/* -----------------------------------------------------------------------------
- * $Id: Signals.c,v 1.5 1999/03/02 20:01:55 sof Exp $
+ * $Id: Signals.c,v 1.16 2000/04/04 10:04:47 simonmar Exp $
*
* (c) The GHC Team, 1998-1999
*
#include "Rts.h"
#include "SchedAPI.h"
+#include "Schedule.h"
#include "Signals.h"
#include "RtsUtils.h"
#include "RtsFlags.h"
I_ i;
if (sig < nHandlers)
- return;
+ return;
if (handlers == NULL)
- handlers = (I_ *) malloc((sig + 1) * sizeof(I_));
+ handlers = (I_ *) malloc((sig + 1) * sizeof(I_));
else
- handlers = (I_ *) realloc(handlers, (sig + 1) * sizeof(I_));
+ handlers = (I_ *) realloc(handlers, (sig + 1) * sizeof(I_));
if (handlers == NULL) {
- fflush(stdout);
- fprintf(stderr, "VM exhausted (in more_handlers)\n");
- exit(EXIT_FAILURE);
+ /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
+ barf("VM exhausted (in more_handlers)");
}
for(i = nHandlers; i <= sig; i++)
- /* Fill in the new slots with default actions */
- handlers[i] = STG_SIG_DFL;
+ /* Fill in the new slots with default actions */
+ handlers[i] = STG_SIG_DFL;
nHandlers = sig + 1;
}
either. However, we have to schedule a new thread somehow.
It's probably ok to request a context switch and allow the
- scheduler to start the handler thread, but how to we
+ scheduler to start the handler thread, but how do we
communicate this to the scheduler?
We need some kind of locking, but with low overhead (i.e. no
sigemptyset(&signals);
sigaddset(&signals, sig);
sigprocmask(SIG_UNBLOCK, &signals, NULL);
+
+ context_switch = 1;
}
/* -----------------------------------------------------------------------------
sigdelset(&userSignals, sig);
action.sa_handler = SIG_DFL;
break;
+
case STG_SIG_HAN:
handlers[sig] = (I_)handler;
sigaddset(&userSignals, sig);
action.sa_handler = generic_handler;
break;
+
default:
barf("sig_install: bad spi");
}
next_pending_handler--;
- /* create*Thread puts the thread on the head of the runnable
- * queue, hence it will be run next. Poor man's priority
- * scheduling.
- */
- createIOThread(RtsFlags.GcFlags.initialStkSize,
- (StgClosure *) *next_pending_handler);
+ scheduleThread(
+ createIOThread(RtsFlags.GcFlags.initialStkSize,
+ (StgClosure *) *next_pending_handler));
}
unblockUserSignals();
StgInt
sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
{
- fflush(stdout);
- fprintf(stderr,
- "No signal handling support in a parallel implementation.\n");
- exit(EXIT_FAILURE);
+ /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
+ barf("no signal handling support in a parallel implementation");
}
void
}
#endif
+/* -----------------------------------------------------------------------------
+ SIGINT handler.
+
+ We like to shutdown nicely after receiving a SIGINT, write out the
+ stats, write profiling info, close open files and flush buffers etc.
+ -------------------------------------------------------------------------- */
+
+#ifdef SMP
+pthread_t startup_guy;
+#endif
+
+static void
+shutdown_handler(int sig STG_UNUSED)
+{
+#ifdef SMP
+ /* if I'm a worker thread, send this signal to the guy who
+ * originally called startupHaskell(). Since we're handling
+ * the signal, it won't be a "send to all threads" type of signal
+ * (according to the POSIX threads spec).
+ */
+ if (pthread_self() != startup_guy) {
+ pthread_kill(startup_guy, sig);
+ } else
+#endif
+
+ /* If we're already trying to interrupt the RTS, terminate with
+ * extreme prejudice. So the first ^C tries to exit the program
+ * cleanly, and the second one just kills it.
+ */
+ if (interrupted) {
+ exit(EXIT_INTERRUPTED);
+ } else {
+ interruptStgRts();
+ }
+}
+
+/*
+ * The RTS installs a default signal handler for catching
+ * SIGINT, so that we can perform an orderly shutdown.
+ *
+ * Haskell code may install their own SIGINT handler, which is
+ * fine, provided they're so kind as to put back the old one
+ * when they de-install.
+ */
+void
+init_default_handlers()
+{
+ struct sigaction action,oact;
+
+#ifdef SMP
+ startup_guy = pthread_self();
+#endif
+ action.sa_handler = shutdown_handler;
+ sigemptyset(&action.sa_mask);
+ action.sa_flags = 0;
+ if (sigaction(SIGINT, &action, &oact) != 0) {
+ /* Oh well, at least we tried. */
+ prog_belch("failed to install SIGINT handler");
+ }
+}
+
#endif /*! mingw32_TARGET_OS */