/*
* ipc_recv_path()
*
* Get the next archive file to process from the queue.
*/
int
ipc_recv_path(char *buf)
{
queue_elem *elem;
int rc;
struct {
long mtype;
char mtext[MSGMAX];
} msg;
while (true)
{
if (ipc_poll(false) < 0)
{
ipc_finish(true);
return -1;
}
/*
* If something requested an immediate shutdown, don't report any
* more logfiles back.
*/
if (shutdown_immed_requested)
{
ipc_finish(true);
return 0;
}
/*
* If a smart shutdown was requested, try to close the queue
* but don't force it.
*/
if (shutdown_smart_requested)
{
if ((rc = ipc_finish(false)) == 0)
{
return 0;
}
if (rc < 0)
{
ipc_finish(true);
return -1;
}
}
/*
* If we have something in the queue, return that.
*/
if (archive_queue_head != NULL)
{
elem = archive_queue_head;
archive_queue_head = archive_queue_head->next;
if (archive_queue_head == NULL)
archive_queue_tail = NULL;
strcpy(buf, elem->archive_path);
free(elem->archive_path);
free(elem);
return 1;
}
/*
* Receive one single message blocking for it.
*/
rc = msgrcv(msgid, &msg, sizeof(msg), 0, IPC_NOWAIT);
if (rc < 0)
{
if (errno == ENOMSG)
return -2;
if (errno == EINTR)
continue;
fprintf(stderr, "msgrcv() failed in ipc_recv_path(): %s\n",
strerror(errno));
ipc_finish(true);
return -1;
}
if (msg.mtype == 2)
shutdown_smart_requested = true;
else if (msg.mtype == 3)
shutdown_immed_requested = true;
else if (msg.mtype == 4)
wait_for_resume = false;
else if (msg.mtype == 5)
logfile_switch_requested = true;
else
if (ipc_add_path(msg.mtext) < 0)
{
ipc_finish(true);
return -1;
}
}
}
/*
* -- start_child
*
* fork a child with the given function and process name.
* If 'procname' is NULL then don't fork, as this is the supervisor.
* The last argument is an optional fd to be passed to the program.
*/
pid_t
start_child(ipc_peer_full_t * child, mainloop_fn mainloop,
memmap_t * shmemmap, FILE *client_stream, como_node_t * node)
{
pid_t pid;
int i, p[2];
char c;
ipc_peer_t * who = (ipc_peer_t *) child;
/* find a slot for the child */
for (i = 0; i < MAX_CHILDREN; i++) {
if (s_child_info[i].who == NULL)
break;
}
if (i == MAX_CHILDREN) {
warn("cannot create child, no more slots\n");
return -1;
}
/*
* set a pipe which will be used to tell child it may start.
* this avoids a race condition when the child exists before
* SU has registered it.
*/
pipe(p);
/* ok, fork a regular process and return pid to the caller. */
debug("start_child -- forking\n");
pid = fork();
if (pid < 0) { /* fork() fails */
warn("fork() failed: %s\n", strerror(errno));
close(p[0]);
close(p[1]);
return -1;
}
else if (pid == 0) { /* child */
int supervisor_fd;
debug("child: waiting for start signal\n");
close(p[1]); /* not going to write to the pipe */
como_read(p[0], &c, 1); /* wait for start signal */
close(p[0]); /* done with the pipe */
debug("child: starting\n");
#ifdef ENABLE_PROFILING
enable_profiling();
#endif
signal(SIGHUP, SIG_IGN); /* ignore SIGHUP */
/* initialize the s_child_info array */
bzero(s_child_info, sizeof(s_child_info));
/* XXX TODO: close unneeded sockets */
// fclose(stdout); // XXX
// fclose(stderr); // XXX
/* ipc_finish will close all FDs. We must retain a copy of client_fd */
ipc_finish(FALSE);
ipc_init(child, NULL, NULL);
/* connect to SUPERVISOR */
supervisor_fd = ipc_connect(COMO_SU);
assert(supervisor_fd != -1);
setproctitle("%s", ipc_peer_get_name(who));
notice("starting process %s pid %d\n",
ipc_peer_get_name(who), getpid());
mainloop((ipc_peer_t *) COMO_SU, shmemmap, client_stream, node);
exit(0);
}
/* parent */
close(p[0]); /* will not read from pipe */
s_child_info[i].who = child; /* register the child info */
s_child_info[i].pid = pid;
s_children++;
como_write(p[1], &c, 1); /* child process can start now */
close(p[1]); /* done with the pipe */
return pid;
}
