mozglue/build/cpuacct.c

   1 /*
   2  * Copyright (C) 2010 The Android Open Source Project
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *  * Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *  * Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in
  12  *    the documentation and/or other materials provided with the
  13  *    distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <sys/stat.h>
  31 #include <fcntl.h>
  32 #include <stdio.h>
  33 #include "cpuacct.h"
  34
  35 int cpuacct_add(uid_t uid)
  36 {
  37     int count;
  38     int fd;
  39     char buf[80];
  40
  41     count = snprintf(buf, sizeof(buf), "/acct/uid/%d/tasks", uid);
  42     fd = open(buf, O_RDWR|O_CREAT|O_TRUNC|O_SYNC);
  43     if (fd < 0) {
  44         /* Note: sizeof("tasks") returns 6, which includes the NULL char */
  45         buf[count - sizeof("tasks")] = 0;
  46         if (mkdir(buf, 0775) < 0)
  47             return -errno;
  48
  49         /* Note: sizeof("tasks") returns 6, which includes the NULL char */
  50         buf[count - sizeof("tasks")] = '/';
  51         fd = open(buf, O_RDWR|O_CREAT|O_TRUNC|O_SYNC);
  52     }
  53     if (fd < 0)
  54         return -errno;
  55
  56     write(fd, "0", 2);
  57     if (close(fd))
  58         return -errno;
  59
  60     return 0;
  61 }