UPDATE: [Patch] poll/unix/poll.c:apr_pollset_poll() optimisation

[gerry]

Greetings,

There's a sneakier (and pretty obvious, once you look at it) way of 
improving this loop which I prefer to my original mail by replacing the 
for-loop condition.

Should be safe: I like poll()... he has an honest face... I don't think 
he will lie to us about the number of signalled descriptors.


--- poll.c      2006/01/02 18:30:27     1.1
+++ poll.c      2006/01/05 00:11:36
@@ -254,13 +254,13 @@
        return apr_get_netos_error();
    }
    if (rv == 0) {
        return APR_TIMEUP;
    }
    j = 0;
-    for (i = 0; i < pollset->nelts; i++) {
+    for (i = 0; j < rv; i++) {
        if (pollset->pollset[i].revents != 0) {
            pollset->result_set[j] = pollset->query_set[i];
            pollset->result_set[j].rtnevents =
                get_revent(pollset->pollset[i].revents);
            j++;
        }



Cheers
Gerry Calderhead

Quoting [EMAIL PROTECTED]:

Greetings,

Spotted an early-exit optimisation in poll/unix/poll.c:apr_pollset_poll().

We know the number of signalled descriptors, NUM, returned from the 
poll() call so we could bust out of the post-processing loop once 
we've added NUM signalled descriptors to our RESULT_SET.

Cheers
Gerry Calderhead

[EMAIL PROTECTED] unix]$ rcsdiff -u6 poll.c
===================================================================
RCS file: RCS/poll.c,v
retrieving revision 1.1
diff -u6 -r1.1 poll.c
--- poll.c      2006/01/02 18:30:27     1.1
+++ poll.c      2006/01/02 20:16:14
@@ -259,13 +259,13 @@
    j = 0;
    for (i = 0; i < pollset->nelts; i++) {
        if (pollset->pollset[i].revents != 0) {
            pollset->result_set[j] = pollset->query_set[i];
            pollset->result_set[j].rtnevents =
                get_revent(pollset->pollset[i].revents);
-            j++;
+            if ((++j)==(*num)) break;
        }
    }
    if (descriptors)
        *descriptors = pollset->result_set;
    return APR_SUCCESS;
}