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
|
'use strict';
const trace_events = process.binding('trace_events');
const async_wrap = process.binding('async_wrap');
const async_hooks = require('async_hooks');
// Use small letters such that chrome://traceing groups by the name.
// The behavior is not only useful but the same as the events emitted using
// the specific C++ macros.
const BEFORE_EVENT = 'b'.charCodeAt(0);
const END_EVENT = 'e'.charCodeAt(0);
// In trace_events it is not only the id but also the name that needs to be
// repeated. Since async_hooks doesn't expose the provider type in the
// non-init events, use a map to manually map the asyncId to the type name.
const typeMemory = new Map();
// It is faster to emit trace_events directly from C++. Thus, this happens in
// async_wrap.cc. However, events emitted from the JavaScript API or the
// Embedder C++ API can't be emitted from async_wrap.cc. Thus they are
// emitted using the JavaScript API. To prevent emitting the same event
// twice the async_wrap.Providers list is used to filter the events.
const nativeProviders = new Set(Object.keys(async_wrap.Providers));
const hook = async_hooks.createHook({
init(asyncId, type, triggerAsyncId, resource) {
if (nativeProviders.has(type)) return;
typeMemory.set(asyncId, type);
trace_events.emit(BEFORE_EVENT, 'node.async_hooks',
type, asyncId,
'triggerAsyncId', triggerAsyncId,
'executionAsyncId', async_hooks.executionAsyncId());
},
before(asyncId) {
const type = typeMemory.get(asyncId);
if (type === undefined) return;
trace_events.emit(BEFORE_EVENT, 'node.async_hooks',
type + '_CALLBACK', asyncId);
},
after(asyncId) {
const type = typeMemory.get(asyncId);
if (type === undefined) return;
trace_events.emit(END_EVENT, 'node.async_hooks',
type + '_CALLBACK', asyncId);
},
destroy(asyncId) {
const type = typeMemory.get(asyncId);
if (type === undefined) return;
trace_events.emit(END_EVENT, 'node.async_hooks',
type, asyncId);
// cleanup asyncId to type map
typeMemory.delete(asyncId);
}
});
exports.setup = function() {
if (trace_events.categoryGroupEnabled('node.async_hooks')) {
hook.enable();
}
};
|
