Atomics.wait()
The static Atomics.wait()
method verifies that a given position in an Int32Array
still contains a
given value and if so sleeps, awaiting a wakeup or a timeout. It returns a string which
is either "ok
", "not-equal
", or "timed-out
".
Note: This operation only works with a shared
Int32Array
and may not be allowed on the main thread.
Syntax
Atomics.wait(typedArray, index, value)
Atomics.wait(typedArray, index, value, timeout)
Parameters
typedArray
-
A shared
Int32Array
. index
-
The position in the
typedArray
to wait on. value
-
The expected value to test.
timeout
Optional-
Time to wait in milliseconds.
Infinity
, if no time is provided.
Return value
A string which is either "ok
", "not-equal
", or
"timed-out
".
Exceptions
-
Throws a
TypeError
, iftypedArray
is not a sharedInt32Array
. -
Throws a
RangeError
, ifindex
is out of bounds in thetypedArray
.
Examples
Using wait()
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);
Specifications
Specification |
---|
ECMAScript Language Specification # sec-atomics.wait |
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