added safe-fd concept and --alarm-fd

core/alarm.c

@@ -11,6 +11,29 @@ void uwsgi_alarm_func_signal(struct uwsgi_alarm_instance *uai, char *msg, size_t
 	uwsgi_route_signal(uai->data8);
 }
 
+// simply log an alarm
+void uwsgi_alarm_init_log(struct uwsgi_alarm_instance *uai) {
+}
+
+void uwsgi_alarm_func_log(struct uwsgi_alarm_instance *uai, char *msg, size_t len) {
+	if (msg[len-1] != '\n') {
+		if (uai->arg && strlen(uai->arg) > 0) {
+			uwsgi_log_alarm("] %s %.*s\n", uai->arg, len, msg);
+		}
+		else {
+			uwsgi_log_alarm("] %.*s\n", len, msg);
+		}
+	}
+	else {
+		if (uai->arg && strlen(uai->arg) > 0) {
+			uwsgi_log_alarm("] %s %.*s", uai->arg, len, msg);
+		}
+		else {
+			uwsgi_log_alarm("] %.*s", len, msg);
+		}
+	}
+}
+
 // run a command on alarm
 void uwsgi_alarm_init_cmd(struct uwsgi_alarm_instance *uai) {
 	uai->data_ptr = uai->arg;
@@ -86,6 +109,7 @@ void uwsgi_register_embedded_alarms() {
 	uwsgi_register_alarm("signal", uwsgi_alarm_init_signal, uwsgi_alarm_func_signal);
 	uwsgi_register_alarm("cmd", uwsgi_alarm_init_cmd, uwsgi_alarm_func_cmd);
 	uwsgi_register_alarm("mule", uwsgi_alarm_init_mule, uwsgi_alarm_func_mule);
+	uwsgi_register_alarm("log", uwsgi_alarm_init_log, uwsgi_alarm_func_log);
 }
 
 static int uwsgi_alarm_add(char *name, char *plugin, char *arg) {
@@ -189,21 +213,54 @@ static int uwsgi_alarm_log_add(char *alarms, char *regexp, int negate) {
 #endif
 
 static void uwsgi_alarm_thread_loop(struct uwsgi_thread *ut) {
+	// add uwsgi_alarm_fd;
+	struct uwsgi_alarm_fd *uafd = uwsgi.alarm_fds;
+	while(uafd) {
+		event_queue_add_fd_read(ut->queue, uafd->fd);
+		uafd = uafd->next;
+	}
 	char *buf = uwsgi_malloc(uwsgi.alarm_msg_size + sizeof(long));
 	for (;;) {
 		int interesting_fd = -1;
                 int ret = event_queue_wait(ut->queue, -1, &interesting_fd);
 		if (ret > 0) {
-			ssize_t len = read(ut->pipe[1], buf, uwsgi.alarm_msg_size + sizeof(long));
-			if (len > (ssize_t)(sizeof(long) + 1)) {
-				size_t msg_size = len - sizeof(long);
-				char *msg = buf + sizeof(long);
-				long ptr = 0;
-				memcpy(&ptr, buf, sizeof(long));
-				struct uwsgi_alarm_instance *uai = (struct uwsgi_alarm_instance *) ptr;
-				if (!uai)
-					break;
-				uwsgi_alarm_run(uai, msg, msg_size);
+			if (interesting_fd == ut->pipe[1]) {
+				ssize_t len = read(ut->pipe[1], buf, uwsgi.alarm_msg_size + sizeof(long));
+				if (len > (ssize_t)(sizeof(long) + 1)) {
+					size_t msg_size = len - sizeof(long);
+					char *msg = buf + sizeof(long);
+					long ptr = 0;
+					memcpy(&ptr, buf, sizeof(long));
+					struct uwsgi_alarm_instance *uai = (struct uwsgi_alarm_instance *) ptr;
+					if (!uai)
+						break;
+					uwsgi_alarm_run(uai, msg, msg_size);
+				}
+			}
+			// check for alarm_fd
+			else {
+				uafd = uwsgi.alarm_fds;
+				int fd_read = 0;
+				while(uafd) {
+					if (interesting_fd == uafd->fd) {
+						if (fd_read) goto raise;	
+						size_t remains = uafd->buf_len;
+						while(remains) {
+							ssize_t len = read(uafd->fd, uafd->buf + (uafd->buf_len-remains), remains);
+							if (len <= 0) {
+								uwsgi_error("[uwsgi-alarm-fd]/read()");
+								uwsgi_log("[uwsgi-alarm-fd] i will stop monitoring fd %d\n", uafd->fd);
+								event_queue_del_fd(ut->queue, uafd->fd, event_queue_read());
+								break;
+							}
+							remains-=len;
+						}
+						fd_read = 1;
+raise:
+						uwsgi_alarm_run(uafd->alarm, uafd->msg, uafd->msg_len);
+					}
+					uafd = uafd->next;
+				}
 			}
 		}
 	}
@@ -243,6 +300,37 @@ void uwsgi_alarms_init() {
 
 	if (!uwsgi.alarm_instances) return;
 
+	// map alarm file descriptors
+	usl = uwsgi.alarm_fd_list;
+	while(usl) {
+		char *space0 = strchr(usl->value, ' ');
+		if (!space0) {
+			uwsgi_log("invalid alarm-fd syntax: %s\n", usl->value);
+			exit(1);
+		}
+		*space0 = 0;
+		size_t buf_len = 1;
+		char *space1 = strchr(space0+1, ' ');
+		if (!space1) {
+			uwsgi_log("invalid alarm-fd syntax: %s\n", usl->value);
+                        exit(1);
+		}
+
+		char *colon = strchr(space0+1, ':');
+		if (colon) {
+			buf_len = strtoul(colon+1, NULL, 10);
+			*colon = 0;
+		}
+		int fd = atoi(space0+1);
+		uwsgi_add_alarm_fd(fd, usl->value, buf_len, space1+1, strlen(space1+1));
+		*space0 = ' ';
+		*space1 = ' ';
+		if (colon) {
+			*colon = ':';
+		}
+		usl = usl->next;
+	}
+
 #ifdef UWSGI_PCRE
 	// then map log-alarm
 	usl = uwsgi.alarm_logs_list;
@@ -340,3 +428,44 @@ void uwsgi_alarm_trigger(char *alarm_instance_name, char *msg, size_t len) {
 		uwsgi_error("[uwsgi-alarm-error] uwsgi_alarm_trigger()/writev()");
 	}
 }
+
+struct uwsgi_alarm_fd *uwsgi_add_alarm_fd(int fd, char *alarm, size_t buf_len, char *msg, size_t msg_len) {
+	struct uwsgi_alarm_fd *old_uafd = NULL, *uafd = uwsgi.alarm_fds;
+	struct uwsgi_alarm_instance *uai = uwsgi_alarm_get_instance(alarm);
+	if (!uai) {
+		uwsgi_log("unable to find alarm \"%s\"\n", alarm);
+		exit(1);
+	}
+
+	if (!buf_len) buf_len = 1;	
+
+	while(uafd) {
+		// check if an equal alarm has been added
+		if (uafd->fd == fd && uafd->alarm == uai) {
+			return uafd;
+		}
+		old_uafd = uafd;
+		uafd = uafd->next;
+	}
+
+	uafd = uwsgi_calloc(sizeof(struct uwsgi_alarm_fd));
+	uafd->fd = fd;
+	uafd->buf = uwsgi_malloc(buf_len);
+	uafd->buf_len = buf_len;
+	uafd->msg = msg;
+	uafd->msg_len = msg_len;
+	uafd->alarm = uai;
+
+	if (!old_uafd) {
+		uwsgi.alarm_fds = uafd;
+	}
+	else {
+		old_uafd->next = uafd;
+	}
+
+	// avoid the fd to be closed
+	uwsgi_add_safe_fd(fd);
+	uwsgi_log("[uwsgi-alarm] added fd %d\n", fd);
+
+	return uafd;
+}

core/io.c

@@ -1054,3 +1054,27 @@ void uwsgi_file_write_do(struct uwsgi_string_list *usl) {
 		fl = fl->next;
 	}
 }
+
+int uwsgi_fd_is_safe(int fd) {
+	int i;
+	for(i=0;i<uwsgi.safe_fds_cnt;i++) {
+		if (uwsgi.safe_fds[i] == fd) {
+			return 1;
+		}
+	}
+	return 0;
+}
+void uwsgi_add_safe_fd(int fd) {
+	// check if the fd is already safe
+	if (uwsgi_fd_is_safe(fd)) return;
+
+	size_t len = sizeof(int) * (uwsgi.safe_fds_cnt+1);
+	int *tmp = realloc(uwsgi.safe_fds, len);
+	if (!tmp) {
+		uwsgi_error("uwsgi_add_safe_fd()/realloc()");
+		exit(1);
+	}
+	uwsgi.safe_fds = tmp;	
+	uwsgi.safe_fds[uwsgi.safe_fds_cnt] = fd;	
+	uwsgi.safe_fds_cnt++;
+}

core/master_utils.c

@@ -351,6 +351,9 @@ void uwsgi_reload(char **argv) {
 	/* check fd table (a module can obviosly open some fd on initialization...) */
 	uwsgi_log("closing all non-uwsgi socket fds > 2 (max_fd = %d)...\n", (int) uwsgi.max_fd);
 	for (i = 3; i < (int) uwsgi.max_fd; i++) {
+
+		if (uwsgi_fd_is_safe(i)) continue;
+
 		int found = 0;
 
 		struct uwsgi_socket *uwsgi_sock = uwsgi.sockets;

core/setup_utils.c

@@ -106,6 +106,9 @@ void uwsgi_setup_inherited_sockets() {
 	//now close all the unbound fd
 	for (j = 3; j < (int) uwsgi.max_fd; j++) {
 		int useless = 1;
+
+		if (uwsgi_fd_is_safe(j)) continue;
+
 		if (uwsgi.has_emperor) {
 			if (j == uwsgi.emperor_fd)
 				continue;

core/uwsgi.c

@@ -218,6 +218,9 @@ static struct uwsgi_option uwsgi_base_options[] = {
 	{"ftok", required_argument, 0, "set the ipcsem key via ftok() for avoiding duplicates", uwsgi_opt_set_str, &uwsgi.ftok, 0},
 	{"sharedarea", required_argument, 'A', "create a raw shared memory area of specified pages", uwsgi_opt_set_int, &uwsgi.sharedareasize, 0},
 
+	{"safe-fd", no_argument, 0, "do not close the specified file descriptor", uwsgi_opt_safe_fd, NULL, 0},
+	{"fd-safe", no_argument, 0, "do not close the specified file descriptor", uwsgi_opt_safe_fd, NULL, 0},
+
 	{"cache", required_argument, 0, "create a shared cache containing given elements", uwsgi_opt_set_64bit, &uwsgi.cache_max_items, 0},
 	{"cache-blocksize", required_argument, 0, "set cache blocksize", uwsgi_opt_set_64bit, &uwsgi.cache_blocksize, 0},
 	{"cache-store", required_argument, 0, "enable persistent cache to disk", uwsgi_opt_set_str, &uwsgi.cache_store, UWSGI_OPT_MASTER},
@@ -453,6 +456,7 @@ static struct uwsgi_option uwsgi_base_options[] = {
 #endif
 	{"alarm", required_argument, 0, "create a new alarm, syntax: <alarm> <plugin:args>", uwsgi_opt_add_string_list, &uwsgi.alarm_list, UWSGI_OPT_MASTER},
 	{"alarm-freq", required_argument, 0, "tune the anti-loop alam system (default 3 seconds)", uwsgi_opt_set_int, &uwsgi.alarm_freq, 0},
+	{"alarm-fd", required_argument, 0, "raise the specified alarm when an fd is read for read (by default it reads 1 byte, set 8 for eventfd)", uwsgi_opt_add_string_list, &uwsgi.alarm_fd_list, UWSGI_OPT_MASTER},
 #ifdef UWSGI_PCRE
 	{"log-alarm", required_argument, 0, "raise the specified alarm when a log line matches the specified regexp, syntax: <alarm>[,alarm...] <regexp>", uwsgi_opt_add_string_list, &uwsgi.alarm_logs_list, UWSGI_OPT_MASTER | UWSGI_OPT_LOG_MASTER},
 	{"alarm-log", required_argument, 0, "raise the specified alarm when a log line matches the specified regexp, syntax: <alarm>[,alarm...] <regexp>", uwsgi_opt_add_string_list, &uwsgi.alarm_logs_list, UWSGI_OPT_MASTER | UWSGI_OPT_LOG_MASTER},
@@ -3269,6 +3273,14 @@ void uwsgi_opt_set_immediate_uid(char *opt, char *value, void *none) {
 	uwsgi_log("immediate uid: %d\n", (int) uid);
 }
 
+void uwsgi_opt_safe_fd(char *opt, char *value, void *foobar) {
+	int fd = atoi(value);
+	if (fd < 0) {
+		uwsgi_log("invalid file descriptor: %d\n", fd);
+		exit(1);
+	}
+	uwsgi_add_safe_fd(fd);
+}
 
 void uwsgi_opt_set_int(char *opt, char *value, void *key) {
 	int *ptr = (int *) key;

uwsgi.h

@@ -1146,6 +1146,18 @@ struct uwsgi_alarm {
 	struct uwsgi_alarm *next;
 };
 
+struct uwsgi_alarm_fd {
+	int fd;
+	size_t buf_len;
+	void *buf;
+	char *msg;
+	size_t msg_len;
+	struct uwsgi_alarm_instance *alarm;
+	struct uwsgi_alarm_fd *next;
+};
+
+struct uwsgi_alarm_fd *uwsgi_add_alarm_fd(int, char *, size_t, char *, size_t);
+
 #ifdef UWSGI_PCRE
 struct uwsgi_alarm_ll {
 	struct uwsgi_alarm_instance *alarm;
@@ -1836,6 +1848,8 @@ struct uwsgi_server {
 	uint64_t alarm_msg_size;
 	struct uwsgi_string_list *alarm_list;
 	struct uwsgi_string_list *alarm_logs_list;
+	struct uwsgi_alarm_fd *alarm_fds;
+	struct uwsgi_string_list *alarm_fd_list;
 	struct uwsgi_alarm *alarms;
 	struct uwsgi_alarm_instance *alarm_instances;
 	struct uwsgi_alarm_log *alarm_logs;
@@ -1844,6 +1858,9 @@ struct uwsgi_server {
 	int threaded_logger;
 	pthread_mutex_t threaded_logger_lock;
 
+	int *safe_fds;
+	int safe_fds_cnt;
+
 	int daemons_honour_stdin;
 	struct uwsgi_daemon *daemons;
 	int daemons_cnt;
@@ -3205,6 +3222,7 @@ void uwsgi_opt_add_cron(char *, char *, void *);
 void uwsgi_opt_load_plugin(char *, char *, void *);
 void uwsgi_opt_load_dl(char *, char *, void *);
 void uwsgi_opt_load(char *, char *, void *);
+void uwsgi_opt_safe_fd(char *, char *, void *);
 #ifdef UWSGI_SSL
 void uwsgi_opt_add_legion_cron(char *, char *, void *);
 void uwsgi_opt_sni(char *, char *, void *);
@@ -3938,6 +3956,9 @@ struct uwsgi_transformation *uwsgi_add_transformation(struct wsgi_request *wsgi_
 
 void uwsgi_file_write_do(struct uwsgi_string_list *);
 
+int uwsgi_fd_is_safe(int);
+void uwsgi_add_safe_fd(int);
+
 void uwsgi_check_emperor(void);
 #ifdef UWSGI_AS_SHARED_LIBRARY
 int uwsgi_init(int, char **, char **);