31 lines
678 B
JavaScript
31 lines
678 B
JavaScript
class Semaphore {
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capacity;
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available;
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deferredTasks = [];
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constructor(capacity) {
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this.capacity = capacity;
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this.available = capacity;
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}
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async acquire() {
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if (this.available > 0) {
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this.available--;
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return;
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}
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return new Promise(resolve => {
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this.deferredTasks.push(resolve);
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});
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}
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release() {
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const deferredTask = this.deferredTasks.shift();
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if (deferredTask != null) {
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deferredTask();
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return;
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}
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if (this.available < this.capacity) {
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this.available++;
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}
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}
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}
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export { Semaphore };
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