зеркало из https://github.com/mozilla/gecko-dev.git
65 строки
2.1 KiB
C++
65 строки
2.1 KiB
C++
// Copyright (c) 2010 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_collision_warner.h"
|
|
|
|
#include "base/logging.h"
|
|
#include "base/threading/platform_thread.h"
|
|
|
|
namespace base {
|
|
|
|
void DCheckAsserter::warn() {
|
|
NOTREACHED() << "Thread Collision";
|
|
}
|
|
|
|
static subtle::Atomic32 CurrentThread() {
|
|
const PlatformThreadId current_thread_id = PlatformThread::CurrentId();
|
|
// We need to get the thread id into an atomic data type. This might be a
|
|
// truncating conversion, but any loss-of-information just increases the
|
|
// chance of a fault negative, not a false positive.
|
|
const subtle::Atomic32 atomic_thread_id =
|
|
static_cast<subtle::Atomic32>(current_thread_id);
|
|
|
|
return atomic_thread_id;
|
|
}
|
|
|
|
void ThreadCollisionWarner::EnterSelf() {
|
|
// If the active thread is 0 then I'll write the current thread ID
|
|
// if two or more threads arrive here only one will succeed to
|
|
// write on valid_thread_id_ the current thread ID.
|
|
subtle::Atomic32 current_thread_id = CurrentThread();
|
|
|
|
int previous_value = subtle::NoBarrier_CompareAndSwap(&valid_thread_id_,
|
|
0,
|
|
current_thread_id);
|
|
if (previous_value != 0 && previous_value != current_thread_id) {
|
|
// gotcha! a thread is trying to use the same class and that is
|
|
// not current thread.
|
|
asserter_->warn();
|
|
}
|
|
|
|
subtle::NoBarrier_AtomicIncrement(&counter_, 1);
|
|
}
|
|
|
|
void ThreadCollisionWarner::Enter() {
|
|
subtle::Atomic32 current_thread_id = CurrentThread();
|
|
|
|
if (subtle::NoBarrier_CompareAndSwap(&valid_thread_id_,
|
|
0,
|
|
current_thread_id) != 0) {
|
|
// gotcha! another thread is trying to use the same class.
|
|
asserter_->warn();
|
|
}
|
|
|
|
subtle::NoBarrier_AtomicIncrement(&counter_, 1);
|
|
}
|
|
|
|
void ThreadCollisionWarner::Leave() {
|
|
if (subtle::Barrier_AtomicIncrement(&counter_, -1) == 0) {
|
|
subtle::NoBarrier_Store(&valid_thread_id_, 0);
|
|
}
|
|
}
|
|
|
|
} // namespace base
|