-/* Copyright (C) 1995,1996 Free Software Foundation, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
-\f
-
-#include <stdio.h>
-#include <signal.h>
-#include "_scm.h"
-
-#include "scmsigs.h"
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-
-\f
-
-#if (__TURBOC__==1)
-#define signal ssignal /* Needed for TURBOC V1.0 */
-#endif
-
-#ifdef USE_MIT_PTHREADS
-#undef signal
-#define signal pthread_signal
-#endif
-
-\f
-
-/* SIGRETTYPE is the type that signal handlers return. See <signal.h>*/
-
-#ifdef RETSIGTYPE
-#define SIGRETTYPE RETSIGTYPE
-#else
-#ifdef STDC_HEADERS
-#if (__TURBOC__==1)
-#define SIGRETTYPE int
-#else
-#define SIGRETTYPE void
-#endif
-#else
-#ifdef linux
-#define SIGRETTYPE void
-#else
-#define SIGRETTYPE int
-#endif
-#endif
-#endif
-
-#ifdef vms
-#ifdef __GNUC__
-#define SIGRETTYPE int
-#endif
-#endif
-
-\f
-
-#define SIGFN(NAME, SCM_NAME, SIGNAL) \
-static SIGRETTYPE \
-NAME (sig) \
- int sig; \
-{ \
- signal (SIGNAL, NAME); \
- scm_take_signal (SCM_NAME); \
-}
-
-#ifdef SIGHUP
-SIGFN(scm_hup_signal, SCM_HUP_SIGNAL, SIGHUP)
-#endif
-
-#ifdef SIGINT
-SIGFN(scm_int_signal, SCM_INT_SIGNAL, SIGINT)
-#endif
-
-#ifdef SIGFPE
-SIGFN(scm_fpe_signal, SCM_FPE_SIGNAL, SIGFPE)
-#endif
-
-#ifdef SIGBUS
-SIGFN(scm_bus_signal, SCM_BUS_SIGNAL, SIGBUS)
-#endif
-
-#ifdef SIGSEGV
-SIGFN(scm_segv_signal, SCM_SEGV_SIGNAL, SIGSEGV)
-#endif
-
-#ifdef SIGALRM
-SIGFN(scm_alrm_signal, SCM_ALRM_SIGNAL, SIGALRM)
-#endif
-
-#define FAKESIGFN(NAME, SCM_NAME) \
-static SIGRETTYPE \
-NAME (sig) \
- int sig; \
-{ \
- scm_take_signal (SCM_NAME); \
-}
-
-#if 0
-/* !!! */
-FAKESIGFN(scm_gc_signal, SCM_GC_SIGNAL)
-FAKESIGFN(scm_tick_signal, SCM_TICK_SIGNAL)
-#endif
-\f
-
-SCM_PROC(s_alarm, "alarm", 1, 0, 0, scm_alarm);
-
-SCM
-scm_alarm (i)
- SCM i;
-{
- unsigned int j;
- SCM_ASSERT (SCM_INUMP (i) && (SCM_INUM (i) >= 0), i, SCM_ARG1, s_alarm);
- SCM_SYSCALL (j = alarm (SCM_INUM (i)));
- return SCM_MAKINUM (j);
-}
-
-
-SCM_PROC(s_pause, "pause", 0, 0, 0, scm_pause);
-
-SCM
-scm_pause ()
-{
- pause ();
- return SCM_UNSPECIFIED;
-}
-
-SCM_PROC(s_sleep, "sleep", 1, 0, 0, scm_sleep);
-
-SCM
-scm_sleep (i)
- SCM i;
-{
- unsigned int j;
- SCM_ASSERT (SCM_INUMP (i) && (SCM_INUM (i) >= 0), i, SCM_ARG1, s_sleep);
-#ifdef __HIGHC__
- SCM_SYSCALL(j = 0; sleep(SCM_INUM(i)););
-#else
- SCM_SYSCALL(j = sleep(SCM_INUM(i)););
-#endif
- return SCM_MAKINUM (j);
-}
-
-SCM_PROC(s_raise, "raise", 1, 0, 0, scm_raise);
-
-SCM
-scm_raise(sig)
- SCM sig;
-{
- SCM_ASSERT(SCM_INUMP(sig), sig, SCM_ARG1, s_raise);
-# ifdef vms
- return SCM_MAKINUM(gsignal((int)SCM_INUM(sig)));
-# else
- return kill (getpid(), (int)SCM_INUM(sig)) ? SCM_BOOL_F : SCM_BOOL_T;
-# endif
-}
-
-\f
-#ifdef SIGHUP
-static SIGRETTYPE (*oldhup) ();
-#endif
-
-#ifdef SIGINT
-static SIGRETTYPE (*oldint) ();
-#endif
-
-#ifdef SIGFPE
-static SIGRETTYPE (*oldfpe) ();
-#endif
-
-#ifdef SIGBUS
-static SIGRETTYPE (*oldbus) ();
-#endif
-
-#ifdef SIGSEGV /* AMIGA lacks! */
-static SIGRETTYPE (*oldsegv) ();
-#endif
-
-#ifdef SIGALRM
-static SIGRETTYPE (*oldalrm) ();
-#endif
-
-#ifdef SIGPIPE
-static SIGRETTYPE (*oldpipe) ();
-#endif
-
-
-
-void
-scm_init_signals ()
-{
-#ifdef SIGINT
- oldint = signal (SIGINT, scm_int_signal);
-#endif
-#ifdef SIGHUP
- oldhup = signal (SIGHUP, scm_hup_signal);
-#endif
-#ifdef SIGFPE
- oldfpe = signal (SIGFPE, scm_fpe_signal);
-#endif
-#ifdef SIGBUS
- oldbus = signal (SIGBUS, scm_bus_signal);
-#endif
-#ifdef SIGSEGV /* AMIGA lacks! */
- oldsegv = signal (SIGSEGV, scm_segv_signal);
-#endif
-#ifdef SIGALRM
- alarm (0); /* kill any pending ALRM interrupts */
- oldalrm = signal (SIGALRM, scm_alrm_signal);
-#endif
-#ifdef SIGPIPE
- oldpipe = signal (SIGPIPE, SIG_IGN);
-#endif
-#ifdef ultrix
- siginterrupt (SIGINT, 1);
- siginterrupt (SIGALRM, 1);
- siginterrupt (SIGHUP, 1);
- siginterrupt (SIGPIPE, 1);
-#endif /* ultrix */
-}
-
-/* This is used in preparation for a possible fork(). Ignore all
- signals before the fork so that child will catch only if it
- establishes a handler */
-
-void
-scm_ignore_signals ()
-{
-#ifdef ultrix
- siginterrupt (SIGINT, 0);
- siginterrupt (SIGALRM, 0);
- siginterrupt (SIGHUP, 0);
- siginterrupt (SIGPIPE, 0);
-#endif /* ultrix */
- signal (SIGINT, SIG_IGN);
-#ifdef SIGHUP
- signal (SIGHUP, SIG_DFL);
-#endif
-#ifdef SCM_FLOATS
- signal (SIGFPE, SIG_DFL);
-#endif
-#ifdef SIGBUS
- signal (SIGBUS, SIG_DFL);
-#endif
-#ifdef SIGSEGV /* AMIGA lacks! */
- signal (SIGSEGV, SIG_DFL);
-#endif
- /* Some documentation claims that ALRMs are cleared accross forks.
- If this is not always true then the value returned by alarm(0)
- will have to be saved and scm_unignore_signals() will have to
- reinstate it. */
- /* This code should be neccessary only if the forked process calls
- alarm() without establishing a handler:
- #ifdef SIGALRM
- oldalrm = signal(SIGALRM, SIG_DFL);
- #endif */
- /* These flushes are per warning in man page on fork(). */
- fflush (stdout);
- fflush (stderr);
-}
-
-
-void
-scm_unignore_signals ()
-{
- signal (SIGINT, scm_int_signal);
-#ifdef SIGHUP
- signal (SIGHUP, scm_hup_signal);
-#endif
-#ifdef SCM_FLOATS
- signal (SIGFPE, scm_fpe_signal);
-#endif
-#ifdef SIGBUS
- signal (SIGBUS, scm_bus_signal);
-#endif
-#ifdef SIGSEGV /* AMIGA lacks! */
- signal (SIGSEGV, scm_segv_signal);
-#endif
-#ifdef SIGALRM
- signal (SIGALRM, scm_alrm_signal);
-#endif
-#ifdef ultrix
- siginterrupt (SIGINT, 1);
- siginterrupt (SIGALRM, 1);
- siginterrupt (SIGHUP, 1);
- siginterrupt (SIGPIPE, 1);
-#endif /* ultrix */
-}
-
-SCM_PROC (s_restore_signals, "restore-signals", 0, 0, 0, scm_restore_signals);
-
-SCM
-scm_restore_signals ()
-{
-#ifdef ultrix
- siginterrupt (SIGINT, 0);
- siginterrupt (SIGALRM, 0);
- siginterrupt (SIGHUP, 0);
- siginterrupt (SIGPIPE, 0);
-#endif /* ultrix */
- signal (SIGINT, oldint);
-#ifdef SIGHUP
- signal (SIGHUP, oldhup);
-#endif
-#ifdef SCM_FLOATS
- signal (SIGFPE, oldfpe);
-#endif
-#ifdef SIGBUS
- signal (SIGBUS, oldbus);
-#endif
-#ifdef SIGSEGV /* AMIGA lacks! */
- signal (SIGSEGV, oldsegv);
-#endif
-#ifdef SIGPIPE
- signal (SIGPIPE, oldpipe);
-#endif
-#ifdef SIGALRM
- alarm (0); /* kill any pending ALRM interrupts */
- signal (SIGALRM, oldalrm);
-#endif
- return SCM_UNSPECIFIED;
-}
-
-
-
-void
-scm_init_scmsigs ()
-{
-#include "scmsigs.x"
-}
-
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2004, 2006,
+ * 2007, 2008, 2009, 2011, 2013, 2014 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+
+\f
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <fcntl.h> /* for mingw */
+#include <signal.h>
+#include <stdio.h>
+#include <errno.h>
+
+#ifdef HAVE_PROCESS_H
+#include <process.h> /* for mingw */
+#endif
+
+#include <unistd.h>
+
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#include <full-write.h>
+
+#include "libguile/_scm.h"
+
+#include "libguile/async.h"
+#include "libguile/eval.h"
+#include "libguile/root.h"
+#include "libguile/vectors.h"
+#include "libguile/threads.h"
+
+#include "libguile/validate.h"
+#include "libguile/scmsigs.h"
+
+
+\f
+
+/* SIGRETTYPE is the type that signal handlers return. See <signal.h> */
+
+#ifdef RETSIGTYPE
+# define SIGRETTYPE RETSIGTYPE
+#else
+# ifdef STDC_HEADERS
+# define SIGRETTYPE void
+# else
+# define SIGRETTYPE int
+# endif
+#endif
+
+\f
+
+/* take_signal is installed as the C signal handler whenever a Scheme
+ handler is set. When a signal arrives, take_signal will write a
+ byte into the 'signal pipe'. The 'signal delivery thread' will
+ read this pipe and queue the appropriate asyncs.
+
+ When Guile is built without threads, the signal handler will
+ install the async directly.
+*/
+
+
+/* Scheme vectors with information about a signal. signal_handlers
+ contains the handler procedure or #f, signal_handler_asyncs
+ contains the thunk to be marked as an async when the signal arrives
+ (or the cell with the thunk in a singlethreaded Guile), and
+ signal_handler_threads points to the thread that a signal should be
+ delivered to.
+*/
+static SCM *signal_handlers;
+static SCM signal_handler_asyncs;
+static SCM signal_handler_threads;
+
+/* The signal delivery thread. */
+scm_i_thread *scm_i_signal_delivery_thread = NULL;
+
+/* The mutex held when launching the signal delivery thread. */
+static scm_i_pthread_mutex_t signal_delivery_thread_mutex =
+ SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
+
+/* saves the original C handlers, when a new handler is installed.
+ set to SIG_ERR if the original handler is installed. */
+#ifdef HAVE_SIGACTION
+static struct sigaction orig_handlers[NSIG];
+#else
+static SIGRETTYPE (*orig_handlers[NSIG])(int);
+#endif
+
+static SCM
+close_1 (SCM proc, SCM arg)
+{
+ return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL,
+ scm_list_2 (proc, arg)));
+}
+
+#if SCM_USE_PTHREAD_THREADS
+/* On mingw there's no notion of inter-process signals, only a raise()
+ within the process itself which apparently invokes the registered handler
+ immediately. Not sure how well the following code will cope in this
+ case. It builds but it may not offer quite the same scheme-level
+ semantics as on a proper system. If you're relying on much in the way of
+ signal handling on mingw you probably lose anyway. */
+
+static int signal_pipe[2];
+
+static SIGRETTYPE
+take_signal (int signum)
+{
+ char sigbyte = signum;
+ full_write (signal_pipe[1], &sigbyte, 1);
+
+#ifndef HAVE_SIGACTION
+ signal (signum, take_signal);
+#endif
+}
+
+struct signal_pipe_data
+{
+ char sigbyte;
+ ssize_t n;
+ int err;
+};
+
+static void*
+read_signal_pipe_data (void * data)
+{
+ struct signal_pipe_data *sdata = data;
+
+ sdata->n = read (signal_pipe[0], &sdata->sigbyte, 1);
+ sdata->err = errno;
+
+ return NULL;
+}
+
+static SCM
+signal_delivery_thread (void *data)
+{
+ int sig;
+#if HAVE_PTHREAD_SIGMASK /* not on mingw, see notes above */
+ sigset_t all_sigs;
+ sigfillset (&all_sigs);
+ scm_i_pthread_sigmask (SIG_SETMASK, &all_sigs, NULL);
+#endif
+
+ while (1)
+ {
+ struct signal_pipe_data sigdata;
+
+ scm_without_guile (read_signal_pipe_data, &sigdata);
+
+ sig = sigdata.sigbyte;
+ if (sigdata.n == 1 && sig >= 0 && sig < NSIG)
+ {
+ SCM h, t;
+
+ h = SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs, sig);
+ t = SCM_SIMPLE_VECTOR_REF (signal_handler_threads, sig);
+ if (scm_is_true (h))
+ scm_system_async_mark_for_thread (h, t);
+ }
+ else if (sigdata.n == 0)
+ break; /* the signal pipe was closed. */
+ else if (sigdata.n < 0 && sigdata.err != EINTR)
+ perror ("error in signal delivery thread");
+ }
+
+ return SCM_UNSPECIFIED; /* not reached unless all other threads exited */
+}
+
+static void
+start_signal_delivery_thread (void)
+{
+ SCM signal_thread;
+
+ scm_i_pthread_mutex_lock (&signal_delivery_thread_mutex);
+
+ if (pipe2 (signal_pipe, O_CLOEXEC) != 0)
+ scm_syserror (NULL);
+ signal_thread = scm_spawn_thread (signal_delivery_thread, NULL,
+ scm_handle_by_message,
+ "signal delivery thread");
+ scm_i_signal_delivery_thread = SCM_I_THREAD_DATA (signal_thread);
+
+ scm_i_pthread_mutex_unlock (&signal_delivery_thread_mutex);
+}
+
+void
+scm_i_ensure_signal_delivery_thread ()
+{
+ static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
+ scm_i_pthread_once (&once, start_signal_delivery_thread);
+}
+
+#else /* !SCM_USE_PTHREAD_THREADS */
+
+static SIGRETTYPE
+take_signal (int signum)
+{
+ SCM cell = SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs, signum);
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
+ if (scm_is_false (SCM_CDR (cell)))
+ {
+ SCM_SETCDR (cell, t->active_asyncs);
+ t->active_asyncs = cell;
+ t->pending_asyncs = 1;
+ }
+
+#ifndef HAVE_SIGACTION
+ signal (signum, take_signal);
+#endif
+}
+
+void
+scm_i_ensure_signal_delivery_thread ()
+{
+ return;
+}
+
+#endif /* !SCM_USE_PTHREAD_THREADS */
+
+static void
+install_handler (int signum, SCM thread, SCM handler)
+{
+ if (scm_is_false (handler))
+ {
+ SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, SCM_BOOL_F);
+ SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, SCM_BOOL_F);
+ }
+ else
+ {
+ SCM async = close_1 (handler, scm_from_int (signum));
+#if !SCM_USE_PTHREAD_THREADS
+ async = scm_cons (async, SCM_BOOL_F);
+#endif
+ SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, handler);
+ SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, async);
+ }
+
+ SCM_SIMPLE_VECTOR_SET (signal_handler_threads, signum, thread);
+}
+
+SCM
+scm_sigaction (SCM signum, SCM handler, SCM flags)
+{
+ return scm_sigaction_for_thread (signum, handler, flags, SCM_UNDEFINED);
+}
+
+/* user interface for installation of signal handlers. */
+SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
+ (SCM signum, SCM handler, SCM flags, SCM thread),
+ "Install or report the signal handler for a specified signal.\n\n"
+ "@var{signum} is the signal number, which can be specified using the value\n"
+ "of variables such as @code{SIGINT}.\n\n"
+ "If @var{handler} is omitted, @code{sigaction} returns a pair: the\n"
+ "CAR is the current\n"
+ "signal hander, which will be either an integer with the value @code{SIG_DFL}\n"
+ "(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n"
+ "handles the signal, or @code{#f} if a non-Scheme procedure handles the\n"
+ "signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n"
+ "If @var{handler} is provided, it is installed as the new handler for\n"
+ "@var{signum}. @var{handler} can be a Scheme procedure taking one\n"
+ "argument, or the value of @code{SIG_DFL} (default action) or\n"
+ "@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n"
+ "was installed before @code{sigaction} was first used. When\n"
+ "a scheme procedure has been specified, that procedure will run\n"
+ "in the given @var{thread}. When no thread has been given, the\n"
+ "thread that made this call to @code{sigaction} is used.\n"
+ "Flags can optionally be specified for the new handler.\n"
+ "The return value is a pair with information about the\n"
+ "old handler as described above.\n\n"
+ "This interface does not provide access to the \"signal blocking\"\n"
+ "facility. Maybe this is not needed, since the thread support may\n"
+ "provide solutions to the problem of consistent access to data\n"
+ "structures.")
+#define FUNC_NAME s_scm_sigaction_for_thread
+{
+ int csig;
+#ifdef HAVE_SIGACTION
+ struct sigaction action;
+ struct sigaction old_action;
+#else
+ SIGRETTYPE (* chandler) (int) = SIG_DFL;
+ SIGRETTYPE (* old_chandler) (int);
+#endif
+ int query_only = 0;
+ int save_handler = 0;
+
+ SCM old_handler;
+
+ csig = scm_to_signed_integer (signum, 0, NSIG-1);
+
+#if defined(HAVE_SIGACTION)
+ action.sa_flags = 0;
+ if (!SCM_UNBNDP (flags))
+ action.sa_flags |= scm_to_int (flags);
+ sigemptyset (&action.sa_mask);
+#endif
+
+ if (SCM_UNBNDP (thread))
+ thread = scm_current_thread ();
+ else
+ {
+ SCM_VALIDATE_THREAD (4, thread);
+ if (scm_c_thread_exited_p (thread))
+ SCM_MISC_ERROR ("thread has already exited", SCM_EOL);
+ }
+
+ scm_i_ensure_signal_delivery_thread ();
+
+ SCM_CRITICAL_SECTION_START;
+ old_handler = SCM_SIMPLE_VECTOR_REF (*signal_handlers, csig);
+ if (SCM_UNBNDP (handler))
+ query_only = 1;
+ else if (scm_is_integer (handler))
+ {
+ long handler_int = scm_to_long (handler);
+
+ if (handler_int == (long) SIG_DFL || handler_int == (long) SIG_IGN)
+ {
+#ifdef HAVE_SIGACTION
+ action.sa_handler = (SIGRETTYPE (*) (int)) handler_int;
+#else
+ chandler = (SIGRETTYPE (*) (int)) handler_int;
+#endif
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ }
+ else
+ {
+ SCM_CRITICAL_SECTION_END;
+ SCM_OUT_OF_RANGE (2, handler);
+ }
+ }
+ else if (scm_is_false (handler))
+ {
+ /* restore the default handler. */
+#ifdef HAVE_SIGACTION
+ if (orig_handlers[csig].sa_handler == SIG_ERR)
+ query_only = 1;
+ else
+ {
+ action = orig_handlers[csig];
+ orig_handlers[csig].sa_handler = SIG_ERR;
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ }
+#else
+ if (orig_handlers[csig] == SIG_ERR)
+ query_only = 1;
+ else
+ {
+ chandler = orig_handlers[csig];
+ orig_handlers[csig] = SIG_ERR;
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ }
+#endif
+ }
+ else
+ {
+ SCM_VALIDATE_PROC (2, handler);
+#ifdef HAVE_SIGACTION
+ action.sa_handler = take_signal;
+ if (orig_handlers[csig].sa_handler == SIG_ERR)
+ save_handler = 1;
+#else
+ chandler = take_signal;
+ if (orig_handlers[csig] == SIG_ERR)
+ save_handler = 1;
+#endif
+ install_handler (csig, thread, handler);
+ }
+
+ /* XXX - Silently ignore setting handlers for `program error signals'
+ because they can't currently be handled by Scheme code.
+ */
+
+ switch (csig)
+ {
+ /* This list of program error signals is from the GNU Libc
+ Reference Manual */
+ case SIGFPE:
+ case SIGILL:
+ case SIGSEGV:
+#ifdef SIGBUS
+ case SIGBUS:
+#endif
+ case SIGABRT:
+#if defined(SIGIOT) && (SIGIOT != SIGABRT)
+ case SIGIOT:
+#endif
+#ifdef SIGTRAP
+ case SIGTRAP:
+#endif
+#ifdef SIGEMT
+ case SIGEMT:
+#endif
+#ifdef SIGSYS
+ case SIGSYS:
+#endif
+ query_only = 1;
+ }
+
+#ifdef HAVE_SIGACTION
+ if (query_only)
+ {
+ if (sigaction (csig, 0, &old_action) == -1)
+ SCM_SYSERROR;
+ }
+ else
+ {
+ if (sigaction (csig, &action , &old_action) == -1)
+ SCM_SYSERROR;
+ if (save_handler)
+ orig_handlers[csig] = old_action;
+ }
+ if (old_action.sa_handler == SIG_DFL || old_action.sa_handler == SIG_IGN)
+ old_handler = scm_from_long ((long) old_action.sa_handler);
+ SCM_CRITICAL_SECTION_END;
+ return scm_cons (old_handler, scm_from_int (old_action.sa_flags));
+#else
+ if (query_only)
+ {
+ if ((old_chandler = signal (csig, SIG_IGN)) == SIG_ERR)
+ SCM_SYSERROR;
+ if (signal (csig, old_chandler) == SIG_ERR)
+ SCM_SYSERROR;
+ }
+ else
+ {
+ if ((old_chandler = signal (csig, chandler)) == SIG_ERR)
+ SCM_SYSERROR;
+ if (save_handler)
+ orig_handlers[csig] = old_chandler;
+ }
+ if (old_chandler == SIG_DFL || old_chandler == SIG_IGN)
+ old_handler = scm_from_long ((long) old_chandler);
+ SCM_CRITICAL_SECTION_END;
+ return scm_cons (old_handler, scm_from_int (0));
+#endif
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_restore_signals, "restore-signals", 0, 0, 0,
+ (void),
+ "Return all signal handlers to the values they had before any call to\n"
+ "@code{sigaction} was made. The return value is unspecified.")
+#define FUNC_NAME s_scm_restore_signals
+{
+ int i;
+ for (i = 0; i < NSIG; i++)
+ {
+#ifdef HAVE_SIGACTION
+ if (orig_handlers[i].sa_handler != SIG_ERR)
+ {
+ if (sigaction (i, &orig_handlers[i], NULL) == -1)
+ SCM_SYSERROR;
+ orig_handlers[i].sa_handler = SIG_ERR;
+ SCM_SIMPLE_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F);
+ }
+#else
+ if (orig_handlers[i] != SIG_ERR)
+ {
+ if (signal (i, orig_handlers[i]) == SIG_ERR)
+ SCM_SYSERROR;
+ orig_handlers[i] = SIG_ERR;
+ SCM_SIMPLE_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F);
+ }
+#endif
+ }
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+#if HAVE_DECL_ALARM
+SCM_DEFINE (scm_alarm, "alarm", 1, 0, 0,
+ (SCM i),
+ "Set a timer to raise a @code{SIGALRM} signal after the specified\n"
+ "number of seconds (an integer). It's advisable to install a signal\n"
+ "handler for\n"
+ "@code{SIGALRM} beforehand, since the default action is to terminate\n"
+ "the process.\n\n"
+ "The return value indicates the time remaining for the previous alarm,\n"
+ "if any. The new value replaces the previous alarm. If there was\n"
+ "no previous alarm, the return value is zero.")
+#define FUNC_NAME s_scm_alarm
+{
+ return scm_from_uint (alarm (scm_to_uint (i)));
+}
+#undef FUNC_NAME
+#endif /* HAVE_ALARM */
+
+#ifdef HAVE_SETITIMER
+SCM_DEFINE (scm_setitimer, "setitimer", 5, 0, 0,
+ (SCM which_timer,
+ SCM interval_seconds, SCM interval_microseconds,
+ SCM value_seconds, SCM value_microseconds),
+ "Set the timer specified by @var{which_timer} according to the given\n"
+ "@var{interval_seconds}, @var{interval_microseconds},\n"
+ "@var{value_seconds}, and @var{value_microseconds} values.\n"
+ "\n"
+ "Return information about the timer's previous setting."
+ "\n"
+ "Errors are handled as described in the guile info pages under ``POSIX\n"
+ "Interface Conventions''.\n"
+ "\n"
+ "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
+ "and @code{ITIMER_PROF}.\n"
+ "\n"
+ "The return value will be a list of two cons pairs representing the\n"
+ "current state of the given timer. The first pair is the seconds and\n"
+ "microseconds of the timer @code{it_interval}, and the second pair is\n"
+ "the seconds and microseconds of the timer @code{it_value}.")
+#define FUNC_NAME s_scm_setitimer
+{
+ int rv;
+ int c_which_timer;
+ struct itimerval new_timer;
+ struct itimerval old_timer;
+
+ c_which_timer = SCM_NUM2INT(1, which_timer);
+ new_timer.it_interval.tv_sec = SCM_NUM2LONG(2, interval_seconds);
+ new_timer.it_interval.tv_usec = SCM_NUM2LONG(3, interval_microseconds);
+ new_timer.it_value.tv_sec = SCM_NUM2LONG(4, value_seconds);
+ new_timer.it_value.tv_usec = SCM_NUM2LONG(5, value_microseconds);
+
+ SCM_SYSCALL(rv = setitimer(c_which_timer, &new_timer, &old_timer));
+
+ if(rv != 0)
+ SCM_SYSERROR;
+
+ return scm_list_2 (scm_cons (scm_from_long (old_timer.it_interval.tv_sec),
+ scm_from_long (old_timer.it_interval.tv_usec)),
+ scm_cons (scm_from_long (old_timer.it_value.tv_sec),
+ scm_from_long (old_timer.it_value.tv_usec)));
+}
+#undef FUNC_NAME
+#endif /* HAVE_SETITIMER */
+
+#ifdef HAVE_GETITIMER
+SCM_DEFINE (scm_getitimer, "getitimer", 1, 0, 0,
+ (SCM which_timer),
+ "Return information about the timer specified by @var{which_timer}"
+ "\n"
+ "Errors are handled as described in the guile info pages under ``POSIX\n"
+ "Interface Conventions''.\n"
+ "\n"
+ "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
+ "and @code{ITIMER_PROF}.\n"
+ "\n"
+ "The return value will be a list of two cons pairs representing the\n"
+ "current state of the given timer. The first pair is the seconds and\n"
+ "microseconds of the timer @code{it_interval}, and the second pair is\n"
+ "the seconds and microseconds of the timer @code{it_value}.")
+#define FUNC_NAME s_scm_getitimer
+{
+ int rv;
+ int c_which_timer;
+ struct itimerval old_timer;
+
+ c_which_timer = SCM_NUM2INT(1, which_timer);
+
+ SCM_SYSCALL(rv = getitimer(c_which_timer, &old_timer));
+
+ if(rv != 0)
+ SCM_SYSERROR;
+
+ return scm_list_2 (scm_cons (scm_from_long (old_timer.it_interval.tv_sec),
+ scm_from_long (old_timer.it_interval.tv_usec)),
+ scm_cons (scm_from_long (old_timer.it_value.tv_sec),
+ scm_from_long (old_timer.it_value.tv_usec)));
+}
+#undef FUNC_NAME
+#endif /* HAVE_GETITIMER */
+
+#ifdef HAVE_PAUSE
+SCM_DEFINE (scm_pause, "pause", 0, 0, 0,
+ (),
+ "Pause the current process (thread?) until a signal arrives whose\n"
+ "action is to either terminate the current process or invoke a\n"
+ "handler procedure. The return value is unspecified.")
+#define FUNC_NAME s_scm_pause
+{
+ pause ();
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+#endif
+
+SCM_DEFINE (scm_sleep, "sleep", 1, 0, 0,
+ (SCM i),
+ "Wait for the given number of seconds (an integer) or until a signal\n"
+ "arrives. The return value is zero if the time elapses or the number\n"
+ "of seconds remaining otherwise.\n"
+ "\n"
+ "See also @code{usleep}.")
+#define FUNC_NAME s_scm_sleep
+{
+ return scm_from_uint (scm_std_sleep (scm_to_uint (i)));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_usleep, "usleep", 1, 0, 0,
+ (SCM i),
+ "Wait the given period @var{usecs} microseconds (an integer).\n"
+ "If a signal arrives the wait stops and the return value is the\n"
+ "time remaining, in microseconds. If the period elapses with no\n"
+ "signal the return is zero.\n"
+ "\n"
+ "On most systems the process scheduler is not microsecond accurate and\n"
+ "the actual period slept by @code{usleep} may be rounded to a system\n"
+ "clock tick boundary. Traditionally such ticks were 10 milliseconds\n"
+ "apart, and that interval is often still used.\n"
+ "\n"
+ "See also @code{sleep}.")
+#define FUNC_NAME s_scm_usleep
+{
+ return scm_from_ulong (scm_std_usleep (scm_to_ulong (i)));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_raise, "raise", 1, 0, 0,
+ (SCM sig),
+ "Sends a specified signal @var{sig} to the current process, where\n"
+ "@var{sig} is as described for the kill procedure.")
+#define FUNC_NAME s_scm_raise
+{
+ if (raise (scm_to_int (sig)) != 0)
+ SCM_SYSERROR;
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+\f
+
+void
+scm_i_close_signal_pipe()
+{
+ /* SIGNAL_DELIVERY_THREAD_MUTEX is only locked while the signal delivery
+ thread is being launched. The thread that calls this function is
+ already holding the thread admin mutex, so if the delivery thread hasn't
+ been launched at this point, it never will be before shutdown. */
+ scm_i_pthread_mutex_lock (&signal_delivery_thread_mutex);
+
+#if SCM_USE_PTHREAD_THREADS
+ if (scm_i_signal_delivery_thread != NULL)
+ close (signal_pipe[1]);
+#endif
+
+ scm_i_pthread_mutex_unlock (&signal_delivery_thread_mutex);
+}
+
+void
+scm_init_scmsigs ()
+{
+ int i;
+
+ signal_handlers =
+ SCM_VARIABLE_LOC (scm_c_define ("signal-handlers",
+ scm_c_make_vector (NSIG, SCM_BOOL_F)));
+ signal_handler_asyncs = scm_c_make_vector (NSIG, SCM_BOOL_F);
+ signal_handler_threads = scm_c_make_vector (NSIG, SCM_BOOL_F);
+
+ for (i = 0; i < NSIG; i++)
+ {
+#ifdef HAVE_SIGACTION
+ orig_handlers[i].sa_handler = SIG_ERR;
+
+#else
+ orig_handlers[i] = SIG_ERR;
+#endif
+ }
+
+ scm_c_define ("NSIG", scm_from_long (NSIG));
+ scm_c_define ("SIG_IGN", scm_from_long ((long) SIG_IGN));
+ scm_c_define ("SIG_DFL", scm_from_long ((long) SIG_DFL));
+#ifdef SA_NOCLDSTOP
+ scm_c_define ("SA_NOCLDSTOP", scm_from_long (SA_NOCLDSTOP));
+#endif
+#ifdef SA_RESTART
+ scm_c_define ("SA_RESTART", scm_from_long (SA_RESTART));
+#endif
+
+#if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER)
+ /* Stuff needed by setitimer and getitimer. */
+ scm_c_define ("ITIMER_REAL", scm_from_int (ITIMER_REAL));
+ scm_c_define ("ITIMER_VIRTUAL", scm_from_int (ITIMER_VIRTUAL));
+ scm_c_define ("ITIMER_PROF", scm_from_int (ITIMER_PROF));
+#endif /* defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) */
+
+#include "libguile/scmsigs.x"
+}
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/