gecko-dev/xpcom/threads/RWLock.cpp
Manish Goregaokar e104a8487b Bug 1367619 - Use RWLock when accessing font prefs service off main thread; r=heycam
MozReview-Commit-ID: Dxdq6Etbwxa

--HG--
extra : rebase_source : ec9f847c7dce6a101db6a3d157395f5b73d87ba1
2017-05-25 15:04:13 -07:00

98 lines
2.1 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/RWLock.h"
#ifdef XP_WIN
#include <windows.h>
static_assert(sizeof(SRWLOCK) <= sizeof(void*), "SRWLOCK is too big!");
#define NativeHandle(m) (reinterpret_cast<SRWLOCK*>(&m))
#else
#define NativeHandle(m) (&m)
#endif
namespace mozilla {
RWLock::RWLock(const char* aName)
: BlockingResourceBase(aName, eMutex)
#ifdef DEBUG
, mOwningThread(nullptr)
#endif
{
#ifdef XP_WIN
InitializeSRWLock(NativeHandle(mRWLock));
#else
MOZ_RELEASE_ASSERT(pthread_rwlock_init(NativeHandle(mRWLock), nullptr) == 0,
"pthread_rwlock_init failed");
#endif
}
#ifdef DEBUG
bool
RWLock::LockedForWritingByCurrentThread()
{
return mOwningThread == PR_GetCurrentThread();
}
#endif
#ifndef XP_WIN
RWLock::~RWLock()
{
MOZ_RELEASE_ASSERT(pthread_rwlock_destroy(NativeHandle(mRWLock)) == 0,
"pthread_rwlock_destroy failed");
}
#endif
void
RWLock::ReadLockInternal()
{
#ifdef XP_WIN
AcquireSRWLockShared(NativeHandle(mRWLock));
#else
MOZ_RELEASE_ASSERT(pthread_rwlock_rdlock(NativeHandle(mRWLock)) == 0,
"pthread_rwlock_rdlock failed");
#endif
}
void
RWLock::ReadUnlockInternal()
{
#ifdef XP_WIN
ReleaseSRWLockShared(NativeHandle(mRWLock));
#else
MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(NativeHandle(mRWLock)) == 0,
"pthread_rwlock_unlock failed");
#endif
}
void
RWLock::WriteLockInternal()
{
#ifdef XP_WIN
AcquireSRWLockExclusive(NativeHandle(mRWLock));
#else
MOZ_RELEASE_ASSERT(pthread_rwlock_wrlock(NativeHandle(mRWLock)) == 0,
"pthread_rwlock_wrlock failed");
#endif
}
void
RWLock::WriteUnlockInternal()
{
#ifdef XP_WIN
ReleaseSRWLockExclusive(NativeHandle(mRWLock));
#else
MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(NativeHandle(mRWLock)) == 0,
"pthread_rwlock_unlock failed");
#endif
}
}
#undef NativeHandle