Re: bug to fix in poll.c

[Joe Orton <jo...@redhat.com>]

On Wed, Aug 25, 2004 at 08:20:49AM +0300, Dror Shilo wrote:
> the num parameter have to return the length of descriptors 
> 
> the select call returns the total number of socket handles that are ready and contained in the fd_set  structures
> therefore if we have 2 socket that one have an FD_READ and the second have FD_READ and FD_WRITE it will return 3 , but the lenght of descriptors is only 2 , this is a bug 
> there for the fix for this bug is to add this  line at file poll.c
> 
> (*num) = j;

Thanks for looking into this.  I don't have a platform using select() to
hand, but it looks like apr_poll() needs to be fixed too.  Can you try
this patch against 0.9.4?

--- poll/unix/poll.c	10 Apr 2004 21:29:52 -0000	1.38.2.2
+++ poll/unix/poll.c	25 Aug 2004 08:37:16 -0000
@@ -244,14 +244,14 @@
     }
 #endif
 
-    (*nsds) = rv;
-    if ((*nsds) == 0) {
+    if (rv == 0) {
         return APR_TIMEUP;
     }
-    if ((*nsds) < 0) {
+    if (rv < 0) {
         return apr_get_netos_error();
     }
-
+    
+    *nsds = 0;
     for (i = 0; i < num; i++) {
         apr_os_sock_t fd;
 
@@ -268,14 +268,18 @@
         else {
             break;
         }
-        if (FD_ISSET(fd, &readset)) {
-            aprset[i].rtnevents |= APR_POLLIN;
-        }
-        if (FD_ISSET(fd, &writeset)) {
-            aprset[i].rtnevents |= APR_POLLOUT;
-        }
-        if (FD_ISSET(fd, &exceptset)) {
-            aprset[i].rtnevents |= APR_POLLERR;
+        if (FD_ISSET(fd, &readset) || FD_ISSET(fd, &writeset) ||
+            FD_ISSET(fd, &exceptset)) {
+            (*nsds)++;
+            if (FD_ISSET(fd, &readset)) {
+                aprset[i].rtnevents |= APR_POLLIN;
+            }
+            if (FD_ISSET(fd, &writeset)) {
+                aprset[i].rtnevents |= APR_POLLOUT;
+            }
+            if (FD_ISSET(fd, &exceptset)) {
+                aprset[i].rtnevents |= APR_POLLERR;
+            }
         }
     }
 
@@ -553,8 +557,6 @@
     else
 #endif
     rv = select(pollset->maxfd + 1, &readset, &writeset, &exceptset, tvptr);
-
-    (*num) = rv;
     if (rv < 0) {
         return apr_get_netos_error();
     }
@@ -590,6 +592,8 @@
             j++;
         }
     }
+
+    (*num) = j;
 
     *descriptors = pollset->result_set;
     return APR_SUCCESS;