aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator
diff options
context:
space:
mode:
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/beam/erl_process.c102
-rw-r--r--erts/emulator/beam/erl_process.h2
-rw-r--r--erts/emulator/beam/erl_process_lock.h7
-rw-r--r--erts/emulator/test/nif_SUITE.erl1
4 files changed, 76 insertions, 36 deletions
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 8e4a42fbe4..99a4011b8f 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -6559,9 +6559,6 @@ suspend_process(Process *c_p, Process *p)
if (suspended) {
- ASSERT(!(ERTS_PSFLG_RUNNING & state)
- || p == erts_get_current_process());
-
if (suspended > 0 && erts_system_profile_flags.runnable_procs) {
/* 'state' is before our change... */
@@ -8508,9 +8505,8 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks,
resume_process(rp, rp_locks);
}
else {
-
rp = erts_pid2proc(c_p, c_p_locks|ERTS_PROC_LOCK_STATUS,
- pid, pid_locks|ERTS_PROC_LOCK_STATUS);
+ pid, ERTS_PROC_LOCK_STATUS);
if (!rp) {
c_p->flags &= ~F_P2PNR_RESCHED;
@@ -8519,40 +8515,84 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks,
ASSERT(!(c_p->flags & F_P2PNR_RESCHED));
- if (suspend) {
- if (suspend_process(c_p, rp))
- goto done;
- }
- else {
- if (!((ERTS_PSFLG_RUNNING|ERTS_PSFLG_RUNNING_SYS)
- & erts_smp_atomic32_read_acqb(&rp->state)))
- goto done;
+ /*
+ * Suspend the other process in order to prevent
+ * it from being selected for normal execution.
+ * This will however not prevent it from being
+ * selected for execution of a system task. If
+ * it is selected for execution of a system task
+ * we might be blocked for quite a while if the
+ * try-lock below fails. That is, there is room
+ * for improvement here...
+ */
- }
+ if (!suspend_process(c_p, rp)) {
+ /* Other process running */
- /* Other process running */
+ ASSERT(ERTS_PSFLG_RUNNING
+ & erts_smp_atomic32_read_nob(&rp->state));
- /*
- * If we got pending suspenders and suspend ourselves waiting
- * to suspend another process we might deadlock.
- * In this case we have to yield, be suspended by
- * someone else and then do it all over again.
- */
- if (!c_p->pending_suspenders) {
- /* Mark rp pending for suspend by c_p */
- add_pend_suspend(rp, c_p->common.id, handle_pend_sync_suspend);
- ASSERT(is_nil(c_p->suspendee));
+ running:
- /* Suspend c_p; when rp is suspended c_p will be resumed. */
- suspend_process(c_p, c_p);
- c_p->flags |= F_P2PNR_RESCHED;
+ /*
+ * If we got pending suspenders and suspend ourselves waiting
+ * to suspend another process we might deadlock.
+ * In this case we have to yield, be suspended by
+ * someone else and then do it all over again.
+ */
+ if (!c_p->pending_suspenders) {
+ /* Mark rp pending for suspend by c_p */
+ add_pend_suspend(rp, c_p->common.id, handle_pend_sync_suspend);
+ ASSERT(is_nil(c_p->suspendee));
+
+ /* Suspend c_p; when rp is suspended c_p will be resumed. */
+ suspend_process(c_p, c_p);
+ c_p->flags |= F_P2PNR_RESCHED;
+ }
+ /* Yield (caller is assumed to yield immediately in bif). */
+ erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS);
+ rp = ERTS_PROC_LOCK_BUSY;
+ }
+ else {
+ ErtsProcLocks need_locks = pid_locks & ~ERTS_PROC_LOCK_STATUS;
+ if (need_locks && erts_smp_proc_trylock(rp, need_locks) == EBUSY) {
+ if (ERTS_PSFLG_RUNNING_SYS
+ & erts_smp_atomic32_read_nob(&rp->state)) {
+ /* Executing system task... */
+ resume_process(rp, ERTS_PROC_LOCK_STATUS);
+ goto running;
+ }
+ erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS);
+ /*
+ * If we are unlucky, the process just got selected for
+ * execution of a system task. In this case we may be
+ * blocked here for quite a while... Execution of system
+ * tasks are fortunately quite rare events. We try to
+ * avoid this by checking if it is in a state executing
+ * system tasks (above), but it will not prevent all
+ * scenarios for a long block here...
+ */
+ rp = erts_pid2proc(c_p, c_p_locks|ERTS_PROC_LOCK_STATUS,
+ pid, pid_locks|ERTS_PROC_LOCK_STATUS);
+ if (!rp)
+ goto done;
+ }
+
+ /*
+ * The previous suspend has prevented the process
+ * from being selected for normal execution regardless
+ * of locks held or not held on it...
+ */
+ ASSERT(!(ERTS_PSFLG_RUNNING
+ & erts_smp_atomic32_read_nob(&rp->state)));
+
+ if (!suspend)
+ resume_process(rp, pid_locks|ERTS_PROC_LOCK_STATUS);
}
- /* Yield (caller is assumed to yield immediately in bif). */
- erts_smp_proc_unlock(rp, pid_locks|ERTS_PROC_LOCK_STATUS);
- rp = ERTS_PROC_LOCK_BUSY;
}
done:
+
if (rp && rp != ERTS_PROC_LOCK_BUSY && !(pid_locks & ERTS_PROC_LOCK_STATUS))
erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS);
if (unlock_c_p_status)
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index f1570a835c..ee8a2e1b7b 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1187,7 +1187,7 @@ void erts_check_for_holes(Process* p);
#define ERTS_PSFLGS_GET_USR_PRIO(PSFLGS) \
(((PSFLGS) >> ERTS_PSFLGS_USR_PRIO_OFFSET) & ERTS_PSFLGS_PRIO_MASK)
#define ERTS_PSFLGS_GET_PRQ_PRIO(PSFLGS) \
- (((PSFLGS) >> ERTS_PSFLGS_USR_PRIO_OFFSET) & ERTS_PSFLGS_PRIO_MASK)
+ (((PSFLGS) >> ERTS_PSFLGS_PRQ_PRIO_OFFSET) & ERTS_PSFLGS_PRIO_MASK)
/*
* Static flags that do not change after process creation.
diff --git a/erts/emulator/beam/erl_process_lock.h b/erts/emulator/beam/erl_process_lock.h
index a64c993e8f..9c59301086 100644
--- a/erts/emulator/beam/erl_process_lock.h
+++ b/erts/emulator/beam/erl_process_lock.h
@@ -523,6 +523,10 @@ erts_smp_proc_lock__(Process *p,
ERTS_LC_ASSERT((locks & ~ERTS_PROC_LOCKS_ALL) == 0);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+ erts_proc_lc_lock(p, locks, file, line);
+#endif
+
old_lflgs = erts_smp_proc_raw_trylock__(p, locks);
if (old_lflgs != 0) {
@@ -544,9 +548,6 @@ erts_smp_proc_lock__(Process *p,
#ifdef ERTS_ENABLE_LOCK_COUNT
erts_lcnt_proc_lock_post_x(&(p->lock), locks, file, line);
#endif
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_proc_lc_lock(p, locks, file, line);
-#endif
#ifdef ERTS_PROC_LOCK_DEBUG
erts_proc_lock_op_debug(p, locks, 1);
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index 3d478654b1..e10460ce78 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -617,7 +617,6 @@ resource_new_do2(Type) ->
?line {PtrA,BinA} = get_resource(Type, ResA),
?line {PtrB,BinB} = get_resource(Type, ResB),
?line true = (PtrA =/= PtrB),
- ?line [] = last_resource_dtor_call(),
%% forget ResA and make it garbage
{{PtrA,BinA}, {ResB,PtrB,BinB}}.
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-10 21:29:28 +0000