brianp 2002/07/30 18:12:43
Modified: poll/unix poll.c
Log:
Use storage on the stack instead of apr_palloc in apr_poll()
when the number of descriptors is small
(Note: The poll API still needs a rewrite in order to be
usable with large numbers of descriptors. This change is
just a short-term hack to work around the memory leak that
apr_poll() was causing in the httpd.)
Revision Changes Path
1.9 +18 -6 apr/poll/unix/poll.c
Index: poll.c
===================================================================
RCS file: /home/cvs/apr/poll/unix/poll.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -r1.8 -r1.9
--- poll.c 16 Jul 2002 20:27:43 -0000 1.8
+++ poll.c 31 Jul 2002 01:12:43 -0000 1.9
@@ -106,17 +106,29 @@
return rv;
}
+#define SMALL_POLLSET_LIMIT 8
+
APR_DECLARE(apr_status_t) apr_poll(apr_pollfd_t *aprset, apr_int32_t num,
apr_int32_t *nsds, apr_interval_time_t timeout)
{
- /* obvious optimization, it would be better if this could be allocated
- * on the stack. For a single file/socket, this can be otpimized
- * very cleanly.
- */
- struct pollfd *pollset = apr_palloc(aprset->p,
- sizeof(struct pollfd) * num);
+ struct pollfd tmp_pollset[SMALL_POLLSET_LIMIT];
+ struct pollfd *pollset;
int i;
+ if (num <= SMALL_POLLSET_LIMIT) {
+ pollset = tmp_pollset;
+ }
+ else {
+ /* XXX There are two problems with this code: it leaks
+ * memory, and it requires an O(n)-time loop to copy
+ * n descriptors from the apr_pollfd_t structs into
+ * the pollfd structs. At the moment, it's best suited
+ * for use with fewer than SMALL_POLLSET_LIMIT
+ * descriptors.
+ */
+ pollset = apr_palloc(aprset->p,
+ sizeof(struct pollfd) * num);
+ }
for (i = 0; i < num; i++) {
if (aprset[i].desc_type == APR_POLL_SOCKET) {
pollset[i].fd = aprset[i].desc.s->socketdes;
