Semaphore class

Semaphore with async api

Signature:

export declare class Semaphore 

Example

const sem = new Semaphore(5) const release = await sem.acquire() // do something release()

Constructor	Modifiers	Description
(constructor)(permits)		constructs a new Semaphore with n permits

Property	Type	Description
frozen?	Future<void>	(Optional) check if semaphore is frozen (non-undefined value), other uses are not guaranteed
isEmpty	boolean	Check if no task is using the semaphore' always return `true` if `permits = 0`
isFull	boolean	Check if all permits are being used always return `true` if `permits = 0`
permits	number	Get the number of total permits currently
remain	number	Get the number of remaining permits

Method	Modifiers	Description
acquire(timeout)		Acquire a permit, resolve when resouce is available.
freeze()		Freeze this semaphore, calling `acquire` won't resolve and `tryAcquire` will throw (release can still be called). NOTE: don't call this again if Semaphore.frozen, not supported yet
grant(permits)		Give n permits to the semaphore, will immediately start this number of waiting tasks if not frozen
revoke(permits)		Destroy n permits, effective until `remain` fills the n permits note: you may need to check if `permits > semaphore.permits`, or it will wait until granted that many permits
schedule(fn)		Schedule a task to run when a permit is available and automatically release after run.
tryAcquire()		Try to synchronosly acquire if there's remaining permits
unfreeze()		unfreeze this semaphore, it is synchronos and the returned value should be ignored