list_add_tail(l, &t->list);
}
+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. */
/* 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);
}
+/* 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 const struct timer *get_first(const struct timers *timers)
+/* FIXME: Suboptimal */
+static const struct timer *brute_force_first(const struct timers *timers)
{
- unsigned int level, i, off;
- bool need_next;
- uint64_t base;
+ unsigned int l, i;
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 find_first(&timers->far, NULL);
-
- need_next = false;
- off = base % PER_LEVEL;
- for (i = 0; i < PER_LEVEL; i++) {
- h = &timers->level[level]->list[(i+off) % PER_LEVEL];
- if (!list_empty(h))
- break;
-
- /* We haven't cascaded yet, so if we wrap, we'll need to
- * check next level, too. */
- if (i + off == PER_LEVEL)
- need_next = true;
- }
- if (i == PER_LEVEL) {
- level++;
- base >>= TIMER_LEVEL_BITS;
- goto next;
+ for (l = 0; l < ARRAY_SIZE(timers->level) && timers->level[l]; l++) {
+ for (i = 0; i < PER_LEVEL; i++)
+ found = find_first(&timers->level[l]->list[i], l,
+ found);
}
- /* Level 0 is exact, so they're all the same. */
- if (level == 0)
- found = list_top(h, struct timer, list);
+ found = find_first(&timers->far, -1U, found);
+ return found;
+}
+
+static const struct timer *get_first(const struct timers *timers)
+{
+ uint64_t time;
+
+ /* Where can we start from? */
+ if (timers->first < timers->base)
+ time = timers->base;
else
- found = find_first(h, NULL);
-
- if (need_next) {
- if (!timers->level[level+1]) {
- found = find_first(&timers->far, found);
- } else {
- base >>= TIMER_LEVEL_BITS;
- off = base % PER_LEVEL;
- h = &timers->level[level+1]->list[off];
- found = find_first(h, found);
+ time = timers->first;
+
+ /* We can have just far timers, for example. */
+ if (timers->level[0]) {
+ /* First search rest of lower buckets; we've already spilled
+ * so if we find one there we don't need to search further. */
+ unsigned int i, off = time % PER_LEVEL;
+
+ for (i = off; i < PER_LEVEL; i++) {
+ struct list_head *h = &timers->level[0]->list[i];
+ if (!list_empty(h))
+ return find_first(h, 0, NULL);
}
}
- return found;
+
+ /* From here on, we're searching non-normalized parts of the
+ * data structure, which is much subtler.
+ *
+ * So we brute force. */
+ return brute_force_first(timers);
}
static bool update_first(struct timers *timers)
timer_add_raw(timers, i);
}
-/* Fills list of expired timers. */
-void timers_expire(struct timers *timers,
- struct timeabs 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;
+ 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);
}
do {
if (timers->first > now) {
timer_fast_forward(timers, now);
- break;
+ return NULL;
}
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;
- } while (update_first(timers));
+ /* 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,
/* 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);
}
#ifdef CCAN_TIMER_DEBUG
-void timers_dump(const struct timers *timers, FILE *fp)
+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
projects / ccan / blobdiff