Module Mwt

make ~init ~at_exit num_threads creates a new pool of num_threads preemptive threads. If no special per-thread state is required you can pass noop to init and at_exit. The returned promise will resolve once all num_threads calls to init have completed. If any instance of init raises an exception then the resulting promise will resolve to the same exception.

• Parameter init: is run from within each newly created thread in the pool. Its return value defines the initial state of the newly initialized thread.
• Parameter at_exit: is run within each thread in the pool immediately before that thread exits. Its argument is the state of the exiting thread.
• Raises Invalid_argument: if num_threads < 1.

noop may be passed to the init and at_exit parameters of make when no special per-thread initialization or cleanup is required. noop is fun () -> ().

run pool f will run f state in one of the preemptive threads in pool, where state carries the state of the thread f runs under. If there is a thread available in pool then the call will block until f completes. If no thread is available from pool then the call to f will be queued until a thread in pool is available.

f may use run_in_main to run code in a program's Lwt context.

close pool immediately marks pool as closed, quits all idle threads in the pool and blocks until all in-use threads have terminated. Any further uses of pool will raise Invalid_argument.

close_async pool marks pool as closed and sends a "quit" signal to all idle threads. Any threads currently in use will quit once they are done with their current task. This function does not block.

run_in_main f can be used from within a preemptive thread to run f () in the program's main Lwt context. It can be seen as a dual to run and run_thread.