Leszek Swirski a12c6fa2ea Revert "[counters] Fix reentrant timers for V8.Execute" ... This reverts commit fffcbaea55. Reason for revert: Breaks in Chromium (e.g. https://ci.chromium.org/p/v8/builders/ci/Linux%20V8%20FYI%20Release%20%28NVIDIA%29) Original change's description: > [counters] Fix reentrant timers for V8.Execute > > This CL fixes a long standing issue where reentering TimedHistograms > scopes would cause spurious measurements. Only the non-nested scopes > yielded correct results. > > Due to the changed numbers, the V8.Execute histogram is renamed to > V8.ExecuteMicroSeconds. Note that this histogram is also guarded > behind the --slow-histograms flag due to the additional overhead. > > Unlike before, it does no longer include time for external callbacks > and only measures self time. The following example illustrates the > new behaviour: > > 1. Enter V8: |--+.......+--| self-time: 4 units (reported) > 2. Exit V8 (callback): |-+...+-| self-time: 2 units (ignored) > 3. Re-enter V8: |---| self-time: 3 units (reported) > > This would result in 2 histogram entries with 4 time units for the first > V8 slice and 3 units for the nested part. Note that the callback time > itself is ignored. > > This CL attempts to clean up how TimedHistograms work: > - Histogram: the base class > - TimedHistograms: used for time-related histograms that are not nested > - NestedTimeHistograms: Extends TimedHistograms and is used for nested > histograms > > This CL changes Histograms to not measure time themselves. Measurements > happen in the *HistogramScopes: > - BaseTimedHistogramScope: Base functionality > - TimedHistogramScope: For non-nested measurements > - NestedTimedHistogramScope: For nested measurements > - PauseNestedTimedHistogramScope: Ignore time during a given scope. > This is used to pause timers during callbacks. > > Additional changes: > - ExternalCallbackScope now contains a PauseNestedTimedHistogramScope > and always sets VMState<EXTERNAL> > > Bug: v8:11946 > Change-Id: I45e4b7ff77b5948b605dd50539044cb26222fa21 > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3001345 > Reviewed-by: Omer Katz <omerkatz@chromium.org> > Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> > Reviewed-by: Victor Gomes <victorgomes@chromium.org> > Reviewed-by: Leszek Swirski <leszeks@chromium.org> > Commit-Queue: Camillo Bruni <cbruni@chromium.org> > Cr-Commit-Position: refs/heads/master@{#76111} Bug: v8:11946 Change-Id: I954de1afbabf101fb5d4f52eca0d3b80a723385b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3077153 Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Commit-Queue: Leszek Swirski <leszeks@chromium.org> Owners-Override: Leszek Swirski <leszeks@chromium.org> Cr-Commit-Position: refs/heads/master@{#76138}		2021-08-06 14:31:44 +00:00
..
condition-variable-unittest.cc	Reland "[d8] Remove maximum workers limitation"	2019-07-30 07:56:17 +00:00
mutex-unittest.cc	[base] Introduce MutexGuard as typedef for LockGuard<Mutex>	2018-10-12 15:44:51 +00:00
platform-unittest.cc	Remove windows.h from win32-headers.h	2021-08-03 16:07:16 +00:00
semaphore-unittest.cc	Reland "[d8] Remove maximum workers limitation"	2019-07-30 07:56:17 +00:00
time-unittest.cc	Revert "[counters] Fix reentrant timers for V8.Execute"	2021-08-06 14:31:44 +00:00