#43695 [Opn]: Asynchronous socket connection timing issue

ID: 43695 User updated by: nicolas dot legland at free dot fr Reported By: nicolas dot legland at free dot fr Status: Open Bug Type: Streams related Operating System: Windows XP Professional SP2 PHP Version: 5.3CVS-2007-12-28 (snap) New Comment: Description: ------------ When using sockets through the "sockets" extension, everything works fine with no delay to notice. Reproduce code: --------------- <?php // Load socket extension dl((('dll' === PHP_SHLIB_SUFFIX) ? 'php_' : '').'sockets.'.PHP_SHLIB_SUFFIX); // Send a [SYN] packet to scanme.nmap.org:70 $time = microtime(true); $resource = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); socket_set_nonblock($resource); @socket_connect($resource, gethostbyname('scanme.nmap.org'), 70); echo 'Open '.number_format((microtime(true) - $time), 6).PHP_EOL; // Wait 3 seconds for a [SYN, ACK] packet $time = microtime(true); $read = $write = $except = array($resource); socket_select($read, $write, $except, 3); echo 'Wait '.number_format((microtime(true) - $time), 6).' read '.count($read).', write '.count($write).', except '.count($except).PHP_EOL; // Cancel connection $time = microtime(true); socket_close($resource); echo 'Close '.number_format((microtime(true) - $time), 6).PHP_EOL; ?> Result: ------- Open 0.030620 Wait 1.518440 read 0, write 0, except 1 Close 0.000108 Previous Comments: ------------------------------------------------------------------------ [2007-12-28 08:37:12] nicolas dot legland at free dot fr Description: ------------ Asynchronously connecting a TCP socket stream to a filtered port times out, but closing the resource using fclose() blocks for 0.5 second. Asynchronously connecting a TCP socket stream to a closed port ends up with the server explicitly refusing the connection by a RST ACK packet. Using stream_select() returns the stream resource as having had an except but trying to close the resource using fclose() blocks for 0.5 second too. No network transfer was captured by Wireshark apart from the initial SYN packet in either case. Using fclose() on a successfully asynchronously connected TCP socket stream to an open port returns instantaneously. If you don't explicitly fclose() the resources of failed connections, the same 0.5 seconds lag appears at the end of the script execution for each one. PHP probably cleanly frees resources at shutdown, but it can reach several seconds when several sockets have failed. When using non-blocking BSD socket with the sockets extension, no delay of any kind is noticed. Reproduce code: --------------- <?php // Send a [SYN] packet to scanme.nmap.org:70 $time = microtime(true); $resource = stream_socket_client('tcp://'.gethostbyname('scanme.nmap.org').':70', $null = null, $null, 0, STREAM_CLIENT_ASYNC_CONNECT | STREAM_CLIENT_CONNECT); stream_set_blocking($resource, 0); echo 'Open '.number_format((microtime(true) - $time), 6).PHP_EOL; // Wait 3 seconds for a [SYN, ACK] packet $time = microtime(true); $read = $write = $except = array($resource); stream_select($read, $write, $except, 3); echo 'Wait '.number_format((microtime(true) - $time), 6).' read '.count($read).', write '.count($write).', except '.count($except).PHP_EOL; // Cancel connection $time = microtime(true); fclose($resource); echo 'Close '.number_format((microtime(true) - $time), 6).PHP_EOL; ?> Expected result: ---------------- Open 0.010317 Wait 1.588449 read 0, write 0, except 1 Close 0.000099 Actual result: -------------- Open 0.010002 Wait 1.547396 read 0, write 0, except 1 Close 0.510161 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=43695&edit=1