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/* -*- c-file-style: "java"; indent-tabs-mode: nil; tab-width: 4; fill-column: 78 -*-
*
* distcc -- A simple distributed compiler system
*
* Copyright (C) 2003 by Martin Pool <mbp@samba.org>
*
* 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; either version 2
* of the License, or (at your option) any later version.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <dirent.h>
#include "types.h"
#include "rpc.h"
#include "distcc.h"
#include "trace.h"
#include "exitcode.h"
#include "snprintf.h"
#include "mon.h"
#include "util.h"
#include "netutil.h"
static volatile int pipe_fd[2];
static void dcc_mon_siginfo_handler (int UNUSED (whatsig))
{
/* Just ignore any errors. If people aren't listening or the pipe
* is full, too bad. */
write (pipe_fd[1], "*", 1);
}
/*
* Try to setup dnotify on the state directory. This returns the
* descriptor of a pipe in @p dummy_fd. Every time the state changes,
* a single byte is written to this pipe. A caller who select()s on
* the pipe will therefore be woken every time there is a change.
*
* If we can do dnotify, create the dummy pipe and turn it on.
*
* @fixme One problem here is that if the state directory is deleted
* and recreated, then we'll never notice and find the new one. I
* don't know of any good fix, other than perhaps polling every so
* often. So just don't do that.
*
* @fixme If this function is called repeatedly it will leak FDs.
*
* @todo Reimplement this on top of kevent for BSD.
*/
int dcc_mon_setup_notify (int *dummy_fd)
{
#ifdef F_NOTIFY
char *state_dir;
int ret;
int fd;
if (signal (SIGIO, dcc_mon_siginfo_handler) == SIG_ERR) {
rs_log_error ("signal(SIGINFO) failed: %s", strerror(errno));
return EXIT_IO_ERROR;
}
if (pipe ((int *) pipe_fd) == -1) {
rs_log_error ("pipe failed: %s", strerror (errno));
return EXIT_IO_ERROR;
}
*dummy_fd = pipe_fd[0]; /* read end */
dcc_set_nonblocking (pipe_fd[0]);
dcc_set_nonblocking (pipe_fd[1]);
if ((ret = dcc_get_state_dir (&state_dir)))
return ret;
if ((fd = open (state_dir, O_RDONLY)) == -1) {
rs_log_error ("failed to open %s: %s", state_dir, strerror (errno));
free (state_dir);
return EXIT_IO_ERROR;
}
/* CAUTION! Signals can start arriving immediately. Be ready. */
if (fcntl (fd, F_NOTIFY, DN_RENAME|DN_DELETE|DN_MULTISHOT) == -1) {
rs_log_warning ("setting F_NOTIFY failed: %s",
strerror (errno));
free (state_dir);
return EXIT_IO_ERROR;
}
return 0;
#else /* F_NOTIFY */
return EXIT_IO_ERROR;
#endif /* F_NOTIFY */
}
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