From 2e5c1dbb32cfe4be0a782216953b4630338edabc Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Thu, 14 Jun 2012 15:37:23 +0200 Subject: Fix faulty use of thread progress in handle_aux_work() As an optimization old thread progress data was kept and used in handle_aux_work() in erl_process.c. This could cause memory to be deallocated at a later time than intended, which is quite harmless. This has, however, now been fixed. --- erts/emulator/beam/erl_process.c | 52 ++++++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 15 deletions(-) (limited to 'erts/emulator/beam/erl_process.c') diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c index 95d408f79d..854360f641 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -906,13 +906,13 @@ unset_aux_work_flags(ErtsSchedulerSleepInfo *ssi, erts_aint32_t flgs) #ifdef ERTS_SMP static ERTS_INLINE void -thr_prgr_current_reset(ErtsAuxWorkData *awdp) +haw_thr_prgr_current_reset(ErtsAuxWorkData *awdp) { awdp->current_thr_prgr = ERTS_THR_PRGR_INVALID; } static ERTS_INLINE ErtsThrPrgrVal -thr_prgr_current(ErtsAuxWorkData *awdp) +haw_thr_prgr_current(ErtsAuxWorkData *awdp) { ErtsThrPrgrVal current = awdp->current_thr_prgr; if (current == ERTS_THR_PRGR_INVALID) { @@ -922,6 +922,21 @@ thr_prgr_current(ErtsAuxWorkData *awdp) return current; } +static ERTS_INLINE void +haw_thr_prgr_current_check_progress(ErtsAuxWorkData *awdp) +{ + ErtsThrPrgrVal current = awdp->current_thr_prgr; + if (current != ERTS_THR_PRGR_INVALID + && !erts_thr_progress_equal(current, erts_thr_progress_current())) { + /* + * We have used a previouly read current value that isn't the + * latest; need to poke ourselfs in order to guarantee no loss + * of wakeups. + */ + erts_sched_poke(awdp->ssi); + } +} + #endif typedef struct erts_misc_aux_work_t_ erts_misc_aux_work_t; @@ -1020,7 +1035,7 @@ static ERTS_INLINE erts_aint32_t handle_misc_aux_work_thr_prgr(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) { - if (!erts_thr_progress_has_reached_this(thr_prgr_current(awdp), + if (!erts_thr_progress_has_reached_this(haw_thr_prgr_current(awdp), awdp->misc.thr_prgr)) return aux_work & ~ERTS_SSI_AUX_WORK_MISC_THR_PRGR; @@ -1125,7 +1140,7 @@ handle_async_ready_clean(ErtsAuxWorkData *awdp, #ifdef ERTS_SMP if (awdp->async_ready.need_thr_prgr - && !erts_thr_progress_has_reached_this(thr_prgr_current(awdp), + && !erts_thr_progress_has_reached_this(haw_thr_prgr_current(awdp), awdp->async_ready.thr_prgr)) { return aux_work & ~ERTS_SSI_AUX_WORK_ASYNC_READY_CLEAN; } @@ -1206,7 +1221,7 @@ handle_delayed_dealloc(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) if (need_thr_progress) { if (wakeup == ERTS_THR_PRGR_INVALID) - wakeup = erts_thr_progress_later_than(thr_prgr_current(awdp)); + wakeup = erts_thr_progress_later(awdp->esdp); awdp->dd.thr_prgr = wakeup; set_aux_work_flags(ssi, ERTS_SSI_AUX_WORK_DD_THR_PRGR); awdp->dd.thr_prgr = wakeup; @@ -1227,7 +1242,7 @@ handle_delayed_dealloc_thr_prgr(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) int need_thr_progress; int more_work; ErtsThrPrgrVal wakeup = ERTS_THR_PRGR_INVALID; - ErtsThrPrgrVal current = thr_prgr_current(awdp); + ErtsThrPrgrVal current = haw_thr_prgr_current(awdp); if (!erts_thr_progress_has_reached_this(current, awdp->dd.thr_prgr)) return aux_work & ~ERTS_SSI_AUX_WORK_DD_THR_PRGR; @@ -1249,7 +1264,7 @@ handle_delayed_dealloc_thr_prgr(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) if (need_thr_progress) { if (wakeup == ERTS_THR_PRGR_INVALID) - wakeup = erts_thr_progress_later_than(current); + wakeup = erts_thr_progress_later(awdp->esdp); awdp->dd.thr_prgr = wakeup; erts_thr_progress_wakeup(awdp->esdp, wakeup); } @@ -1438,7 +1453,7 @@ handle_setup_aux_work_timer(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) } static erts_aint32_t -handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work) +handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work, int waiting) { #undef HANDLE_AUX_WORK #define HANDLE_AUX_WORK(FLG, HNDLR) \ @@ -1456,7 +1471,7 @@ handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work) erts_aint32_t ignore = 0; #ifdef ERTS_SMP - thr_prgr_current_reset(awdp); + haw_thr_prgr_current_reset(awdp); #endif ERTS_DBG_CHK_AUX_WORK_VAL(aux_work); @@ -1522,6 +1537,11 @@ handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work) ERTS_DBG_CHK_AUX_WORK_VAL(aux_work); +#ifdef ERTS_SMP + if (waiting && !aux_work) + haw_thr_prgr_current_check_progress(awdp); +#endif + return aux_work; #undef HANDLE_AUX_WORK @@ -1982,7 +2002,7 @@ aux_thread(void *unused) if (aux_work) { if (!thr_prgr_active) erts_thr_progress_active(NULL, thr_prgr_active = 1); - aux_work = handle_aux_work(awdp, aux_work); + aux_work = handle_aux_work(awdp, aux_work, 1); if (aux_work && erts_thr_progress_update(NULL)) erts_thr_progress_leader_update(NULL); } @@ -2061,7 +2081,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq) erts_thr_progress_active(esdp, thr_prgr_active = 1); sched_wall_time_change(esdp, 1); } - aux_work = handle_aux_work(&esdp->aux_work_data, aux_work); + aux_work = handle_aux_work(&esdp->aux_work_data, aux_work, 1); if (aux_work && erts_thr_progress_update(esdp)) erts_thr_progress_leader_update(esdp); } @@ -2163,7 +2183,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq) if (!thr_prgr_active) erts_thr_progress_active(esdp, thr_prgr_active = 1); #endif - aux_work = handle_aux_work(&esdp->aux_work_data, aux_work); + aux_work = handle_aux_work(&esdp->aux_work_data, aux_work, 1); #ifdef ERTS_SMP if (aux_work && erts_thr_progress_update(esdp)) erts_thr_progress_leader_update(esdp); @@ -4170,7 +4190,9 @@ suspend_scheduler(ErtsSchedulerData *esdp) erts_thr_progress_active(esdp, thr_prgr_active = 1); sched_wall_time_change(esdp, 1); } - aux_work = handle_aux_work(&esdp->aux_work_data, aux_work); + aux_work = handle_aux_work(&esdp->aux_work_data, + aux_work, + 1); if (aux_work && erts_thr_progress_update(esdp)) erts_thr_progress_leader_update(esdp); } @@ -6412,7 +6434,7 @@ Process *schedule(Process *p, int calls) if (leader_update) erts_thr_progress_leader_update(esdp); if (aux_work) - handle_aux_work(&esdp->aux_work_data, aux_work); + handle_aux_work(&esdp->aux_work_data, aux_work, 0); erts_smp_runq_lock(rq); } } @@ -6425,7 +6447,7 @@ Process *schedule(Process *p, int calls) erts_aint32_t aux_work; aux_work = erts_atomic32_read_acqb(&esdp->ssi->aux_work); if (aux_work) - handle_aux_work(&esdp->aux_work_data, aux_work); + handle_aux_work(&esdp->aux_work_data, aux_work, 0); } #endif /* ERTS_SMP */ -- cgit v1.2.3