forked from quic-issues/427e7578-d7bf-49c8-aee9-2dd999e25316
44 lines
857 B
JavaScript
44 lines
857 B
JavaScript
/**
|
|
* Mutual exclude for JavaScript.
|
|
*
|
|
* @module mutex
|
|
*/
|
|
|
|
/**
|
|
* @callback mutex
|
|
* @param {function():void} cb Only executed when this mutex is not in the current stack
|
|
* @param {function():void} [elseCb] Executed when this mutex is in the current stack
|
|
*/
|
|
|
|
/**
|
|
* Creates a mutual exclude function with the following property:
|
|
*
|
|
* ```js
|
|
* const mutex = createMutex()
|
|
* mutex(() => {
|
|
* // This function is immediately executed
|
|
* mutex(() => {
|
|
* // This function is not executed, as the mutex is already active.
|
|
* })
|
|
* })
|
|
* ```
|
|
*
|
|
* @return {mutex} A mutual exclude function
|
|
* @public
|
|
*/
|
|
export const createMutex = () => {
|
|
let token = true
|
|
return (f, g) => {
|
|
if (token) {
|
|
token = false
|
|
try {
|
|
f()
|
|
} finally {
|
|
token = true
|
|
}
|
|
} else if (g !== undefined) {
|
|
g()
|
|
}
|
|
}
|
|
}
|