/* -----------------------------------------------------------------------------
- * $Id: Signals.c,v 1.3 1999/01/26 11:12:49 simonm Exp $
+ * $Id: Signals.c,v 1.21 2001/08/14 13:40:09 sewardj Exp $
+ *
+ * (c) The GHC Team, 1998-1999
*
* Signal processing / handling.
*
* ---------------------------------------------------------------------------*/
+/* This is non=Posix compliant.
+ #include "PosixSource.h"
+*/
#include "Rts.h"
#include "SchedAPI.h"
+#include "Schedule.h"
#include "Signals.h"
#include "RtsUtils.h"
#include "RtsFlags.h"
#include "StablePriv.h"
+#ifdef alpha_TARGET_ARCH
+#include <machine/fpu.h>
+#endif
+
+#ifndef mingw32_TARGET_OS
+
#ifndef PAR
+/* SUP: The type of handlers is a little bit, well, doubtful... */
static StgInt *handlers = NULL; /* Dynamically grown array of signal handlers */
static StgInt nHandlers = 0; /* Size of handlers array */
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
circumstances, depending on the signal.
*/
- *next_pending_handler++ = deRefStablePtr(handlers[sig]);
+ *next_pending_handler++ = deRefStablePtr(stgCast(StgStablePtr,handlers[sig]));
/* stack full? */
if (next_pending_handler == &pending_handler_buf[N_PENDING_HANDLERS]) {
sigemptyset(&signals);
sigaddset(&signals, sig);
sigprocmask(SIG_UNBLOCK, &signals, NULL);
+
+ context_switch = 1;
}
/* -----------------------------------------------------------------------------
-------------------------------------------------------------------------- */
StgInt
-sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
+stg_sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
{
sigset_t signals;
struct sigaction action;
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");
+ barf("stg_sig_install: bad spi");
}
if (mask != 0)
* by freeing the previous handler if there was one.
*/
if (previous_spi >= 0) {
- freeStablePtr(handlers[sig]);
+ freeStablePtr(stgCast(StgStablePtr,handlers[sig]));
}
return STG_SIG_ERR;
}
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();
#else /* PAR */
StgInt
-sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
+stg_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.
+ *
+ * In addition to handling SIGINT, the RTS also handles SIGFPE
+ * by ignoring it. Apparently IEEE requires floating-point
+ * exceptions to be ignored by default, but alpha-dec-osf3
+ * doesn't seem to do so.
+ */
+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");
+ }
+
+ siginterrupt(SIGINT, 1);
+
+ action.sa_handler = SIG_IGN;
+ sigemptyset(&action.sa_mask);
+ action.sa_flags = 0;
+ if (sigaction(SIGFPE, &action, &oact) != 0) {
+ /* Oh well, at least we tried. */
+ prog_belch("failed to install SIGFPE handler");
+ }
+#ifdef alpha_TARGET_ARCH
+ ieee_set_fp_control(0);
+#endif
+}
+
+#endif /*! mingw32_TARGET_OS */
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