The static Atomics.notify()
method notifies up some agents that are sleeping in the wait queue.
Note: This operation works with a shared Int32Array
only. It will return 0
on non-shared ArrayBuffer
objects.
The static Atomics.notify()
method notifies up some agents that are sleeping in the wait queue.
Note: This operation works with a shared Int32Array
only. It will return 0
on non-shared ArrayBuffer
objects.
Atomics.notify(typedArray, index, count)
typedArray
A shared Int32Array
.
index
The position in the typedArray
to wake up on.
count
Optional
The number of sleeping agents to notify. Defaults to +Infinity
.
0
, if a non-shared ArrayBuffer
object is used.TypeError
, if typedArray
is not a Int32Array
. RangeError
, if index
is out of bounds in the typedArray
. notify
Given a shared Int32Array
:
const sab = new SharedArrayBuffer(1024); const int32 = new Int32Array(sab);
A reading thread is sleeping and waiting on location 0 which is expected to be 0. As long as that is true, it will not go on. However, once the writing thread has stored a new value, it will be notified by the writing thread and return the new value (123).
Atomics.wait(int32, 0, 0); console.log(int32[0]); // 123
A writing thread stores a new value and notifies the waiting thread once it has written:
console.log(int32[0]); // 0; Atomics.store(int32, 0, 123); Atomics.notify(int32, 0, 1);
Specification |
---|
ECMAScript Language Specification # sec-atomics.notify |
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
notify |
68
60-63
Chrome disabled
SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of
speculative side-channel attacks. This was a temporary removal while mitigations were put in place.
|
79
|
78
63
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
57
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
55-57
48-55
46-48
The
count parameter defaults to
0 instead of the later-specified
+Infinity .
|
No
|
No
|
15.2
Like
SharedArrayBuffer ,
Atomics is gated behind COOP/COEP. For more detail, read
Making your website "cross-origin isolated" using COOP and COEP.
10.1-11.1
|
60-63
Chrome disabled
SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of
speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.
|
60-63
Chrome disabled
SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of
speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.
|
63
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
57
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
55-57
48-55
46-48
The
count parameter defaults to
0 instead of the later-specified
+Infinity .
|
No
|
15.2
Like
SharedArrayBuffer ,
Atomics is gated behind COOP/COEP. For more detail, read
Making your website "cross-origin isolated" using COOP and COEP.
10.3-11.3
|
No
|
1.0
|
8.10.0
|
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/notify