struct list_head list[PER_LEVEL];
};
-static uint64_t time_to_grains(struct timespec ts)
+static uint64_t time_to_grains(struct timeabs t)
{
- return ts.tv_sec * ((uint64_t)1000000000 / TIMER_GRANULARITY)
- + (ts.tv_nsec / TIMER_GRANULARITY);
+ return t.ts.tv_sec * ((uint64_t)1000000000 / TIMER_GRANULARITY)
+ + (t.ts.tv_nsec / TIMER_GRANULARITY);
}
-static struct timespec grains_to_time(uint64_t grains)
+static struct timeabs grains_to_time(uint64_t grains)
{
- struct timespec ts;
+ struct timeabs t;
- ts.tv_sec = grains / (1000000000 / TIMER_GRANULARITY);
- ts.tv_nsec = (grains % (1000000000 / TIMER_GRANULARITY))
+ t.ts.tv_sec = grains / (1000000000 / TIMER_GRANULARITY);
+ t.ts.tv_nsec = (grains % (1000000000 / TIMER_GRANULARITY))
* TIMER_GRANULARITY;
- return ts;
+ return t;
}
-void timers_init(struct timers *timers, struct timespec start)
+void timers_init(struct timers *timers, struct timeabs start)
{
unsigned int i;
list_head_init(&timers->far);
timers->base = time_to_grains(start);
+ timers->first = -1ULL;
for (i = 0; i < ARRAY_SIZE(timers->level); i++)
timers->level[i] = NULL;
}
-static void timer_add_raw(struct timers *timers, struct timer *t)
+static unsigned int level_of(const struct timers *timers, uint64_t time)
{
- struct list_head *l;
uint64_t diff;
- unsigned int level;
/* Level depends how far away it is. */
- diff = t->time - timers->base;
- level = ilog64(diff / 2) / TIMER_LEVEL_BITS;
+ diff = time - timers->base;
+ return ilog64(diff / 2) / TIMER_LEVEL_BITS;
+}
+
+static void timer_add_raw(struct timers *timers, struct timer *t)
+{
+ struct list_head *l;
+ unsigned int level = level_of(timers, t->time);
if (!timers->level[level])
l = &timers->far;
list_add_tail(l, &t->list);
}
-void timer_add(struct timers *timers, struct timer *t, struct timespec when)
+void timer_init(struct timer *t)
+{
+ list_node_init(&t->list);
+}
+
+static bool list_node_initted(const struct list_node *n)
+{
+ return n->prev == n;
+}
+
+void timer_add(struct timers *timers, struct timer *t, struct timeabs when)
{
+ assert(list_node_initted(&t->list));
+
t->time = time_to_grains(when);
/* Added in the past? Treat it as imminent. */
if (t->time < timers->base)
t->time = timers->base;
+ if (t->time < timers->first)
+ timers->first = t->time;
timer_add_raw(timers, t);
}
/* FIXME: inline */
void timer_del(struct timers *timers, struct timer *t)
{
- list_del(&t->list);
+ list_del_init(&t->list);
}
static void timers_far_get(struct timers *timers,
timer_add_raw(timers, t);
}
-/* Take timers from level and distribute them down one. */
-static void cascade(struct timers *timers, unsigned int level)
-{
- struct timer *i;
- struct list_head from_far, *list;
-
- if (level == ARRAY_SIZE(timers->level) || !timers->level[level]) {
- list_head_init(&from_far);
- timers_far_get(timers, &from_far,
- timers->base
- + (1ULL << (level*TIMER_LEVEL_BITS))-1);
- list = &from_far;
- if (level != ARRAY_SIZE(timers->level))
- add_level(timers, level);
- } else {
- unsigned src;
-
- src = (timers->base >> (level * TIMER_LEVEL_BITS)) % PER_LEVEL;
- if (src == 0)
- cascade(timers, level + 1);
- list = &timers->level[level]->list[src];
- }
-
- while ((i = list_pop(list, struct timer, list)) != NULL) {
- unsigned dst;
-
- assert(i->time >= timers->base);
- assert(i->time < (timers->base
- + (1ULL << ((level+1)*TIMER_LEVEL_BITS))));
-
- dst = (i->time >> ((level-1)*TIMER_LEVEL_BITS)) % PER_LEVEL;
- list_add_tail(&timers->level[level-1]->list[dst], &i->list);
- }
-}
-
+/* We don't need to search past the first at level 0, since the
+ * bucket range is 1; they're all the same. */
static const struct timer *find_first(const struct list_head *list,
+ unsigned int level,
const struct timer *prev)
{
struct timer *t;
list_for_each(list, t, list) {
if (!prev || t->time < prev->time)
prev = t;
+ if (level == 0)
+ break;
}
return prev;
}
-static struct timer *get_first(const struct timers *timers)
+static const struct timer *get_first(const struct timers *timers)
{
- unsigned int level = 0, i, off;
+ unsigned int level, i, off;
bool need_next;
- uint64_t base = timers->base;
+ uint64_t base;
const struct timer *found = NULL;
struct list_head *h;
+ if (timers->first < timers->base) {
+ base = timers->base;
+ level = 0;
+ } else {
+ /* May not be accurate, due to timer_del / expiry. */
+ level = level_of(timers, timers->first);
+ base = timers->first >> (TIMER_LEVEL_BITS * level);
+ }
+
next:
if (!timers->level[level])
- return (struct timer *)find_first(&timers->far, NULL);
+ return find_first(&timers->far, -1U, NULL);
need_next = false;
off = base % PER_LEVEL;
if (i == PER_LEVEL) {
level++;
base >>= TIMER_LEVEL_BITS;
+ if (off != 0)
+ /* We need *next* bucket: we've started reusing the
+ * one above */
+ base++;
goto next;
}
/* Level 0 is exact, so they're all the same. */
- if (level == 0)
- found = list_top(h, struct timer, list);
- else
- found = find_first(h, NULL);
+ found = find_first(h, level, NULL);
- if (need_next) {
+ while (need_next) {
+ need_next = false;
if (!timers->level[level+1]) {
- found = find_first(&timers->far, found);
+ found = find_first(&timers->far, -1U, found);
} else {
+ /* Current upper bucket has emptied into this
+ * bucket; we want *next* one. */
base >>= TIMER_LEVEL_BITS;
+ base++;
off = base % PER_LEVEL;
- h = &timers->level[level+1]->list[off];
- found = find_first(h, found);
+
+ if (off == 0) {
+ need_next = true;
+ } else {
+ h = &timers->level[level+1]->list[off];
+ found = find_first(h, level+1, found);
+ }
}
}
-
- return (struct timer *)found;
+ return found;
}
-bool timer_earliest(const struct timers *timers, struct timespec *first)
+static bool update_first(struct timers *timers)
{
- struct timer *found = get_first(timers);
+ const struct timer *found = get_first(timers);
- if (!found)
+ if (!found) {
+ timers->first = -1ULL;
return false;
- *first = grains_to_time(found->time);
+ }
+
+ timers->first = found->time;
+ return true;
+}
+
+bool timer_earliest(struct timers *timers, struct timeabs *first)
+{
+ if (!update_first(timers))
+ return false;
+
+ *first = grains_to_time(timers->first);
return true;
}
timer_add_raw(timers, i);
}
-/* Fills list of expired timers. */
-void timers_expire(struct timers *timers,
- struct timespec expire,
- struct list_head *list)
+/* Returns an expired timer. */
+struct timer *timers_expire(struct timers *timers, struct timeabs expire)
{
uint64_t now = time_to_grains(expire);
unsigned int off;
- const struct timer *first;
+ struct timer *t;
assert(now >= timers->base);
- list_head_init(list);
-
if (!timers->level[0]) {
if (list_empty(&timers->far))
- return;
+ return NULL;
add_level(timers, 0);
}
- while ((first = get_first(timers)) != NULL) {
- assert(first->time >= timers->base);
- if (first->time > now) {
+ do {
+ if (timers->first > now) {
timer_fast_forward(timers, now);
- break;
+ return NULL;
}
- timer_fast_forward(timers, first->time);
+ timer_fast_forward(timers, timers->first);
off = timers->base % PER_LEVEL;
- list_append_list(list, &timers->level[0]->list[off]);
- if (timers->base == now)
- break;
- }
+ /* This *may* be NULL, if we deleted the first timer */
+ t = list_pop(&timers->level[0]->list[off], struct timer, list);
+ if (t)
+ list_node_init(&t->list);
+ } while (!t && update_first(timers));
+
+ return t;
}
static bool timer_list_check(const struct list_head *l,
- uint64_t min, uint64_t max,
+ uint64_t min, uint64_t max, uint64_t first,
const char *abortstr)
{
const struct timer *t;
if (abortstr) {
fprintf(stderr,
"%s: timer %p %llu not %llu-%llu\n",
- abortstr, t, t->time, min, max);
+ abortstr, t, (long long)t->time,
+ (long long)min, (long long)max);
+ abort();
+ }
+ return false;
+ }
+ if (t->time < first) {
+ if (abortstr) {
+ fprintf(stderr,
+ "%s: timer %p %llu < minimum %llu\n",
+ abortstr, t, (long long)t->time,
+ (long long)first);
abort();
}
return false;
h = &timers->level[l]->list[(i+off) % PER_LEVEL];
if (!timer_list_check(h, timers->base + i, timers->base + i,
- abortstr))
+ timers->first, abortstr))
return NULL;
}
/* For other levels, "current" bucket has been emptied, and may contain
* entries for the current + level_size bucket. */
- for (l = 1; timers->level[l] && l < PER_LEVEL; l++) {
+ for (l = 1; l < ARRAY_SIZE(timers->level) && timers->level[l]; l++) {
uint64_t per_bucket = 1ULL << (TIMER_LEVEL_BITS * l);
off = ((timers->base >> (l*TIMER_LEVEL_BITS)) % PER_LEVEL);
h = &timers->level[l]->list[(i+off) % PER_LEVEL];
if (!timer_list_check(h, base, base + per_bucket - 1,
- abortstr))
+ timers->first, abortstr))
return NULL;
base += per_bucket;
}
past_levels:
base = (timers->base & ~((1ULL << (TIMER_LEVEL_BITS * l)) - 1))
+ (1ULL << (TIMER_LEVEL_BITS * l)) - 1;
- if (!timer_list_check(&timers->far, base, -1ULL, abortstr))
+ if (!timer_list_check(&timers->far, base, -1ULL, timers->first,
+ abortstr))
return NULL;
return (struct timers *)timers;
}
-//#ifdef CCAN_TIMER_DEBUG
-void timers_dump(const struct timers *timers, FILE *fp)
+#ifdef CCAN_TIMER_DEBUG
+static void dump_bucket_stats(FILE *fp, const struct list_head *h)
{
- unsigned int l, i;
- uint64_t min, max, num;
+ unsigned long long min, max, num;
struct timer *t;
- if (!fp)
- fp = stderr;
-
- fprintf(fp, "Base: %llu\n", timers->base);
-
- for (l = 0; timers->level[l] && l < ARRAY_SIZE(timers->level); l++) {
- fprintf(fp, "Level %i (+%llu):\n",
- l, (uint64_t)1 << (TIMER_LEVEL_BITS * l));
- for (i = 0; i < (1 << TIMER_LEVEL_BITS); i++) {
-
- if (list_empty(&timers->level[l]->list[i]))
- continue;
- min = -1ULL;
- max = 0;
- num = 0;
- list_for_each(&timers->level[l]->list[i], t, list) {
- if (t->time < min)
- min = t->time;
- if (t->time > max)
- max = t->time;
- num++;
- }
- fprintf(stderr, " %llu (+%llu-+%llu)\n",
- num, min - timers->base, max - timers->base);
- }
+ if (list_empty(h)) {
+ printf("\n");
+ return;
}
min = -1ULL;
max = 0;
num = 0;
- list_for_each(&timers->far, t, list) {
+ list_for_each(h, t, list) {
if (t->time < min)
min = t->time;
if (t->time > max)
max = t->time;
num++;
}
- fprintf(stderr, "Far: %llu (%llu-%llu)\n", num, min, max);
+ fprintf(fp, " %llu (%llu-%llu)\n",
+ num, min, max);
+}
+
+void timers_dump(const struct timers *timers, FILE *fp)
+{
+ unsigned int l, i, off;
+ unsigned long long base;
+
+ if (!fp)
+ fp = stderr;
+
+ fprintf(fp, "Base: %llu\n", (unsigned long long)timers->base);
+
+ if (!timers->level[0])
+ goto past_levels;
+
+ fprintf(fp, "Level 0:\n");
+
+ /* First level is simple. */
+ off = timers->base % PER_LEVEL;
+ for (i = 0; i < PER_LEVEL; i++) {
+ const struct list_head *h;
+
+ fprintf(fp, " Bucket %llu (%lu):",
+ (i+off) % PER_LEVEL, timers->base + i);
+ h = &timers->level[0]->list[(i+off) % PER_LEVEL];
+ dump_bucket_stats(fp, h);
+ }
+
+ /* For other levels, "current" bucket has been emptied, and may contain
+ * entries for the current + level_size bucket. */
+ for (l = 1; l < ARRAY_SIZE(timers->level) && timers->level[l]; l++) {
+ uint64_t per_bucket = 1ULL << (TIMER_LEVEL_BITS * l);
+
+ off = ((timers->base >> (l*TIMER_LEVEL_BITS)) % PER_LEVEL);
+ /* We start at *next* bucket. */
+ base = (timers->base & ~(per_bucket - 1)) + per_bucket;
+
+ fprintf(fp, "Level %u:\n", l);
+ for (i = 1; i <= PER_LEVEL; i++) {
+ const struct list_head *h;
+
+ fprintf(fp, " Bucket %llu (%llu - %llu):",
+ (i+off) % PER_LEVEL,
+ base, base + per_bucket - 1);
+
+ h = &timers->level[l]->list[(i+off) % PER_LEVEL];
+ dump_bucket_stats(fp, h);
+ base += per_bucket;
+ }
+ }
+
+past_levels:
+ if (!list_empty(&timers->far)) {
+ fprintf(fp, "Far timers:");
+ dump_bucket_stats(fp, &timers->far);
+ }
}
-//#endif
+#endif
void timers_cleanup(struct timers *timers)
{
projects / ccan / blobdiff