Tizen 2.0 Releasesubmit/tizen_2.0/20130215.192206accepted/tizen_2.0/20130215.202315tizen_2.0

1 files changed, 177 insertions, 0 deletions

diff --git a/base/threading/thread.cc b/base/threading/thread.cc
new file mode 100644
index 000000000000..616aac8933a5
--- /dev/null
+++ b/base/threading/thread.cc
@@ -0,0 +1,177 @@
+// Copyright (c) 2011 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/thread.h"
+
+#include "base/lazy_instance.h"
+#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
+#include "base/threading/thread_local.h"
+#include "base/synchronization/waitable_event.h"
+
+namespace base {
+
+namespace {
+
+// We use this thread-local variable to record whether or not a thread exited
+// because its Stop method was called.  This allows us to catch cases where
+// MessageLoop::Quit() is called directly, which is unexpected when using a
+// Thread to setup and run a MessageLoop.
+base::LazyInstance<base::ThreadLocalBoolean> lazy_tls_bool(
+    base::LINKER_INITIALIZED);
+
+}  // namespace
+
+// This task is used to trigger the message loop to exit.
+class ThreadQuitTask : public Task {
+ public:
+  virtual void Run() {
+    MessageLoop::current()->Quit();
+    Thread::SetThreadWasQuitProperly(true);
+  }
+};
+
+// Used to pass data to ThreadMain.  This structure is allocated on the stack
+// from within StartWithOptions.
+struct Thread::StartupData {
+  // We get away with a const reference here because of how we are allocated.
+  const Thread::Options& options;
+
+  // Used to synchronize thread startup.
+  WaitableEvent event;
+
+  explicit StartupData(const Options& opt)
+      : options(opt),
+        event(false, false) {}
+};
+
+Thread::Thread(const char* name)
+    : started_(false),
+      stopping_(false),
+      startup_data_(NULL),
+      thread_(0),
+      message_loop_(NULL),
+      thread_id_(kInvalidThreadId),
+      name_(name) {
+}
+
+Thread::~Thread() {
+  Stop();
+}
+
+bool Thread::Start() {
+  return StartWithOptions(Options());
+}
+
+bool Thread::StartWithOptions(const Options& options) {
+  DCHECK(!message_loop_);
+
+  SetThreadWasQuitProperly(false);
+
+  StartupData startup_data(options);
+  startup_data_ = &startup_data;
+
+  if (!PlatformThread::Create(options.stack_size, this, &thread_)) {
+    DLOG(ERROR) << "failed to create thread";
+    startup_data_ = NULL;
+    return false;
+  }
+
+  // Wait for the thread to start and initialize message_loop_
+  startup_data.event.Wait();
+
+  // set it to NULL so we don't keep a pointer to some object on the stack.
+  startup_data_ = NULL;
+  started_ = true;
+
+  DCHECK(message_loop_);
+  return true;
+}
+
+void Thread::Stop() {
+  if (!thread_was_started())
+    return;
+
+  StopSoon();
+
+  // Wait for the thread to exit.
+  //
+  // TODO(darin): Unfortunately, we need to keep message_loop_ around until
+  // the thread exits.  Some consumers are abusing the API.  Make them stop.
+  //
+  PlatformThread::Join(thread_);
+
+  // The thread should NULL message_loop_ on exit.
+  DCHECK(!message_loop_);
+
+  // The thread no longer needs to be joined.
+  started_ = false;
+
+  stopping_ = false;
+}
+
+void Thread::StopSoon() {
+  // We should only be called on the same thread that started us.
+
+  // Reading thread_id_ without a lock can lead to a benign data race
+  // with ThreadMain, so we annotate it to stay silent under ThreadSanitizer.
+  DCHECK_NE(ANNOTATE_UNPROTECTED_READ(thread_id_), PlatformThread::CurrentId());
+
+  if (stopping_ || !message_loop_)
+    return;
+
+  stopping_ = true;
+  message_loop_->PostTask(FROM_HERE, new ThreadQuitTask());
+}
+
+void Thread::Run(MessageLoop* message_loop) {
+  message_loop->Run();
+}
+
+void Thread::SetThreadWasQuitProperly(bool flag) {
+  lazy_tls_bool.Pointer()->Set(flag);
+}
+
+bool Thread::GetThreadWasQuitProperly() {
+  bool quit_properly = true;
+#ifndef NDEBUG
+  quit_properly = lazy_tls_bool.Pointer()->Get();
+#endif
+  return quit_properly;
+}
+
+void Thread::ThreadMain() {
+  {
+    // The message loop for this thread.
+    MessageLoop message_loop(startup_data_->options.message_loop_type);
+
+    // Complete the initialization of our Thread object.
+    thread_id_ = PlatformThread::CurrentId();
+    PlatformThread::SetName(name_.c_str());
+    ANNOTATE_THREAD_NAME(name_.c_str());  // Tell the name to race detector.
+    message_loop.set_thread_name(name_);
+    message_loop_ = &message_loop;
+
+    // Let the thread do extra initialization.
+    // Let's do this before signaling we are started.
+    Init();
+
+    startup_data_->event.Signal();
+    // startup_data_ can't be touched anymore since the starting thread is now
+    // unlocked.
+
+    Run(message_loop_);
+
+    // Let the thread do extra cleanup.
+    CleanUp();
+
+    // Assert that MessageLoop::Quit was called by ThreadQuitTask.
+    DCHECK(GetThreadWasQuitProperly());
+
+    // We can't receive messages anymore.
+    message_loop_ = NULL;
+  }
+  thread_id_ = kInvalidThreadId;
+}
+
+}  // namespace base