1GETTID(2)                  Linux Programmer's Manual                 GETTID(2)
2
3
4

NAME

6       gettid - get thread identification
7

SYNOPSIS

9       #include <sys/types.h>
10
11       pid_t gettid(void);
12

DESCRIPTION

14       gettid()  returns  the  caller's thread ID (TID).  In a single-threaded
15       process, the thread ID is equal to the process ID (PID, as returned  by
16       getpid(2)).  In a multithreaded process, all threads have the same PID,
17       but each one has a unique TID.  For further details, see the discussion
18       of CLONE_THREAD in clone(2).
19

RETURN VALUE

21       On success, returns the thread ID of the calling thread.
22

ERRORS

24       This call is always successful.
25

VERSIONS

27       The  gettid()  system  call  first  appeared on Linux in kernel 2.4.11.
28       Library support was added in glibc 2.30.  (Earlier glibc  versions  did
29       not  provide  a  wrapper for this system call, necessitating the use of
30       syscall(2).)
31

CONFORMING TO

33       gettid() is Linux-specific and should not be used in programs that  are
34       intended to be portable.
35

NOTES

37       The  thread  ID  returned by this call is not the same thing as a POSIX
38       thread ID (i.e., the opaque value returned by pthread_self(3)).
39
40       In a new thread group created by a clone(2) call that does not  specify
41       the  CLONE_THREAD  flag  (or,  equivalently,  a  new process created by
42       fork(2)), the new process is a thread  group  leader,  and  its  thread
43       group ID (the value returned by getpid(2)) is the same as its thread ID
44       (the value returned by gettid()).
45

SEE ALSO

47       capget(2), clone(2), fcntl(2), fork(2), getpid(2),  get_robust_list(2),
48       ioprio_set(2),   perf_event_open(2),  sched_setaffinity(2),  sched_set‐
49       param(2), sched_setscheduler(2), tgkill(2), timer_create(2)
50

COLOPHON

52       This page is part of release 5.02 of the Linux  man-pages  project.   A
53       description  of  the project, information about reporting bugs, and the
54       latest    version    of    this    page,    can     be     found     at
55       https://www.kernel.org/doc/man-pages/.
56
57
58
59Linux                             2019-03-06                         GETTID(2)
Impressum