Messages in this thread | | | From | Stijn Devriendt <> | Subject | [RFC][PATCH] sched_wait_block: wait for blocked threads | Date | Sun, 15 Nov 2009 20:04:18 +0100 |
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Hi Ingo, Peter, all,
The attached patch is a prototype for a new system call which allows threads to wait for other threads being blocked.
Its main use is to allow threading libraries to resume executing more CPU-bound work when one of its threads is blocked while not having to over-allocating threads in a normal situation.
Benefit over asynchronous I/O is that a threadpool thread that performs asynchronous I/O might not have work enough in one item to keep the CPU busy during the whole asynchronous operation and that not all operations are async capable. Giving control back to the library through a thread waiting for the blocked one allows new workitems to be executed as long as the former is blocked.
Code performing this wait could look like: pid_t parent = ...; while (waitpid(parent, NULL, WNOHANG) != 0) { if (sched_wait_block(parent, NULL) == 0) { // do work, possibly notify threadpool manager // to start another thread blocked on this one // first } }
Any feedback on the concept is much appreciated.
Regards, Stijn Devriendt
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