113 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			113 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  *  Copyright 2019 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 "rtc_base/synchronization/sequence_checker.h"
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| 
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| #if defined(WEBRTC_MAC)
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| #include <dispatch/dispatch.h>
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| #endif
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| 
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| #include "rtc_base/strings/string_builder.h"
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| 
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| namespace webrtc {
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| namespace {
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| // On Mac, returns the label of the current dispatch queue; elsewhere, return
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| // null.
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| const void* GetSystemQueueRef() {
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| #if defined(WEBRTC_MAC)
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|   return dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL);
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| #else
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|   return nullptr;
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| #endif
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| }
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| 
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| }  // namespace
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| 
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| std::string ExpectationToString(const webrtc::SequenceChecker* checker) {
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| #if RTC_DCHECK_IS_ON
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|   return checker->ExpectationToString();
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| #endif
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|   return std::string();
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| }
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| 
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| SequenceCheckerImpl::SequenceCheckerImpl()
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|     : attached_(true),
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|       valid_thread_(rtc::CurrentThreadRef()),
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|       valid_queue_(TaskQueueBase::Current()),
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|       valid_system_queue_(GetSystemQueueRef()) {}
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| 
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| SequenceCheckerImpl::~SequenceCheckerImpl() = default;
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| 
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| bool SequenceCheckerImpl::IsCurrent() const {
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|   const TaskQueueBase* const current_queue = TaskQueueBase::Current();
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|   const rtc::PlatformThreadRef current_thread = rtc::CurrentThreadRef();
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|   const void* const current_system_queue = GetSystemQueueRef();
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|   MutexLock scoped_lock(&lock_);
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|   if (!attached_) {  // Previously detached.
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|     attached_ = true;
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|     valid_thread_ = current_thread;
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|     valid_queue_ = current_queue;
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|     valid_system_queue_ = current_system_queue;
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|     return true;
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|   }
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|   if (valid_queue_ || current_queue) {
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|     return valid_queue_ == current_queue;
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|   }
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|   if (valid_system_queue_ && valid_system_queue_ == current_system_queue) {
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|     return true;
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|   }
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|   return rtc::IsThreadRefEqual(valid_thread_, current_thread);
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| }
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| 
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| void SequenceCheckerImpl::Detach() {
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|   MutexLock scoped_lock(&lock_);
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|   attached_ = false;
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|   // We don't need to touch the other members here, they will be
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|   // reset on the next call to IsCurrent().
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| }
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| 
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| #if RTC_DCHECK_IS_ON
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| std::string SequenceCheckerImpl::ExpectationToString() const {
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|   const TaskQueueBase* const current_queue = TaskQueueBase::Current();
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|   const rtc::PlatformThreadRef current_thread = rtc::CurrentThreadRef();
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|   const void* const current_system_queue = GetSystemQueueRef();
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|   MutexLock scoped_lock(&lock_);
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|   if (!attached_)
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|     return "Checker currently not attached.";
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| 
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|   // The format of the string is meant to compliment the one we have inside of
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|   // FatalLog() (checks.cc).  Example:
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|   //
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|   // # Expected: TQ: 0x0 SysQ: 0x7fff69541330 Thread: 0x11dcf6dc0
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|   // # Actual:   TQ: 0x7fa8f0604190 SysQ: 0x7fa8f0604a30 Thread: 0x700006f1a000
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|   // TaskQueue doesn't match
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| 
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|   rtc::StringBuilder message;
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|   message.AppendFormat(
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|       "# Expected: TQ: %p SysQ: %p Thread: %p\n"
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|       "# Actual:   TQ: %p SysQ: %p Thread: %p\n",
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|       valid_queue_, valid_system_queue_,
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|       reinterpret_cast<const void*>(valid_thread_), current_queue,
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|       current_system_queue, reinterpret_cast<const void*>(current_thread));
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| 
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|   if ((valid_queue_ || current_queue) && valid_queue_ != current_queue) {
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|     message << "TaskQueue doesn't match\n";
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|   } else if (valid_system_queue_ &&
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|              valid_system_queue_ != current_system_queue) {
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|     message << "System queue doesn't match\n";
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|   } else if (!rtc::IsThreadRefEqual(valid_thread_, current_thread)) {
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|     message << "Threads don't match\n";
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|   }
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| 
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|   return message.Release();
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| }
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| #endif  // RTC_DCHECK_IS_ON
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| 
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| }  // namespace webrtc
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