android: Add thread time to early TraceEvent, make timings more precise.

base/trace_event/trace_event.h

 // 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.
 
 #ifndef BASE_TRACE_EVENT_TRACE_EVENT_H_
 #define BASE_TRACE_EVENT_TRACE_EVENT_H_
 
 // This header file defines implementation details of how the trace macros in
 // trace_event_common.h collect and store trace events. Anything not
 // implementation-specific should go in trace_event_common.h instead of here.
@@ skipping 165 matching lines @@
       ->AddTraceEventWithThreadIdAndTimestamp
 
 // Set the duration field of a COMPLETE trace event.
 // void TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
 //     const unsigned char* category_group_enabled,
 //     const char* name,
 //     base::trace_event::TraceEventHandle id)
 #define TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION \
     base::trace_event::TraceLog::GetInstance()->UpdateTraceEventDuration
 
+// Set the duration field of a COMPLETE trace event.
+// void TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION_EXPLICIT(
+//     const unsigned char* category_group_enabled,
+//     const char* name,
+//     base::trace_event::TraceEventHandle id,
+//     const TimeTicks& now,
+//     const ThreadTicks* thread_now)
+#define TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION_EXPLICIT \
+  base::trace_event::TraceLog::GetInstance()->UpdateTraceEventDurationExplicit
+
 // Adds a metadata event to the trace log. The |AppendValueAsTraceFormat| method
 // on the convertable value will be called at flush time.
 // TRACE_EVENT_API_ADD_METADATA_EVENT(
 //     const unsigned char* category_group_enabled,
 //     const char* event_name,
 //     const char* arg_name,
 //     std::unique_ptr<ConvertableToTraceFormat> arg_value)
 #define TRACE_EVENT_API_ADD_METADATA_EVENT \
     trace_event_internal::AddMetadataEvent
 
@@ skipping 136 matching lines @@
           flags | trace_event_trace_id.id_flags();                       \
       trace_event_internal::AddTraceEventWithThreadIdAndTimestamp(       \
           phase, INTERNAL_TRACE_EVENT_UID(category_group_enabled), name, \
           trace_event_trace_id.scope(), trace_event_trace_id.raw_id(),   \
           thread_id, timestamp,                                          \
           trace_event_flags | TRACE_EVENT_FLAG_EXPLICIT_TIMESTAMP,       \
           trace_event_internal::kNoId, ##__VA_ARGS__);                   \
     }                                                                    \
   } while (0)
 
+// Implementation detail: internal macro to create static category and add
+// event if the category is enabled.
+#define INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMPS(                \
+    category_group, name, id, thread_id, begin_timestamp, end_timestamp,    \
+    thread_end_timestamp, flags, ...)                                       \
+  do {                                                                      \
+    INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group);                 \
+    if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED()) {                    \
+      trace_event_internal::TraceID trace_event_trace_id((id));             \
+      unsigned int trace_event_flags =                                      \
+          flags | trace_event_trace_id.id_flags();                          \
+      const unsigned char* uid_category_group_enabled =                     \
+          INTERNAL_TRACE_EVENT_UID(category_group_enabled);                 \
+      auto handle =                                                         \
+          trace_event_internal::AddTraceEventWithThreadIdAndTimestamp(      \
+              TRACE_EVENT_PHASE_COMPLETE, uid_category_group_enabled, name, \
+              trace_event_trace_id.scope(), trace_event_trace_id.raw_id(),  \
+              thread_id, begin_timestamp,                                   \
+              trace_event_flags | TRACE_EVENT_FLAG_EXPLICIT_TIMESTAMP,      \
+              trace_event_internal::kNoId, ##__VA_ARGS__);                  \
+      TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION_EXPLICIT(                 \

[Primiano Tucci (use gerrit), 2017/07/10 13:09:15]

(mostly note to future-myself and git archaeologist): ah yeah, I see the problem
here. Having to leverage the after-the-fact update is a bit awkward (I wished we
never had that feature) but, at the same time, the alternative here would be
adding a new set of N new internal::AddTraceEventWithThreadIdAndTimestamp*s*
functions (one for each combination of argument types) and then change TraceLog,
which would make this CL and the resulting trace_event.h incredibly more complex
and unreadable. Pragmatism wins.

+          uid_category_group_enabled, name, handle, end_timestamp,          \
+          thread_end_timestamp);                                            \
+    }                                                                       \
+  } while (0)
+
 // The linked ID will not be mangled.
 #define INTERNAL_TRACE_EVENT_ADD_LINK_IDS(category_group, name, id1, id2) \
   do {                                                                    \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group);               \
     if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED()) {                  \
       trace_event_internal::TraceID source_id((id1));                     \
       unsigned int source_flags = source_id.id_flags();                   \
       trace_event_internal::TraceID target_id((id2));                     \
       trace_event_internal::AddTraceEvent(                                \
           TRACE_EVENT_PHASE_LINK_IDS,                                     \
@@ skipping 757 matching lines @@
   const char* name_;
   IDType id_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceScopedTrackableObject);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_H_