spool is a simple worker-pool for Go. Each job is a func() which is sent to the worker-pool. A worker will pick up the job from the mailbox and execute it.
First, initialize the worker-poll with a mailbox of a certain size:
pool := New(n)
defer pool.Stop()The mailbox is just a chan func(). In fact the worker-pool itself is defined as:
type WorkerPool chan func()Jobs can be sent to the worker-pool in two different manners, blocking and nonblocking. To send a job to the worker-pool and block until it's completed:
pool.Blocking(ctx, func() {
// ...
})And to send a job to the worker-pool and then move on:
pool.SemiBlocking(ctx, func() {
// ...
})As long as there is an empty space in the mailbox, SemiBlocking will just queue the job, and moves on. When there are no more empty spaces in the mailbox, SemiBlocking becomes blocking.
A worker-pool by default has no workers and they should be added explicitly. To add workers to the worker-pool:
pool.Grow(ctx, 10)Now, the worker-pool has 10 workers.
It's possible to add temporary workers to the worker-pool:
pool.Grow(ctx, 9, WithAbsoluteTimeout(time.Minute * 5))Also, instead of using and absolute timeout, an idle timeout can be used. In this case, added workers will stop, if they are idle for a certain duration:
pool.Grow(ctx, 9, WithIdleTimeout(time.Minute * 5))The Blocking and SemiBlocking methods will panic if the worker-pool is stopped - to enforce visibility on job execution.
TODO