THR_SELF(2)               FreeBSD System Calls Manual              THR_SELF(2)

NAME
     thr_self - return thread identifier for the calling thread

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/thr.h>

     int
     thr_self(long *id);

DESCRIPTION
     The thr_self() system call stores the system-wide thread identifier for
     the current kernel-scheduled thread in the variable pointed by the
     argument id.

     The thread identifier is an integer in the range from PID_MAX + 2
     (100001) to INT_MAX.  The thread identifier is guaranteed to be unique at
     any given time, for each running thread in the system.  After the thread
     exits, the identifier may be reused.

RETURN VALUES
     If successful, thr_self() will return zero, otherwise -1 is returned, and
     errno is set to indicate the error.

ERRORS
     The thr_self() operation may return the following errors:

     [EFAULT]           The memory pointed to by the id argument is not valid.

SEE ALSO
     _umtx_op(2), thr_exit(2), thr_kill(2), thr_kill2(2), thr_new(2),
     thr_set_name(2), pthread_getthreadid_np(3), pthread_self(3)

STANDARDS
     The thr_self() system call is non-standard and is used by 1:1 Threading
     Library (libthr, -lthr) to implement IEEE Std 1003.1-2001 ("POSIX.1")
     pthread(3) functionality.

HISTORY
     The thr_self() system call first appeared in FreeBSD 5.2.

FreeBSD 13.1-RELEASE-p6           May 5, 2020          FreeBSD 13.1-RELEASE-p6