The devtools frontend used this to set a lower interval (100us). Now the
frontend will stop setting this category and we will always profile
with 100us (which was already the default).
Bug: chromium:1082220
Change-Id: Iaa671d9750ad4c13b95c2c1ba1e433a1077c858a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2198989
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67805}
This patch replaces V8's tracing implementation (i.e., the TRACE_EVENT
macros) with the track event base implementation from Perfetto. The
advantages of doing this are:
1) This allows us to remove most tracing-related backend code from V8.
2) V8 can start writing strongly typed trace event arguments, which
are more compact, easier to process and more extensible than legacy
JSON-based trace arguments.
For the time being, we still support the old trace macros when V8 is
embedded into Chrome and other embedders.
Design doc: https://docs.google.com/document/d/1f7tt4cb-JcA5bQFR1oXk60ncJPpkL02_Hi_Bc6MfTQk/edit#heading=h.398p6b4eaen2
Bug: chromium:1006766
Change-Id: Ie71474fbe065821772b13d851487ebbca680c4ae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1947688
Commit-Queue: Sami Kyöstilä <skyostil@chromium.org>
Auto-Submit: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67217}
Since we switched to C++14 now, we can use {std::make_unique} instead
of our own {base::make_unique} from {template-utils.h}.
R=mstarzinger@chromium.org, yangguo@chromium.org
Bug: v8:9687
No-Try: true
Change-Id: I660eb30038bbb079cee93c7861cd87ccd134f01b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1789300
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63642}
This is a reland of 096d9c5663
Fixed DEPS files which were not caught by presubmit trybot
Original change's description:
> [tracing] Roll perfetto @ 28b633cd
>
> This catches up with [1] that make the proto include path
> relative to the project root rather than ./protos/
>
> [1] https://android-review.googlesource.com/c/platform/external/perfetto/+/1108421
>
> Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
> Bug: v8:8339
> Change-Id: I1f2dec93120142ea61cee864e4bf76a6947d958d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1776088
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Tamer Tas <tmrts@chromium.org>
> Commit-Queue: Primiano Tucci <primiano@chromium.org>
> Auto-Submit: Primiano Tucci <primiano@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63584}
Bug: v8:8339
Change-Id: I70e8b2d4520c620d02d5251d14bd61b90fb1d73f
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1789143
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63598}
This catches up with [1] that make the proto include path
relative to the project root rather than ./protos/
[1] https://android-review.googlesource.com/c/platform/external/perfetto/+/1108421
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I1f2dec93120142ea61cee864e4bf76a6947d958d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1776088
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Primiano Tucci <primiano@chromium.org>
Auto-Submit: Primiano Tucci <primiano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63584}
Update the TracingCpuProfiler test to work properly with perfetto.
Roll perfetto to get fixes for bugs encountered with starting/stopping
tracing rapidly, which happens in the test for the tracing profiler.
Add a check that the DataSource::Register call was successful to flush
out any errors there (although they are fixed by the perfetto roll).
Emit a fake trace event when stopping tracing in order to avoid
losing the final trace event that the user provided. Remove the ad-hoc
fake final trace events that the cctests for perfetto added.
Add a test StartAndStopRepeated which flushes out the issues fixed by
the perfetto roll.
TBR=yangguo@chromium.org
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I042d7385486bf42c86f1631406974693868a477f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1731006
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63083}
Previously both tracing implementations would be run side-by-side when
perfetto was enabled with the V8_USE_PERFETTO build flag. This CL
makes them run separately.
Both implementations now use the trace file provided by the user in D8
or the default v8_trace.json.
Add tests for perfetto events (which must be tested differently
due to the proto output format).
Drive-by fix: Fix pass-by non-const ref in GetJSONStrings.
Remove the TraceEvent struct for testing; we can just store a copy of
the protobuf directly.
Bug: v8:8339
Change-Id: Id50003e0f96e44b99a63a26693da6bdaca989504
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1702619
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62810}
The client API provides a much simpler interface so that we don't have
to deal with producers, consumers etc. directly. This CL removes all the
code that dealt with the more complex API used previously.
The architecture used here requires that the embedder call into
Tracing::Initialize() to set up the tracing backend. The tracing
controller then connects to this backend when calling
DataSource::Register() and Tracing::NewTrace(). This will ultimately
avoid the need for a virtual call (or two) for every trace event that
need to be dispatched over the API - chrome can provide a backend
and V8 will connect to it opaquely with the same code when tracing is
enabled.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I6b74fbb49ffcc89638caeb59ed3d5cc81238f3e8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1634916
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62568}
Cpplint usually checks for non-const reference arguments. They are
forbidden in the style guide, and v8 does not explicitly make an
exception here.
This CL re-enables that warning, and fixes all current violations by
adding an explicit "NOLINT(runtime/references)" comment. In follow-up
CLs, we should aim to remove as many of them as possible.
TBR=mlippautz@chromium.org
Bug: v8:9429
Change-Id: If7054d0b366138b731972ed5d4e304b5ac8423bb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1687891
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62551}
Add test harness so that we can avoid all this boilerplate for common
tests in the future. Use it for the existing perfetto tracing test.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: Iddc716aade3eef2431bcc7eaa8b8b6502edaaa00
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1631418
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61857}
Add a new abstract class TraceEventListener which is just an interface
for consuming trace events. This separates the V8-specific stuff that
an actual perfetto consumer needs to do e.g. handling the has_more flag
and signalling back to the controller with a semaphore.
This is a change from the previous plan of making the PerfettoConsumer
class sub-classable to implement custom consumption of trace events.
This will be difficult when the consumer is created outside of the
PerfettoTracingController as we can't hook up the
consumer_finished_semaphore_ that belongs to the controller.
Now the PerfettoTracingController is responsible for the Consumer life-
cycle and hides it entirely from callers. We add the
AddTraceEventListener() method to allow callers to register a listener
either for testing or a JSON listener for real tracing.
This lets us write tests that can store all the trace events in memory
without first converting them to JSON, letting us write test more
easily. There's an example test add to test-tracing - more tests using
this style will follow.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I2d2b0f408b1c7bed954144163e1968f40d772c1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628789
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Auto-Submit: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61854}
I accidentally broke this with the last CL because the FYI bot does not
block landing.
Add initialization of perfetto when building with perfetto enabled.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I10378b72bff731fac6caa75df37a355df4b804dc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627345
Auto-Submit: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61783}
This reverts commit a03ed62679.
Reason for revert: Fails on win32: https://ci.chromium.org/p/v8/builders/ci/V8%20Win32/21252
Original change's description:
> [tracing] Add a configurable output stream for perfetto tracing
>
> Add the ability to provide perfetto with an output stream for the JSON
> consumer rather than hardcode it. D8 will use this interface exclusively
> once the old trace controller is removed.
>
> Also add a test for scope-managed trace events and their duration - this
> was leftover from a previous CL.
>
> Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
> Bug: v8:8339
> Change-Id: I1c45e17e528b549a4cfdaecabd33c7ac4ab4af77
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611801
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61753}
TBR=ulan@chromium.org,yangguo@chromium.org,jgruber@chromium.org,petermarshall@chromium.org
Change-Id: Ie7dbe4fc5f9e496fafc8e3ad2b05011b88c9e2c3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8339
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1625465
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61754}
Add the ability to provide perfetto with an output stream for the JSON
consumer rather than hardcode it. D8 will use this interface exclusively
once the old trace controller is removed.
Also add a test for scope-managed trace events and their duration - this
was leftover from a previous CL.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I1c45e17e528b549a4cfdaecabd33c7ac4ab4af77
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611801
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61753}
COMPLETE events are being deprecated and don't work well with perfetto
because we can't give out a handle into the buffer like we used to so
that the caller can update the existing event with the duration.
BEGIN/END pairs should be used instead to add two separate trace events
to the buffer which can be associated with one another by the trace
processor e.g. the trace viewer UI.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: Ib73c19d77ad58456ce23d15f0b658c26f3dc3d53
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1615257
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61641}
The TraceObject passed to AppendTraceEvent can be completely
uninitialized (set to all 0s) in some situations where a flush happens
between creation and initialization of the TraceObject.
Fix the MockTraceWriter in test-tracing to expect nullptr strings for
the name of the object so that it does not try to construct an
std::string from a null char*.
Bug: v8:9214
Change-Id: Ib4f3b039ab98d5d786991134cb71ecc62f127179
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1598751
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Auto-Submit: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61265}
Based on Primiano's prototype:
https://chromium-review.googlesource.com/c/v8/v8/+/1290549
This is still behind a build flag. I'll add functionality incrementally
rather than land everything in one giant CL.
This CL sets up the basic classes that will be used for the Perfetto
implementation, e.g. the producer, consumer, controller and task runner.
This implementation produces a binary proto file in the current
directory named v8_trace.proto. It doesn't yet produce JSON output,
that is coming in a following CL.
Currently the old tracing and perfetto tracing are both run alongside
each other if the build flag is enabled.
Cq-Include-Trybots: luci.v8.try:v8_linux64_perfetto_dbg_ng
Bug: v8:8339
Change-Id: I0eb9ecefa191ceead60aadd5b591d75c99395a6e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1408995
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61209}
The JSONTraceWriter didn't write the "flow_in", "flow_out" and "bind_id"
fields, which are necessary to support TRACE_EVENT_WITH_FLOW and
friends. This just mirrors the logic from trace_event_impl.cc in Chrome.
Bug: v8:8991
Change-Id: I496db587fbb74d3c7205bbab4c23ec41c63fa715
Document: http://bit.ly/v8-tracing-signals
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1521108
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60218}
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}
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}
With this CL, {CreateDefaultPlatform} returns a unique_ptr to indicate
that the caller owns the returned memory. We had several memory leaks
where the memory of the DefaultPlatform did not get deallocated.
In addition, the {TracingController} of the {DefaultPlatform} also gets
received as a unique_ptr. Thereby we document that the {DefaultPlatform}
takes ownership of the {TracingController}. Note that the memory of the
{TracingController} was already owned by the {DefaultPlatform}, but it
was not documented in the interface, and it was used incorrectly in
tests.
This CL fixes the asan issues in
https://chromium-review.googlesource.com/c/v8/v8/+/753583
([platform] Implement TaskRunners in the DefaultPlatform)
R=rmcilroy@chromium.org
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I0d1a6d3b22bb8289dc050b1977e4f58381cec675
Reviewed-on: https://chromium-review.googlesource.com/755033
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49349}
jasongin@ created this patch.
dcc50445a3
This patch adds the support to emit a trace event by using a comma-separated
list of categories, so that the trace event will be emitted if there is at least
one category is enabled in the categories list.
TBR=jochen@chromium.org
Review-Url: https://codereview.chromium.org/2558193002
Cr-Commit-Position: refs/heads/master@{#41567}
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}
The test now checks the case when an observer is added after tracing is started.
BUG=chromium:406277
Review-Url: https://codereview.chromium.org/2376953002
Cr-Commit-Position: refs/heads/master@{#39874}
Escape sequences may now be written to a trace file (previously,
any string with a valid escapable character would fail a check).
Also, string properties are now surrounded with quotes.
BUG=v8:4561
Review-Url: https://codereview.chromium.org/2309943005
Cr-Commit-Position: refs/heads/master@{#39319}
1. The third parameter of strncpy should be the length of source string.
2. Value contains " should be valid.
BUG=v8:4561
Review-Url: https://codereview.chromium.org/2232683002
Cr-Commit-Position: refs/heads/master@{#38563}
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}
