From 17c838402c6d71aef041548ad36ee66db6f24a56 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Thu, 11 Aug 2016 15:45:05 +0200 Subject: Fix race causing lost wakeup on receive-after timeout --- erts/emulator/beam/beam_emu.c | 5 ++++- erts/emulator/beam/erl_hl_timer.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index 8b409e139b..17df14acfe 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -2166,7 +2166,10 @@ void process_main(void) c_p->i = (BeamInstr *) Arg(0); /* L1 */ SWAPOUT; c_p->arity = 0; - erts_smp_atomic32_read_band_relb(&c_p->state, ~ERTS_PSFLG_ACTIVE); + + if (!ERTS_PTMR_IS_TIMED_OUT(c_p)) + erts_smp_atomic32_read_band_relb(&c_p->state, + ~ERTS_PSFLG_ACTIVE); ASSERT(!ERTS_PROC_IS_EXITING(c_p)); erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE); c_p->current = NULL; diff --git a/erts/emulator/beam/erl_hl_timer.c b/erts/emulator/beam/erl_hl_timer.c index 51a0d68247..96bb5ac9fa 100644 --- a/erts/emulator/beam/erl_hl_timer.c +++ b/erts/emulator/beam/erl_hl_timer.c @@ -735,7 +735,10 @@ proc_timeout_common(Process *proc, void *tmr) if (tmr == (void *) erts_smp_atomic_cmpxchg_mb(&proc->common.timer, ERTS_PTMR_TIMEDOUT, (erts_aint_t) tmr)) { - erts_aint32_t state = erts_smp_atomic32_read_acqb(&proc->state); + erts_aint32_t state; + erts_smp_proc_lock(proc, ERTS_PROC_LOCKS_MSG_RECEIVE); + state = erts_smp_atomic32_read_acqb(&proc->state); + erts_smp_proc_unlock(proc, ERTS_PROC_LOCKS_MSG_RECEIVE); if (!(state & (ERTS_PSFLG_ACTIVE|ERTS_PSFLG_EXITING))) erts_schedule_process(proc, state, 0); return 1; -- cgit v1.2.1