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.

1 files changed, 1 insertions, 1 deletions

diff --git a/rts/posix/itimer/Pthread.c b/rts/posix/itimer/Pthread.c
index 5098d4f117..84501acb6f 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;