[tracing] Adding task information to heap profiler

base/debug/task_annotator.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_DEBUG_TASK_ANNOTATOR_H_
 #define BASE_DEBUG_TASK_ANNOTATOR_H_
 
 #include <stdint.h>
 
 #include "base/base_export.h"
 #include "base/macros.h"
+#include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 
 namespace base {
 struct PendingTask;
 namespace debug {
 
 // Implements common debug annotations for posted tasks. This includes data
 // such as task origins, queueing durations and memory usage.
 class BASE_EXPORT TaskAnnotator {
  public:
   TaskAnnotator();
@@ skipping 10 matching lines @@
 
  private:
   // Creates a process-wide unique ID to represent this task in trace events.
   // This will be mangled with a Process ID hash to reduce the likelyhood of
   // colliding with TaskAnnotator pointers on other processes.
   uint64_t GetTaskTraceID(const PendingTask& task) const;
 
   DISALLOW_COPY_AND_ASSIGN(TaskAnnotator);
 };
 
+class ScopedTaskExecutionEvent {
+ public:
+  ScopedTaskExecutionEvent(const char* file_name, const char* function_name)
+      : function_name_(function_name) {
+    if (trace_event::AllocationContextTracker::capture_enabled()) {

[Sami, 2016/03/17 17:06:26]

Might want to add a throw an UNLIKELY() around this here and below.

+      trace_event::AllocationContextTracker::SetCurrentTaskFileName(file_name);

[Sami, 2016/03/17 17:06:26]

Why isn't the file name also part of the pseudo stack? The fact that we reset it
to null in the destructor might make for some confusing traces when nested tasks
are involved.

+      trace_event::AllocationContextTracker::PushPseudoStackFrame(
+          function_name_);
+    }
+  }
+
+  ~ScopedTaskExecutionEvent() {
+    if (trace_event::AllocationContextTracker::capture_enabled()) {
+      trace_event::AllocationContextTracker::PopPseudoStackFrame(
+          function_name_);
+      trace_event::AllocationContextTracker::SetCurrentTaskFileName(nullptr);
+    }
+  }
+
+ private:
+  const char* function_name_;
+};
+
 #define TRACE_TASK_EXECUTION(run_function, task)           \
   TRACE_EVENT2("toplevel", (run_function), "src_file",     \
                (task).posted_from.file_name(), "src_func", \
-               (task).posted_from.function_name());
+               (task).posted_from.function_name());        \
+  base::debug::ScopedTaskExecutionEvent scoped_task_event( \
+      (task).posted_from.file_name(), (task).posted_from.function_name());
 
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_TASK_ANNOTATOR_H_