From 24da853729d1f02a8c8a3aec1f0c992e00b5ca3f Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Tue, 31 May 2016 17:36:07 +0200 Subject: erts: Fix possible race in poller wakeup on windows Similar bug that was fixed for unix in 7bbb207b30360c60fb99653. --- erts/emulator/sys/win32/erl_poll.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'erts') diff --git a/erts/emulator/sys/win32/erl_poll.c b/erts/emulator/sys/win32/erl_poll.c index 94f3840b5f..f23c7ab03d 100644 --- a/erts/emulator/sys/win32/erl_poll.c +++ b/erts/emulator/sys/win32/erl_poll.c @@ -424,7 +424,7 @@ static ERTS_INLINE int wakeup_cause(ErtsPollSet ps) { int res; - erts_aint32_t wakeup_state = erts_atomic32_read_nob(&ps->wakeup_state); + erts_aint32_t wakeup_state = erts_atomic32_read_acqb(&ps->wakeup_state); switch (wakeup_state) { case ERTS_POLL_WOKEN_IO_READY: res = 0; @@ -487,9 +487,8 @@ wake_poller(ErtsPollSet ps, int io_ready) { erts_aint32_t wakeup_state; if (io_ready) { - /* We may set the event multiple times. This is, however, harmless. */ - wakeup_state = erts_atomic32_read_nob(&ps->wakeup_state); - erts_atomic32_set_relb(&ps->wakeup_state, ERTS_POLL_WOKEN_IO_READY); + wakeup_state = erts_atomic32_xchg_relb(&ps->wakeup_state, + ERTS_POLL_WOKEN_IO_READY); } else { ERTS_THR_MEMORY_BARRIER; -- cgit v1.2.3