)", 1, (cq));
+ cq->vtable->shutdown(cq);
+}
+
+void grpc_completion_queue_destroy(grpc_completion_queue* cq) {
+ GPR_TIMER_SCOPE("grpc_completion_queue_destroy", 0);
+ GRPC_API_TRACE("grpc_completion_queue_destroy(cq=%p)", 1, (cq));
+ grpc_completion_queue_shutdown(cq);
+
+ grpc_core::ExecCtx exec_ctx;
+ GRPC_CQ_INTERNAL_UNREF(cq, "destroy");
+}
+
+grpc_pollset* grpc_cq_pollset(grpc_completion_queue* cq) {
+ return cq->poller_vtable->can_get_pollset ? POLLSET_FROM_CQ(cq) : nullptr;
+}
+
+bool grpc_cq_can_listen(grpc_completion_queue* cq) {
+ return cq->poller_vtable->can_listen;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff