treewide: Remove trailing whitespace

[sliver-openvswitch.git] / lib / daemon.c

diff --git a/lib/daemon.c b/lib/daemon.c
index 46c9a88..5486504 100644 (file)
--- a/lib/daemon.c
+++ b/lib/daemon.c
@@ -18,8 +18,10 @@
 #include "daemon.h"
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/resource.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include "command-line.h"
@@ -30,20 +32,21 @@
 #include "socket-util.h"
 #include "timeval.h"
 #include "util.h"
-
-#define THIS_MODULE VLM_daemon
 #include "vlog.h"
 
-/* Should we run in the background? */
+VLOG_DEFINE_THIS_MODULE(daemon)
+
+/* --detach: Should we run in the background? */
 static bool detach;
 
-/* Name of pidfile (null if none). */
+/* --pidfile: Name of pidfile (null if none). */
 static char *pidfile;
 
-/* Create pidfile even if one already exists and is locked? */
+/* --overwrite-pidfile: Create pidfile even if one already exists and is
+   locked? */
 static bool overwrite_pidfile;
 
-/* Should we chdir to "/"? */
+/* --no-chdir: Should we chdir to "/"? */
 static bool chdir_ = true;
 
 /* File descriptor used by daemonize_start() and daemonize_complete(). */
@@ -56,11 +59,11 @@ static bool monitor;
 /* Returns the file name that would be used for a pidfile if 'name' were
  * provided to set_pidfile().  The caller must free the returned string. */
 char *
-make_pidfile_name(const char *name) 
+make_pidfile_name(const char *name)
 {
-    return (!name ? xasprintf("%s/%s.pid", ovs_rundir, program_name)
-            : *name == '/' ? xstrdup(name)
-            : xasprintf("%s/%s", ovs_rundir, name));
+    return (!name
+            ? xasprintf("%s/%s.pid", ovs_rundir, program_name)
+            : abs_file_name(ovs_rundir, name));
 }
 
 /* Sets up a following call to daemonize() to create a pidfile named 'name'.
@@ -172,9 +175,9 @@ die_if_already_running(void)
     }
 }
 
-/* If a pidfile has been configured, creates it and stores the running process'
- * pid init.  Ensures that the pidfile will be deleted when the process
- * exits. */
+/* If a pidfile has been configured, creates it and stores the running
+ * process's pid in it.  Ensures that the pidfile will be deleted when the
+ * process exits. */
 static void
 make_pidfile(void)
 {
@@ -323,14 +326,15 @@ should_restart(int status)
 static void
 monitor_daemon(pid_t daemon_pid)
 {
-    /* XXX Should limit the rate at which we restart the daemon. */
     /* XXX Should log daemon's stderr output at startup time. */
     const char *saved_program_name;
+    time_t last_restart;
     char *status_msg;
 
     saved_program_name = program_name;
     program_name = xasprintf("monitor(%s)", program_name);
     status_msg = xstrdup("healthy");
+    last_restart = TIME_MIN;
     for (;;) {
         int retval;
         int status;
@@ -353,6 +357,33 @@ monitor_daemon(pid_t daemon_pid)
             free(s);
 
             if (should_restart(status)) {
+                if (WCOREDUMP(status)) {
+                    /* Disable further core dumps to save disk space. */
+                    struct rlimit r;
+
+                    r.rlim_cur = 0;
+                    r.rlim_max = 0;
+                    if (setrlimit(RLIMIT_CORE, &r) == -1) {
+                        VLOG_WARN("failed to disable core dumps: %s",
+                                  strerror(errno));
+                    }
+                }
+
+                /* Throttle restarts to no more than once every 10 seconds. */
+                if (time(NULL) < last_restart + 10) {
+                    VLOG_WARN("%s, waiting until 10 seconds since last "
+                              "restart", status_msg);
+                    for (;;) {
+                        time_t now = time(NULL);
+                        time_t wakeup = last_restart + 10;
+                        if (now >= wakeup) {
+                            break;
+                        }
+                        sleep(wakeup - now);
+                    }
+                }
+                last_restart = time(NULL);
+
                 VLOG_ERR("%s, restarting", status_msg);
                 daemon_pid = fork_and_wait_for_startup(&daemonize_fd);
                 if (!daemon_pid) {
@@ -418,6 +449,10 @@ daemonize_start(void)
     }
 
     make_pidfile();
+
+    /* Make sure that the unixctl commands for vlog get registered in a
+     * daemon, even before the first log message. */
+    vlog_init();
 }
 
 /* If daemonization is configured, then this function notifies the parent