/* -----------------------------------------------------------------------------
- * $Id: Signals.c,v 1.28 2002/09/06 14:34:13 simonmar Exp $
+ * $Id: Signals.c,v 1.33 2003/01/25 15:54:50 wolfgang Exp $
*
* (c) The GHC Team, 1998-1999
*
StgInt nocldstop = 0;
+
+#ifdef RTS_SUPPORTS_THREADS
+pthread_t signalHandlingThread;
+#endif
+
+ // Handle all signals in the current thread.
+ // Called from Capability.c whenever the main capability is granted to a thread
+ // and in installDefaultHandlers
+void
+handleSignalsInThisThread()
+{
+#ifdef RTS_SUPPORTS_THREADS
+ signalHandlingThread = pthread_self();
+#endif
+}
+
+
/* -----------------------------------------------------------------------------
* Allocate/resize the table of signal handlers.
* -------------------------------------------------------------------------- */
{
sigset_t signals;
+#if defined(THREADED_RTS)
+ // Make the thread that currently holds the main capability
+ // handle the signal.
+ // This makes sure that awaitEvent() is interrupted
+ // and it (hopefully) prevents race conditions
+ // (signal handlers are not atomic with respect to other threads)
+
+ if(pthread_self() != signalHandlingThread) {
+ pthread_kill(signalHandlingThread, sig);
+ return;
+ }
+#endif
+
/* Can't call allocate from here. Probably can't call malloc
either. However, we have to schedule a new thread somehow.
// stack full?
if (next_pending_handler == &pending_handler_buf[N_PENDING_HANDLERS]) {
- barf("too many pending signals");
+ prog_belch("too many pending signals");
+ stg_exit(EXIT_FAILURE);
}
// re-establish the signal handler, and carry on
void
blockUserSignals(void)
{
- sigprocmask(SIG_SETMASK, &userSignals, &savedSignals);
+ sigprocmask(SIG_BLOCK, &userSignals, &savedSignals);
}
void
previous_spi = handlers[sig];
+ action.sa_flags = 0;
+
switch(spi) {
case STG_SIG_IGN:
handlers[sig] = STG_SIG_IGN;
break;
case STG_SIG_HAN:
+ case STG_SIG_RST:
handlers[sig] = (StgInt)*handler;
sigaddset(&userSignals, sig);
action.sa_handler = generic_handler;
+ if (spi == STG_SIG_RST) {
+ action.sa_flags = SA_RESETHAND;
+ }
n_haskell_handlers++;
break;
else
sigemptyset(&action.sa_mask);
- action.sa_flags = sig == SIGCHLD && nocldstop ? SA_NOCLDSTOP : 0;
+ action.sa_flags |= sig == SIGCHLD && nocldstop ? SA_NOCLDSTOP : 0;
if (sigaction(sig, &action, NULL) ||
sigprocmask(SIG_SETMASK, &osignals, NULL))
unblockUserSignals();
}
+/* ----------------------------------------------------------------------------
+ * Mark signal handlers during GC.
+ *
+ * We do this rather than trying to start all the signal handlers
+ * prior to GC, because that requires extra heap for the new threads.
+ * Signals must be blocked (see blockUserSignals() above) during GC to
+ * avoid race conditions.
+ * -------------------------------------------------------------------------- */
+
+void
+markSignalHandlers (evac_fn evac)
+{
+ StgPtr *p;
+
+ p = next_pending_handler;
+ while (p != pending_handler_buf) {
+ p--;
+ evac((StgClosure **)p);
+ }
+}
+
#else // PAR
StgInt
stg_sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
pthread_kill(startup_guy, sig);
return;
}
+ // ToDo: The code for the threaded RTS below does something very
+ // similar. Maybe the SMP special case is not needed
+ // -- Wolfgang Thaller
+#elif defined(THREADED_RTS)
+ // Make the thread that currently holds the main capability
+ // handle the signal.
+ // This makes sure that awaitEvent() is interrupted
+ if(pthread_self() != signalHandlingThread) {
+ pthread_kill(signalHandlingThread, sig);
+ return;
+ }
#endif
// If we're already trying to interrupt the RTS, terminate with
#ifdef SMP
startup_guy = pthread_self();
#endif
+#ifdef RTS_SUPPORTS_THREADS
+ handleSignalsInThisThread();
+#endif
// install the SIGINT handler
action.sa_handler = shutdown_handler;