15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved.
25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be
35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file.
45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/synchronization/lock_impl.h"
65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base {
85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace internal {
95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)LockImpl::LockImpl() {
115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // The second parameter is the spin count, for short-held locks it avoid the
125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // contending thread from going to sleep which helps performance greatly.
13d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)  ::InitializeCriticalSectionAndSpinCount(&native_handle_, 2000);
145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)LockImpl::~LockImpl() {
17d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)  ::DeleteCriticalSection(&native_handle_);
185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool LockImpl::Try() {
21d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)  if (::TryEnterCriticalSection(&native_handle_) != FALSE) {
225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)    return true;
235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  }
245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  return false;
255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void LockImpl::Lock() {
28d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)  ::EnterCriticalSection(&native_handle_);
295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void LockImpl::Unlock() {
32d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)  ::LeaveCriticalSection(&native_handle_);
335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}  // namespace internal
365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}  // namespace base
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