X-Git-Url: http://git.jankratochvil.net/?p=inetdmx.git;a=blobdiff_plain;f=inetdmx.c;h=0c5d89a7392b1ebac4f25773877a18273c79faa2;hp=006a4f2947e233280cd963ccffcea68daf96dfde;hb=192c63da403f7633394265411dc1b246fecace9f;hpb=be1836412ce05f1ed3902fa90d433a95e4ff8281

diff --git a/inetdmx.c b/inetdmx.c
index 006a4f2..0c5d89a 100644
--- a/inetdmx.c
+++ b/inetdmx.c
@@ -1,4 +1,21 @@
-/* $Id$ */
+/*
+ * $Id$
+ * Latest:
+ * 	http://cvs.jankratochvil.net/viewcvs/nethome/src/inetdmx.c?rev=HEAD
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; you must use version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
 
 
 #define _GNU_SOURCE 1
@@ -154,11 +171,11 @@ static void usage(void)
 	fprintf(stderr,"\
 Syntax: %s {-1|--start} [{-T|--start-command-timeout} <start-command-timeout>]\n\
         \t[{-l|--lock} <filename>] [-S|--syslog] [-e|--stderr]\n\
-        \t\[-I|--ignore-spawned-command-output]\n\
+        \t[-I|--ignore-spawned-command-output]\n\
         \t{-p|--port} <server-port> <start-server-command>\n\
      or %s {-0|--stop}  [{-i|--idle-server-timeout} <idle-server-timeout>]\n\
         \t[{-l|--lock} <filename>] [-S|--syslog] [-e|--stderr]\n\
-        \t\[-I|--ignore-spawned-command-output]\n\
+        \t[-I|--ignore-spawned-command-output]\n\
         \t<stop-server-command>\n\
 \n\
 Error messages are printed to stderr by default,\n\
@@ -193,21 +210,35 @@ static void sighandler_flock_timeout(int signo)
 	sighandler_flock_timeout_hit=1;
 }
 
-static int lock_create(int lock_mode)
+enum lock_create_rc {
+	LOCK_CREATE_NO_LOCK_FILENAME,
+	LOCK_CREATE_FILE_NOT_FOUND,		/* only if: lock_mode&LOCK_NB */
+	LOCK_CREATE_ALREADY_LOCKED,		/* only if: lock_mode&LOCK_NB */
+	LOCK_CREATE_MYSELF_LOCKED,		/* only for: lock_create() */
+	LOCK_CREATE_MYSELF_LOCKED_AND_FRESH,	/* only for: lock_open_and_time_check() */
+	LOCK_CREATE_MYSELF_LOCKED_AND_STALE,	/* only for: lock_open_and_time_check() */
+	};
+/* It will never create the lock file if: lock_mode&LOCK_NB */
+static enum lock_create_rc lock_create(int lock_mode)
 {
 int retries=3;
 sighandler_t sighandler_alrm_orig;
 int flock_rc;
 
 	if (!opt_lock)
-		return 1;
+		return LOCK_CREATE_NO_LOCK_FILENAME;
 	/* Never drop the lock if the lock is already being held. */
 	if (lock_fd!=-1)
 		retries=-1;
 retry:
 	if (lock_fd==-1) {
-		if (-1==(lock_fd=open(opt_lock,O_CREAT|O_RDWR,0600)))
+		if (-1==(lock_fd=open(opt_lock,
+				O_RDWR | (lock_mode&LOCK_NB ? 0 : O_CREAT),
+				0600))) {
+			if (errno==ENOENT && lock_mode&LOCK_NB)
+				return LOCK_CREATE_FILE_NOT_FOUND;
 			fatal("Error creating lock file \"%s\": %m",opt_lock);
+			}
 		}
 	sighandler_alrm_orig=signal(SIGALRM,sighandler_flock_timeout);
 	alarm(opt_start_command_timeout+FLOCK_TIMEOUT_OVER_START_TIMEOUT);
@@ -218,7 +249,7 @@ retry:
 		fatal("Timeout locking lock file \"%s\": %m",opt_lock);
 	if (flock_rc) {
 		if (lock_mode&LOCK_NB && errno==EWOULDBLOCK)
-			return 0;
+			return LOCK_CREATE_ALREADY_LOCKED;
 		fatal("Error locking lock file \"%s\": %m",opt_lock);
 		}
 	if (access(opt_lock,R_OK|W_OK)) {
@@ -229,7 +260,7 @@ retry:
 		lock_fd=-1;
 		goto retry;
 		}
-	return 1;
+	return LOCK_CREATE_MYSELF_LOCKED;
 }
 
 static void lock_touch(void)
@@ -453,19 +484,17 @@ int retry;
 			opt_start_command_timeout,opt_port,opt_command);
 }
 
-/* Returns: Is fresh? */
-static int lock_create_and_time_check(int lock_mode)
+static enum lock_create_rc lock_open_and_time_check(int lock_mode)
 {
+enum lock_create_rc rc;
 struct stat statbuf;
 
-	if (!opt_lock)
-		return 0;
-
-	if (!lock_create(lock_mode|LOCK_NB))
-		exit(EXIT_SUCCESS);
+	if (LOCK_CREATE_MYSELF_LOCKED!=(rc=lock_create(lock_mode|LOCK_NB)))
+		return rc;
 	if (lock_fd==-1 || fstat(lock_fd,&statbuf))
 		fatal("Error fstat(2)ting lock file \"%s\": %m",opt_lock);
-	return statbuf.st_mtime>=time(NULL)-opt_idle_server_timeout;
+	return (statbuf.st_mtime>=time(NULL)-opt_idle_server_timeout
+			? LOCK_CREATE_MYSELF_LOCKED_AND_FRESH : LOCK_CREATE_MYSELF_LOCKED_AND_STALE);
 }
 
 static void lock_delete_and_close(void)
@@ -476,10 +505,22 @@ static void lock_delete_and_close(void)
 	lock_close();
 }
 
+static void lock_open_and_return_if_stale(int lock_mode)
+{
+	switch (lock_open_and_time_check(lock_mode)) {
+		case LOCK_CREATE_NO_LOCK_FILENAME:        return;
+		case LOCK_CREATE_FILE_NOT_FOUND:          exit(EXIT_SUCCESS);
+		case LOCK_CREATE_ALREADY_LOCKED:          exit(EXIT_SUCCESS);
+		case LOCK_CREATE_MYSELF_LOCKED:           assert(0);
+		case LOCK_CREATE_MYSELF_LOCKED_AND_FRESH: exit(EXIT_SUCCESS);
+		case LOCK_CREATE_MYSELF_LOCKED_AND_STALE: return;
+		}
+	assert(0);
+}
+
 static void stop(void) G_GNUC_NORETURN;
 static void stop(void)
 {
-int is_fresh;
 
 	/* Lock still being held! */
 	if (opt_port)
@@ -489,12 +530,10 @@ int is_fresh;
 	if (opt_idle_server_timeout!=DEFAULT_IDLE_SERVER_TIMEOUT && !opt_lock)
 		fatal("-l|--lock is a required argument for -i|--idle-server-timeout of -1|--start");
 
-	is_fresh=lock_create_and_time_check(LOCK_SH);
+	lock_open_and_return_if_stale(LOCK_SH);
 	lock_close();
-	if (is_fresh)
-		exit(EXIT_SUCCESS);
 
-	lock_create_and_time_check(LOCK_EX);
+	lock_open_and_return_if_stale(LOCK_EX);
 	system_checked(opt_command);
 	lock_delete_and_close();