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