1/* Copyright (C) 2003-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <unistd.h>
20#include <tls.h>
21#include <sysdep.h>
22
23
24#if IS_IN (libc)
25static inline __attribute__((always_inline)) pid_t really_getpid (pid_t oldval);
26
27static inline __attribute__((always_inline)) pid_t
28really_getpid (pid_t oldval)
29{
30 if (__glibc_likely (oldval == 0))
31 {
32 pid_t selftid = THREAD_GETMEM (THREAD_SELF, tid);
33 if (__glibc_likely (selftid != 0))
34 return selftid;
35 }
36
37 INTERNAL_SYSCALL_DECL (err);
38 pid_t result = INTERNAL_SYSCALL (getpid, err, 0);
39
40 /* We do not set the PID field in the TID here since we might be
41 called from a signal handler while the thread executes fork. */
42 if (oldval == 0)
43 THREAD_SETMEM (THREAD_SELF, tid, result);
44 return result;
45}
46#endif
47
48pid_t
49__getpid (void)
50{
51#if !IS_IN (libc)
52 INTERNAL_SYSCALL_DECL (err);
53 pid_t result = INTERNAL_SYSCALL (getpid, err, 0);
54#else
55 pid_t result = THREAD_GETMEM (THREAD_SELF, pid);
56 if (__glibc_unlikely (result <= 0))
57 result = really_getpid (result);
58#endif
59 return result;
60}
61
62libc_hidden_def (__getpid)
63weak_alias (__getpid, getpid)
64libc_hidden_def (getpid)
65