59 lines
1.6 KiB
C++
59 lines
1.6 KiB
C++
/*
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* Copyright (c) 2017 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 "modules/desktop_capture/screen_drawer_lock_posix.h"
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#include <fcntl.h>
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#include <sys/stat.h>
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#include "rtc_base/checks.h"
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#include "rtc_base/logging.h"
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namespace webrtc {
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namespace {
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// A uuid as the name of semaphore.
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static constexpr char kSemaphoreName[] = "GSDL54fe5552804711e6a7253f429a";
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} // namespace
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ScreenDrawerLockPosix::ScreenDrawerLockPosix()
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: ScreenDrawerLockPosix(kSemaphoreName) {}
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ScreenDrawerLockPosix::ScreenDrawerLockPosix(const char* name) {
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semaphore_ = sem_open(name, O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO, 1);
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if (semaphore_ == SEM_FAILED) {
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RTC_LOG_ERRNO(LS_ERROR) << "Failed to create named semaphore with " << name;
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RTC_NOTREACHED();
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}
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sem_wait(semaphore_);
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}
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ScreenDrawerLockPosix::~ScreenDrawerLockPosix() {
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if (semaphore_ == SEM_FAILED) {
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return;
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}
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sem_post(semaphore_);
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sem_close(semaphore_);
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// sem_unlink a named semaphore won't wait until other clients to release the
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// sem_t. So if a new process starts, it will sem_open a different kernel
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// object with the same name and eventually breaks the cross-process lock.
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}
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// static
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void ScreenDrawerLockPosix::Unlink(const char* name) {
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sem_unlink(name);
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}
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} // namespace webrtc
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