base: Support setting thread priorities generically.

media/audio/audio_device_thread.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 "media/audio/audio_device_thread.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 76 matching lines @@
 
 bool AudioDeviceThread::IsStopped() {
   base::AutoLock auto_lock(thread_lock_);
   return thread_ == NULL;
 }
 
 // AudioDeviceThread::Thread implementation
 AudioDeviceThread::Thread::Thread(AudioDeviceThread::Callback* callback,
                                   base::SyncSocket::Handle socket,
                                   const char* thread_name)
-    : thread_(base::kNullThreadHandle),
+    : thread_(),
       callback_(callback),
       socket_(socket),
       thread_name_(thread_name) {
 }
 
 AudioDeviceThread::Thread::~Thread() {
-  DCHECK_EQ(thread_, base::kNullThreadHandle) << "Stop wasn't called";
+  DCHECK(thread_.is_null());
 }
 
 void AudioDeviceThread::Thread::Start() {
   base::AutoLock auto_lock(callback_lock_);
-  DCHECK_EQ(thread_, base::kNullThreadHandle);
+  DCHECK(thread_.is_null());
   // This reference will be released when the thread exists.
   AddRef();
 
   PlatformThread::CreateWithPriority(0, this, &thread_,
                                      base::kThreadPriority_RealtimeAudio);
-  CHECK(thread_ != base::kNullThreadHandle);
+  CHECK(!thread_.is_null());
 }
 
 void AudioDeviceThread::Thread::Stop(base::MessageLoop* loop_for_join) {
   socket_.Shutdown();
 
-  base::PlatformThreadHandle thread = base::kNullThreadHandle;
+  base::PlatformThreadHandle thread = base::PlatformThreadHandle();
 
   {  // NOLINT
     base::AutoLock auto_lock(callback_lock_);
     callback_ = NULL;
     std::swap(thread, thread_);
   }
 
-  if (thread != base::kNullThreadHandle) {
+  if (!thread.is_null()) {
     if (loop_for_join) {
       loop_for_join->PostTask(FROM_HERE,
           base::Bind(&base::PlatformThread::Join, thread));
     } else {
       base::PlatformThread::Join(thread);
     }
   }
 }
 
 void AudioDeviceThread::Thread::ThreadMain() {
@@ skipping 56 matching lines @@
 }
 
 AudioDeviceThread::Callback::~Callback() {}
 
 void AudioDeviceThread::Callback::InitializeOnAudioThread() {
   MapSharedMemory();
   CHECK(shared_memory_.memory());
 }
 
 }  // namespace media.