1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/simple_thread.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,118 @@
1.4 +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#include "base/simple_thread.h"
1.9 +
1.10 +#include "base/waitable_event.h"
1.11 +#include "base/logging.h"
1.12 +#include "base/platform_thread.h"
1.13 +#include "base/string_util.h"
1.14 +
1.15 +namespace base {
1.16 +
1.17 +void SimpleThread::Start() {
1.18 + DCHECK(!HasBeenStarted()) << "Tried to Start a thread multiple times.";
1.19 + bool success = PlatformThread::Create(options_.stack_size(), this, &thread_);
1.20 + CHECK(success);
1.21 + event_.Wait(); // Wait for the thread to complete initialization.
1.22 +}
1.23 +
1.24 +void SimpleThread::Join() {
1.25 + DCHECK(HasBeenStarted()) << "Tried to Join a never-started thread.";
1.26 + DCHECK(!HasBeenJoined()) << "Tried to Join a thread multiple times.";
1.27 + PlatformThread::Join(thread_);
1.28 + joined_ = true;
1.29 +}
1.30 +
1.31 +void SimpleThread::ThreadMain() {
1.32 + tid_ = PlatformThread::CurrentId();
1.33 + // Construct our full name of the form "name_prefix_/TID".
1.34 + name_.push_back('/');
1.35 + name_.append(IntToString(tid_));
1.36 + PlatformThread::SetName(name_.c_str());
1.37 +
1.38 + // We've initialized our new thread, signal that we're done to Start().
1.39 + event_.Signal();
1.40 +
1.41 + Run();
1.42 +}
1.43 +
1.44 +SimpleThread::~SimpleThread() {
1.45 + DCHECK(HasBeenStarted()) << "SimpleThread was never started.";
1.46 + DCHECK(HasBeenJoined()) << "SimpleThread destroyed without being Join()ed.";
1.47 +}
1.48 +
1.49 +void DelegateSimpleThread::Run() {
1.50 + DCHECK(delegate_) << "Tried to call Run without a delegate (called twice?)";
1.51 + delegate_->Run();
1.52 + delegate_ = NULL;
1.53 +}
1.54 +
1.55 +DelegateSimpleThreadPool::~DelegateSimpleThreadPool() {
1.56 + DCHECK(threads_.empty());
1.57 + DCHECK(delegates_.empty());
1.58 + DCHECK(!dry_.IsSignaled());
1.59 +}
1.60 +
1.61 +void DelegateSimpleThreadPool::Start() {
1.62 + DCHECK(threads_.empty()) << "Start() called with outstanding threads.";
1.63 + for (int i = 0; i < num_threads_; ++i) {
1.64 + DelegateSimpleThread* thread = new DelegateSimpleThread(this, name_prefix_);
1.65 + thread->Start();
1.66 + threads_.push_back(thread);
1.67 + }
1.68 +}
1.69 +
1.70 +void DelegateSimpleThreadPool::JoinAll() {
1.71 + DCHECK(!threads_.empty()) << "JoinAll() called with no outstanding threads.";
1.72 +
1.73 + // Tell all our threads to quit their worker loop.
1.74 + AddWork(NULL, num_threads_);
1.75 +
1.76 + // Join and destroy all the worker threads.
1.77 + for (int i = 0; i < num_threads_; ++i) {
1.78 + threads_[i]->Join();
1.79 + delete threads_[i];
1.80 + }
1.81 + threads_.clear();
1.82 + DCHECK(delegates_.empty());
1.83 +}
1.84 +
1.85 +void DelegateSimpleThreadPool::AddWork(Delegate* delegate, int repeat_count) {
1.86 + AutoLock locked(lock_);
1.87 + for (int i = 0; i < repeat_count; ++i)
1.88 + delegates_.push(delegate);
1.89 + // If we were empty, signal that we have work now.
1.90 + if (!dry_.IsSignaled())
1.91 + dry_.Signal();
1.92 +}
1.93 +
1.94 +void DelegateSimpleThreadPool::Run() {
1.95 + Delegate* work;
1.96 +
1.97 + while (true) {
1.98 + dry_.Wait();
1.99 + {
1.100 + AutoLock locked(lock_);
1.101 + if (!dry_.IsSignaled())
1.102 + continue;
1.103 +
1.104 + DCHECK(!delegates_.empty());
1.105 + work = delegates_.front();
1.106 + delegates_.pop();
1.107 +
1.108 + // Signal to any other threads that we're currently out of work.
1.109 + if (delegates_.empty())
1.110 + dry_.Reset();
1.111 + }
1.112 +
1.113 + // A NULL delegate pointer signals us to quit.
1.114 + if (!work)
1.115 + break;
1.116 +
1.117 + work->Run();
1.118 + }
1.119 +}
1.120 +
1.121 +} // namespace base
