The default TracingController (used by d8 and Node) has some concurrency
issues. The new test flushes these out, when a second thread logs trace
events while the main thread calls StopTracing().
- Use an acquire load in UpdateCategoryGroupEnabledFlags() because this
was racing with GetCategoryGroupEnabled() where a new category is
added in the slow path. g_category_groups is append-only, but
reads/writes to g_category_index need to be correctly ordered so that
new categories are added and only then is the change to the index
visible. The relaxed load ignored this and caused unsynchronized
read/write.
- Use a relaxed load in ~ScopedTracer() to access category_group_enabled
as this previously used a non-atomic operation which caused a race
with UpdateCategoryGroupEnabledFlag() which does a relaxed store.
- Replace TracingController::mode_ with an atomic bool as read/writes to
mode_ were not synchronized and caused TSAN errors. It only has two
states and it doesn't seem like we will extend this so just convert it
to bool.
- Take the lock around calling trace_object->Initialize in
AddTraceEvent(), and around trace_buffer_->Flush() in StopTracing().
These two raced previously as the underlying TraceBufferRingBuffer
passes out pointers to TraceObjects in a synchronized way, but the
caller (AddTraceEvent) then writes into the object without
synchronization. This leads to races when Flush() is called, at which
time TraceBufferRingBuffer assumes that all the pointers it handed out
are to valid, initialized TraceObjects - which is not true because
AddTraceEvent may still be calling Initialize on them. This could be
the cause of issues in Node.js where the last line of tracing/logging
sometimes gets cut off. This is kind of a band-aid solution - access
to the TraceObjects handed out by the ring buffer really needs proper
synchronization which at this point would require redesign. It's quite
likely we will replace this with Perfetto in the near future so not
much point investing in this code right now.
- Enable TracingCpuProfiler test which was flaky due to these bugs.
Bug: v8:8821
Change-Id: I141296800c6906ac0e7f3f21dd16d861b07dae62
Reviewed-on: https://chromium-review.googlesource.com/c/1477283
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ali Ijaz Sheikh <ofrobots@google.com>
Cr-Commit-Position: refs/heads/master@{#59752}
- Switch #define constant to static const
- Remove unnecessary Internal version of GetCategoryGroupEnabled()
- Fix a typo in a comment
Change-Id: I4af71dc62c7c4742bdfbcaa1ad336298eb325c42
Reviewed-on: https://chromium-review.googlesource.com/c/1477221
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59708}
This API will be used by Node.js to provide output compatible with
Chrome devtools.
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I265495f8af39bfc78d7fdbe43ac308f0920e817d
Reviewed-on: https://chromium-review.googlesource.com/1044491
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Eugene Ostroukhov <eostroukhov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53041}
Make it possible for embedders to provide their own tracing timetamps by
providing an overridable virtual function on V8's tracing controller.
Bug:
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I727e633cb7f63d4b41c2e427ecca3c9174c90bfe
Reviewed-on: https://chromium-review.googlesource.com/847690
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
Cr-Commit-Position: refs/heads/master@{#50489}
This will allow for embedders to easily implement their own Platform
without duplicating the tracing controller code.
BUG=v8:6511
R=fmeawad@chromium.org
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I7c64933d12b2cf53f0636fbc87f6ad5d22019f5c
Reviewed-on: https://chromium-review.googlesource.com/543015
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46118}
We only need included categories list, excluded categories list will only work
if we use regular expression in categories list, which is not supported in V8.
TBR=jochen@chromium.org
Review-Url: https://codereview.chromium.org/2462143002
Cr-Commit-Position: refs/heads/master@{#40681}
The state sampling was implemented in chrome, we had an interface for it
V8 but it was not implemented yet.
The chrome version version has been removed in
https://codereview.chromium.org/2406703002/
Therefore following up with its removal in V8 as well.
This CL can land independent of the Chromium related CL.
R=primiano@chromium.org,alph@chromium.org
Review-Url: https://codereview.chromium.org/2410523002
Cr-Commit-Position: refs/heads/master@{#40232}
Reason for revert:
Revert this CL due to V8 Arm Builder failure and V8 Mips Builder failure.
https://build.chromium.org/p/client.v8.ports/builders/V8%20Arm%20-%20builder/builds/2456https://build.chromium.org/p/client.v8.ports/builders/V8%20Mips%20-%20builder/builds/2506
Original issue's description:
> [Tracing] V8 Tracing Controller
>
> V8 has had a trace event macro interface for while, but without a tracing
> controller a standalone V8 would be unable to collect traces.
>
> This CL introduces a complete Tracing Controller system for V8.
> It is fully function except that it does not yet store trace event args.
>
> This CL has a few components,
> The tracing controller itself, contributed by the author of this CL
> The Trace config (including the parser), contributed by lpy@
> The Trace Object, Trace Writer, and Trace Buffer are all contributed by rksang@
>
> BUG=v8:4561
> LOG=N
>
> Committed: https://crrev.com/3d598452679ce208ad9b2f48e0fb3fae352ce375
> Cr-Commit-Position: refs/heads/master@{#38073}
TBR=jochen@chromium.org,mattloring@google.com,rskang@google.com,yangguo@chromium.org,fmeawad@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4561
Review-Url: https://codereview.chromium.org/2183943002
Cr-Commit-Position: refs/heads/master@{#38074}
V8 has had a trace event macro interface for while, but without a tracing
controller a standalone V8 would be unable to collect traces.
This CL introduces a complete Tracing Controller system for V8.
It is fully function except that it does not yet store trace event args.
This CL has a few components,
The tracing controller itself, contributed by the author of this CL
The Trace config (including the parser), contributed by lpy@
The Trace Object, Trace Writer, and Trace Buffer are all contributed by rksang@
BUG=v8:4561
LOG=N
Review-Url: https://codereview.chromium.org/2137013006
Cr-Commit-Position: refs/heads/master@{#38073}
