File: waitid.c

package info (click to toggle)
glibc 2.19-18+deb8u7
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 204,748 kB
  • sloc: ansic: 970,427; asm: 241,207; sh: 10,069; makefile: 8,476; cpp: 3,595; perl: 2,077; pascal: 1,839; awk: 1,704; yacc: 317; sed: 73
file content (170 lines) | stat: -rw-r--r-- 4,185 bytes parent folder | download | duplicates (10)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/* Pseudo implementation of waitid.
   Copyright (C) 1997-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1997.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <assert.h>
#include <errno.h>
#include <signal.h>
#define __need_NULL
#include <stddef.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sysdep-cancel.h>


#ifdef DO_WAITID
# define OUR_WAITID DO_WAITID
#elif !defined NO_DO_WAITID
# define OUR_WAITID do_waitid
#endif

#ifdef OUR_WAITID
static int
OUR_WAITID (idtype_t idtype, id_t id, siginfo_t *infop, int options)
{
  pid_t pid, child;
  int status;

  switch (idtype)
    {
    case P_PID:
      if(id <= 0)
	goto invalid;
      pid = (pid_t) id;
      break;
    case P_PGID:
      if (id < 0 || id == 1)
	goto invalid;
      pid = (pid_t) -id;
      break;
    case P_ALL:
      pid = -1;
      break;
    default:
    invalid:
      __set_errno (EINVAL);
      return -1;
    }

  /* Technically we're supposed to return EFAULT if infop is bogus,
     but that would involve mucking with signals, which is
     too much hassle.  User will have to deal with SIGSEGV/SIGBUS.
     We just check for a null pointer. */

  if (infop == NULL)
    {
      __set_errno (EFAULT);
      return -1;
    }

  /* This emulation using waitpid cannot support the waitid modes in which
     we do not reap the child, or match only stopped and not dead children.  */
  if (0
#ifdef WNOWAIT
      || (options & WNOWAIT)
#endif
#ifdef WEXITED
      || ((options & (WEXITED|WSTOPPED|WCONTINUED))
	  != (WEXITED | (options & WUNTRACED)))
#endif
      )
    {
      __set_errno (ENOTSUP);
      return -1;
    }

  /* Note the waitid() is a cancellation point.  But since we call
     waitpid() which itself is a cancellation point we do not have
     to do anything here.  */
  child = __waitpid (pid, &status,
		     options
#ifdef WEXITED
		     &~ WEXITED
#endif
		     );

  if (child == -1)
    /* `waitpid' set `errno' for us.  */
    return -1;

  if (child == 0)
    {
      /* The WHOHANG bit in OPTIONS is set and there are children available
	 but none has a status for us.  The XPG docs do not mention this
	 case so we clear the `siginfo_t' struct and return successfully.  */
      infop->si_signo = 0;
      infop->si_code = 0;
      return 0;
    }

  /* Decode the status field and set infop members... */
  infop->si_signo = SIGCHLD;
  infop->si_pid = child;
  infop->si_errno = 0;

  if (WIFEXITED (status))
    {
      infop->si_code = CLD_EXITED;
      infop->si_status = WEXITSTATUS (status);
    }
  else if (WIFSIGNALED (status))
    {
      infop->si_code = WCOREDUMP (status) ? CLD_DUMPED : CLD_KILLED;
      infop->si_status = WTERMSIG (status);
    }
  else if (WIFSTOPPED (status))
    {
      infop->si_code = CLD_STOPPED;
      infop->si_status = WSTOPSIG (status);
    }
#ifdef WIFCONTINUED
  else if (WIFCONTINUED (status))
    {
      infop->si_code = CLD_CONTINUED;
      infop->si_status = SIGCONT;
    }
#endif
  else
    /* Can't happen. */
    assert (! "What?");

  return 0;
}
#endif


int
__waitid (idtype, id, infop, options)
     idtype_t idtype;
     id_t id;
     siginfo_t *infop;
     int options;
{
  if (SINGLE_THREAD_P)
    return do_waitid (idtype, id, infop, options);

  int oldtype = LIBC_CANCEL_ASYNC ();

  int result = do_waitid (idtype, id, infop, options);

  LIBC_CANCEL_RESET (oldtype);

  return result;
}
weak_alias (__waitid, waitid)
strong_alias (__waitid, __libc_waitid)