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authorJeremy Kerr <jk@ozlabs.org>2013-05-21 11:52:00 +0800
committerJeremy Kerr <jk@ozlabs.org>2013-06-24 12:52:49 +0800
commit658d9e98eec02f92e3cf263a1bb27beb3d395b2f (patch)
tree8ba272fa5ca895aba1e2ed88cc424e88bbb0db33 /lib/waiter
parenta3de0330fd61eca35cfe360dbb4ea266223f387e (diff)
downloadpetitboot-658d9e98eec02f92e3cf263a1bb27beb3d395b2f.zip
petitboot-658d9e98eec02f92e3cf263a1bb27beb3d395b2f.tar.gz
lib/waiter: Add timeout waiters
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Diffstat (limited to 'lib/waiter')
-rw-r--r--lib/waiter/waiter.c175
-rw-r--r--lib/waiter/waiter.h5
2 files changed, 146 insertions, 34 deletions
diff --git a/lib/waiter/waiter.c b/lib/waiter/waiter.c
index 78ba045..513ab60 100644
--- a/lib/waiter/waiter.c
+++ b/lib/waiter/waiter.c
@@ -3,15 +3,21 @@
#include <stdbool.h>
#include <string.h>
#include <assert.h>
+#include <sys/time.h>
#include <talloc/talloc.h>
#include "waiter.h"
struct waiter {
+ enum {
+ WAITER_IO,
+ WAITER_TIME,
+ } type;
struct waitset *set;
int fd;
int events;
+ struct timeval timeout;
waiter_cb callback;
void *arg;
};
@@ -21,12 +27,17 @@ struct waitset {
int n_waiters;
bool waiters_changed;
+ struct timeval next_timeout;
+
/* These are kept consistent over each call to waiter_poll, as
* set->waiters may be updated (by waiters' callbacks calling
* waiter_register or waiter_remove) during iteration. */
struct pollfd *pollfds;
- struct waiter **cur_waiters;
- int cur_n_waiters;
+ int n_pollfds;
+ struct waiter **io_waiters;
+ int n_io_waiters;
+ struct waiter **time_waiters;
+ int n_time_waiters;
};
struct waitset *waitset_create(void *ctx)
@@ -40,8 +51,7 @@ void waitset_destroy(struct waitset *set)
talloc_free(set);
}
-struct waiter *waiter_register(struct waitset *set, int fd, int events,
- waiter_cb callback, void *arg)
+static struct waiter *waiter_new(struct waitset *set)
{
struct waiter **waiters, *waiter;
@@ -62,7 +72,15 @@ struct waiter *waiter_register(struct waitset *set, int fd, int events,
set->n_waiters++;
set->waiters[set->n_waiters - 1] = waiter;
+ return waiter;
+}
+
+struct waiter *waiter_register_io(struct waitset *set, int fd, int events,
+ waiter_cb callback, void *arg)
+{
+ struct waiter *waiter = waiter_new(set);
+ waiter->type = WAITER_IO;
waiter->set = set;
waiter->fd = fd;
waiter->events = events;
@@ -72,6 +90,27 @@ struct waiter *waiter_register(struct waitset *set, int fd, int events,
return waiter;
}
+struct waiter *waiter_register_timeout(struct waitset *set, int delay_ms,
+ waiter_cb callback, void *arg)
+{
+ struct waiter *waiter = waiter_new(set);
+ struct timeval now, delay;
+
+ delay.tv_sec = delay_ms / 1000;
+ delay.tv_usec = 1000 * (delay_ms % 1000);
+
+ gettimeofday(&now, NULL);
+
+ timeradd(&now, &delay, &waiter->timeout);
+
+ waiter->type = WAITER_TIME;
+ waiter->set = set;
+ waiter->callback = callback;
+ waiter->arg = arg;
+
+ return waiter;
+}
+
void waiter_remove(struct waiter *waiter)
{
struct waitset *set = waiter->set;
@@ -94,47 +133,117 @@ void waiter_remove(struct waiter *waiter)
talloc_free(waiter);
}
+static void update_waiters(struct waitset *set)
+{
+ int n_io, n_time, i_io, i_time, i;
+
+ if (!set->waiters_changed)
+ return;
+
+ n_io = n_time = 0;
+
+ for (i = 0; i < set->n_waiters; i++) {
+ if (set->waiters[i]->type == WAITER_IO)
+ n_io++;
+ else if (set->waiters[i]->type == WAITER_TIME)
+ n_time++;
+ }
+
+ /* realloc if counts have changed */
+ if (set->n_io_waiters != n_io) {
+ set->io_waiters = talloc_realloc(set, set->io_waiters,
+ struct waiter *, n_io);
+ set->pollfds = talloc_realloc(set, set->pollfds,
+ struct pollfd, n_io);
+ set->n_io_waiters = n_io;
+ }
+ if (set->n_time_waiters != n_time) {
+ set->time_waiters = talloc_realloc(set, set->time_waiters,
+ struct waiter *, n_time);
+ set->n_time_waiters = n_time;
+ }
+
+ /* IO waiters: copy to io_waiters, populate pollfds */
+ for (i = i_io = 0; i < set->n_waiters; i++) {
+ struct waiter *waiter = set->waiters[i];
+
+ if (waiter->type != WAITER_IO)
+ continue;
+
+ set->pollfds[i_io].fd = waiter->fd;
+ set->pollfds[i_io].events = waiter->events;
+ set->io_waiters[i_io] = waiter;
+ i_io++;
+ }
+
+ /* time waiters: copy to time_waiters, calculate next expiry */
+ timerclear(&set->next_timeout);
+ for (i = i_time = 0; i < set->n_waiters; i++) {
+ struct waiter *waiter = set->waiters[i];
+
+ if (waiter->type != WAITER_TIME)
+ continue;
+
+ if (!timerisset(&set->next_timeout) ||
+ timercmp(&waiter->timeout,
+ &set->next_timeout, <))
+ set->next_timeout = waiter->timeout;
+
+ set->time_waiters[i_time] = waiter;
+ i_time++;
+ }
+}
+
int waiter_poll(struct waitset *set)
{
+ struct timeval now, timeout;
+ int timeout_ms;
int i, rc;
/* If the waiters have been updated, we need to update our
* consistent copy */
- if (set->waiters_changed) {
-
- /* We need to reallocate if the count has changes */
- if (set->cur_n_waiters != set->n_waiters) {
- set->cur_waiters = talloc_realloc(set, set->cur_waiters,
- struct waiter *, set->n_waiters);
- set->pollfds = talloc_realloc(set, set->pollfds,
- struct pollfd, set->n_waiters);
- set->cur_n_waiters = set->n_waiters;
- }
-
- /* Populate cur_waiters and pollfds from ->waiters data */
- for (i = 0; i < set->n_waiters; i++) {
- set->pollfds[i].fd = set->waiters[i]->fd;
- set->pollfds[i].events = set->waiters[i]->events;
- set->pollfds[i].revents = 0;
- set->cur_waiters[i] = set->waiters[i];
- }
-
- set->waiters_changed = false;
+ update_waiters(set);
+
+ if (timerisset(&set->next_timeout)) {
+ gettimeofday(&now, NULL);
+ timersub(&set->next_timeout, &now, &timeout);
+ timeout_ms = timeout.tv_sec * 1000 +
+ timeout.tv_usec / 1000;
+ if (timeout_ms < 0)
+ timeout_ms = 0;
+ } else {
+ timeout_ms = -1;
}
- rc = poll(set->pollfds, set->cur_n_waiters, -1);
- if (rc <= 0)
+ rc = poll(set->pollfds, set->n_io_waiters, timeout_ms);
+
+ if (rc < 0)
return rc;
- for (i = 0; i < set->cur_n_waiters; i++) {
- if (set->pollfds[i].revents) {
- rc = set->cur_waiters[i]->callback(
- set->cur_waiters[i]->arg);
+ for (i = 0; i < set->n_io_waiters; i++) {
+ struct waiter *waiter = set->io_waiters[i];
+
+ if (!set->pollfds[i].revents)
+ continue;
+ rc = waiter->callback(waiter->arg);
+
+ if (rc)
+ waiter_remove(waiter);
+ }
+
+ if (set->n_time_waiters > 0)
+ gettimeofday(&now, NULL);
+
+ for (i = 0; i < set->n_time_waiters; i++) {
+ struct waiter *waiter = set->time_waiters[i];
+
+ if (timercmp(&waiter->timeout, &now, >))
+ continue;
+
+ waiter->callback(waiter->arg);
- if (rc)
- waiter_remove(set->cur_waiters[i]);
- }
+ waiter_remove(waiter);
}
return 0;
diff --git a/lib/waiter/waiter.h b/lib/waiter/waiter.h
index ed7f6bb..58ea04c 100644
--- a/lib/waiter/waiter.h
+++ b/lib/waiter/waiter.h
@@ -16,7 +16,10 @@ typedef int (*waiter_cb)(void *);
struct waitset *waitset_create(void *ctx);
void waitset_destroy(struct waitset *waitset);
-struct waiter *waiter_register(struct waitset *waitset, int fd, int events,
+struct waiter *waiter_register_io(struct waitset *waitset, int fd, int events,
+ waiter_cb callback, void *arg);
+
+struct waiter *waiter_register_timeout(struct waitset *set, int delay_ms,
waiter_cb callback, void *arg);
void waiter_remove(struct waiter *waiter);
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