added gracefull shutdown and max-connections

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-merge-1.4.x@653 152afb58-edef-0310-8abb-c4023f1b3aa9

src/base.h

@@ -441,6 +441,7 @@ typedef struct {
 	
 	unsigned short max_worker;
 	unsigned short max_fds;
+	unsigned short max_conns;
 	
 	unsigned short log_request_header_on_error;
 	unsigned short log_state_handling;
@@ -503,6 +504,8 @@ typedef struct {
 	int want_fds;   /* waiting fds */
 	int sockets_disabled;
 	
+	int max_conns;
+
 	/* buffers */
 	buffer *parse_full_path;
 	buffer *response_header;

src/configfile.c

@@ -76,6 +76,7 @@ static int config_insert(server *srv) {
 		{ "server.errorlog-use-syslog",  NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_SERVER },     /* 39 */
 		{ "server.range-requests",       NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION }, /* 40 */
 		{ "server.stat-cache-engine",    NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },  /* 41 */
+		{ "server.max-connections",      NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_SERVER },       /* 42 */
 		
 		{ "server.host",                 "use server.bind instead", T_CONFIG_DEPRECATED, T_CONFIG_SCOPE_UNSET },
 		{ "server.docroot",              "use server.document-root instead", T_CONFIG_DEPRECATED, T_CONFIG_SCOPE_UNSET },
@@ -112,6 +113,7 @@ static int config_insert(server *srv) {
 	stat_cache_string = buffer_init();
 	cv[41].destination = stat_cache_string;
 	
+	cv[42].destination = &(srv->srvconf.max_conns);
 	srv->config_storage = calloc(1, srv->config_context->used * sizeof(specific_config *));
 
 	assert(srv->config_storage);
@@ -1018,6 +1020,7 @@ int config_set_defaults(server *srv) {
 #endif
 #ifdef USE_FREEBSD_KQUEUE
 		{ FDEVENT_HANDLER_FREEBSD_KQUEUE, "freebsd-kqueue" },
+		{ FDEVENT_HANDLER_FREEBSD_KQUEUE, "kqueue" },
 #endif
 		{ FDEVENT_HANDLER_UNSET,          NULL }
 	};

src/fdevent_select.c

@@ -7,6 +7,7 @@
 #include <errno.h>
 #include <signal.h>
 #include <fcntl.h>
+#include <assert.h>
 
 #include "fdevent.h"
 #include "settings.h"
@@ -36,6 +37,9 @@ static int fdevent_select_event_del(fdevents *ev, int fde_ndx, int fd) {
 static int fdevent_select_event_add(fdevents *ev, int fde_ndx, int fd, int events) {
 	UNUSED(fde_ndx);
 
+	/* we should be protected by max-fds, but you never know */
+	assert(fd < FD_SETSIZE);
+
 	if (events & FDEVENT_IN) {
 		FD_SET(fd, &(ev->select_set_read));
 		FD_CLR(fd, &(ev->select_set_write));

src/network.c

@@ -345,7 +345,7 @@ int network_close(server *srv) {
 	for (i = 0; i < srv->srv_sockets.used; i++) {
 		server_socket *srv_socket = srv->srv_sockets.ptr[i];
 		
-		if (srv_socket->fd) {
+		if (srv_socket->fd != -1) {
 			/* check if server fd are already registered */
 			if (srv_socket->fde_ndx != -1) {
 				fdevent_event_del(srv->ev, &(srv_socket->fde_ndx), srv_socket->fd);

src/server.c

@@ -56,6 +56,7 @@
 #endif
 
 static volatile sig_atomic_t srv_shutdown = 0;
+static volatile sig_atomic_t gracefull_shutdown = 0;
 static volatile sig_atomic_t handle_sig_alarm = 1;
 static volatile sig_atomic_t handle_sig_hup = 0;
 
@@ -65,8 +66,8 @@ static void sigaction_handler(int sig, siginfo_t *si, void *context) {
 	UNUSED(context);
 
 	switch (sig) {
-	case SIGINT: srv_shutdown = 1; break;
 	case SIGTERM: srv_shutdown = 1; break;
+	case SIGINT: gracefull_shutdown = 1; break;
 	case SIGALRM: handle_sig_alarm = 1; break;
 	case SIGHUP:  handle_sig_hup = 1; break;
 	case SIGCHLD: break;
@@ -75,8 +76,8 @@ static void sigaction_handler(int sig, siginfo_t *si, void *context) {
 #elif defined(HAVE_SIGNAL) || defined(HAVE_SIGACTION)
 static void signal_handler(int sig) {
 	switch (sig) {
-	case SIGINT: srv_shutdown = 1; break;
 	case SIGTERM: srv_shutdown = 1; break;
+	case SIGINT: gracefull_shutdown = 1; break;
 	case SIGALRM: handle_sig_alarm = 1; break;
 	case SIGHUP:  handle_sig_hup = 1; break;
 	case SIGCHLD:  break;
@@ -631,6 +632,18 @@ int main (int argc, char **argv) {
 			return -1;
 		}
 	}
+
+	/* set max-conns */
+	if (srv->srvconf.max_conns > srv->max_fds) {
+		/* we can't have more connections than max-fds */
+		srv->max_conns = srv->max_fds;
+	} else if (srv->srvconf.max_conns) {
+		/* otherwise respect thw wishes of the user */
+		srv->max_conns = srv->srvconf.max_conns;
+	} else {
+		/* or use the default */
+		srv->max_conns = srv->max_fds;
+	}
 	
 	if (HANDLER_GO_ON != plugins_call_init(srv)) {
 		log_error_write(srv, __FILE__, __LINE__, "s", "Initialization of plugins failed. Going down.");
@@ -960,31 +973,63 @@ int main (int argc, char **argv) {
 			}
 		}
 
-		/* handle out of fd condition */
-		if (!srv->sockets_disabled &&
-		    srv->cur_fds + srv->want_fds > srv->max_fds * 0.9) {
+		if (srv->sockets_disabled) {
+			/* our server sockets are disabled, why ? */
+
+			if ((srv->cur_fds + srv->want_fds < srv->max_fds * 0.8) && /* we have enough unused fds */
+			    (srv->conns->used < srv->max_conns * 0.9) &&
+			    (0 == gracefull_shutdown)) {
+				for (i = 0; i < srv->srv_sockets.used; i++) {
+					server_socket *srv_socket = srv->srv_sockets.ptr[i];
+					fdevent_event_add(srv->ev, &(srv_socket->fde_ndx), srv_socket->fd, FDEVENT_IN);
+				}
 			
-			/* disable server-fds */
+				log_error_write(srv, __FILE__, __LINE__, "s", "[note] sockets enabled again");
 			
-			for (i = 0; i < srv->srv_sockets.used; i++) {
-				server_socket *srv_socket = srv->srv_sockets.ptr[i];
-				fdevent_event_del(srv->ev, &(srv_socket->fde_ndx), srv_socket->fd);
+				srv->sockets_disabled = 0;
 			}
+		} else {
+			if ((srv->cur_fds + srv->want_fds > srv->max_fds * 0.9) || /* out of fds */
+			    (srv->conns->used > srv->max_conns) || /* out of connections */
+			    (gracefull_shutdown)) { /* gracefull_shutdown */ 
+
+				/* disable server-fds */
 			
-			log_error_write(srv, __FILE__, __LINE__, "s", "[note] sockets disabled, out-of-fds");
-			
-			srv->sockets_disabled = 1;
-		} else if (srv->sockets_disabled &&
-			   srv->cur_fds + srv->want_fds < srv->max_fds * 0.8) {
+				for (i = 0; i < srv->srv_sockets.used; i++) {
+					server_socket *srv_socket = srv->srv_sockets.ptr[i];
+					fdevent_event_del(srv->ev, &(srv_socket->fde_ndx), srv_socket->fd);
+
+					if (gracefull_shutdown) {
+						/* we don't want this socket anymore,
+						 *
+						 * closing it right away will make it possible for
+						 * the next lighttpd to take over (gracefull restart)
+						 *  */
+
+						fdevent_unregister(srv->ev, srv_socket->fd);
+						close(srv_socket->fd);
+						srv_socket->fd = -1;
+
+						/* network_close() will cleanup after us */
+					}
+				}
+		
+				if (gracefull_shutdown) {
+					log_error_write(srv, __FILE__, __LINE__, "s", "[note] gracefull shutdown started");
+				} else if (srv->conns->used > srv->max_conns) {
+					log_error_write(srv, __FILE__, __LINE__, "s", "[note] sockets disabled, connection limit reached");
+				} else {
+					log_error_write(srv, __FILE__, __LINE__, "s", "[note] sockets disabled, out-of-fds");
+				}
 			
-			for (i = 0; i < srv->srv_sockets.used; i++) {
-				server_socket *srv_socket = srv->srv_sockets.ptr[i];
-				fdevent_event_add(srv->ev, &(srv_socket->fde_ndx), srv_socket->fd, FDEVENT_IN);
+				srv->sockets_disabled = 1;
 			}
-			
-			log_error_write(srv, __FILE__, __LINE__, "s", "[note] sockets enabled, out-of-fds");
-			
-			srv->sockets_disabled = 0;
+		}
+
+		if (gracefull_shutdown && srv->conns->used == 0) {
+			/* we are in gracefull shutdown phase and all connections are closed
+			 * we are ready to terminate without harming anyone */
+			srv_shutdown = 1;
 		}
 		
 		/* we still have some fds to share */