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Library
Module
Module type
Parameter
Class
Class type
Work-stealing thread pool.
A pool of threads with a worker-stealing scheduler. The pool contains a fixed number of threads that wait for work items to come, process these, and loop.
This is good for CPU-intensive tasks that feature a lot of small tasks. Note that tasks will not always be processed in the order they are scheduled, so this is not great for workloads where the latency of individual tasks matter (for that see Fifo_pool).
If a pool is no longer needed, shutdown can be used to signal all threads in it to stop (after they finish their work), and wait for them to stop.
The threads are distributed across a fixed domain pool (whose size is determined by Domain.recommended_domain_count on OCaml 5, and simply the single runtime on OCaml 4).
If a runner is no longer needed, shutdown can be used to signal all worker threads in it to stop (after they finish their work), and wait for them to stop.
The threads are distributed across a fixed domain pool (whose size is determined by Domain.recommended_domain_count on OCaml 5, and simple the single runtime on OCaml 4).
run_wait_block pool f schedules f for later execution on the pool, like run_async. It then blocks the current thread until f() is done executing, and returns its result. If f() raises an exception, then run_wait_block pool f will raise it as well.
NOTE be careful with deadlocks (see notes in Fut.wait_block about the required discipline to avoid deadlocks).
called at the beginning of each new thread in the pool.
parameternum_threads
size of the pool, ie. number of worker threads. It will be at least 1 internally, so 0 or negative values make no sense. The default is Domain.recommended_domain_count(), ie one worker thread per CPU core. On OCaml 4 the default is 4 (since there is only one domain).
parameteron_exit_thread
called at the end of each thread in the pool
parameteraround_task
a pair of before, after, where before pool is called before a task is processed, on the worker thread about to run it, and returns x; and after pool x is called by the same thread after the task is over. (since 0.2)
parametername
a name for this thread pool, used if tracing is enabled (since 0.6)