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| author | wangxianzhu <wangxianzhu@chromium.org> | 2015-02-23 11:13:52 -0800 |
|---|---|---|
| committer | Commit bot <commit-bot@chromium.org> | 2015-02-23 19:14:26 +0000 |
| commit | 02769c33ee568c5329ce85702428635e2ef442ee (patch) | |
| tree | 798e2d9d9fc1736a0be2f61314454ff8ee862b6e /base/trace_event/trace_event_impl.cc | |
| parent | 88db1a01502634619859cc428151bc571d6eebac (diff) | |
| download | chromium_src-02769c33ee568c5329ce85702428635e2ef442ee.zip chromium_src-02769c33ee568c5329ce85702428635e2ef442ee.tar.gz chromium_src-02769c33ee568c5329ce85702428635e2ef442ee.tar.bz2 | |
Avoid twice clock reading
Add TRACE_EVENT_FLAG_EXPLICIT_TIMESTAMP which is set when an explicit
timestamp is specified for the trace event. Only re-read clock if the
flag is set.
BUG=457441
Review URL: https://codereview.chromium.org/928563003
Cr-Commit-Position: refs/heads/master@{#317618}
Diffstat (limited to 'base/trace_event/trace_event_impl.cc')
| -rw-r--r-- | base/trace_event/trace_event_impl.cc | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/base/trace_event/trace_event_impl.cc b/base/trace_event/trace_event_impl.cc index 9ca0ddc..445cb6d 100644 --- a/base/trace_event/trace_event_impl.cc +++ b/base/trace_event/trace_event_impl.cc @@ -1914,7 +1914,8 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp( id ^= process_id_hash_; TimeTicks offset_event_timestamp = OffsetTimestamp(timestamp); - TimeTicks now = OffsetNow(); + TimeTicks now = flags & TRACE_EVENT_FLAG_EXPLICIT_TIMESTAMP ? + OffsetNow() : offset_event_timestamp; TimeTicks thread_now = ThreadNow(); ThreadLocalEventBuffer* thread_local_event_buffer = NULL; @@ -2035,9 +2036,6 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp( } } - // Use |now| instead of |offset_event_timestamp| to compute overhead, because - // event timestamp may be not the real time that we started to add the event - // (e.g. event with zero timestamp or that was generated some time ago). if (thread_local_event_buffer) thread_local_event_buffer->ReportOverhead(now, thread_now); |