50 lines
1.7 KiB
JavaScript
50 lines
1.7 KiB
JavaScript
/* eslint-disable no-console */
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const setTimeoutPromise = require('util').promisify(setTimeout);
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const {isMainThread, parentPort} = require('bthreads');
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let shutdown = false;
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if (!isMainThread) {
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parentPort.on('message', (message) => {
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console.log(`parent message received: ${message}`);
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// 'cancel' event is triggered when job has to to terminated before it finishes execution
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// usually it would come in when SIGINT signal is sent to a parent process
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if (message === 'cancel') {
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shutdown = true;
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}
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});
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}
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(async () => {
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console.log('started graceful job');
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for (;;) {
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await setTimeoutPromise(1000);
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console.log('worked for 1000 ms');
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if (shutdown) {
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console.log('exiting gracefully');
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await setTimeoutPromise(100); // async cleanup imitation
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if (parentPort) {
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// `done' is a preferred method of shutting down the worker
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// it signals job manager about finished job and the thread
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// is later terminated through `terminate()` method allowing
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// for unfinished pipes to flush (e.g. loggers)
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//
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// 'cancelled' is an allternative method to signal job was terminated
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// because of parent initiated reason (e.g.: parent process interuption)
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// differs from 'done' by producing different
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// logging - shows the job was cancelled instead of completing
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parentPort.postMessage('done');
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// parentPort.postMessage('cancelled');
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} else {
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process.exit(0);
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}
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}
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}
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})();
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