struct list_head list[PER_LEVEL];
};
-static uint64_t time_to_grains(struct timeabs t)
+static uint64_t time_to_grains(struct timemono t)
{
return t.ts.tv_sec * ((uint64_t)1000000000 / TIMER_GRANULARITY)
+ (t.ts.tv_nsec / TIMER_GRANULARITY);
}
-static struct timeabs grains_to_time(uint64_t grains)
+static struct timemono grains_to_time(uint64_t grains)
{
- struct timeabs t;
+ struct timemono t;
t.ts.tv_sec = grains / (1000000000 / TIMER_GRANULARITY);
t.ts.tv_nsec = (grains % (1000000000 / TIMER_GRANULARITY))
return t;
}
-void timers_init(struct timers *timers, struct timeabs start)
+void timers_init(struct timers *timers, struct timemono start)
{
unsigned int i;
list_head_init(&timers->far);
timers->base = time_to_grains(start);
timers->first = -1ULL;
+ memset(timers->firsts, 0xFF, sizeof(timers->firsts));
for (i = 0; i < ARRAY_SIZE(timers->level); i++)
timers->level[i] = NULL;
}
{
struct list_head *l;
unsigned int level = level_of(timers, t->time);
+ uint64_t *first;
- if (!timers->level[level])
+ if (!timers->level[level]) {
l = &timers->far;
- else {
+ first = &timers->firsts[ARRAY_SIZE(timers->level)];
+ } else {
int off = (t->time >> (level*TIMER_LEVEL_BITS)) & (PER_LEVEL-1);
l = &timers->level[level]->list[off];
+ first = &timers->firsts[level];
}
list_add_tail(l, &t->list);
+ if (t->time < *first)
+ *first = t->time;
}
void timer_init(struct timer *t)
return n->prev == n;
}
-void timer_add(struct timers *timers, struct timer *t, struct timeabs when)
+void timer_addrel(struct timers *timers, struct timer *t, struct timerel rel)
+{
+ assert(list_node_initted(&t->list));
+
+ t->time = time_to_grains(timemono_add(time_mono(), rel));
+
+#if TIME_HAVE_MONOTONIC
+ assert(t->time >= timers->base);
+#else
+ /* Added in the past? Treat it as imminent. */
+ if (t->time < timers->base)
+ t->time = timers->base;
+#endif
+ if (t->time < timers->first)
+ timers->first = t->time;
+
+ timer_add_raw(timers, t);
+}
+
+void timer_addmono(struct timers *timers, struct timer *t, struct timemono when)
{
assert(list_node_initted(&t->list));
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)
+/* Update level's first watermark, and return overall first. */
+static const struct timer *first_for_level(struct timers *timers,
+ size_t level,
+ const struct timer *level_first,
+ const struct timer *first)
{
- unsigned int level, i, off;
- bool need_next;
- uint64_t base;
- const struct timer *found = NULL;
- struct list_head *h;
-
- if (timers->first < timers->base) {
- base = timers->base;
- level = 0;
+ if (level_first) {
+ timers->firsts[level] = level_first->time;
+ if (!first || level_first->time < first->time)
+ first = level_first;
} else {
- /* May not be accurate, due to timer_del / expiry. */
- level = level_of(timers, timers->first);
- base = timers->first >> (TIMER_LEVEL_BITS * level);
+ timers->firsts[level] = -1ULL;
}
+ return first;
+}
-next:
- if (!timers->level[level])
- return find_first(&timers->far, NULL);
+static bool level_may_beat(const struct timers *timers, size_t level,
+ const struct timer *first)
+{
+ return !first || timers->firsts[level] < first->time;
+}
- need_next = false;
- off = base % PER_LEVEL;
- for (i = 0; i < PER_LEVEL; i++) {
- h = &timers->level[level]->list[(i+off) % PER_LEVEL];
+/* FIXME: Suboptimal */
+static const struct timer *brute_force_first(struct timers *timers)
+{
+ unsigned int l, i;
+ const struct timer *found = NULL;
- if (!list_empty(h))
- break;
+ for (l = 0; l < ARRAY_SIZE(timers->level) && timers->level[l]; l++) {
+ const struct timer *t = NULL;
+
+ /* Do we know they don't have a better one? */
+ if (!level_may_beat(timers, l, found))
+ continue;
- /* 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;
+ /* Find first timer on this level. */
+ for (i = 0; i < PER_LEVEL; i++)
+ t = find_first(&timers->level[l]->list[i], l, t);
+
+ found = first_for_level(timers, l, t, found);
}
- if (i == PER_LEVEL) {
- level++;
- base >>= TIMER_LEVEL_BITS;
- goto next;
+
+ /* Check (and update) far list if there's a chance. */
+ l = ARRAY_SIZE(timers->level);
+ if (level_may_beat(timers, l, found)) {
+ const struct timer *t = find_first(&timers->far, l, NULL);
+ found = first_for_level(timers, l, t, found);
}
- /* 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);
+ return found;
+}
- 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);
+static const struct timer *get_first(struct timers *timers)
+{
+ /* 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 = timers->base % 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)
if (!found) {
timers->first = -1ULL;
return false;
- }
+ }
timers->first = found->time;
return true;
}
-bool timer_earliest(struct timers *timers, struct timeabs *first)
+bool timer_earliest(struct timers *timers, struct timemono *first)
{
if (!update_first(timers))
return false;
}
/* Returns an expired timer. */
-struct timer *timers_expire(struct timers *timers, struct timeabs expire)
+struct timer *timers_expire(struct timers *timers, struct timemono expire)
{
uint64_t now = time_to_grains(expire);
unsigned int off;
h = &timers->level[l]->list[(i+off) % PER_LEVEL];
if (!timer_list_check(h, timers->base + i, timers->base + i,
- timers->first, abortstr))
+ timers->firsts[l], abortstr))
return NULL;
}
h = &timers->level[l]->list[(i+off) % PER_LEVEL];
if (!timer_list_check(h, base, base + per_bucket - 1,
- timers->first, abortstr))
+ timers->firsts[l], 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, timers->first,
+ if (!timer_list_check(&timers->far, base, -1ULL,
+ timers->firsts[ARRAY_SIZE(timers->level)],
abortstr))
return NULL;
projects / ccan / blobdiff