106 lines
3.5 KiB
C++
106 lines
3.5 KiB
C++
/*
|
|
* Copyright (C) 2016 Apple Inc. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
|
|
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <wtf/Lock.h>
|
|
#include <wtf/Threading.h>
|
|
|
|
namespace WTF {
|
|
|
|
template<typename LockType>
|
|
class RecursiveLockAdapter {
|
|
public:
|
|
RecursiveLockAdapter() = default;
|
|
|
|
// Use WTF_IGNORES_THREAD_SAFETY_ANALYSIS because the function does conditional locking, which is
|
|
// not supported by analysis. Also RecursiveLockAdapter may wrap a lock type besides WTF::Lock
|
|
// which doesn't support analysis.
|
|
void lock() WTF_IGNORES_THREAD_SAFETY_ANALYSIS
|
|
{
|
|
Thread& me = Thread::current();
|
|
if (&me == m_owner) {
|
|
m_recursionCount++;
|
|
return;
|
|
}
|
|
|
|
m_lock.lock();
|
|
ASSERT(!m_owner);
|
|
ASSERT(!m_recursionCount);
|
|
m_owner = &me;
|
|
m_recursionCount = 1;
|
|
}
|
|
|
|
// Use WTF_IGNORES_THREAD_SAFETY_ANALYSIS because the function does conditional unlocking, which is
|
|
// not supported by analysis. Also RecursiveLockAdapter may wrap a lock type besides WTF::Lock
|
|
// which doesn't support analysis.
|
|
void unlock() WTF_IGNORES_THREAD_SAFETY_ANALYSIS
|
|
{
|
|
if (--m_recursionCount)
|
|
return;
|
|
m_owner = nullptr;
|
|
m_lock.unlock();
|
|
}
|
|
|
|
// Use WTF_IGNORES_THREAD_SAFETY_ANALYSIS because the function does conditional locking, which is
|
|
// not supported by analysis. Also RecursiveLockAdapter may wrap a lock type besides WTF::Lock
|
|
// which doesn't support analysis.
|
|
bool tryLock() WTF_IGNORES_THREAD_SAFETY_ANALYSIS
|
|
{
|
|
Thread& me = Thread::current();
|
|
if (&me == m_owner) {
|
|
m_recursionCount++;
|
|
return true;
|
|
}
|
|
|
|
if (!m_lock.tryLock())
|
|
return false;
|
|
|
|
ASSERT(!m_owner);
|
|
ASSERT(!m_recursionCount);
|
|
m_owner = &me;
|
|
m_recursionCount = 1;
|
|
return true;
|
|
}
|
|
|
|
bool isLocked() const
|
|
{
|
|
return m_lock.isLocked();
|
|
}
|
|
|
|
bool isOwner() const { return m_owner == &Thread::current(); }
|
|
|
|
private:
|
|
Thread* m_owner { nullptr }; // Use Thread* instead of RefPtr<Thread> since m_owner thread is always alive while m_onwer is set.
|
|
unsigned m_recursionCount { 0 };
|
|
LockType m_lock;
|
|
};
|
|
|
|
using RecursiveLock = RecursiveLockAdapter<Lock>;
|
|
|
|
} // namespace WTF
|
|
|
|
using WTF::RecursiveLock;
|