"use strict";
var rawAsap = require("./raw");
var freeTasks = [];
/**
* Calls a task as soon as possible after returning, in its own event, with
* priority over IO events. An exception thrown in a task can be handled by
* `process.on("uncaughtException") or `domain.on("error")`, but will otherwise
* crash the process. If the error is handled, all subsequent tasks will
* resume.
*
* @param {{call}} task A callable object, typically a function that takes no
* arguments.
*/
module.exports = asap;
function asap(task) {
var rawTask;
if (freeTasks.length) {
rawTask = freeTasks.pop();
} else {
rawTask = new RawTask();
}
rawTask.task = task;
rawTask.domain = process.domain;
rawAsap(rawTask);
}
function RawTask() {
this.task = null;
this.domain = null;
}
RawTask.prototype.call = function () {
if (this.domain) {
this.domain.enter();
}
var threw = true;
try {
this.task.call();
threw = false;
// If the task throws an exception (presumably) Node.js restores the
// domain stack for the next event.
if (this.domain) {
this.domain.exit();
}
} finally {
// We use try/finally and a threw flag to avoid messing up stack traces
// when we catch and release errors.
if (threw) {
// In Node.js, uncaught exceptions are considered fatal errors.
// Re-throw them to interrupt flushing!
// Ensure that flushing continues if an uncaught exception is
// suppressed listening process.on("uncaughtException") or
// domain.on("error").
rawAsap.requestFlush();
}
// If the task threw an error, we do not want to exit the domain here.
// Exiting the domain would prevent the domain from catching the error.
this.task = null;
this.domain = null;
freeTasks.push(this);
}
};
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