[PATCH] udev - next round of udev event order daemon

[elogind.git] / udevsend.c

diff --git a/udevsend.c b/udevsend.c
index 1a897451c0beda11cbb1c8bf20d7047d3f295317..d3e5378285e8ea7797e1d7d86b97ba3c64abbadb 100644 (file)
--- a/udevsend.c
+++ b/udevsend.c
@@ -29,6 +29,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <wait.h>
 
 #include "udev.h"
 #include "udevd.h"
@@ -78,6 +81,39 @@ static void free_hotplugmsg(struct hotplug_msg *pmsg)
        free(pmsg);
 }
 
+static int start_daemon(void)
+{
+       pid_t pid;
+       pid_t child_pid;
+
+       pid = fork();
+       switch (pid) {
+       case 0:
+               /* helper child */
+               child_pid = fork();
+               switch (child_pid) {
+               case 0:
+                       /* daemon */
+                       execl(DEFAULT_UDEVD_EXEC, NULL);
+                       dbg("exec of daemon failed");
+                       exit(1);
+               case -1:
+                       dbg("fork of daemon failed");
+                       return -1;
+               default:
+                       exit(0);
+               }
+               break;
+       case -1:
+               dbg("fork of helper failed");
+               return -1;
+       default:
+               wait(0);
+       }
+       return 0;
+}
+
+
 int main(int argc, char* argv[])
 {
        int msgid;
@@ -91,6 +127,8 @@ int main(int argc, char* argv[])
        int seq;
        int retval = -EINVAL;
        int size;
+       int loop;
+       struct timespec tspec;
 
        subsystem = argv[1];
        if (subsystem == NULL) {
@@ -117,34 +155,41 @@ int main(int argc, char* argv[])
        }
        seq = atoi(seqnum);
 
-       key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID);
+       /* create ipc message queue or get id of our existing one */
+       key = ftok(DEFAULT_UDEVD_EXEC, IPC_KEY_ID);
        size =  build_hotplugmsg( (struct hotplug_msg**) &pmsg, action, devpath, subsystem, seq);
        msgid = msgget(key, IPC_CREAT);
        if (msgid == -1) {
-               dbg("open ipc queue error");
+               dbg("error open ipc queue");
                goto exit;
        }
 
-       /* get state of queue */
-       retval = msgctl(msgid, IPC_STAT, &msg_queue);
-       if (retval == -1) {
-               dbg("error getting info on ipc queue");
-               goto exit;
-       }
-       if (msg_queue.msg_qnum > 0)
-               dbg("%li messages already in the ipc queue", msg_queue.msg_qnum);
-
+       /* send ipc message to the daemon */
        retval = msgsnd(msgid, pmsg, size, 0);
        free_hotplugmsg( (struct hotplug_msg*) pmsg);
        if (retval == -1) {
-               dbg("send ipc message error");
+               dbg("error sending ipc message");
                goto exit;
        }
-       return 0;
 
-exit:
-       if (retval > 0)
-               retval = 0;
+       /* get state of ipc queue */
+       tspec.tv_sec = 0;
+       tspec.tv_nsec = 10000000;  /* 10 millisec */
+       loop = 20;
+       while (loop--) {
+               retval = msgctl(msgid, IPC_STAT, &msg_queue);
+               if (retval == -1) {
+                       dbg("error getting info on ipc queue");
+                       goto exit;
+               }
+               if (msg_queue.msg_qnum == 0)
+                       goto exit;
+               nanosleep(&tspec, NULL);
+       }
+
+       info("message is still in the ipc queue, starting daemon...");
+       retval = start_daemon();
 
+exit:
        return retval;
 }