Description:
------------
I am using (a slight variation of) the user-contributed example on this page:http://uk2.php.net/manual/en/function.curl-multi-exec.php.

Sometimes it works and sometimes it causes php to fail, without displaying any error notice (error reporting set to E_WARNING).  I cannot work out what it is that causes it to fail or not fail, but if I run the same requests on the script multiple times it behaves the same every time.

By getting php to print a message between each line of code I have narrowed the problem down to this line:
if (curl_multi_select($mh) != -1)

This is the php info for the server:
http://phpinfo.hostultra.com/

The problem does NOT occur when the script is executed on my local testing server (Mac OS X 10.4.8, PHP 5.2.1).



Reproduce code:
---------------
<?php
$mh = curl_multi_init();
foreach(array_keys($arr_requests) as $i)
		curl_multi_add_handle ($mh,$arr_requests[$i]); //each element of $arr_requests is a curl handle

print "got as far as executing the curl stuff<br>"; while (@ob_end_flush()); while (@flush());

do		{
		$mrc = curl_multi_exec($mh, $active);
		} while ($mrc == CURLM_CALL_MULTI_PERFORM && $active>0 && microtime(1)<$time);


print "1<br>"; while (@ob_end_flush()); while (@flush());

while ($active>0 and $mrc == CURLM_OK && microtime(1)<$time){
		print "2<br>"; while (@ob_end_flush()); while (@flush()); //this gets printed out fine
		// wait for network
		if (curl_multi_select($mh) != -1){
				// pull in any new data, or at least handle timeouts
    			do		{
						print "3<br>"; while (@ob_end_flush()); while (@flush()); //php never gets this far
						$mrc = curl_multi_exec($mh, $active);
						} while ($mrc == CURLM_CALL_MULTI_PERFORM && $active>0 && microtime(1)<$time);
				}
		}//end while

Expected result:
----------------
If curl_multi_select($mh) was equal to -1 then I would expect the while loop
while ($active>0 and $mrc == CURLM_OK && microtime(1)<$time)

Actual result:
--------------
PHP outputs:
got as far as executing the curl stuff
1
2

...and then it stops.  The connection to the browser is no longer active.  That's it, it just stops there and does no more.  No error message.


Even if I change the line
if (curl_multi_select($mh) != -1)
to just
if (curl_multi_select($mh))

the result is exactly the same