When using the native Solaris Threads API, the Threads Module terminates threads using the thr_kill() method. This method really just sends a signal to the target thread. The Threads Module arbitrarily uses the SIGPWR signal to perform thread termination. Any thread created using the Threads Module will unmask this signal prior to entering user code. If this signal is already used within an application, another signal may be specified by changing the source code. Simply search for the macro definition RW_THR_TERMINATE_SIGNAL and change its value to the desired signal value (the definition currently resides in rw/thread/RWThread.h).

When the Threads Module is built using the POSIX API, it uses the thread cancellation mechanism to terminate threads, which does not involve the use of signals.