note 80691 modified in function.socket-connect by danbrown

If you want to make a daemon process that forks on each client connection, you'll find out that there's a bug in PHP. The child processes send SIGCHLD to their parent when they exit but the parent can't handle signals while it's waiting for socket_accept (blocking). Here is a piece of code that makes a non-blocking forking server. #!/usr/bin/php -q <?php /** * Listens for requests and forks on each connection */ $__server_listening = true; error_reporting(E_ALL); set_time_limit(0); ob_implicit_flush(); declare(ticks = 1); become_daemon(); /* nobody/nogroup, change to your host's uid/gid of the non-priv user */ change_identity(65534, 65534); /* handle signals */ pcntl_signal(SIGTERM, 'sig_handler'); pcntl_signal(SIGINT, 'sig_handler'); pcntl_signal(SIGCHLD, 'sig_handler'); /* change this to your own host / port */ server_loop("127.0.0.1", 1234); /** * Change the identity to a non-priv user */ function change_identity( $uid, $gid ) { if( !posix_setgid( $gid ) ) { print "Unable to setgid to " . $gid . "!\n"; exit; } if( !posix_setuid( $uid ) ) { print "Unable to setuid to " . $uid . "!\n"; exit; } } /** * Creates a server socket and listens for incoming client connections * @param string $address The address to listen on * @param int $port The port to listen on */ function server_loop($address, $port) { GLOBAL $__server_listening; if(($sock = socket_create(AF_INET, SOCK_STREAM, 0)) < 0) { echo "failed to create socket: ".socket_strerror($sock)."\n"; exit(); } if(($ret = socket_bind($sock, $address, $port)) < 0) { echo "failed to bind socket: ".socket_strerror($ret)."\n"; exit(); } if( ( $ret = socket_listen( $sock, 0 ) ) < 0 ) { echo "failed to listen to socket: ".socket_strerror($ret)."\n"; exit(); } socket_set_nonblock($sock); echo "waiting for clients to connect\n"; while ($__server_listening) { $connection = @socket_accept($sock); if ($connection === false) { usleep(100); }elseif ($connection > 0) { handle_client($sock, $connection); }else { echo "error: ".socket_strerror($connection); die; } } } /** * Signal handler */ function sig_handler($sig) { switch($sig) { case SIGTERM: case SIGINT: exit(); break; case SIGCHLD: pcntl_waitpid(-1, $status); break; } } /** * Handle a new client connection */ function handle_client($ssock, $csock) { GLOBAL $__server_listening; $pid = pcntl_fork(); if ($pid == -1) { /* fork failed */ echo "fork failure!\n"; die; }elseif ($pid == 0) { /* child process */ $__server_listening = false; socket_close($ssock); interact($csock); socket_close($csock); }else { socket_close($csock); } } function interact($socket) { /* TALK TO YOUR CLIENT */ } /** * Become a daemon by forking and closing the parent */ function become_daemon() { $pid = pcntl_fork(); if ($pid == -1) { /* fork failed */ echo "fork failure!\n"; exit(); }elseif ($pid) { /* close the parent */ exit(); }else { /* child becomes our daemon */ posix_setsid(); chdir('/'); umask(0); return posix_getpid(); } } ?> --was-- If you want to make a daemon process that forks on each client connection, you'll find out that there's a bug in PHP. The child processes send SIGCHLD to their parent when they exit but the parent can't handle signals while it's waiting for socket_accept (blocking). Here is a piece of code that makes a non-blocking forking server. #!/usr/bin/php -q <?php /** * Listens for requests and forks on each connection */ $__server_listening = true; error_reporting(E_ALL); set_time_limit(0); ob_implicit_flush(); declare(ticks = 1); become_daemon(); /* nobody/nogroup, change to your host's uid/gid of the non-priv user */ change_identity(65534, 65534); /* handle signals */ pcntl_signal(SIGTERM, 'sig_handler'); pcntl_signal(SIGINT, 'sig_handler'); pcntl_signal(SIGCHLD, 'sig_handler'); /* change this to your own host / port */ server_loop("127.0.0.1", 1234); /** * Change the identity to a non-priv user */ function change_identity( $uid, $gid ) { if( !posix_setgid( $gid ) ) { print "Unable to setgid to " . $gid . "!\n"; exit; } if( !posix_setuid( $uid ) ) { print "Unable to setuid to " . $uid . "!\n"; exit; } } /** * Creates a server socket and listens for incoming client connections * @param string $address The address to listen on * @param int $port The port to listen on */ function server_loop($address, $port) { GLOBAL $__server_listening; if(($sock = socket_create(AF_INET, SOCK_STREAM, 0)) < 0) { echo "failed to create socket: ".socket_strerror($sock)."\n"; exit(); } if(($ret = socket_bind($sock, $address, $port)) < 0) { echo "failed to bind socket: ".socket_strerror($ret)."\n"; exit(); } if( ( $ret = socket_listen( $sock, 0 ) ) < 0 ) { echo "failed to listen to socket: ".socket_strerror($ret)."\n"; exit(); } socket_set_nonblock($sock); echo "waiting for clients to connect\n"; while ($__server_listening) { $connection = @socket_accept($sock); if ($connection === false) { usleep(100); }elseif ($connection > 0) { handle_client($sock, $connection); }else { echo "error: ".socket_strerror($connection); die; } } } /** * Signal handler */ function sig_handler($sig) { switch($sig) { case SIGTERM: case SIGINT: exit(); break; case SIGCHLD: pcntl_waitpid(-1, $status); break; } } /** * Handle a new client connection */ function handle_client($ssock, $csock) { GLOBAL $__server_listening; $pid = pcntl_fork(); if ($pid == -1) { /* fork failed */ echo "fork failure!\n"; die; }elseif ($pid == 0) { /* child process */ $__server_listening = false; socket_close($ssock); interact($csock); socket_close($csock); }else { socket_close($csock); } } function interact($socket) { /* TALK TO YOUR CLIENT */ } /** * Become a daemon by forking and closing the parent */ function become_daemon() { $pid = pcntl_fork(); if ($pid == -1) { /* fork failed */ echo "fork failure!\n"; exit(); }elseif ($pid) { /* close the parent */ exit(); }else { /* child becomes our daemon */ posix_setsid(); chdir('/'); umask(0); return posix_getpid(); } } ?> http://php.net/manual/en/function.socket-connect.php