| created | 2020-01-21T20:43:55Z |
|---|---|
| begin | 2019-12-12T15:55:36Z |
| end | 2019-12-12T16:31:06Z |
| path | src/sys |
| commits | 1 |
| date | 2019-12-12T16:31:06Z | |||
|---|---|---|---|---|
| author | visa | |||
| files | src/sys/kern/kern_event.c | log | diff | annotate |
| src/sys/sys/event.h | log | diff | annotate | |
| message |
Allow sleeping inside kqueue event filters. In kqueue_scan(), threads have to get an exclusive access to a knote before processing by calling knote_acquire(). This prevents the knote from being destroyed while it is still in use. knote_acquire() also blocks other threads from processing the knote. Once knote processing has finished, the thread has to call knote_release(). The kqueue subsystem is still serialized by the kernel lock. If an event filter sleeps, the kernel lock is released and another thread might enter kqueue_scan(). kqueue_scan() uses start and end markers to keep track of the scan's progress and it has to be aware of other threads' markers. This patch is a revised version of mpi@'s work derived from DragonFly BSD. kqueue_check() has been adapted from NetBSD. Tested by anton@, sashan@ OK mpi@, anton@, sashan@ |
|||