Add support for TraceEvent before the native library is loaded.

base/trace_event/trace_event_impl.cc

 // Copyright (c) 2012 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.
 
 #include "base/trace_event/trace_event_impl.h"
 
 #include <algorithm>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 1720 matching lines @@
     flush_message_loop_proxy_->PostDelayedTask(
         FROM_HERE,
         Bind(&TraceLog::OnFlushTimeout, Unretained(this), generation),
         TimeDelta::FromMilliseconds(kThreadFlushTimeoutMs));
     return;
   }
 
   FinishFlush(generation);
 }
 
+
 void TraceLog::ConvertTraceEventsToTraceFormat(
     scoped_ptr<TraceBuffer> logged_events,
     const TraceLog::OutputCallback& flush_output_callback) {
 
   if (flush_output_callback.is_null())
     return;
 
-  // The callback need to be called at least once even if there is no events
-  // to let the caller know the completion of flush.
+  // The callback needs to be called at least once even if there is no events to
+  // let the caller know the completion of flush.
   bool has_more_events = true;
+
   do {
     scoped_refptr<RefCountedString> json_events_str_ptr =
         new RefCountedString();
 
     for (size_t i = 0; i < kTraceEventBatchChunks; ++i) {
       const TraceBufferChunk* chunk = logged_events->NextChunk();
       if (!chunk) {
         has_more_events = false;
         break;
       }
@@ skipping 121 matching lines @@
                                                convertable_values, flags);
 }
 
 TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     char phase,
     const unsigned char* category_group_enabled,
     const char* name,
     unsigned long long id,
     int thread_id,
     const TimeTicks& timestamp,
+    const TimeTicks& thread_time,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
+    unsigned char flags) {
+  return AddTraceEventInternal(
+      phase, category_group_enabled, name, id, thread_id, timestamp,
+      thread_time, num_args, arg_names, arg_types, arg_values,
+      convertable_values, flags);
+}
+
+TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
+    char phase,
+    const unsigned char* category_group_enabled,
+    const char* name,
+    unsigned long long id,
+    int thread_id,
+    const TimeTicks& timestamp,
     int num_args,
     const char** arg_names,
     const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
+    unsigned char flags) {
+  return AddTraceEventWithThreadIdAndTimestamp(
+      phase, category_group_enabled, name, id, thread_id, timestamp,
+      ThreadNow(), num_args, arg_names, arg_types, arg_values,
+      convertable_values, flags);
+}
+
+TraceEventHandle TraceLog::AddTraceEventInternal(
+    char phase,
+    const unsigned char* category_group_enabled,
+    const char* name,
+    unsigned long long id,
+    int thread_id,
+    const TimeTicks& timestamp,
+    const TimeTicks& thread_time,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
     const unsigned long long* arg_values,
     const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
     unsigned char flags) {
   TraceEventHandle handle = { 0, 0, 0 };
   if (!*category_group_enabled)
     return handle;
 
   // Avoid re-entrance of AddTraceEvent. This may happen in GPU process when
   // ECHO_TO_CONSOLE is enabled: AddTraceEvent -> LOG(ERROR) ->
   // GpuProcessLogMessageHandler -> PostPendingTask -> TRACE_EVENT ...
   if (thread_is_in_trace_event_.Get())
     return handle;
 
   AutoThreadLocalBoolean thread_is_in_trace_event(&thread_is_in_trace_event_);
 
   DCHECK(name);
   DCHECK(!timestamp.is_null());
 
   if (flags & TRACE_EVENT_FLAG_MANGLE_ID)
     id ^= process_id_hash_;
 
   TimeTicks offset_event_timestamp = OffsetTimestamp(timestamp);
   TimeTicks now = flags & TRACE_EVENT_FLAG_EXPLICIT_TIMESTAMP ?
       OffsetNow() : offset_event_timestamp;
   TimeTicks thread_now = ThreadNow();

[dsinclair, 2015/03/16 14:41:23]

Can this be removed and we just use thread_time?

[Benoit L, 2015/03/19 16:50:47]

I'm not sure that I understand what you mean here. This is not part of this CL,
it was added for something else.

[dsinclair, 2015/03/19 18:35:32]

Right, but we've added another TimeTicks called thread_time which you use below.
It seems like this TimeTicks is redundant?

 
   ThreadLocalEventBuffer* thread_local_event_buffer = NULL;
   // A ThreadLocalEventBuffer needs the message loop
   // - to know when the thread exits;
   // - to handle the final flush.
   // For a thread without a message loop or the message loop may be blocked, the
   // trace events will be added into the main buffer directly.
   if (!thread_blocks_message_loop_.Get() && MessageLoop::current()) {
     thread_local_event_buffer = thread_local_event_buffer_.Get();
     if (thread_local_event_buffer &&
@@ skipping 100 matching lines @@
       event_callback(offset_event_timestamp,
                      phase == TRACE_EVENT_PHASE_COMPLETE ?
                          TRACE_EVENT_PHASE_BEGIN : phase,
                      category_group_enabled, name, id,
                      num_args, arg_names, arg_types, arg_values,
                      flags);
     }
   }
 
   if (thread_local_event_buffer)
-    thread_local_event_buffer->ReportOverhead(now, thread_now);
+    thread_local_event_buffer->ReportOverhead(now, thread_time);
 
   return handle;
 }
 
 // May be called when a COMPELETE event ends and the unfinished event has been
 // recycled (phase == TRACE_EVENT_PHASE_END and trace_event == NULL).
 std::string TraceLog::EventToConsoleMessage(unsigned char phase,
                                             const TimeTicks& timestamp,
                                             TraceEvent* trace_event) {
   AutoLock thread_info_lock(thread_info_lock_);
@@ skipping 537 matching lines @@
 }
 
 ScopedTraceBinaryEfficient::~ScopedTraceBinaryEfficient() {
   if (*category_group_enabled_) {
     TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_group_enabled_,
                                                 name_, event_handle_);
   }
 }
 
 }  // namespace trace_event_internal