1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/debug/task_annotator.h" 6 7 #include "base/debug/alias.h" 8 #include "base/pending_task.h" 9 #include "base/trace_event/trace_event.h" 10 #include "base/tracked_objects.h" 11 12 namespace base { 13 namespace debug { 14 15 TaskAnnotator::TaskAnnotator() { 16 } 17 18 TaskAnnotator::~TaskAnnotator() { 19 } 20 21 void TaskAnnotator::DidQueueTask(const char* queue_function, 22 const PendingTask& pending_task) { 23 TRACE_EVENT_WITH_FLOW0(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"), 24 queue_function, 25 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)), 26 TRACE_EVENT_FLAG_FLOW_OUT); 27 } 28 29 void TaskAnnotator::RunTask(const char* queue_function, 30 const PendingTask& pending_task) { 31 tracked_objects::TaskStopwatch stopwatch; 32 stopwatch.Start(); 33 tracked_objects::Duration queue_duration = 34 stopwatch.StartTime() - pending_task.EffectiveTimePosted(); 35 36 TRACE_EVENT_WITH_FLOW1(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"), 37 queue_function, 38 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)), 39 TRACE_EVENT_FLAG_FLOW_IN, 40 "queue_duration", 41 queue_duration.InMilliseconds()); 42 43 // Before running the task, store the program counter where it was posted 44 // and deliberately alias it to ensure it is on the stack if the task 45 // crashes. Be careful not to assume that the variable itself will have the 46 // expected value when displayed by the optimizer in an optimized build. 47 // Look at a memory dump of the stack. 48 const void* program_counter = pending_task.posted_from.program_counter(); 49 debug::Alias(&program_counter); 50 51 pending_task.task.Run(); 52 53 stopwatch.Stop(); 54 tracked_objects::ThreadData::TallyRunOnNamedThreadIfTracking( 55 pending_task, stopwatch); 56 } 57 58 uint64_t TaskAnnotator::GetTaskTraceID(const PendingTask& task) const { 59 return (static_cast<uint64_t>(task.sequence_num) << 32) | 60 ((static_cast<uint64_t>(reinterpret_cast<intptr_t>(this)) << 32) >> 61 32); 62 } 63 64 } // namespace debug 65 } // namespace base 66
