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-rw-r--r--erts/emulator/beam/utils.c684
1 files changed, 2 insertions, 682 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 2d621e8be6..65485241aa 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -77,6 +77,7 @@ typedef struct {
#ifdef ERTS_SMP
+#if 0 /* Unused */
static void
dispatch_profile_msg_q(profile_sched_msg_q *psmq)
{
@@ -88,6 +89,7 @@ dispatch_profile_msg_q(profile_sched_msg_q *psmq)
profile_scheduler_q(make_small(msg->scheduler_id), msg->state, am_undefined, msg->Ms, msg->s, msg->us);
}
}
+#endif
#endif
@@ -3405,688 +3407,6 @@ sys_alloc_stat(SysAllocStat *sasp)
}
-#ifdef ERTS_SMP
-
-/* Local system block state */
-
-struct {
- int emergency;
- long emergency_timeout;
- erts_smp_cnd_t watchdog_cnd;
- erts_smp_tid_t watchdog_tid;
- int threads_to_block;
- int have_blocker;
- erts_smp_tid_t blocker_tid;
- int recursive_block;
- Uint32 allowed_activities;
- erts_smp_tsd_key_t blockable_key;
- erts_smp_mtx_t mtx;
- erts_smp_cnd_t cnd;
-#ifdef ERTS_ENABLE_LOCK_CHECK
- int activity_changing;
- int checking;
-#endif
-} system_block_state;
-
-/* Global system block state */
-erts_system_block_state_t erts_system_block_state;
-
-
-static ERTS_INLINE int
-is_blockable_thread(void)
-{
- return erts_smp_tsd_get(system_block_state.blockable_key) != NULL;
-}
-
-static ERTS_INLINE int
-is_blocker(void)
-{
- return (system_block_state.have_blocker
- && erts_smp_equal_tids(system_block_state.blocker_tid,
- erts_smp_thr_self()));
-}
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
-int
-erts_lc_is_blocking(void)
-{
- int res;
- erts_smp_mtx_lock(&system_block_state.mtx);
- res = erts_smp_pending_system_block() && is_blocker();
- erts_smp_mtx_unlock(&system_block_state.mtx);
- return res;
-}
-#endif
-
-static ERTS_INLINE void
-block_me(void (*prepare)(void *),
- void (*resume)(void *),
- void *arg,
- int mtx_locked,
- int want_to_block,
- int update_act_changing,
- profile_sched_msg_q *psmq)
-{
- if (prepare)
- (*prepare)(arg);
-
- /* Locks might be held... */
-
- if (!mtx_locked)
- erts_smp_mtx_lock(&system_block_state.mtx);
-
- if (erts_smp_pending_system_block() && !is_blocker()) {
- int is_blockable = is_blockable_thread();
- ASSERT(is_blockable);
-
- if (is_blockable)
- system_block_state.threads_to_block--;
-
- if (erts_system_profile_flags.scheduler && psmq) {
- ErtsSchedulerData *esdp = erts_get_scheduler_data();
- if (esdp) {
- profile_sched_msg *msg = NULL;
-
- ASSERT(psmq->n < 2);
- msg = &((psmq->msg)[psmq->n]);
- msg->scheduler_id = esdp->no;
- get_now(&(msg->Ms), &(msg->s), &(msg->us));
- msg->no_schedulers = 0;
- msg->state = am_inactive;
- psmq->n++;
- }
- }
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- if (update_act_changing)
- system_block_state.activity_changing--;
-#endif
-
- erts_smp_cnd_broadcast(&system_block_state.cnd);
-
- do {
- erts_smp_cnd_wait(&system_block_state.cnd, &system_block_state.mtx);
- } while (erts_smp_pending_system_block()
- && !(want_to_block && !system_block_state.have_blocker));
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- if (update_act_changing)
- system_block_state.activity_changing++;
-#endif
- if (erts_system_profile_flags.scheduler && psmq) {
- ErtsSchedulerData *esdp = erts_get_scheduler_data();
- if (esdp) {
- profile_sched_msg *msg = NULL;
-
- ASSERT(psmq->n < 2);
- msg = &((psmq->msg)[psmq->n]);
- msg->scheduler_id = esdp->no;
- get_now(&(msg->Ms), &(msg->s), &(msg->us));
- msg->no_schedulers = 0;
- msg->state = am_active;
- psmq->n++;
- }
- }
-
- if (is_blockable)
- system_block_state.threads_to_block++;
- }
-
- if (!mtx_locked)
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (resume)
- (*resume)(arg);
-}
-
-void
-erts_block_me(void (*prepare)(void *),
- void (*resume)(void *),
- void *arg)
-{
- profile_sched_msg_q psmq;
- psmq.n = 0;
- if (prepare)
- (*prepare)(arg);
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_lc_check_exact(NULL, 0); /* No locks should be locked */
-#endif
-
- block_me(NULL, NULL, NULL, 0, 0, 0, &psmq);
-
- if (erts_system_profile_flags.scheduler && psmq.n > 0)
- dispatch_profile_msg_q(&psmq);
-
- if (resume)
- (*resume)(arg);
-}
-
-void
-erts_register_blockable_thread(void)
-{
- profile_sched_msg_q psmq;
- psmq.n = 0;
- if (!is_blockable_thread()) {
- erts_smp_mtx_lock(&system_block_state.mtx);
- system_block_state.threads_to_block++;
- erts_smp_tsd_set(system_block_state.blockable_key,
- (void *) &erts_system_block_state);
-
- /* Someone might be waiting for us to block... */
- if (erts_smp_pending_system_block())
- block_me(NULL, NULL, NULL, 1, 0, 0, &psmq);
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (erts_system_profile_flags.scheduler && psmq.n > 0)
- dispatch_profile_msg_q(&psmq);
- }
-}
-
-void
-erts_unregister_blockable_thread(void)
-{
- if (is_blockable_thread()) {
- erts_smp_mtx_lock(&system_block_state.mtx);
- system_block_state.threads_to_block--;
- ASSERT(system_block_state.threads_to_block >= 0);
- erts_smp_tsd_set(system_block_state.blockable_key, NULL);
-
- /* Someone might be waiting for us to block... */
- if (erts_smp_pending_system_block())
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- erts_smp_mtx_unlock(&system_block_state.mtx);
- }
-}
-
-void
-erts_note_activity_begin(erts_activity_t activity)
-{
- erts_smp_mtx_lock(&system_block_state.mtx);
- if (erts_smp_pending_system_block()) {
- Uint32 broadcast = 0;
- switch (activity) {
- case ERTS_ACTIVITY_GC:
- broadcast = (system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_GC);
- break;
- case ERTS_ACTIVITY_IO:
- broadcast = (system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_IO);
- break;
- case ERTS_ACTIVITY_WAIT:
- broadcast = 1;
- break;
- default:
- abort();
- break;
- }
- if (broadcast)
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- }
- erts_smp_mtx_unlock(&system_block_state.mtx);
-}
-
-void
-erts_check_block(erts_activity_t old_activity,
- erts_activity_t new_activity,
- int locked,
- void (*prepare)(void *),
- void (*resume)(void *),
- void *arg)
-{
- int do_block;
- profile_sched_msg_q psmq;
-
- psmq.n = 0;
- if (!locked && prepare)
- (*prepare)(arg);
-
- erts_smp_mtx_lock(&system_block_state.mtx);
-
- /* First check if it is ok to block... */
- if (!locked)
- do_block = 1;
- else {
- switch (old_activity) {
- case ERTS_ACTIVITY_UNDEFINED:
- do_block = 0;
- break;
- case ERTS_ACTIVITY_GC:
- do_block = (system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_GC);
- break;
- case ERTS_ACTIVITY_IO:
- do_block = (system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_IO);
- break;
- case ERTS_ACTIVITY_WAIT:
- /* You are not allowed to leave activity waiting
- * without supplying the possibility to block
- * unlocked.
- */
- erts_set_activity_error(ERTS_ACT_ERR_LEAVE_WAIT_UNLOCKED,
- __FILE__, __LINE__);
- do_block = 0;
- break;
- default:
- erts_set_activity_error(ERTS_ACT_ERR_LEAVE_UNKNOWN_ACTIVITY,
- __FILE__, __LINE__);
- do_block = 0;
- break;
- }
- }
-
- if (do_block) {
- /* ... then check if it is necessary to block... */
-
- switch (new_activity) {
- case ERTS_ACTIVITY_UNDEFINED:
- do_block = 1;
- break;
- case ERTS_ACTIVITY_GC:
- do_block = !(system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_GC);
- break;
- case ERTS_ACTIVITY_IO:
- do_block = !(system_block_state.allowed_activities
- & ERTS_BS_FLG_ALLOW_IO);
- break;
- case ERTS_ACTIVITY_WAIT:
- /* No need to block if we are going to wait */
- do_block = 0;
- break;
- default:
- erts_set_activity_error(ERTS_ACT_ERR_ENTER_UNKNOWN_ACTIVITY,
- __FILE__, __LINE__);
- break;
- }
- }
-
- if (do_block) {
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- if (!locked) {
- /* Only system_block_state.mtx should be held */
- erts_lc_check_exact(&system_block_state.mtx.lc, 1);
- }
-#endif
-
- block_me(NULL, NULL, NULL, 1, 0, 1, &psmq);
-
- }
-
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (erts_system_profile_flags.scheduler && psmq.n > 0)
- dispatch_profile_msg_q(&psmq);
-
- if (!locked && resume)
- (*resume)(arg);
-}
-
-
-
-void
-erts_set_activity_error(erts_activity_error_t error, char *file, int line)
-{
- switch (error) {
- case ERTS_ACT_ERR_LEAVE_WAIT_UNLOCKED:
- erl_exit(1, "%s:%d: Fatal error: Leaving activity waiting without "
- "supplying the possibility to block unlocked.",
- file, line);
- break;
- case ERTS_ACT_ERR_LEAVE_UNKNOWN_ACTIVITY:
- erl_exit(1, "%s:%d: Fatal error: Leaving unknown activity.",
- file, line);
- break;
- case ERTS_ACT_ERR_ENTER_UNKNOWN_ACTIVITY:
- erl_exit(1, "%s:%d: Fatal error: Leaving unknown activity.",
- file, line);
- break;
- default:
- erl_exit(1, "%s:%d: Internal error in erts_smp_set_activity()",
- file, line);
- break;
- }
-
-}
-
-
-static ERTS_INLINE erts_aint32_t
-threads_not_under_control(void)
-{
- erts_aint32_t res = system_block_state.threads_to_block;
-
- ERTS_THR_MEMORY_BARRIER;
-
- /* Waiting is always an allowed activity... */
- res -= erts_smp_atomic32_read_nob(&erts_system_block_state.in_activity.wait);
-
- if (system_block_state.allowed_activities & ERTS_BS_FLG_ALLOW_GC)
- res -= erts_smp_atomic32_read_nob(&erts_system_block_state.in_activity.gc);
-
- if (system_block_state.allowed_activities & ERTS_BS_FLG_ALLOW_IO)
- res -= erts_smp_atomic32_read_nob(&erts_system_block_state.in_activity.io);
-
- if (res < 0) {
- ASSERT(0);
- return 0;
- }
- return res;
-}
-
-/*
- * erts_block_system() blocks all threads registered as blockable.
- * It doesn't return until either all threads have blocked (0 is returned)
- * or it has timed out (ETIMEDOUT) is returned.
- *
- * If allowed activities == 0, blocked threads will release all locks
- * before blocking.
- *
- * If allowed_activities is != 0, erts_block_system() will allow blockable
- * threads to continue executing as long as they are doing an allowed
- * activity. When they are done with the allowed activity they will block,
- * *but* they will block holding locks. Therefore, the thread calling
- * erts_block_system() must *not* try to aquire any locks that might be
- * held by blocked threads holding locks from allowed activities.
- *
- * Currently allowed_activities are:
- * * ERTS_BS_FLG_ALLOW_GC Thread continues with garbage
- * collection and blocks with
- * main process lock on current
- * process locked.
- * * ERTS_BS_FLG_ALLOW_IO Thread continues with I/O
- */
-
-void
-erts_block_system(Uint32 allowed_activities)
-{
- int do_block;
- profile_sched_msg_q psmq;
-
- psmq.n = 0;
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_lc_check_exact(NULL, 0); /* No locks should be locked */
-#endif
-
- erts_smp_mtx_lock(&system_block_state.mtx);
-
- do_block = erts_smp_pending_system_block();
- if (do_block
- && system_block_state.have_blocker
- && erts_smp_equal_tids(system_block_state.blocker_tid,
- erts_smp_thr_self())) {
- ASSERT(system_block_state.recursive_block >= 0);
- system_block_state.recursive_block++;
-
- /* You are not allowed to restrict allowed activites
- in a recursive block! */
- ERTS_SMP_LC_ASSERT((system_block_state.allowed_activities
- & ~allowed_activities) == 0);
- }
- else {
-
- erts_smp_atomic32_inc_nob(&erts_system_block_state.do_block);
-
- /* Someone else might be waiting for us to block... */
- if (do_block) {
- do_block_me:
- block_me(NULL, NULL, NULL, 1, 1, 0, &psmq);
- }
-
- ASSERT(!system_block_state.have_blocker);
- system_block_state.have_blocker = 1;
- system_block_state.blocker_tid = erts_smp_thr_self();
- system_block_state.allowed_activities = allowed_activities;
-
- if (is_blockable_thread())
- system_block_state.threads_to_block--;
-
- while (threads_not_under_control() && !system_block_state.emergency)
- erts_smp_cnd_wait(&system_block_state.cnd, &system_block_state.mtx);
-
- if (system_block_state.emergency) {
- system_block_state.have_blocker = 0;
- goto do_block_me;
- }
- }
-
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (erts_system_profile_flags.scheduler && psmq.n > 0 )
- dispatch_profile_msg_q(&psmq);
-}
-
-/*
- * erts_emergency_block_system() should only be called when we are
- * about to write a crash dump...
- */
-
-int
-erts_emergency_block_system(long timeout, Uint32 allowed_activities)
-{
- int res = 0;
- long another_blocker;
-
- erts_smp_mtx_lock(&system_block_state.mtx);
-
- if (system_block_state.emergency) {
- /* Argh... */
- res = EINVAL;
- goto done;
- }
-
- another_blocker = erts_smp_pending_system_block();
- system_block_state.emergency = 1;
- erts_smp_atomic32_inc_nob(&erts_system_block_state.do_block);
-
- if (another_blocker) {
- if (is_blocker()) {
- erts_smp_atomic32_dec_nob(&erts_system_block_state.do_block);
- res = 0;
- goto done;
- }
- /* kick the other blocker */
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- while (system_block_state.have_blocker)
- erts_smp_cnd_wait(&system_block_state.cnd, &system_block_state.mtx);
- }
-
- ASSERT(!system_block_state.have_blocker);
- system_block_state.have_blocker = 1;
- system_block_state.blocker_tid = erts_smp_thr_self();
- system_block_state.allowed_activities = allowed_activities;
-
- if (is_blockable_thread())
- system_block_state.threads_to_block--;
-
- if (timeout < 0) {
- while (threads_not_under_control())
- erts_smp_cnd_wait(&system_block_state.cnd, &system_block_state.mtx);
- }
- else {
- system_block_state.emergency_timeout = timeout;
- erts_smp_cnd_signal(&system_block_state.watchdog_cnd);
-
- while (system_block_state.emergency_timeout >= 0
- && threads_not_under_control()) {
- erts_smp_cnd_wait(&system_block_state.cnd,
- &system_block_state.mtx);
- }
- }
- done:
- erts_smp_mtx_unlock(&system_block_state.mtx);
- return res;
-}
-
-void
-erts_release_system(void)
-{
- long do_block;
- profile_sched_msg_q psmq;
-
- psmq.n = 0;
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_lc_check_exact(NULL, 0); /* No locks should be locked */
-#endif
-
- erts_smp_mtx_lock(&system_block_state.mtx);
- ASSERT(is_blocker());
-
- ASSERT(system_block_state.recursive_block >= 0);
-
- if (system_block_state.recursive_block)
- system_block_state.recursive_block--;
- else {
- do_block = erts_smp_atomic32_dec_read_nob(&erts_system_block_state.do_block);
- system_block_state.have_blocker = 0;
- if (is_blockable_thread())
- system_block_state.threads_to_block++;
- else
- do_block = 0;
-
- /* Someone else might be waiting for us to block... */
- if (do_block)
- block_me(NULL, NULL, NULL, 1, 0, 0, &psmq);
- else
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- }
-
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (erts_system_profile_flags.scheduler && psmq.n > 0)
- dispatch_profile_msg_q(&psmq);
-}
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
-
-void
-erts_lc_activity_change_begin(void)
-{
- erts_smp_mtx_lock(&system_block_state.mtx);
- system_block_state.activity_changing++;
- erts_smp_mtx_unlock(&system_block_state.mtx);
-}
-
-void
-erts_lc_activity_change_end(void)
-{
- erts_smp_mtx_lock(&system_block_state.mtx);
- system_block_state.activity_changing--;
- if (system_block_state.checking && !system_block_state.activity_changing)
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- erts_smp_mtx_unlock(&system_block_state.mtx);
-}
-
-#endif
-
-int
-erts_is_system_blocked(erts_activity_t allowed_activities)
-{
- int blkd;
-
- erts_smp_mtx_lock(&system_block_state.mtx);
- blkd = (erts_smp_pending_system_block()
- && system_block_state.have_blocker
- && erts_smp_equal_tids(system_block_state.blocker_tid,
- erts_smp_thr_self())
- && !(system_block_state.allowed_activities & ~allowed_activities));
-#ifdef ERTS_ENABLE_LOCK_CHECK
- if (blkd) {
- system_block_state.checking = 1;
- while (system_block_state.activity_changing)
- erts_smp_cnd_wait(&system_block_state.cnd, &system_block_state.mtx);
- system_block_state.checking = 0;
- blkd = !threads_not_under_control();
- }
-#endif
- erts_smp_mtx_unlock(&system_block_state.mtx);
- return blkd;
-}
-
-static void *
-emergency_watchdog(void *unused)
-{
- erts_smp_mtx_lock(&system_block_state.mtx);
- while (1) {
- long timeout;
- while (system_block_state.emergency_timeout < 0)
- erts_smp_cnd_wait(&system_block_state.watchdog_cnd, &system_block_state.mtx);
- timeout = system_block_state.emergency_timeout;
- erts_smp_mtx_unlock(&system_block_state.mtx);
-
- if (erts_disable_tolerant_timeofday)
- erts_milli_sleep(timeout);
- else {
- SysTimeval to;
- erts_get_timeval(&to);
- to.tv_sec += timeout / 1000;
- to.tv_usec += timeout % 1000;
-
- while (1) {
- SysTimeval curr;
- erts_milli_sleep(timeout);
- erts_get_timeval(&curr);
- if (curr.tv_sec > to.tv_sec
- || (curr.tv_sec == to.tv_sec && curr.tv_usec >= to.tv_usec)) {
- break;
- }
- timeout = (to.tv_sec - curr.tv_sec)*1000;
- timeout += (to.tv_usec - curr.tv_usec)/1000;
- }
- }
-
- erts_smp_mtx_lock(&system_block_state.mtx);
- system_block_state.emergency_timeout = -1;
- erts_smp_cnd_broadcast(&system_block_state.cnd);
- }
- erts_smp_mtx_unlock(&system_block_state.mtx);
- return NULL;
-}
-
-void
-erts_system_block_init(void)
-{
- erts_smp_thr_opts_t thr_opts = ERTS_SMP_THR_OPTS_DEFAULT_INITER;
- /* Local state... */
- system_block_state.emergency = 0;
- system_block_state.emergency_timeout = -1;
- erts_smp_cnd_init(&system_block_state.watchdog_cnd);
- system_block_state.threads_to_block = 0;
- system_block_state.have_blocker = 0;
- /* system_block_state.block_tid */
- system_block_state.recursive_block = 0;
- system_block_state.allowed_activities = 0;
- erts_smp_tsd_key_create(&system_block_state.blockable_key);
- erts_smp_mtx_init(&system_block_state.mtx, "system_block");
- erts_smp_cnd_init(&system_block_state.cnd);
-#ifdef ERTS_ENABLE_LOCK_CHECK
- system_block_state.activity_changing = 0;
- system_block_state.checking = 0;
-#endif
-
- thr_opts.suggested_stack_size = 8;
- erts_smp_thr_create(&system_block_state.watchdog_tid,
- emergency_watchdog,
- NULL,
- &thr_opts);
-
- /* Global state... */
-
- erts_smp_atomic32_init_nob(&erts_system_block_state.do_block, 0);
- erts_smp_atomic32_init_nob(&erts_system_block_state.in_activity.wait, 0);
- erts_smp_atomic32_init_nob(&erts_system_block_state.in_activity.gc, 0);
- erts_smp_atomic32_init_nob(&erts_system_block_state.in_activity.io, 0);
-
- /* Make sure blockable threads unregister when exiting... */
- erts_smp_install_exit_handler(erts_unregister_blockable_thread);
-}
-
-
-#endif /* #ifdef ERTS_SMP */
-
char *
erts_read_env(char *key)
{