feat: [contentTracing] allow calling stopTracing() with no arguments (#18411)

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Jeremy Apthorp 2019-05-28 14:15:42 -07:00 committed by GitHub
parent 1a609f0caf
commit 815b9d7707
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6 changed files with 137 additions and 62 deletions

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@ -4,6 +4,7 @@
#include <set>
#include <string>
#include <utility>
#include "atom/common/native_mate_converters/callback.h"
#include "atom/common/native_mate_converters/file_path_converter.h"
@ -12,6 +13,7 @@
#include "atom/common/promise_util.h"
#include "base/bind.h"
#include "base/files/file_util.h"
#include "base/optional.h"
#include "base/threading/thread_restrictions.h"
#include "content/public/browser/tracing_controller.h"
#include "native_mate/dictionary.h"
@ -53,36 +55,44 @@ struct Converter<base::trace_event::TraceConfig> {
namespace {
using CompletionCallback = base::RepeatingCallback<void(const base::FilePath&)>;
using CompletionCallback = base::OnceCallback<void(const base::FilePath&)>;
scoped_refptr<TracingController::TraceDataEndpoint> GetTraceDataEndpoint(
const base::FilePath& path,
const CompletionCallback& callback) {
base::FilePath result_file_path = path;
// base::CreateTemporaryFile prevents blocking so we need to allow it
// for now since offloading this to a different sequence would require
// changing the api shape
base::ThreadRestrictions::ScopedAllowIO allow_io;
if (result_file_path.empty() && !base::CreateTemporaryFile(&result_file_path))
LOG(ERROR) << "Creating temporary file failed";
return TracingController::CreateFileEndpoint(
result_file_path, base::BindRepeating(callback, result_file_path));
base::Optional<base::FilePath> CreateTemporaryFileOnIO() {
base::FilePath temp_file_path;
if (!base::CreateTemporaryFile(&temp_file_path))
return base::nullopt;
return base::make_optional(std::move(temp_file_path));
}
v8::Local<v8::Promise> StopRecording(v8::Isolate* isolate,
const base::FilePath& path) {
atom::util::Promise promise(isolate);
void StopTracing(atom::util::Promise promise,
base::Optional<base::FilePath> file_path) {
if (file_path) {
auto endpoint = TracingController::CreateFileEndpoint(
*file_path, base::AdaptCallbackForRepeating(base::BindOnce(
&atom::util::Promise::ResolvePromise<base::FilePath>,
std::move(promise), *file_path)));
TracingController::GetInstance()->StopTracing(endpoint);
} else {
promise.RejectWithErrorMessage(
"Failed to create temporary file for trace data");
}
}
v8::Local<v8::Promise> StopRecording(mate::Arguments* args) {
atom::util::Promise promise(args->isolate());
v8::Local<v8::Promise> handle = promise.GetHandle();
// TODO(zcbenz): Remove the use of CopyablePromise when the
// CreateFileEndpoint API accepts OnceCallback.
TracingController::GetInstance()->StopTracing(GetTraceDataEndpoint(
path,
base::BindRepeating(atom::util::CopyablePromise::ResolveCopyablePromise<
const base::FilePath&>,
atom::util::CopyablePromise(promise))));
base::FilePath path;
if (args->GetNext(&path) && !path.empty()) {
StopTracing(std::move(promise), base::make_optional(path));
} else {
// use a temporary file.
base::PostTaskWithTraitsAndReplyWithResult(
FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_VISIBLE},
base::BindOnce(CreateTemporaryFileOnIO),
base::BindOnce(StopTracing, std::move(promise)));
}
return handle;
}
@ -104,10 +114,15 @@ v8::Local<v8::Promise> StartTracing(
atom::util::Promise promise(isolate);
v8::Local<v8::Promise> handle = promise.GetHandle();
// Note: This method always succeeds.
TracingController::GetInstance()->StartTracing(
trace_config, base::BindOnce(atom::util::Promise::ResolveEmptyPromise,
std::move(promise)));
if (!TracingController::GetInstance()->StartTracing(
trace_config, base::BindOnce(atom::util::Promise::ResolveEmptyPromise,
std::move(promise)))) {
// If StartTracing returns false, that means it didn't invoke its callback.
// Return an already-resolved promise and abandon the previous promise (it
// was std::move()d into the StartTracing callback and has been deleted by
// this point).
return atom::util::Promise::ResolvedPromise(isolate);
}
return handle;
}

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@ -82,6 +82,21 @@ class Promise {
}
}
// Returns an already-resolved promise.
template <typename T>
static v8::Local<v8::Promise> ResolvedPromise(v8::Isolate* isolate,
T result) {
Promise resolved(isolate);
resolved.Resolve(result);
return resolved.GetHandle();
}
static v8::Local<v8::Promise> ResolvedPromise(v8::Isolate* isolate) {
Promise resolved(isolate);
resolved.Resolve();
return resolved.GetHandle();
}
v8::Local<v8::Promise> GetHandle() const;
v8::Maybe<bool> Resolve() {

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@ -1,13 +1,11 @@
# contentTracing
> Collect tracing data from Chromium's content module for finding performance
bottlenecks and slow operations.
> Collect tracing data from Chromium to find performance bottlenecks and slow operations.
Process: [Main](../glossary.md#main-process)
This module does not include a web interface so you need to open
`chrome://tracing/` in a Chrome browser and load the generated file to view the
result.
This module does not include a web interface. To view recorded traces, use
[trace viewer][], available at `chrome://tracing` in Chrome.
**Note:** You should not use this module until the `ready` event of the app
module is emitted.
@ -16,20 +14,15 @@ module is emitted.
const { app, contentTracing } = require('electron')
app.on('ready', () => {
const options = {
categoryFilter: '*',
traceOptions: 'record-until-full,enable-sampling'
}
contentTracing.startRecording(options, () => {
(async () => {
await contentTracing.startRecording({
include_categories: ['*']
})
console.log('Tracing started')
setTimeout(() => {
contentTracing.stopRecording('', (path) => {
console.log('Tracing data recorded to ' + path)
})
}, 5000)
})
await new Promise(resolve => setTimeout(resolve, 5000))
const path = await contentTracing.stopRecording()
console.log('Tracing data recorded to ' + path)
})()
})
```
@ -41,11 +34,13 @@ The `contentTracing` module has the following methods:
Returns `Promise<String[]>` - resolves with an array of category groups once all child processes have acknowledged the `getCategories` request
Get a set of category groups. The category groups can change as new code paths are reached.
Get a set of category groups. The category groups can change as new code paths
are reached. See also the [list of built-in tracing
categories](https://chromium.googlesource.com/chromium/src/+/master/base/trace_event/builtin_categories.h).
### `contentTracing.startRecording(options)`
* `options` ([TraceCategoriesAndOptions](structures/trace-categories-and-options.md) | [TraceConfig](structures/trace-config.md))
* `options` ([TraceConfig](structures/trace-config.md) | [TraceCategoriesAndOptions](structures/trace-categories-and-options.md))
Returns `Promise<void>` - resolved once all child processes have acknowledged the `startRecording` request.
@ -54,22 +49,26 @@ Start recording on all processes.
Recording begins immediately locally and asynchronously on child processes
as soon as they receive the EnableRecording request.
If a recording is already running, the promise will be immediately resolved, as
only one trace operation can be in progress at a time.
### `contentTracing.stopRecording(resultFilePath)`
* `resultFilePath` String
* `resultFilePath` String (optional)
Returns `Promise<String>` - resolves with a file that contains the traced data once all child processes have acknowledged the `stopRecording` request
Returns `Promise<String>` - resolves with a path to a file that contains the traced data once all child processes have acknowledged the `stopRecording` request
Stop recording on all processes.
Child processes typically cache trace data and only rarely flush and send
trace data back to the main process. This helps to minimize the runtime overhead
of tracing since sending trace data over IPC can be an expensive operation. So,
to end tracing, we must asynchronously ask all child processes to flush any
to end tracing, Chromium asynchronously asks all child processes to flush any
pending trace data.
Trace data will be written into `resultFilePath` if it is not empty or into a
temporary file.
Trace data will be written into `resultFilePath`. If `resultFilePath` is empty
or not provided, trace data will be written to a temporary file, and the path
will be returned in the promise.
### `contentTracing.getTraceBufferUsage()`
@ -77,3 +76,5 @@ Returns `Promise<Object>` - Resolves with an object containing the `value` and `
Get the maximum usage across processes of trace buffer as a percentage of the
full state.
[trace viewer]: https://github.com/catapult-project/catapult/blob/master/tracing

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@ -1,9 +1,51 @@
# TraceConfig Object
* `included_categories` String[] (optional)
* `excluded_categories` String[] (optional)
* `memory_dump_config` Object (optional)
* `recording_mode` String (optional) - one of "record-until-full" | "record-continuously" | "record-as-much-as-possible" | "trace-to-console". Defaults to "record-until-full".
* `trace_buffer_size_in_kb` number (optional) - maximum size of the trace
recording buffer in kilobytes. Defaults to 100MB.
* `trace_buffer_size_in_events` number (optional) - maximum size of the trace
recording buffer in events.
* `enable_argument_filter` boolean (optional) - if true, filter event data
according to a whitelist of events that have been manually vetted to not
include any PII. See [the implementation in
Chromium][trace_event_args_whitelist.cc] for specifics.
* `included_categories` String[] (optional) - a list of tracing categories to
include. Can include glob-like patterns using `*` at the end of the category
name. See [tracing categories][] for the list of categories.
* `excluded_categories` String[] (optional) - a list of tracing categories to
exclude. Can include glob-like patterns using `*` at the end of the category
name. See [tracing categories][] for the list of categories.
* `included_process_ids` number[] (optional) - a list of process IDs to
include in the trace. If not specified, trace all processes.
* `histogram_names` String[] (optional) - a list of [histogram][] names to report
with the trace.
* `memory_dump_config` Object (optional) - if the
`disabled-by-default-memory-infra` category is enabled, this contains
optional additional configuration for data callection. See the [Chromium
memory-infra docs][memory-infra docs] for more information.
See an example in the [Chromium docs][1].
An example TraceConfig that roughly matches what Chrome DevTools records:
[1]: https://chromium.googlesource.com/chromium/src/+/master/docs/memory-infra/memory_infra_startup_tracing.md#the-advanced-way
```js
{
recording_mode: 'record-until-full',
included_categories: [
'devtools.timeline',
'disabled-by-default-devtools.timeline',
'disabled-by-default-devtools.timeline.frame',
'disabled-by-default-devtools.timeline.stack',
'v8.execute',
'blink.console',
'blink.user_timing',
'latencyInfo',
'disabled-by-default-v8.cpu_profiler',
'disabled-by-default-v8.cpu_profiler.hires'
],
excluded_categories: [ '*' ]
}
```
[tracing categories]: https://chromium.googlesource.com/chromium/src/+/master/base/trace_event/builtin_categories.h
[memory-infra docs]: https://chromium.googlesource.com/chromium/src/+/master/docs/memory-infra/memory_infra_startup_tracing.md#the-advanced-way
[trace_event_args_whitelist.cc]: https://chromium.googlesource.com/chromium/src/+/master/services/tracing/public/cpp/trace_event_args_whitelist.cc
[histogram]: https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md

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@ -1,5 +1,2 @@
'use strict'
const { deprecate } = require('electron')
const contentTracing =
module.exports = process.electronBinding('content_tracing')

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@ -132,5 +132,10 @@ describe('contentTracing', () => {
const resultFilePath = await record(/* options */ {}, /* outputFilePath */ '')
expect(resultFilePath).to.be.a('string').that.is.not.empty()
})
it('creates a temporary file when no path is passed', async function () {
const resultFilePath = await record(/* options */ {}, /* outputFilePath */ undefined)
expect(resultFilePath).to.be.a('string').that.is.not.empty()
})
})
})