Send a Signal to a Thread
thr_kill(3C) sends a signal to a thread.
For POSIX threads, see pthread_kill Syntax.
int thr_kill(thread_t target_thread, int sig);
thr_kill Return Values
Upon successful completion, thr_kill() returns
0. When any of the following conditions is detected, thr_kill() fails
and returns the corresponding value. When a failure occurs, no signal is sent.
No thread was found associated with the
thread designated by thread ID.
The sig argument
value is not zero. sig is an invalid or unsupported