code.delx.au - pulseaudio/blob - polyp/pid.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2 of the
   9   License, or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30 #include <string.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <stdlib.h>
  34 #include <limits.h>
  35 #include <signal.h>
  36
  37 #include "pid.h"
  38 #include "util.h"
  39 #include "log.h"
  40
  41 static pid_t read_pid(const char *fn, int fd) {
  42     ssize_t r;
  43     char t[20], *e = NULL;
  44     long int pid;
  45
  46     assert(fn && fd >= 0);
  47
  48     if ((r = pa_loop_read(fd, t, sizeof(t)-1)) < 0) {
  49         pa_log(__FILE__": WARNING: failed to read PID file '%s': %s\n", fn, strerror(errno));
  50         return (pid_t) -1;
  51     }
  52
  53     if (r == 0)
  54         return (pid_t) 0;
  55
  56     t[r] = 0;
  57
  58     if (!t[0] || (pid = strtol(t, &e, 0)) == 0 || (*e != 0 && *e != '\n')) {
  59         pa_log(__FILE__": WARNING: failed to parse PID file '%s'\n", fn);
  60         return (pid_t) -1;
  61     }
  62
  63     return (pid_t) pid;
  64 }
  65
  66 int pa_pid_file_create(void) {
  67     int fd = -1, lock = -1;
  68     int ret = -1;
  69     char fn[PATH_MAX];
  70     char t[20];
  71     pid_t pid;
  72     size_t l;
  73
  74     pa_runtime_path("pid", fn, sizeof(fn));
  75     if ((fd = open(fn, O_CREAT|O_RDWR, S_IRUSR|S_IWUSR)) < 0) {
  76         pa_log(__FILE__": WARNING: failed to open PID file '%s': %s\n", fn, strerror(errno));
  77         goto fail;
  78     }
  79
  80     lock = pa_lock_fd(fd, 1);
  81
  82     if ((pid = read_pid(fn, fd)) == (pid_t) -1)
  83         pa_log(__FILE__": corrupt PID file, overwriting.\n");
  84     else if (pid > 0) {
  85         if (kill(pid, 0) >= 0 || errno != ESRCH) {
  86             pa_log(__FILE__": valid PID file.\n");
  87             goto fail;
  88         }
  89
  90         pa_log(__FILE__": stale PID file, overwriting.\n");
  91     }
  92
  93     lseek(fd, 0, SEEK_SET);
  94
  95     snprintf(t, sizeof(t), "%lu", (unsigned long) getpid());
  96     l = strlen(t);
  97
  98     if (pa_loop_write(fd, t, l) != (ssize_t) l) {
  99         pa_log(__FILE__": failed to write PID file.\n");
 100         goto fail;
 101     }
 102
 103     ret = 0;
 104
 105 fail:
 106     if (fd >= 0) {
 107         if (lock >= 0)
 108             pa_lock_fd(fd, 0);
 109
 110         close(fd);
 111     }
 112
 113     return ret;
 114 }
 115
 116 int pa_pid_file_remove(void) {
 117     int fd = -1, lock = -1;
 118     char fn[PATH_MAX];
 119     int ret = -1;
 120     pid_t pid;
 121
 122     pa_runtime_path("pid", fn, sizeof(fn));
 123     if ((fd = open(fn, O_RDWR)) < 0) {
 124         pa_log(__FILE__": WARNING: failed to open PID file '%s': %s\n", fn, strerror(errno));
 125         goto fail;
 126     }
 127
 128     lock = pa_lock_fd(fd, 1);
 129
 130     if ((pid = read_pid(fn, fd)) == (pid_t) -1)
 131         goto fail;
 132
 133     if (pid != getpid()) {
 134         pa_log(__FILE__": WARNING: PID file '%s' not mine!\n", fn);
 135         goto fail;
 136     }
 137
 138     if (ftruncate(fd, 0) < 0) {
 139         pa_log(__FILE__": failed to truncate PID file '%s': %s\n", fn, strerror(errno));
 140         goto fail;
 141     }
 142
 143     if (unlink(fn) < 0) {
 144         pa_log(__FILE__": failed to remove PID file '%s': %s\n", fn, strerror(errno));
 145         goto fail;
 146     }
 147
 148     ret = 0;
 149
 150 fail:
 151
 152     if (fd >= 0) {
 153         if (lock >= 0)
 154             pa_lock_fd(fd, 0);
 155
 156         close(fd);
 157     }
 158
 159     return ret;
 160 }
 161
 162 int pa_pid_file_check_running(pid_t *pid) {
 163     return pa_pid_file_kill(0, pid);
 164 }
 165
 166 int pa_pid_file_kill(int sig, pid_t *pid) {
 167     int fd = -1, lock = -1;
 168     char fn[PATH_MAX];
 169     int ret = -1;
 170     pid_t _pid;
 171
 172     if (!pid)
 173         pid = &_pid;
 174
 175     pa_runtime_path("pid", fn, sizeof(fn));
 176     if ((fd = open(fn, O_RDONLY)) < 0)
 177         goto fail;
 178
 179     lock = pa_lock_fd(fd, 1);
 180
 181     if ((*pid = read_pid(fn, fd)) == (pid_t) -1)
 182         goto fail;
 183
 184     ret = kill(*pid, sig);
 185
 186 fail:
 187
 188     if (fd >= 0) {
 189         if (lock >= 0)
 190             pa_lock_fd(fd, 0);
 191
 192         close(fd);
 193     }
 194
 195     return ret;
 196
 197 }