Paul LietarandJames Laird
aef689c07c
This allows to get a better error message than "Spawning the daemon failed." when initialization fails. The error message is sent through the pipe. When init is OK, just send a null byte.
108 lines
3.0 KiB
C
108 lines
3.0 KiB
C
/*
|
|
* This file is part of Shairport.
|
|
* Copyright (c) Paul Lietar 2013
|
|
* All rights reserved.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person
|
|
* obtaining a copy of this software and associated documentation
|
|
* files (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use,
|
|
* copy, modify, merge, publish, distribute, sublicense, and/or
|
|
* sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
|
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
|
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
* OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
|
|
#include "common.h"
|
|
|
|
static int lock_fd = -1;
|
|
static int daemon_pipe[2] = {-1, -1};
|
|
|
|
void daemon_init() {
|
|
int ret;
|
|
ret = pipe(daemon_pipe);
|
|
if (ret < 0)
|
|
die("couldn't create a pipe?!");
|
|
|
|
pid_t pid = fork();
|
|
if (pid < 0)
|
|
die("failed to fork!");
|
|
|
|
if (pid) {
|
|
close(daemon_pipe[1]);
|
|
|
|
char buf[64];
|
|
ret = read(daemon_pipe[0], buf, sizeof(buf));
|
|
if (ret < 0) {
|
|
// No response from child, something failed
|
|
fprintf(stderr, "Spawning the daemon failed.\n");
|
|
exit(1);
|
|
} else if (buf[0] != 0) {
|
|
// First byte is non zero, child sent error message
|
|
write(STDERR_FILENO, buf, ret);
|
|
fprintf(stderr, "\n");
|
|
exit(1);
|
|
} else {
|
|
// Success !
|
|
printf("%d\n", pid);
|
|
exit(0);
|
|
}
|
|
} else {
|
|
close(daemon_pipe[0]);
|
|
|
|
if (config.pidfile) {
|
|
lock_fd = open(config.pidfile, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
|
|
if (lock_fd < 0) {
|
|
die("Could not open pidfile");
|
|
}
|
|
|
|
ret = lockf(lock_fd,F_TLOCK,0);
|
|
if (ret < 0) {
|
|
die("Could not lock pidfile. Is an other instance running ?");
|
|
}
|
|
|
|
dprintf(lock_fd, "%d\n", getpid());
|
|
}
|
|
}
|
|
}
|
|
|
|
void daemon_ready() {
|
|
char ok = 0;
|
|
write(daemon_pipe[1], &ok, 1);
|
|
close(daemon_pipe[1]);
|
|
daemon_pipe[1] = -1;
|
|
}
|
|
|
|
void daemon_fail(const char *format, va_list arg) {
|
|
// Are we still initializing ?
|
|
if (daemon_pipe[1] > 0) {
|
|
vdprintf(daemon_pipe[1], format, arg);
|
|
}
|
|
}
|
|
|
|
void daemon_exit() {
|
|
if (lock_fd > 0) {
|
|
lockf(lock_fd, F_ULOCK, 0);
|
|
close(lock_fd);
|
|
unlink(config.pidfile);
|
|
lock_fd = -1;
|
|
}
|
|
}
|
|
|