SharedArrayBuffer.sharedArrayBuffer
Note that SharedArrayBuffer
was disabled by default in all major browsers on 5 January, 2018 in response to Spectre. Chrome re-enabled it in v67 on platforms where its site-isolation feature is enabled to protect against Spectre-style vulnerabilities.
The SharedArrayBuffer()
is used to create a SharedArrayBuffer
object representing a generic, fixed-length raw binary data buffer, similar to the ArrayBuffer
object.
Syntax
new SharedArrayBuffer([length])
Parameters
length
- The size, in bytes, of the array buffer to create.
Return value
A new SharedArrayBuffer
object of the specified size. Its contents are initialized to 0.
Examples
Always use the new operator to create a SharedArrayBuffer
SharedArrayBuffer
constructors are required to be constructed with a new
operator. Calling a SharedArrayBuffer
constructor as a function without new
will throw a TypeError
.
var sab = SharedArrayBuffer(1024);
// TypeError: calling a builtin SharedArrayBuffer constructor
// without new is forbidden
var sab = new SharedArrayBuffer(1024);
Specifications
|
Desktop |
|
Chrome |
Edge |
Firefox |
Internet Explorer |
Opera |
Safari |
SharedArrayBuffer() constructor |
68
- 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
|
79
- 79
- 57
Disabled
- Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog).
- Disabled From version 57: this feature is behind the
javascript.options.shared_memory preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
- 55 — 57
- 46 — 55
Disabled
- Disabled From version 46 until version 55 (exclusive): this feature is behind the
javascript.options.shared_memory preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
|
No |
No |
10.1 — 11 |
|
Mobile |
|
Android webview |
Chrome for Android |
Firefox for Android |
Opera for Android |
Safari on iOS |
Samsung Internet |
SharedArrayBuffer() constructor |
60 — 63
- 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
- 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.
|
79
- 79
- 57
Disabled
- Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog).
- Disabled From version 57: this feature is behind the
javascript.options.shared_memory preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
- 55 — 57
- 46 — 55
Disabled
- Disabled From version 46 until version 55 (exclusive): this feature is behind the
javascript.options.shared_memory preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
|
No |
10.3 — 11 |
No
- 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.
|
|
Server |
|
Node.js |
SharedArrayBuffer() constructor |
8.10.0 |
See also