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) |
25 | static inline __attribute__((always_inline)) pid_t really_getpid (pid_t oldval); |
26 | |
27 | static inline __attribute__((always_inline)) pid_t |
28 | really_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 | |
48 | pid_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 | |
62 | libc_hidden_def (__getpid) |
63 | weak_alias (__getpid, getpid) |
64 | libc_hidden_def (getpid) |
65 | |