src/system/libroot/posix/unistd/process.c

   1 /*
   2  * Copyright 2002-2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  */
   5
   6
   7 #include <syscalls.h>
   8 #include <syscall_process_info.h>
   9
  10 #include <unistd.h>
  11 #include <string.h>
  12 #include <errno.h>
  13
  14 #include <errno_private.h>
  15
  16
  17 #define RETURN_AND_SET_ERRNO(err) \
  18         if (err < 0) { \
  19                 __set_errno(err); \
  20                 return -1; \
  21         } \
  22         return err;
  23
  24
  25 extern thread_id __main_thread_id;
  26
  27
  28 pid_t
  29 getpgrp(void)
  30 {
  31         return getpgid(__main_thread_id);
  32 }
  33
  34
  35 pid_t
  36 getpid(void)
  37 {
  38         // this one returns the ID of the main thread
  39         return __main_thread_id;
  40 }
  41
  42
  43 pid_t
  44 getppid(void)
  45 {
  46         return _kern_process_info(0, PARENT_ID);
  47                 // this is not supposed to return an error value
  48 }
  49
  50
  51 pid_t
  52 getsid(pid_t process)
  53 {
  54         pid_t session = _kern_process_info(process, SESSION_ID);
  55
  56         RETURN_AND_SET_ERRNO(session);
  57 }
  58
  59
  60 pid_t
  61 getpgid(pid_t process)
  62 {
  63         pid_t group = _kern_process_info(process, GROUP_ID);
  64
  65         RETURN_AND_SET_ERRNO(group);
  66 }
  67
  68
  69 int
  70 setpgid(pid_t process, pid_t group)
  71 {
  72         pid_t result = _kern_setpgid(process, group);
  73         if (result >= 0)
  74                 return 0;
  75
  76         RETURN_AND_SET_ERRNO(result);
  77 }
  78
  79
  80 pid_t
  81 setpgrp(void)
  82 {
  83         // setpgrp() never fails -- setpgid() fails when the process is a session
  84         // leader, though.
  85         pid_t result = _kern_setpgid(0, 0);
  86         return result >= 0 ? result : getpgrp();
  87 }
  88
  89
  90 pid_t
  91 setsid(void)
  92 {
  93         status_t status = _kern_setsid();
  94
  95         RETURN_AND_SET_ERRNO(status);
  96 }
  97