Atomics.waitAsync()
Atomics.waitAsync() 静态方法在共享内存位置异步等待并返回 Promise。
¥The Atomics.waitAsync() static method waits asynchronously on a shared memory location and returns a Promise.
与 Atomics.wait() 不同,waitAsync 是非阻塞的并且可在主线程上使用。
¥Unlike Atomics.wait(), waitAsync is non-blocking and usable on the main thread.
注意:此操作仅适用于查看
SharedArrayBuffer的Int32Array或BigInt64Array。¥Note: This operation only works with an
Int32ArrayorBigInt64Arraythat views aSharedArrayBuffer.
语法
参数
¥Parameters
typedArray-
查看
SharedArrayBuffer的Int32Array或BigInt64Array。 index-
在
typedArray的位置等待。 value-
要测试的期望值。
timeoutOptional-
等待时间以毫秒为单位。
NaN(以及转换为NaN的值,例如undefined)变为Infinity。负值变为0。
返回值
例外情况
¥Exceptions
TypeError-
如果
typedArray不是查看SharedArrayBuffer的Int32Array或BigInt64Array,则抛出该异常。 RangeError-
如果
index在typedArray中出界,则抛出该球。
示例
使用 waitAsync()
¥Using waitAsync()
给定一个共享的 Int32Array。
¥Given a shared Int32Array.
const sab = new SharedArrayBuffer(1024);
const int32 = new Int32Array(sab);
读取线程正在睡眠并等待位置 0,该位置预计为 0。result.value 将是一个承诺。
¥A reading thread is sleeping and waiting on location 0 which is expected to be 0.
The result.value will be a promise.
const result = Atomics.waitAsync(int32, 0, 0, 1000);
// { async: true, value: Promise {<pending>} }
在读取线程或另一个线程中,调用内存位置 0,并且可以使用 "ok" 解析 Promise。
¥In the reading thread or in another thread, the memory location 0 is called and the promise can be resolved with "ok".
Atomics.notify(int32, 0);
// { async: true, value: Promise {<fulfilled>: 'ok'} }
如果它没有解析为 "ok",则共享内存位置中的值不是预期的(value 将是 "not-equal" 而不是承诺)或已达到超时(承诺将解析为 "time-out")。
¥If it isn't resolving to "ok", the value in the shared memory location wasn't the expected (the value would be "not-equal" instead of a promise) or the timeout was reached (the promise will resolve to "time-out").
规范
| Specification |
|---|
| ECMAScript Language Specification # sec-atomics.waitasync |
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¥See also