642965c678
No-Typo-Check: Not related to this change. Bug: 161477208 Change-Id: I99e4780f6855b7045aa0cd5a49c13d2d0d51ed64
61 lines
1.2 KiB
C++
61 lines
1.2 KiB
C++
// Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
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// source code may only be used and distributed under the Widevine License
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// Agreement.
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#include "rw_lock.h"
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#include "log.h"
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namespace wvutil {
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shared_mutex::~shared_mutex() {
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if (reader_count_ > 0) {
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LOGE("shared_mutex destroyed with active readers!");
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}
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if (has_writer_) {
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LOGE("shared_mutex destroyed with an active writer!");
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}
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}
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void shared_mutex::lock_shared() {
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std::unique_lock<std::mutex> lock(mutex_);
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while (has_writer_) {
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condition_variable_.wait(lock);
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}
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++reader_count_;
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}
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void shared_mutex::unlock_shared() {
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std::unique_lock<std::mutex> lock(mutex_);
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--reader_count_;
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if (reader_count_ == 0) {
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condition_variable_.notify_all();
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}
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}
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bool shared_mutex::lock_implementation(bool abort_if_unavailable) {
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std::unique_lock<std::mutex> lock(mutex_);
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while (reader_count_ > 0 || has_writer_) {
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if (abort_if_unavailable) return false;
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condition_variable_.wait(lock);
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}
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has_writer_ = true;
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return true;
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}
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void shared_mutex::unlock() {
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std::unique_lock<std::mutex> lock(mutex_);
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has_writer_ = false;
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condition_variable_.notify_all();
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}
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} // namespace wvutil
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