Funnel a function's invocations into a queue or guard them with a nonblocking mutex.
Forces a function's calls into a queue, causing them to execute sequentially.
Example:
var queuedFn = fnl.queued(function(release, a, doRelease) {
console.log("value:", a);
if (doRelease) {
console.log("I will release.");
setTimeout(release, 100);
} else {
console.log("I will not release; I will time out");
}
}, { timeout: 100 });
queuedFn(1, true);
queuedFn(2, true);
queuedFn(3, true);
queuedFn(4, false);
console.log("Done queueing calls");
Sample output:
value: 1
I will release.
Done queueing calls
value: 2
I will release.
value: 3
I will release.
value: 4
I will not release; I will time out
Wraps the provided function in a limited-lifespan, nonblocking mutex, preventing
reentry into the function until the provided release callback is called.
Example:
var noReentry = fnl.locked(function(release, a, b, c) {
db.find('foo', function(result) {
process(result); // Assume this call is synchronous
release(); // Release the mutex here
}, release); // We provide `release` as an error callback to `find`,
// so that the lock will be released even if the find
// fails
}, 5000); // Finally, if all else fails, the lock will be
// released in 5 seconds no matter what.
- support custom release/timeout functions
- optionally raise an exception when lock cannot be obtained