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Sara Tang 8b33c87239 Step 1 (of 3-ish): Basic ETW Instrumentation in V8
Design doc:
https://docs.google.com/document/d/1xkXj94iExFgLWc_OszTNyNGi523ARaKMWPZTeomhI4U
A lot has changed since the last patchset! I recommend revisiting this
design doc and reading the parts in green. I explain the roadmap for
what changes to expect from ETW instrumentation as well as the
instrumentation of this particular CL.

I'll do my best to answer any further questions anyone has about my
particular instrumentation or ETW in general :)

---

This is the first of a series of changelists to round out ETW
instrumentation for V8.

This changelist represents the most minimal change needed to instrument
ETW in V8. In particular, it:
  - defines and registers the ETW provider,
  - interacts minimally with the rest of V8, by hooking into the
    existing TracingController::AddTraceEvent function,
  - is designed with a platform-agnostic layer, so that event tracers
    for other platforms can be instrumented in teh future.

Some notes on instrumentation (aka I copied stuff from the design doc):

We make heavy use of the TraceLogging API to log events. It differs from
previous methods of emitting ETW events in that it doesn<E2><80><99>t
require the overhead of a separate manifest file to keep track of
metadata; rather, events using this API are self-descriptive.

Here are the five major steps to instrument the TraceLogging API:
  - Forward declare the provider (from provider-win.h)
  - Define the provider in a .cc file (from provider-win.cc)
  - Register the provider (called from v8.cc).
  - Write events (called from libplatform/tracing-controller.cc)
  - Unregister the provider (called from v8.cc)

At the base, we have an abstract provider class that encapsulates the
functionality of an event provider. These are things like registering
and unregistering the provider, and the actual event-logging.

The provider class is split into provider-win and provider-mac
(currently not instantiated) classes, with OS-dependent implementations
of the above functions.

In particular, the TraceLogging API is used only in provider-win. It is
here that we forward declare and define the provider, as well as write
ETW events.

Finally, there is a v8-provider class that serves as a top-level API and
is exposed to the rest of V8. It acts as a wrapper for the
platform-specific providers.

The .wprp file is needed so that Windows Performance Recorder knows how
to capture our events.

Some considerations:
  - Is TracingController::AddTraceEvent the best place from which to
    write my events?
  - Is src/libplatform/tracing the best place to put my instrumentation?
  - Right now, I fail the preupload because of this, which tells me my
    files are probably not in the best location:

You added one or more #includes that violate checkdeps rules.
src\init\v8.cc Illegal include: "src/libplatform/tracing/v8-provider.h"
Because of "-src/libplatform" from src's include_rules.

Change-Id: Id53e4a034c9e526524a17000da0a647a95d93edf
Bug: v8:11043
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2233407
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Sara Tang <sartang@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#71918}
2021-01-05 20:11:03 +00:00
build_overrides tracing: Enable using Perfetto client library from Chromium 2020-05-11 11:17:57 +00:00
custom_deps Use relative paths to OWNERS files 2019-08-12 13:52:52 +00:00
docs Add OWNERS for docs/ 2019-05-15 12:06:15 +00:00
gni cppgc: Fix cppgc build 2020-11-24 09:35:50 +00:00
include Step 1 (of 3-ish): Basic ETW Instrumentation in V8 2021-01-05 20:11:03 +00:00
infra Add official builder for mac-arm64 release and debug 2020-12-16 13:02:24 +00:00
samples [api] Use shorter 8::Local::As<*> casts in more places 2020-11-28 11:04:26 +00:00
src Step 1 (of 3-ish): Basic ETW Instrumentation in V8 2021-01-05 20:11:03 +00:00
test [logging] Fix expected death message in official builds 2021-01-05 13:37:28 +00:00
testing build: Remove no-op calls to set_sources_assignment_filter 2020-10-08 14:44:01 +00:00
third_party Roll inspector_protocol to 94298cef795ec994106bdaff002c41182911b767 2020-12-09 11:17:27 +00:00
tools Step 1 (of 3-ish): Basic ETW Instrumentation in V8 2021-01-05 20:11:03 +00:00
.clang-format [clang-format] Don't derive pointer alignment 2017-01-17 09:28:19 +00:00
.clang-tidy [tool] Remove unfixed clang-tidy warnings to ease use. 2018-10-26 07:40:32 +00:00
.editorconfig Add .editorconfig 2017-07-28 13:39:24 +00:00
.flake8 Add .flake8 to allow for python style checking. 2019-07-19 21:44:03 +00:00
.git-blame-ignore-revs [infra] Update .git-blame-ignore-revs 2020-03-03 12:59:13 +00:00
.gitattributes .gitattributes: Mark minified emscripten js files as -diff 2018-09-19 16:27:10 +00:00
.gitignore [cleanup] Add .cache to .gitignore 2020-12-16 10:37:28 +00:00
.gn [build] Dynamically decide if to use system xcode 2019-07-29 08:20:24 +00:00
.vpython [tools] Implement confidence-based number of runs 2019-05-09 09:42:28 +00:00
.ycm_extra_conf.py Fix ycm config for headers without source 2019-12-09 11:59:21 +00:00
AUTHORS Remove duplicate AUTHORS entry 2020-12-08 13:49:34 +00:00
BUILD.gn Step 1 (of 3-ish): Basic ETW Instrumentation in V8 2021-01-05 20:11:03 +00:00
CODE_OF_CONDUCT.md Explicitly state that the Chromium Code of Conduct also applies to V8 2016-03-02 09:51:24 +00:00
codereview.settings Make Gerrit the default code review for V8 2017-06-30 17:37:37 +00:00
COMMON_OWNERS Adding vahl@ to the common owners to be able to handle 2020-08-21 09:04:56 +00:00
DEPS Update V8 DEPS. 2021-01-05 03:48:17 +00:00
DIR_METADATA Add DIR_METADATA files to v8. 2020-10-20 22:12:28 +00:00
ENG_REVIEW_OWNERS Add eng review owners as escalation path 2019-05-15 19:12:10 +00:00
INFRA_OWNERS Add team members as owners 2020-08-18 08:29:04 +00:00
INTL_OWNERS add ftang as owner 2020-04-24 19:19:36 +00:00
LICENSE [wasm] Draft version of C/C++ Wasm API 2019-04-17 16:00:26 +00:00
LICENSE.fdlibm Add LICENSE.fdlibm for all the fdlibm imported sources. 2016-06-09 07:17:03 +00:00
LICENSE.strongtalk Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.v8 Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
MIPS_OWNERS [mips] Request to be an owner of MIPS files 2020-11-23 09:43:49 +00:00
OWNERS Add DIR_METADATA files to v8. 2020-10-20 22:12:28 +00:00
PPC_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
PRESUBMIT.py [tools] Format JS files in system-analyzer/ if they're unformatted 2020-11-10 11:02:32 +00:00
README.md [docs] Change links from old wiki to v8.dev 2019-03-07 12:13:30 +00:00
S390_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
WATCHLISTS Stop watching for API changes in WATCHLISTS 2020-04-08 07:06:45 +00:00

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://v8.dev/docs

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*

Contributing

Please follow the instructions mentioned at v8.dev/docs/contribute.