/* -----------------------------------------------------------------------------
- * $Id: Signals.c,v 1.27 2002/09/03 14:07:03 simonmar Exp $
+ * $Id: Signals.c,v 1.41 2004/08/13 13:10:44 simonmar Exp $
*
* (c) The GHC Team, 1998-1999
*
#include "Signals.h"
#include "RtsUtils.h"
#include "RtsFlags.h"
-#include "StablePriv.h"
#ifdef alpha_TARGET_ARCH
-# include <machine/fpu.h>
+# if defined(linux_TARGET_OS)
+# include <asm/fpu.h>
+# else
+# include <machine/fpu.h>
+# endif
#endif
#ifdef HAVE_UNISTD_H
#include <stdlib.h>
-#ifndef mingw32_TARGET_OS
+/* This curious flag is provided for the benefit of the Haskell binding
+ * to POSIX.1 to control whether or not to include SA_NOCLDSTOP when
+ * installing a SIGCHLD handler.
+ *
+ */
+StgInt nocldstop = 0;
-#ifndef PAR
+#if defined(RTS_USER_SIGNALS)
/* SUP: The type of handlers is a little bit, well, doubtful... */
static StgInt *handlers = NULL; /* Dynamically grown array of signal handlers */
StgPtr pending_handler_buf[N_PENDING_HANDLERS];
StgPtr *next_pending_handler = pending_handler_buf;
-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.
return;
if (handlers == NULL)
- handlers = (StgInt *) malloc((sig + 1) * sizeof(StgInt));
+ handlers = (StgInt *)stgMallocBytes((sig + 1) * sizeof(StgInt), "more_handlers");
else
- handlers = (StgInt *) realloc(handlers, (sig + 1) * sizeof(StgInt));
+ handlers = (StgInt *)stgReallocBytes(handlers, (sig + 1) * sizeof(StgInt), "more_handlers");
- if (handlers == NULL) {
- // 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;
{
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
* Install a Haskell signal handler.
* -------------------------------------------------------------------------- */
-StgInt
-stg_sig_install(StgInt sig, StgInt spi, StgStablePtr handler, void *mask)
+int
+stg_sig_install(int sig, int spi, StgStablePtr *handler, void *mask)
{
sigset_t signals, osignals;
struct sigaction action;
previous_spi = handlers[sig];
+ action.sa_flags = 0;
+
switch(spi) {
case STG_SIG_IGN:
handlers[sig] = STG_SIG_IGN;
break;
case STG_SIG_HAN:
- handlers[sig] = (StgInt)handler;
+ 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))
}
return STG_SIG_ERR;
}
-
- return previous_spi;
+
+ if (previous_spi == STG_SIG_DFL || previous_spi == STG_SIG_IGN
+ || previous_spi == STG_SIG_ERR) {
+ return previous_spi;
+ } else {
+ *handler = (StgStablePtr)previous_spi;
+ return STG_SIG_HAN;
+ }
}
/* -----------------------------------------------------------------------------
unblockUserSignals();
}
-#else // PAR
-StgInt
-stg_sig_install(StgInt sig, StgInt spi, StgStablePtr handler, sigset_t *mask)
+/* ----------------------------------------------------------------------------
+ * 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)
{
- // don't fflush(stdout); WORKAROUND bug in Linux glibc
- barf("no signal handling support in a parallel implementation");
+ StgPtr *p;
+
+ p = next_pending_handler;
+ while (p != pending_handler_buf) {
+ p--;
+ evac((StgClosure **)p);
+ }
}
-void
-startSignalHandlers(void)
+#else /* !RTS_USER_SIGNALS */
+StgInt
+stg_sig_install(StgInt sig STG_UNUSED,
+ StgInt spi STG_UNUSED,
+ StgStablePtr* handler STG_UNUSED,
+ void* mask STG_UNUSED)
{
+ //barf("User signals not supported");
+ return STG_SIG_DFL;
}
+
#endif
+#if defined(RTS_USER_SIGNALS)
/* -----------------------------------------------------------------------------
* SIGINT handler.
*
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
// extreme prejudice. So the first ^C tries to exit the program
// cleanly, and the second one just kills it.
if (interrupted) {
- exit(EXIT_INTERRUPTED);
+ stg_exit(EXIT_INTERRUPTED);
} else {
interruptStgRts();
}
#ifdef SMP
startup_guy = pthread_self();
#endif
+#ifdef RTS_SUPPORTS_THREADS
+ handleSignalsInThisThread();
+#endif
// install the SIGINT handler
action.sa_handler = shutdown_handler;
prog_belch("warning: failed to install SIGINT handler");
}
-#ifndef cygwin32_TARGET_OS
+#if defined(HAVE_SIGINTERRUPT)
siginterrupt(SIGINT, 1); // isn't this the default? --SDM
#endif
#endif
}
-#endif /*! mingw32_TARGET_OS */
+#endif /* RTS_USER_SIGNALS */
projects / ghc-hetmet.git / blobdiff