MySQL  8.0.26
Source Code Documentation
my_thread_os_id.h
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1 /* Copyright (c) 2015, 2021, Oracle and/or its affiliates.
2 
3  This program is free software; you can redistribute it and/or modify
4  it under the terms of the GNU General Public License, version 2.0,
5  as published by the Free Software Foundation.
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7  This program is also distributed with certain software (including
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13 
14  This program is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  GNU General Public License, version 2.0, for more details.
18 
19  You should have received a copy of the GNU General Public License
20  along with this program; if not, write to the Free Software
21  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22 
23 /**
24  @file include/my_thread_os_id.h
25  Portable wrapper for gettid().
26 */
27 
28 #ifndef MY_THREAD_OS_ID_INCLUDED
29 #define MY_THREAD_OS_ID_INCLUDED
30 
31 #include "my_config.h"
32 #include "my_macros.h"
33 #include "my_thread.h"
34 #ifndef _WIN32
35 #include <sys/syscall.h>
36 #include <unistd.h>
37 #endif
38 
39 #ifdef HAVE_PTHREAD_GETTHREADID_NP
40 #include <pthread_np.h> /* pthread_getthreadid_np() */
41 #endif /* HAVE_PTHREAD_GETTHREADID_NP */
42 
43 #ifdef HAVE_PTHREAD_THREADID_NP
44 #include <pthread.h>
45 #endif /* HAVE_PTHREAD_THREADID_NP */
46 
47 typedef unsigned long long my_thread_os_id_t;
48 
49 /**
50  Return the operating system thread id.
51  With Linux, threads have:
52  - an internal id, @c pthread_self(), visible in process
53  - an external id, @c gettid(), visible in the operating system,
54  for example with perf in linux.
55  This helper returns the underling operating system thread id.
56 */
58 #ifdef HAVE_PTHREAD_THREADID_NP
59  /*
60  macOS.
61 
62  Be careful to use this version first, and to not use SYS_gettid on macOS,
63  as SYS_gettid has a different meaning compared to linux gettid().
64  */
65  uint64_t tid64;
66  pthread_threadid_np(nullptr, &tid64);
67  return (pid_t)tid64;
68 #else
69 #ifdef HAVE_SYS_GETTID
70  /*
71  Linux.
72  See man gettid
73  See GLIBC Bug 6399 - gettid() should have a wrapper
74  https://sourceware.org/bugzilla/show_bug.cgi?id=6399
75  */
76  return syscall(SYS_gettid);
77 #else
78 #ifdef _WIN32
79  /* Windows */
80  return GetCurrentThreadId();
81 #else
82 #ifdef HAVE_PTHREAD_GETTHREADID_NP
83  /* FreeBSD 10.2 */
84  return pthread_getthreadid_np();
85 #else
86 #ifdef HAVE_INTEGER_PTHREAD_SELF
87  /* Unknown platform, fallback. */
88  return pthread_self();
89 #else
90  /* Feature not available. */
91  return 0;
92 #endif /* HAVE_INTEGER_PTHREAD_SELF */
93 #endif /* HAVE_PTHREAD_GETTHREADID_NP */
94 #endif /* _WIN32 */
95 #endif /* HAVE_SYS_GETTID */
96 #endif /* HAVE_SYS_THREAD_SELFID */
97 }
98 
99 #endif /* MY_THREAD_OS_ID_INCLUDED */
Some common macros.
Defines to make different thread packages compatible.
unsigned long long my_thread_os_id_t
Definition: my_thread_os_id.h:47
static my_thread_os_id_t my_thread_os_id()
Return the operating system thread id.
Definition: my_thread_os_id.h:57