blob: 1debe7d97ac64271ea0abe5e4ab3ce61e59c9c1b [file] [log] [blame]
/*
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "system_wrappers/source/rw_lock_win.h"
#include "rtc_base/logging.h"
namespace webrtc {
static bool native_rw_locks_supported = false;
static bool module_load_attempted = false;
static HMODULE library = NULL;
typedef void (WINAPI* InitializeSRWLock)(PSRWLOCK);
typedef void (WINAPI* AcquireSRWLockExclusive)(PSRWLOCK);
typedef void (WINAPI* ReleaseSRWLockExclusive)(PSRWLOCK);
typedef void (WINAPI* AcquireSRWLockShared)(PSRWLOCK);
typedef void (WINAPI* ReleaseSRWLockShared)(PSRWLOCK);
InitializeSRWLock initialize_srw_lock;
AcquireSRWLockExclusive acquire_srw_lock_exclusive;
AcquireSRWLockShared acquire_srw_lock_shared;
ReleaseSRWLockShared release_srw_lock_shared;
ReleaseSRWLockExclusive release_srw_lock_exclusive;
RWLockWin::RWLockWin() {
initialize_srw_lock(&lock_);
}
RWLockWin* RWLockWin::Create() {
if (!LoadModule()) {
return NULL;
}
return new RWLockWin();
}
void RWLockWin::AcquireLockExclusive() {
acquire_srw_lock_exclusive(&lock_);
}
void RWLockWin::ReleaseLockExclusive() {
release_srw_lock_exclusive(&lock_);
}
void RWLockWin::AcquireLockShared() {
acquire_srw_lock_shared(&lock_);
}
void RWLockWin::ReleaseLockShared() {
release_srw_lock_shared(&lock_);
}
bool RWLockWin::LoadModule() {
if (module_load_attempted) {
return native_rw_locks_supported;
}
module_load_attempted = true;
// Use native implementation if supported (i.e Vista+)
library = LoadLibrary(TEXT("Kernel32.dll"));
if (!library) {
return false;
}
LOG(LS_VERBOSE) << "Loaded Kernel.dll";
initialize_srw_lock =
(InitializeSRWLock)GetProcAddress(library, "InitializeSRWLock");
acquire_srw_lock_exclusive =
(AcquireSRWLockExclusive)GetProcAddress(library,
"AcquireSRWLockExclusive");
release_srw_lock_exclusive =
(ReleaseSRWLockExclusive)GetProcAddress(library,
"ReleaseSRWLockExclusive");
acquire_srw_lock_shared =
(AcquireSRWLockShared)GetProcAddress(library, "AcquireSRWLockShared");
release_srw_lock_shared =
(ReleaseSRWLockShared)GetProcAddress(library, "ReleaseSRWLockShared");
if (initialize_srw_lock && acquire_srw_lock_exclusive &&
release_srw_lock_exclusive && acquire_srw_lock_shared &&
release_srw_lock_shared) {
LOG(LS_VERBOSE) << "Loaded Native RW Lock";
native_rw_locks_supported = true;
}
return native_rw_locks_supported;
}
} // namespace webrtc