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| author | Sylvain Henry <sylvain@haskus.fr> | 2021-07-21 11:18:14 +0200 |
|---|---|---|
| committer | Zubin Duggal <zubin.duggal@gmail.com> | 2021-09-21 22:28:28 +0530 |
| commit | 48cdaaefc3247b90eaf8d9dbecf1aef1cc2ababf (patch) | |
| tree | cf82a61403eb46c2322ec1dd9535f85927958c65 | |
| parent | b6345f562d70ed7045ebd4e736aec23461dc238e (diff) | |
| download | haskell-48cdaaefc3247b90eaf8d9dbecf1aef1cc2ababf.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.
(cherry picked from commit d99e76ad3600b4c5051da6923fb7454346ed0b7b)
| -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; |