Related links:

http://bugs.php.net/bug.php?id=41593
http://bugs.php.net/bug.php?id=36158
http://php-fpm.anight.org/

--- php5.3-200711071330/sapi/cgi/cgi_main.c	2007-11-01 13:32:38.000000000 +0200
+++ php5.3-200711071330-graceful/sapi/cgi/cgi_main.c	2007-11-07 17:40:37.884171760 +0200
@@ -101,6 +101,9 @@
  */
 static int parent = 1;
 
+/* Socket we are listening on incoming connections */
+static int fcgi_fd = 0;
+
 /**
  * Process group
  */
@@ -1211,16 +1215,38 @@
 #endif
 
 #ifndef PHP_WIN32
-	sigaction(SIGTERM, &old_term, 0);
-
 	/* Kill all the processes in our process group */
-	kill(-pgroup, SIGTERM);
+	if (signal == SIGINT) {
+		sigaction(SIGTERM, &old_int, 0);
+		kill(-pgroup, SIGINT);
+	} else {
+		sigaction(SIGTERM, &old_term, 0);
+		kill(-pgroup, SIGTERM);
+	}
 #endif
 
 	/* We should exit at this point, but MacOSX doesn't seem to */
 	exit(0);
 }
 
+/**
+ * Graceful shutdown. Close listening sockets.
+ */
+void fastcgi_graceful_shutdown(int signal)
+{
+#ifdef DEBUG_FASTCGI
+	fprintf(stderr, "FastCGI graceful shutdown, pid %d\n", getpid());
+#endif
+
+	/* This will make FCGI shutdown itself later in the loop, however we should finish our request cleanly */
+	fcgi_shutdown();
+
+	/* Whoever we also close the listeing socket (which PHP itself doesn't seem to do?!) */
+	closesocket(fcgi_fd);
+	fcgi_fd = 0;
+}
+
+
 PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY("cgi.rfc2616_headers",     "0",  PHP_INI_ALL,    OnUpdateBool,   rfc2616_headers, php_cgi_globals_struct, php_cgi_globals)
 	STD_PHP_INI_ENTRY("cgi.nph",                 "0",  PHP_INI_ALL,    OnUpdateBool,   nph, php_cgi_globals_struct, php_cgi_globals)
@@ -1328,7 +1354,6 @@
 	int requests = 0;
 	int fastcgi = fcgi_is_fastcgi();
 	char *bindpath = NULL;
-	int fcgi_fd = 0;
 	fcgi_request request;
 	int repeats = 1;
 	int benchmark = 0;
@@ -1581,7 +1606,10 @@
 					/* don't catch our signals */
 					sigaction(SIGTERM, &old_term, 0);
 					sigaction(SIGQUIT, &old_quit, 0);
-					sigaction(SIGINT,  &old_int,  0);
+					/* handler for SIGINT */
+					act.sa_flags = 0;
+					act.sa_handler = fastcgi_graceful_shutdown;
+					sigaction(SIGINT, &act, &old_int);
 					break;
 				case -1:
 					perror("php (pre-forking)");