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authorBjörn-Egil Dahlberg <[email protected]>2010-12-16 19:39:07 +0100
committerBjörn-Egil Dahlberg <[email protected]>2010-12-29 12:25:26 +0100
commite7a56088a38bf79a650659b5b6381f71af75c740 (patch)
tree27c002551bc1c037910000db5f0c71079ca5b9fb
parent454f2ef1c95a9d543fc5a66eca4f286a3144b7ce (diff)
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Teach timer-wheel slots to use double linked lists
Conflicts: erts/emulator/beam/erl_time.h
-rw-r--r--erts/emulator/beam/erl_time.h1
-rw-r--r--erts/emulator/beam/time.c82
2 files changed, 50 insertions, 33 deletions
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index f4e230655d..93d8ea4cb4 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -28,6 +28,7 @@ extern SysTimeval erts_first_emu_time;
*/
typedef struct erl_timer {
struct erl_timer* next; /* next entry tiw slot or chain */
+ struct erl_timer* prev; /* prev entry tiw slot or chain */
Uint slot; /* slot in timer wheel */
Uint count; /* number of loops remaining */
int active; /* 1=activated, 0=deactivated */
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 4f491aa66f..c65cc37fc6 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -165,6 +165,31 @@ static erts_aint_t next_time_internal(void) /* PRE: tiw_lock taken by caller */
return ((min >= dt) ? (min - dt) : 0);
}
+static void remove_timer(ErlTimer *p) {
+ /* first */
+ if (!p->prev) {
+ tiw[p->slot] = p->next;
+ if(p->next)
+ p->next->prev = NULL;
+ } else {
+ p->prev->next = p->next;
+ }
+
+ /* last */
+ if (!p->next) {
+ if (p->prev)
+ p->prev->next = NULL;
+ } else {
+ p->next->prev = p->prev;
+ }
+
+ p->next = NULL;
+ p->prev = NULL;
+ /* Make sure cancel callback isn't called */
+ p->active = 0;
+ tiw_nto--;
+}
+
/* Private export to erl_time_sup.c */
erts_aint_t erts_next_time(void)
{
@@ -210,11 +235,9 @@ static ERTS_INLINE void bump_timer_internal(erts_aint_t dt) /* PRE: tiw_lock is
tiw_min_ptr = NULL;
tiw_min = 0;
}
- *prev = p->next; /* Remove from list */
- tiw_nto--;
- p->next = NULL;
- p->active = 0; /* Make sure cancel callback
- isn't called */
+
+ /* Remove from list */
+ remove_timer(p);
*timeout_tail = p; /* Insert in timeout queue */
timeout_tail = &p->next;
}
@@ -244,6 +267,7 @@ static ERTS_INLINE void bump_timer_internal(erts_aint_t dt) /* PRE: tiw_lock is
* callback is called.
*/
p->next = NULL;
+ p->prev = NULL;
p->slot = 0;
(*p->timeout)(p->arg);
}
@@ -284,6 +308,9 @@ erts_init_time(void)
tiw_min = 0;
}
+
+
+
/*
** Insert a process into the time queue, with a timeout 't'
*/
@@ -313,8 +340,12 @@ insert_timer(ErlTimer* p, Uint t)
/* insert at head of list at slot */
p->next = tiw[tm];
+ p->prev = NULL;
+ if (p->next != NULL)
+ p->next->prev = p;
tiw[tm] = p;
+
/* insert min time */
if ((tiw_nto == 0) || ((tiw_min_ptr != NULL) && (ticks < tiw_min))) {
tiw_min = ticks;
@@ -355,40 +386,25 @@ erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
void
erts_cancel_timer(ErlTimer* p)
{
- ErlTimer *tp;
- ErlTimer **prev;
-
erts_smp_mtx_lock(&tiw_lock);
if (!p->active) { /* allow repeated cancel (drivers) */
erts_smp_mtx_unlock(&tiw_lock);
return;
}
- /* find p in linked list at slot p->slot and remove it */
- prev = &tiw[p->slot];
- while ((tp = *prev) != NULL) {
- if (tp == p) {
-
- /* is it the 'min' timer ? */
- if (p == tiw_min_ptr) {
- tiw_min_ptr = NULL;
- tiw_min = 0;
- }
- *prev = p->next; /* Remove from list */
- tiw_nto--;
- p->next = NULL;
- p->slot = p->count = 0;
- p->active = 0;
- if (p->cancel != NULL) {
- erts_smp_mtx_unlock(&tiw_lock);
- (*p->cancel)(p->arg);
- } else {
- erts_smp_mtx_unlock(&tiw_lock);
- }
- return;
- } else {
- prev = &tp->next;
- }
+ /* is it the 'min' timer, remove min */
+ if (p == tiw_min_ptr) {
+ tiw_min_ptr = NULL;
+ tiw_min = 0;
+ }
+
+ remove_timer(p);
+ p->slot = p->count = 0;
+
+ if (p->cancel != NULL) {
+ erts_smp_mtx_unlock(&tiw_lock);
+ (*p->cancel)(p->arg);
+ return;
}
erts_smp_mtx_unlock(&tiw_lock);
}