Add a notice to the description of the signal event system: interrupt

handlers have to be disabled before using the event system.

doc/scsh-manual/syscalls.tex

@@ -2585,6 +2585,7 @@ or integer process ids.
 \end{desc}
 
 \subsubsection{Interrupt handlers}
+\label{sec:int_handlers}
 Scsh interrupt handlers are complicated by the fact that scsh is implemented on
 top of the {\scm} virtual machine, which has its own interrupt system, 
 independent of the Unix signal system.

doc/scsh-manual/threads.tex

@@ -191,6 +191,15 @@ variable \texttt{state} by USR1 and USR2:
       (set! state #t)
       (lp next))))
 \end{code}
+
+\textbf{Warning:} The current version of scsh also defines
+asynchronous handlers for interrupts (See Section
+\ref{sec:int_handlers}). The default action of some of these handlers
+is to terminate the process in which case you will most likely not see
+an effect of the synchronous event interface described here. It is
+therefore recommended to disable the corresponding interrupt handler
+using \texttt{(set-interrupt-handler interrupt \#f)}.
+
 \section{Interaction between threads and process state}
 \label{sec:ps_interac}
 
@@ -239,4 +248,7 @@ Therefore they remain global process state: If a thread changes one of
 these values, all other threads see the new value. Consequently, scsh
 does not provide \texttt{with-uid} and friends.
 
-
+%%% Local Variables: 
+%%% mode: latex
+%%% TeX-master: "man"
+%%% End: