gettid

GETTID(2)                  Linux Programmer's Manual                 GETTID(2)



NAME
       gettid - get thread identification

SYNOPSIS
       #include <sys/types.h>

       pid_t gettid(void);

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

RETURN VALUE
       On success, returns the thread ID of the calling thread.

ERRORS
       This call is always successful.

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

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

NOTES
       The thread ID returned by this call is not the same thing as a POSIX
       thread ID (i.e., the opaque value returned by pthread_self(3)).

       In a new thread group created by a clone(2) call that does not specify
       the CLONE_THREAD flag (or, equivalently, a new process created by
       fork(2)), the new process is a thread group leader, and its thread
       group ID (the value returned by getpid(2)) is the same as its thread ID
       (the value returned by gettid()).

SEE ALSO
       capget(2), clone(2), fcntl(2), fork(2), getpid(2), get_robust_list(2),
       ioprio_set(2), perf_event_open(2), sched_setaffinity(2),
       sched_setparam(2), sched_setscheduler(2), tgkill(2), timer_create(2)

COLOPHON
       This page is part of release 5.03 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux                             2019-03-06                         GETTID(2)