diff options
Diffstat (limited to 'node_modules/asap/asap.js')
-rw-r--r-- | node_modules/asap/asap.js | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/node_modules/asap/asap.js b/node_modules/asap/asap.js new file mode 100644 index 000000000..f04fcd58f --- /dev/null +++ b/node_modules/asap/asap.js @@ -0,0 +1,65 @@ +"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); + } +}; + |