X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=lib%2Fwaiter%2Fwaiter.c;h=78ba045f8b18fe5088d8c11422175b4654f87752;hb=a610837ff38f5cc80bcbad465a80ab920e67927d;hp=68f483acac03adaea7955cf91dd1fc2f2197a75a;hpb=e058e90117300125af7b6e93eb0e5aeb23543af9;p=petitboot

diff --git a/lib/waiter/waiter.c b/lib/waiter/waiter.c
index 68f483a..78ba045 100644
--- a/lib/waiter/waiter.c
+++ b/lib/waiter/waiter.c
@@ -1,5 +1,6 @@
 
 #include <poll.h>
+#include <stdbool.h>
 #include <string.h>
 #include <assert.h>
 
@@ -8,76 +9,131 @@
 #include "waiter.h"
 
 struct waiter {
+	struct waitset	*set;
 	int		fd;
 	int		events;
 	waiter_cb	callback;
 	void		*arg;
 };
 
-static struct waiter *waiters;
-static int n_waiters;
+struct waitset {
+	struct waiter	**waiters;
+	int		n_waiters;
+	bool		waiters_changed;
+
+	/* 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;
+};
 
-struct waiter *waiter_register(int fd, int events,
+struct waitset *waitset_create(void *ctx)
+{
+	struct waitset *set = talloc_zero(ctx, struct waitset);
+	return set;
+}
+
+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)
 {
-	struct waiter *waiter;
+	struct waiter **waiters, *waiter;
+
+	waiter = talloc(set->waiters, struct waiter);
+	if (!waiter)
+		return NULL;
+
+	waiters = talloc_realloc(set, set->waiters,
+			struct waiter *, set->n_waiters + 1);
 
-	n_waiters++;
+	if (!waiters) {
+		talloc_free(waiter);
+		return NULL;
+	}
+
+	set->waiters_changed = true;
+	set->waiters = waiters;
+	set->n_waiters++;
 
-	waiters = talloc_realloc(NULL, waiters, struct waiter, n_waiters);
-	waiter = &waiters[n_waiters - 1];
+	set->waiters[set->n_waiters - 1] = waiter;
 
+	waiter->set = set;
 	waiter->fd = fd;
 	waiter->events = events;
 	waiter->callback = callback;
 	waiter->arg = arg;
 
-	return 0;
+	return waiter;
 }
 
 void waiter_remove(struct waiter *waiter)
 {
+	struct waitset *set = waiter->set;
 	int i;
 
-	i = waiter - waiters;
-	assert(i >= 0 && i < n_waiters);
+	for (i = 0; i < set->n_waiters; i++)
+		if (set->waiters[i] == waiter)
+			break;
+
+	assert(i < set->n_waiters);
+
+	set->n_waiters--;
+	memmove(&set->waiters[i], &set->waiters[i+1],
+		(set->n_waiters - i) * sizeof(set->waiters[0]));
 
-	n_waiters--;
-	memmove(&waiters[i], &waiters[i+1],
-		(n_waiters - i) * sizeof(waiters[0]));
+	set->waiters = talloc_realloc(set->waiters, set->waiters,
+			struct waiter *, set->n_waiters);
+	set->waiters_changed = true;
 
-	waiters = talloc_realloc(NULL, waiters, struct waiter, n_waiters);
+	talloc_free(waiter);
 }
 
-int waiter_poll(void)
+int waiter_poll(struct waitset *set)
 {
-	static struct pollfd *pollfds;
-	static int n_pollfds;
 	int i, rc;
 
-	if (n_waiters != n_pollfds) {
-		pollfds = talloc_realloc(NULL, pollfds,
-				struct pollfd, n_waiters);
-		n_pollfds = n_waiters;
-	}
+	/* 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];
+		}
 
-	for (i = 0; i < n_waiters; i++) {
-		pollfds[i].fd = waiters[i].fd;
-		pollfds[i].events = waiters[i].events;
-		pollfds[i].revents = 0;
+		set->waiters_changed = false;
 	}
 
-	rc = poll(pollfds, n_waiters, -1);
+	rc = poll(set->pollfds, set->cur_n_waiters, -1);
 
 	if (rc <= 0)
 		return rc;
 
-	for (i = 0; i < n_waiters; i++) {
-		if (pollfds[i].revents) {
-			rc = waiters[i].callback(waiters[i].arg);
+	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);
 
 			if (rc)
-				waiter_remove(&waiters[i]);
+				waiter_remove(set->cur_waiters[i]);
 		}
 	}