The static Atomics.sub()
method subtracts a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.
Atomics.sub()
Try it
Syntax
Atomics.sub(typedArray, index, value)
Parameters
-
typedArray
-
An integer typed array. One of
Int8Array
,Uint8Array
,Int16Array
,Uint16Array
,Int32Array
,Uint32Array
,BigInt64Array
, orBigUint64Array
. -
index
-
The position in the
typedArray
to subtract avalue
from. -
value
-
The number to subtract.
Return value
The old value at the given position (typedArray[index]
).
Exceptions
- Throws a
TypeError
, iftypedArray
is not one of the allowed integer types. - Throws a
RangeError
, ifindex
is out of bounds in thetypedArray
.
Examples
Using sub
const sab = new SharedArrayBuffer(1024); const ta = new Uint8Array(sab); ta[0] = 48; Atomics.sub(ta, 0, 12); // returns 48, the old value Atomics.load(ta, 0); // 36
Specifications
Specification |
---|
ECMAScript Language Specification # sec-atomics.sub |
Browser compatibility
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 | |
sub |
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
16-17
Support was removed to mitigate
speculative execution side-channel attacks (Windows blog).
|
78
57
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
55-57
46-55
|
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.
|
57
Support was disabled by default to mitigate
speculative execution side-channel attacks (Mozilla Security Blog).
55-57
46-55
|
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
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.
|
1.0
|
8.10.0
|
See also
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/sub