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