From 5b740336b0d7d0aec7c4df3b3e5c968ec0456766 Mon Sep 17 00:00:00 2001 From: Raimo Niskanen Date: Tue, 20 Mar 2012 09:49:09 +0100 Subject: erts: Implement erl_halt --- erts/emulator/beam/erl_process.c | 118 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 111 insertions(+), 7 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 138acfeb2c..45f6dc800c 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -104,6 +104,9 @@ do { \ #define ERTS_EMPTY_RUNQ(RQ) \ ((RQ)->len == 0 && (RQ)->misc.start == NULL) +#define ERTS_EMPTY_RUNQ_PORTS(RQ) \ + ((RQ)->ports.info.len == 0 && (RQ)->misc.start == NULL) + extern BeamInstr beam_apply[]; extern BeamInstr beam_exit[]; extern BeamInstr beam_continue_exit[]; @@ -366,6 +369,9 @@ dbg_chk_aux_work_val(erts_aint32_t value) #ifdef ERTS_SMP_SCHEDULERS_NEED_TO_CHECK_CHILDREN valid |= ERTS_SSI_AUX_WORK_CHECK_CHILDREN; #endif +#ifdef ERTS_SSI_AUX_WORK_REAP_PORTS + valid |= ERTS_SSI_AUX_WORK_REAP_PORTS; +#endif if (~valid & value) erl_exit(ERTS_ABORT_EXIT, @@ -861,8 +867,6 @@ set_aux_work_flags_wakeup_nob(ErtsSchedulerSleepInfo *ssi, } } -#if 0 /* Currently not used */ - static ERTS_INLINE void set_aux_work_flags_wakeup_relb(ErtsSchedulerSleepInfo *ssi, erts_aint32_t flgs) @@ -882,8 +886,6 @@ set_aux_work_flags_wakeup_relb(ErtsSchedulerSleepInfo *ssi, } } -#endif - static ERTS_INLINE erts_aint32_t set_aux_work_flags(ErtsSchedulerSleepInfo *ssi, erts_aint32_t flgs) { @@ -1351,6 +1353,65 @@ handle_check_children(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) #endif +static void +notify_reap_ports_relb(void) +{ + int i; + for (i = 0; i < erts_no_schedulers; i++) { + set_aux_work_flags_wakeup_relb(ERTS_SCHED_SLEEP_INFO_IX(i), + ERTS_SSI_AUX_WORK_REAP_PORTS); + } +} + +erts_smp_atomic32_t erts_halt_progress; +int erts_halt_code; + +static ERTS_INLINE erts_aint32_t +handle_reap_ports(ErtsAuxWorkData *awdp, erts_aint32_t aux_work) +{ + unset_aux_work_flags(awdp->ssi, ERTS_SSI_AUX_WORK_REAP_PORTS); + awdp->esdp->run_queue->halt_in_progress = 1; + if (erts_smp_atomic32_dec_read_acqb(&erts_halt_progress) == 0) { + int i; + erts_smp_atomic32_set_nob(&erts_halt_progress, 1); + for (i = 0; i < erts_max_ports; i++) { + Port *prt = &erts_port[i]; + erts_smp_port_state_lock(prt); + if ((prt->status & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP + | ERTS_PORT_SFLG_HALT))) { + erts_smp_port_state_unlock(prt); + continue; + } + /* We need to set the halt flag - get the port lock */ +#ifdef ERTS_SMP + erts_smp_atomic_inc_nob(&prt->refc); +#endif + erts_smp_port_state_unlock(prt); +#ifdef ERTS_SMP + erts_smp_mtx_lock(prt->lock); +#endif + if ((prt->status & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP + | ERTS_PORT_SFLG_HALT))) { + erts_port_release(prt); + continue; + } + erts_port_status_bor_set(prt, ERTS_PORT_SFLG_HALT); + erts_smp_atomic32_inc_nob(&erts_halt_progress); + if (prt->status & (ERTS_PORT_SFLG_EXITING + | ERTS_PORT_SFLG_CLOSING)) { + erts_port_release(prt); + continue; + } + erts_do_exit_port(prt, prt->id, am_killed); + erts_port_release(prt); + } + if (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0) { + erl_exit_flush_async(erts_halt_code, ""); + } + } + return aux_work & ~ERTS_SSI_AUX_WORK_REAP_PORTS; +} + #if HAVE_ERTS_MSEG static ERTS_INLINE erts_aint32_t @@ -1451,6 +1512,9 @@ handle_aux_work(ErtsAuxWorkData *awdp, erts_aint32_t orig_aux_work) handle_mseg_cache_check); #endif + HANDLE_AUX_WORK(ERTS_SSI_AUX_WORK_REAP_PORTS, + handle_reap_ports); + ERTS_DBG_CHK_AUX_WORK_VAL(aux_work); return aux_work; @@ -2716,6 +2780,9 @@ try_steal_task_from_victim(ErtsRunQueue *rq, int *rq_lockedp, ErtsRunQueue *vrq) ERTS_SMP_LC_CHK_RUNQ_LOCK(rq, *rq_lockedp); ERTS_SMP_LC_CHK_RUNQ_LOCK(vrq, vrq_locked); + if (rq->halt_in_progress) + goto try_steal_port; + /* * Check for a runnable process to steal... */ @@ -2802,6 +2869,8 @@ try_steal_task_from_victim(ErtsRunQueue *rq, int *rq_lockedp, ErtsRunQueue *vrq) vrq_locked = 1; } + try_steal_port: + ERTS_SMP_LC_CHK_RUNQ_LOCK(rq, *rq_lockedp); ERTS_SMP_LC_CHK_RUNQ_LOCK(vrq, vrq_locked); @@ -2917,7 +2986,8 @@ try_steal_task(ErtsRunQueue *rq) erts_smp_runq_lock(rq); if (!res) - res = !ERTS_EMPTY_RUNQ(rq); + res = rq->halt_in_progress ? + !ERTS_EMPTY_RUNQ_PORTS(rq) : !ERTS_EMPTY_RUNQ(rq); return res; } @@ -3583,6 +3653,7 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online) rq->len = 0; rq->wakeup_other = 0; rq->wakeup_other_reds = 0; + rq->halt_in_progress = 0; rq->procs.len = 0; rq->procs.pending_exiters = NULL; @@ -3777,6 +3848,9 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online) ERTS_VERIFY_UNUSED_TEMP_ALLOC(NULL); #endif #endif + + erts_smp_atomic32_init_relb(&erts_halt_progress, -1); + erts_halt_code = 0; } ErtsRunQueue * @@ -6343,7 +6417,9 @@ Process *schedule(Process *p, int calls) ASSERT(rq->len == rq->procs.len + rq->ports.info.len); - if (rq->len == 0 && !rq->misc.start) { + if ((rq->len == 0 && !rq->misc.start) + || (rq->halt_in_progress + && rq->ports.info.len == 0 && !rq->misc.start)) { #ifdef ERTS_SMP @@ -6441,7 +6517,8 @@ Process *schedule(Process *p, int calls) if (rq->ports.info.len) { int have_outstanding_io; have_outstanding_io = erts_port_task_execute(rq, &esdp->current_port); - if (have_outstanding_io && fcalls > 2*input_reductions) { + if ((have_outstanding_io && fcalls > 2*input_reductions) + || rq->halt_in_progress) { /* * If we have performed more than 2*INPUT_REDUCTIONS since * last call to erl_sys_schedule() and we still haven't @@ -9867,3 +9944,30 @@ debug_processes_assert_error(char* expr, char* file, int line) /* *\ * End of the processes/0 BIF implementation. * \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * A nice system halt closing all open port goes as follows: + * 1) This function schedules the aux work ERTS_SSI_AUX_WORK_REAP_PORTS + * on all schedulers, then schedules itself out. + * 2) All shedulers detect this and set the flag halt_in_progress + * on their run queue. The last scheduler sets all non-closed ports + * ERTS_PORT_SFLG_HALT. Global atomic erts_halt_progress is used + * as refcount to determine which is last. + * 3) While the run ques has flag halt_in_progress no processes + * will be scheduled, only ports. + * 4) When the last port closes that scheduler calls erlang:halt/1. + * The same global atomic is used as refcount. + * + * A BIF that calls this should make sure to schedule out to never come back: + * erl_halt((int)(- code)); + * ERTS_BIF_YIELD1(bif_export[BIF_erlang_halt_1], BIF_P, NIL); + */ +void erl_halt(int code) +{ + if (-1 == erts_smp_atomic32_cmpxchg_acqb(&erts_halt_progress, + erts_no_schedulers, + -1)) { + erts_halt_code = code; + notify_reap_ports_relb(); + } +} -- cgit v1.2.3