[project @ 2001-10-22 16:02:44 by sewardj]

[ghc-hetmet.git] / ghc / rts / Signals.c

diff --git a/ghc/rts/Signals.c b/ghc/rts/Signals.c
index 0b9f3a9..d476a01 100644 (file)
--- a/ghc/rts/Signals.c
+++ b/ghc/rts/Signals.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Signals.c,v 1.15 2000/03/15 15:31:36 simonmar Exp $
+ * $Id: Signals.c,v 1.21 2001/08/14 13:40:09 sewardj Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -7,6 +7,9 @@
  *
  * ---------------------------------------------------------------------------*/
 
+/* This is non=Posix compliant.
+   #include "PosixSource.h" 
+*/
 #include "Rts.h"
 #include "SchedAPI.h"
 #include "Schedule.h"
@@ -15,10 +18,15 @@
 #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 */
 
@@ -97,7 +105,7 @@ generic_handler(int sig)
        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]) {
@@ -143,7 +151,7 @@ unblockUserSignals(void)
    -------------------------------------------------------------------------- */
 
 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;
@@ -179,7 +187,7 @@ sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
        break;
 
     default:
-        barf("sig_install: bad spi");
+        barf("stg_sig_install: bad spi");
     }
 
     if (mask != 0)
@@ -196,7 +204,7 @@ sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
        * 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;
     }
@@ -227,7 +235,7 @@ start_signal_handlers(void)
 
 #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)
 {
   /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
   barf("no signal handling support in a parallel implementation");
@@ -264,7 +272,15 @@ shutdown_handler(int sig STG_UNUSED)
   } else
 #endif
 
-    interruptStgRts();
+  /* 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();
+  }
 }
 
 /*
@@ -275,9 +291,10 @@ shutdown_handler(int sig STG_UNUSED)
  * fine, provided they're so kind as to put back the old one
  * when they de-install.
  *
- * We ignore SIGPIPE, because our I/O library handles EPIPE properly,
- * and a SIGPIPE tends to cause the program to exit silently and
- * mysteriously.
+ * 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()
@@ -295,10 +312,18 @@ init_default_handlers()
       prog_belch("failed to install SIGINT handler");
     }
 
+    siginterrupt(SIGINT, 1);
+
     action.sa_handler = SIG_IGN;
-    if (sigaction(SIGPIPE, &action, &oact) != 0) {
-      prog_belch("failed to install SIGINT handler");
+    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 */