diff options
author | Sylvain Henry <sylvain@haskus.fr> | 2021-07-21 11:18:14 +0200 |
---|---|---|
committer | Ben Gamari <ben@smart-cactus.org> | 2021-08-04 13:03:39 -0400 |
commit | d99e76ad3600b4c5051da6923fb7454346ed0b7b (patch) | |
tree | 2fff26d39551f73dcbc9705b4c9f18b0e2305b74 | |
parent | e0aa6de799463d0868da7e8a5ad29141141e7855 (diff) | |
download | haskell-d99e76ad3600b4c5051da6923fb7454346ed0b7b.tar.gz |
RTS: try to fix timer races
* Pthread based timer was initialized started while some other parts of
the RTS assume it is initialized stopped, e.g. in hs_init_ghc:
/* Start the "ticker" and profiling timer but don't start until the
* scheduler is up. However, the ticker itself needs to be initialized
* before the scheduler to ensure that the ticker mutex is initialized as
* moreCapabilities will attempt to acquire it.
*/
* after a fork, don't start the timer before the IOManager is
initialized: the timer handler (handle_tick) might call wakeUpRts to
perform an idle GC, which calls wakeupIOManager/ioManagerWakeup
Found while debugging #18033/#20132 but I couldn't confirm if it fixes
them.
-rw-r--r-- | rts/Schedule.c | 5 | ||||
-rw-r--r-- | rts/posix/itimer/Pthread.c | 2 |
2 files changed, 5 insertions, 2 deletions
diff --git a/rts/Schedule.c b/rts/Schedule.c index 5722181f59..ae6b30917c 100644 --- a/rts/Schedule.c +++ b/rts/Schedule.c @@ -2196,7 +2196,6 @@ forkProcess(HsStablePtr *entry // On Unix, all timers are reset in the child, so we need to start // the timer again. initTimer(); - startTimer(); // TODO: need to trace various other things in the child // like startup event, capabilities, process info etc @@ -2206,6 +2205,10 @@ forkProcess(HsStablePtr *entry ioManagerStartCap(&cap); #endif + // start timer after the IOManager is initialized + // (the idle GC may wake up the IOManager) + startTimer(); + // Install toplevel exception handlers, so interruption // signal will be sent to the main thread. // See #12903 diff --git a/rts/posix/itimer/Pthread.c b/rts/posix/itimer/Pthread.c index 7b968f28f0..71a8622181 100644 --- a/rts/posix/itimer/Pthread.c +++ b/rts/posix/itimer/Pthread.c @@ -169,7 +169,7 @@ void initTicker (Time interval, TickProc handle_tick) { itimer_interval = interval; - stopped = false; + stopped = true; exited = false; #if defined(HAVE_SIGNAL_H) sigset_t mask, omask; |