THR_kill(2)               FreeBSD System Calls Manual              THR_kill(2)

NAME
     thr_kill - send signal to thread

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/thr.h>

     int
     thr_kill(long id, int sig);

     int
     thr_kill2(pid_t pid, long id, int sig);

DESCRIPTION
     The thr_kill() and thr_kill2() system calls allow sending a signal,
     specified by the sig argument, to some threads in a process.  For the
     thr_kill() function, signalled threads are always limited to the current
     process.  For the thr_kill2() function, the pid argument specifies the
     process with threads to be signalled.

     The id argument specifies which threads get the signal.  If id is equal
     to -1, all threads in the specified process are signalled.  Otherwise,
     only the thread with the thread identifier equal to the argument is
     signalled.

     The sig argument defines the delivered signal.  It must be a valid signal
     number or zero.  In the latter case no signal is actually sent, and the
     call is used to verify the liveness of the thread.

     The signal is delivered with siginfo si_code set to SI_LWP.

RETURN VALUES
     If successful, thr_kill() and thr_kill2() will return zero, otherwise -1
     is returned, and errno is set to indicate the error.

ERRORS
     The thr_kill() and thr_kill2() operations return the following errors:

     [EINVAL]           The sig argument is not zero and does not specify
                        valid signal.

     [ESRCH]            The specified process or thread was not found.

     Additionally, the thr_kill2() may return the following errors:

     [EPERM]            The current process does not have sufficient privilege
                        to check existence or send a signal to the specified
                        process.

SEE ALSO
     kill(2), thr_exit(2), thr_new(2), thr_self(2), thr_set_name(2),
     _umtx_op(2), pthread_kill(3), signal(3)

STANDARDS
     The thr_kill() and thr_kill2() system calls are non-standard and are used
     by the 1:1 Threading Library (libthr, -lthr) to implement IEEE Std
     1003.1-2001 ("POSIX.1") pthread(3) functionality.

HISTORY
     The thr_kill() and thr_kill2() system calls first appeared in
     FreeBSD 5.2.

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