From: info at tphnet dot com
Operating system: Windows XP SP1
PHP version: 5.0.0
PHP Bug Type: Sockets related
Bug description: Listening on non-blocking socket leaks memory
Description:
------------
I've been trying to write a simple multi-client server application in PHP.
Everything is working just fine, the only problem is that the server is
leaking memory.
Reproduce code:
---------------
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_bind($socket, 'localhost', 1234);
socket_listen($socket);
socket_set_nonblock($socket);
while(true){
$new_connection = @socket_accept($socket);
unset($new_connection);
}
Expected result:
----------------
The above server will accept connections on localhot:1234 and will
disconnect you directly after you connect.
The socket is setup in non-blocking mode, so that with a couple of minor
modifications it becomes possible to handle multiple clients at the same
time.
Actual result:
--------------
The code does exactly what it is supposed to do, but its memory use
increases very fast. It fills up my 512 megs in about a minute.
The memory leak occours in the socket_accept() function. Removing this
line will stop the memory leak from occouring.
If you remove the socket_set_nonblock() function it also does not leak
memory anymore. This seems kind of logical because the script will "hang"
on the socket_accept() function instead of looping over it constantly.
In the version of the script I'm actually using, a "usleep(100000)" has
been added in the while loop to make sure the script doesn't consume all
available resources, but the memory leak still remains. Although it takes
much longer to fill all memory because socket_accept() is called less
frequent.
Removing the "@" sign infront of the socket_accept() function causes the
following two errors to be printed on the console for every call to
socket_accpet():
Warning: socket_accept(): unable to accept incoming connection [0]: Een
niet-blokkerende socketbewerking kan niet onmiddellijk worden voltooid.
Warning: socket_accept(): unable to accept socket connection [0]: De
bewerking is voltooid.
The first error roughly translates to "A non-blocking socket action cannot
be executed immediately" and the second to "The action has been
completed".
I'm not really an expert on sockets so I'm not sure if my script is just
flawed or this is a real bug. I've used the above code in a somewhat more
advanced form to create a small POP3 server. This server is functioning
just fine, the only problem is that it is leaking memory.
--
Edit bug report at http://bugs.php.net/?id=29560&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=29560&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=29560&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=29560&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=29560&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=29560&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=29560&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=29560&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=29560&r=support
Expected behavior: http://bugs.php.net/fix.php?id=29560&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=29560&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=29560&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=29560&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=29560&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=29560&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=29560&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=29560&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=29560&r=float
