1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const { Actor } = require("resource://devtools/shared/protocol.js");
const { perfSpec } = require("resource://devtools/shared/specs/perf.js");
loader.lazyRequireGetter(
this,
"RecordingUtils",
"resource://devtools/shared/performance-new/recording-utils.js"
);
// Some platforms are built without the Gecko Profiler.
const IS_SUPPORTED_PLATFORM = "nsIProfiler" in Ci;
/**
* The PerfActor wraps the Gecko Profiler interface (aka Services.profiler).
*/
exports.PerfActor = class PerfActor extends Actor {
constructor(conn) {
super(conn, perfSpec);
// Only setup the observers on a supported platform.
if (IS_SUPPORTED_PLATFORM) {
this._observer = {
observe: this._observe.bind(this),
};
Services.obs.addObserver(this._observer, "profiler-started");
Services.obs.addObserver(this._observer, "profiler-stopped");
}
}
destroy() {
super.destroy();
if (!IS_SUPPORTED_PLATFORM) {
return;
}
Services.obs.removeObserver(this._observer, "profiler-started");
Services.obs.removeObserver(this._observer, "profiler-stopped");
}
startProfiler(options) {
if (!IS_SUPPORTED_PLATFORM) {
return false;
}
// For a quick implementation, decide on some default values. These may need
// to be tweaked or made configurable as needed.
const settings = {
entries: options.entries || 1000000,
duration: options.duration || 0,
interval: options.interval || 1,
features: options.features || [
"js",
"stackwalk",
"cpu",
"responsiveness",
],
threads: options.threads || ["GeckoMain", "Compositor"],
activeTabID: RecordingUtils.getActiveBrowserID(),
};
try {
// This can throw an error if the profiler is in the wrong state.
Services.profiler.StartProfiler(
settings.entries,
settings.interval,
settings.features,
settings.threads,
settings.activeTabID,
settings.duration
);
} catch (e) {
// In case any errors get triggered, bailout with a false.
return false;
}
return true;
}
stopProfilerAndDiscardProfile() {
if (!IS_SUPPORTED_PLATFORM) {
return;
}
Services.profiler.StopProfiler();
}
/**
* @type {string} debugPath
* @type {string} breakpadId
* @returns {Promise<[number[], number[], number[]]>}
*/
async getSymbolTable(debugPath, breakpadId) {
const [addr, index, buffer] = await Services.profiler.getSymbolTable(
debugPath,
breakpadId
);
// The protocol does not support the transfer of typed arrays, so we convert
// these typed arrays to plain JS arrays of numbers now.
// Our return value type is declared as "array:array:number".
return [Array.from(addr), Array.from(index), Array.from(buffer)];
}
async getProfileAndStopProfiler() {
if (!IS_SUPPORTED_PLATFORM) {
return null;
}
// Pause profiler before we collect the profile, so that we don't capture
// more samples while the parent process or android threads wait for subprocess profiles.
Services.profiler.Pause();
let profile;
try {
// Attempt to pull out the data.
profile = await Services.profiler.getProfileDataAsync();
if (Object.keys(profile).length === 0) {
console.error(
"An empty object was received from getProfileDataAsync.getProfileDataAsync(), " +
"meaning that a profile could not successfully be serialized and captured."
);
profile = null;
}
} catch (e) {
// Explicitly set the profile to null if there as an error.
profile = null;
console.error(`There was an error fetching a profile`, e);
}
// Stop and discard the buffers.
Services.profiler.StopProfiler();
// Returns a profile when successful, and null when there is an error.
return profile;
}
isActive() {
if (!IS_SUPPORTED_PLATFORM) {
return false;
}
return Services.profiler.IsActive();
}
isSupportedPlatform() {
return IS_SUPPORTED_PLATFORM;
}
/**
* Watch for events that happen within the browser. These can affect the
* current availability and state of the Gecko Profiler.
*/
_observe(subject, topic, _data) {
// Note! If emitting new events make sure and update the list of bridged
// events in the perf actor.
switch (topic) {
case "profiler-started":
const param = subject.QueryInterface(Ci.nsIProfilerStartParams);
this.emit(
topic,
param.entries,
param.interval,
param.features,
param.duration,
param.activeTabID
);
break;
case "profiler-stopped":
this.emit(topic);
break;
}
}
/**
* Lists the supported features of the profiler for the current browser.
* @returns {string[]}
*/
getSupportedFeatures() {
if (!IS_SUPPORTED_PLATFORM) {
return [];
}
return Services.profiler.GetFeatures();
}
};
|
