base: Change WeakPtr to use SequenceChecker instead of ThreadChecker.

base/threading/sequenced_worker_pool.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/threading/sequenced_worker_pool.h"
 
 #include <list>
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/atomicops.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/critical_closure.h"
 #include "base/debug/trace_event.h"
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/linked_ptr.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/simple_thread.h"
+#include "base/threading/thread_local.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "base/tracked_objects.h"
 
 #if defined(OS_MACOSX)
 #include "base/mac/scoped_nsautorelease_pool.h"
 #endif
 
 namespace base {
 
 namespace {
 
+base::LazyInstance<base::ThreadLocalPointer<SequencedWorkerPool> >
+    lazy_tls_ptr = LAZY_INSTANCE_INITIALIZER;
+
 struct SequencedTask : public TrackingInfo  {
   SequencedTask()
       : sequence_token_id(0),
         trace_id(0),
         sequence_task_number(0),
         shutdown_behavior(SequencedWorkerPool::BLOCK_SHUTDOWN) {}
 
   explicit SequencedTask(const tracked_objects::Location& from_here)
       : base::TrackingInfo(from_here, TimeTicks()),
         sequence_token_id(0),
@@ skipping 210 matching lines @@
   Inner(SequencedWorkerPool* worker_pool, size_t max_threads,
         const std::string& thread_name_prefix,
         TestingObserver* observer);
 
   ~Inner();
 
   SequenceToken GetSequenceToken();
 
   SequenceToken GetNamedSequenceToken(const std::string& name);
 
+  bool GetCurrentThreadSequenceToken(SequenceToken* result_token) const;
+
   // This function accepts a name and an ID. If the name is null, the
   // token ID is used. This allows us to implement the optional name lookup
   // from a single function without having to enter the lock a separate time.
   bool PostTask(const std::string* optional_token_name,
                 SequenceToken sequence_token,
                 WorkerShutdown shutdown_behavior,
                 const tracked_objects::Location& from_here,
                 const Closure& task,
                 TimeDelta delay);
 
@@ skipping 192 matching lines @@
           prefix + StringPrintf("Worker%d", thread_number).c_str()),
       worker_pool_(worker_pool),
       running_shutdown_behavior_(CONTINUE_ON_SHUTDOWN) {
   Start();
 }
 
 SequencedWorkerPool::Worker::~Worker() {
 }
 
 void SequencedWorkerPool::Worker::Run() {
+  // Store the SequencedWorkerPool associated with this worker thread.
+  lazy_tls_ptr.Get().Set(worker_pool_.get());
+
   // Just jump back to the Inner object to run the thread, since it has all the
   // tracking information and queues. It might be more natural to implement
   // using DelegateSimpleThread and have Inner implement the Delegate to avoid
   // having these worker objects at all, but that method lacks the ability to
   // send thread-specific information easily to the thread loop.
   worker_pool_->inner_->ThreadLoop(this);
   // Release our cyclic reference once we're done.
   worker_pool_ = NULL;
 }
 
@@ skipping 44 matching lines @@
       subtle::NoBarrier_AtomicIncrement(&last_sequence_number_, 1);
   return SequenceToken(static_cast<int>(result));
 }
 
 SequencedWorkerPool::SequenceToken
 SequencedWorkerPool::Inner::GetNamedSequenceToken(const std::string& name) {
   AutoLock lock(lock_);
   return SequenceToken(LockedGetNamedTokenID(name));
 }
 
+bool SequencedWorkerPool::Inner::GetCurrentThreadSequenceToken(
+    SequenceToken* result_token) const {
+  DCHECK(result_token);
+  AutoLock lock(lock_);
+  ThreadMap::const_iterator found = threads_.find(PlatformThread::CurrentId());
+  if (found == threads_.end())
+    return false;
+  *result_token = found->second->running_sequence();
+  return true;
+}
+
 bool SequencedWorkerPool::Inner::PostTask(
     const std::string* optional_token_name,
     SequenceToken sequence_token,
     WorkerShutdown shutdown_behavior,
     const tracked_objects::Location& from_here,
     const Closure& task,
     TimeDelta delay) {
   DCHECK(delay == TimeDelta() || shutdown_behavior == SKIP_ON_SHUTDOWN);
   SequencedTask sequenced(from_here);
   sequenced.sequence_token_id = sequence_token.id_;
@@ skipping 48 matching lines @@
   return true;
 }
 
 bool SequencedWorkerPool::Inner::RunsTasksOnCurrentThread() const {
   AutoLock lock(lock_);
   return ContainsKey(threads_, PlatformThread::CurrentId());
 }
 
 bool SequencedWorkerPool::Inner::IsRunningSequenceOnCurrentThread(
     SequenceToken sequence_token) const {
-  AutoLock lock(lock_);
-  ThreadMap::const_iterator found = threads_.find(PlatformThread::CurrentId());
-  if (found == threads_.end())
+  SequenceToken current_thread_token;
+  if (!GetCurrentThreadSequenceToken(&current_thread_token))
     return false;
-  return found->second->running_sequence().Equals(sequence_token);
+  return current_thread_token.Equals(sequence_token);
 }
 
 // See https://code.google.com/p/chromium/issues/detail?id=168415
 void SequencedWorkerPool::Inner::CleanupForTesting() {
   DCHECK(!RunsTasksOnCurrentThread());
   base::ThreadRestrictions::ScopedAllowWait allow_wait;
   AutoLock lock(lock_);
   CHECK_EQ(CLEANUP_DONE, cleanup_state_);
   if (shutdown_called_)
     return;
@@ skipping 454 matching lines @@
 bool SequencedWorkerPool::Inner::CanShutdown() const {
   lock_.AssertAcquired();
   // See PrepareToStartAdditionalThreadIfHelpful for how thread creation works.
   return !thread_being_created_ &&
          blocking_shutdown_thread_count_ == 0 &&
          blocking_shutdown_pending_task_count_ == 0;
 }
 
 // SequencedWorkerPool --------------------------------------------------------
 
+// static
+SequencedWorkerPool* SequencedWorkerPool::Get() {
+  return lazy_tls_ptr.Get().Get();
+}
+
 SequencedWorkerPool::SequencedWorkerPool(
     size_t max_threads,
     const std::string& thread_name_prefix)
     : constructor_message_loop_(MessageLoopProxy::current()),
       inner_(new Inner(this, max_threads, thread_name_prefix, NULL)) {
 }
 
 SequencedWorkerPool::SequencedWorkerPool(
     size_t max_threads,
     const std::string& thread_name_prefix,
@@ skipping 17 matching lines @@
 
 SequencedWorkerPool::SequenceToken SequencedWorkerPool::GetSequenceToken() {
   return inner_->GetSequenceToken();
 }
 
 SequencedWorkerPool::SequenceToken SequencedWorkerPool::GetNamedSequenceToken(
     const std::string& name) {
   return inner_->GetNamedSequenceToken(name);
 }
 
+bool SequencedWorkerPool::GetCurrentThreadSequenceToken(
+    SequenceToken* result_token) const {
+  return inner_->GetCurrentThreadSequenceToken(result_token);
+}
+
 scoped_refptr<SequencedTaskRunner> SequencedWorkerPool::GetSequencedTaskRunner(
     SequenceToken token) {
   return GetSequencedTaskRunnerWithShutdownBehavior(token, BLOCK_SHUTDOWN);
 }
 
 scoped_refptr<SequencedTaskRunner>
 SequencedWorkerPool::GetSequencedTaskRunnerWithShutdownBehavior(
     SequenceToken token, WorkerShutdown shutdown_behavior) {
   return new SequencedWorkerPoolSequencedTaskRunner(
       this, token, shutdown_behavior);
@@ skipping 90 matching lines @@
 void SequencedWorkerPool::SignalHasWorkForTesting() {
   inner_->SignalHasWorkForTesting();
 }
 
 void SequencedWorkerPool::Shutdown(int max_new_blocking_tasks_after_shutdown) {
   DCHECK(constructor_message_loop_->BelongsToCurrentThread());
   inner_->Shutdown(max_new_blocking_tasks_after_shutdown);
 }
 
 }  // namespace base