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authorRickard Green <[email protected]>2010-09-10 15:08:27 +0200
committerRickard Green <[email protected]>2010-09-10 15:08:27 +0200
commitc9638ec9656ce052331a8c1c96ec4740c228a7d4 (patch)
tree55ba6578563ad9607cd746d028737bd32a2498bc /erts/emulator/beam
parentd90480306e4fcd3abc9717034a38868f639d45b1 (diff)
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Use mutex instead of rwlock
Use mutex instead of rwlock since the read lock is more or less unused and it can be quite contended.
Diffstat (limited to 'erts/emulator/beam')
-rw-r--r--erts/emulator/beam/time.c62
1 files changed, 23 insertions, 39 deletions
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index a07d6a5327..53d39aef0e 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -83,24 +83,8 @@
#define ASSERT_NO_LOCKED_LOCKS
#endif
+static erts_smp_mtx_t tiw_lock;
-#if defined(ERTS_TIMER_THREAD) || 1
-/* I don't yet know why, but using a mutex instead of a spinlock
- or spin-based rwlock avoids excessive delays at startup. */
-static erts_smp_rwmtx_t tiw_lock;
-#define tiw_read_lock() erts_smp_rwmtx_rlock(&tiw_lock)
-#define tiw_read_unlock() erts_smp_rwmtx_runlock(&tiw_lock)
-#define tiw_write_lock() erts_smp_rwmtx_rwlock(&tiw_lock)
-#define tiw_write_unlock() erts_smp_rwmtx_rwunlock(&tiw_lock)
-#define tiw_init_lock() erts_smp_rwmtx_init(&tiw_lock, "timer_wheel")
-#else
-static erts_smp_rwlock_t tiw_lock;
-#define tiw_read_lock() erts_smp_read_lock(&tiw_lock)
-#define tiw_read_unlock() erts_smp_read_unlock(&tiw_lock)
-#define tiw_write_lock() erts_smp_write_lock(&tiw_lock)
-#define tiw_write_unlock() erts_smp_write_unlock(&tiw_lock)
-#define tiw_init_lock() erts_smp_rwlock_init(&tiw_lock, "timer_wheel")
-#endif
/* BEGIN tiw_lock protected variables
**
@@ -224,10 +208,10 @@ int next_time(void)
{
int ret;
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
(void)do_time_update();
ret = next_time_internal();
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return ret;
}
#endif
@@ -241,7 +225,7 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
/* no need to bump the position if there aren't any timeouts */
if (tiw_nto == 0) {
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return;
}
@@ -278,7 +262,7 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
}
tiw_pos = keep_pos;
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
/* Call timedout timers callbacks */
while (timeout_head) {
@@ -299,13 +283,13 @@ static ERTS_INLINE void bump_timer_internal(long dt) /* PRE: tiw_lock is write-l
#if defined(ERTS_TIMER_THREAD)
static void timer_thread_bump_timer(void)
{
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
bump_timer_internal(do_time_reset());
}
#else
void bump_timer(long dt) /* dt is value from do_time */
{
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
bump_timer_internal(dt);
}
#endif
@@ -324,7 +308,7 @@ static int timer_thread_setup_delay(SysTimeval *rem_time)
long elapsed;
int ticks;
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
elapsed = do_time_update();
ticks = next_time_internal();
if (ticks == -1) /* timer queue empty */
@@ -336,7 +320,7 @@ static int timer_thread_setup_delay(SysTimeval *rem_time)
rem_time->tv_sec = ticks / 1000;
rem_time->tv_usec = 1000 * (ticks % 1000);
ticks_end = ticks;
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return ticks;
}
@@ -399,7 +383,7 @@ init_time(void)
if timer thread is enabled */
itime = erts_init_time_sup();
- tiw_init_lock();
+ erts_smp_mtx_init(&tiw_lock, "timer_wheel");
tiw = (ErlTimer**) erts_alloc(ERTS_ALC_T_TIMER_WHEEL,
TIW_SIZE * sizeof(ErlTimer*));
@@ -451,9 +435,9 @@ erl_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
void* arg, Uint t)
{
erts_deliver_time();
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
if (p->active) { /* XXX assert ? */
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return;
}
p->timeout = timeout;
@@ -461,7 +445,7 @@ erl_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
p->arg = arg;
p->active = 1;
insert_timer(p, t);
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
#if defined(ERTS_SMP) && !defined(ERTS_TIMER_THREAD)
if (t <= (Uint) LONG_MAX)
erts_sys_schedule_interrupt_timed(1, (long) t);
@@ -474,9 +458,9 @@ erl_cancel_timer(ErlTimer* p)
ErlTimer *tp;
ErlTimer **prev;
- tiw_write_lock();
+ erts_smp_mtx_lock(&tiw_lock);
if (!p->active) { /* allow repeated cancel (drivers) */
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return;
}
/* find p in linked list at slot p->slot and remove it */
@@ -489,17 +473,17 @@ erl_cancel_timer(ErlTimer* p)
p->slot = p->count = 0;
p->active = 0;
if (p->cancel != NULL) {
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
(*p->cancel)(p->arg);
} else {
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
}
return;
} else {
prev = &tp->next;
}
}
- tiw_write_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
}
/*
@@ -514,10 +498,10 @@ time_left(ErlTimer *p)
Uint left;
long dt;
- tiw_read_lock();
+ erts_smp_mtx_lock(&tiw_lock);
if (!p->active) {
- tiw_read_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return 0;
}
@@ -531,7 +515,7 @@ time_left(ErlTimer *p)
else
left -= dt;
- tiw_read_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
return left * itime;
}
@@ -543,7 +527,7 @@ void p_slpq()
int i;
ErlTimer* p;
- tiw_read_lock();
+ erts_smp_mtx_lock(&tiw_lock);
/* print the whole wheel, starting at the current position */
erts_printf("\ntiw_pos = %d tiw_nto %d\n", tiw_pos, tiw_nto);
@@ -565,7 +549,7 @@ void p_slpq()
}
}
- tiw_read_unlock();
+ erts_smp_mtx_unlock(&tiw_lock);
}
#endif /* DEBUG */