-/* 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, 675 Mass Ave, Cambridge, MA 02139, 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 "eval.h"
-#include "throw.h"
-#include "smob.h"
-
-#include "async.h"
-
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-
-\f
-/* {Asynchronous Events}
- *
- *
- * Async == thunk + mark.
- *
- * Setting the mark guarantees future execution of the thunk. More
- * than one set may be satisfied by a single execution.
- *
- * scm_tick_clock decremented once per SCM_ALLOW_INTS.
- * Async execution triggered by SCM_ALLOW_INTS when scm_tick_clock drops to 0.
- * Async execution prevented by scm_mask_ints != 0.
- *
- * If the clock reaches 0 when scm_mask_ints != 0, then reset the clock
- * to 1.
- *
- * If the clock reaches 0 any other time, run marked asyncs.
- *
- * From a unix signal handler, mark a corresponding async and set the clock
- * to 1. Do SCM_REDEFER_INTS;/SCM_REALLOW_INTS so that if the signal handler is not
- * called in the dynamic scope of a critical section, it is excecuted immediately.
- *
- * Overall, closely timed signals of a particular sort may be combined. Pending signals
- * are delivered in a fixed priority order, regardless of arrival order.
- *
- */
-
-
-#define min(A,B) ((A) < (B) ? (A) : (B))
-
-
-unsigned int scm_async_clock = 20;
-static unsigned int scm_async_rate = 20;
-unsigned int scm_mask_ints = 1;
-
-static unsigned int scm_tick_clock = 0;
-static unsigned int scm_tick_rate = 0;
-static unsigned int scm_desired_tick_rate = 0;
-static unsigned int scm_switch_clock = 0;
-static unsigned int scm_switch_rate = 0;
-static unsigned int scm_desired_switch_rate = 0;
-
-static SCM system_signal_asyncs[SCM_NUM_SIGS];
-static SCM handler_var;
-static SCM symbol_signal;
-
-
-struct scm_async
-{
- int got_it; /* needs to be delivered? */
- SCM thunk; /* the handler. */
-};
-
-
-static long scm_tc16_async;
-
-#define SCM_ASYNCP(X) (scm_tc16_async == SCM_GCTYP16 (X))
-#define SCM_ASYNC(X) ((struct scm_async *)SCM_CDR (X))
-
-
-
-
-\f
-
-#ifdef __STDC__
-static int
-asyncs_pending (void)
-#else
-static int
-asyncs_pending ()
-#endif
-{
- SCM pos;
- pos = scm_asyncs;
- while (pos != SCM_EOL)
- {
- SCM a;
- struct scm_async * it;
- a = SCM_CAR (pos);
- it = SCM_ASYNC (a);
- if (it->got_it)
- return 1;
- pos = SCM_CDR (pos);
- }
- return 0;
-}
-
-
-#ifdef __STDC__
-void
-scm_async_click (void)
-#else
-void
-scm_async_click ()
-#endif
-{
- int owe_switch;
- int owe_tick;
-
- if (!scm_switch_rate)
- {
- owe_switch = 0;
- scm_switch_clock = scm_switch_rate = scm_desired_switch_rate;
- scm_desired_switch_rate = 0;
- }
- else
- {
- owe_switch = (scm_async_rate >= scm_switch_clock);
- if (owe_switch)
- {
- if (scm_desired_switch_rate)
- {
- scm_switch_clock = scm_switch_rate = scm_desired_switch_rate;
- scm_desired_switch_rate = 0;
- }
- else
- scm_switch_clock = scm_switch_rate;
- }
- else
- {
- if (scm_desired_switch_rate)
- {
- scm_switch_clock = scm_switch_rate = scm_desired_switch_rate;
- scm_desired_switch_rate = 0;
- }
- else
- scm_switch_clock -= scm_async_rate;
- }
- }
-
- if (scm_mask_ints)
- {
- if (owe_switch)
- scm_switch ();
- scm_async_clock = 1;
- return;;
- }
-
- if (!scm_tick_rate)
- {
- unsigned int r;
- owe_tick = 0;
- r = scm_desired_tick_rate;
- if (r)
- {
- scm_desired_tick_rate = 0;
- scm_tick_rate = r;
- scm_tick_clock = r;
- }
- }
- else
- {
- owe_tick = (scm_async_rate >= scm_tick_clock);
- if (owe_tick)
- {
- scm_tick_clock = scm_tick_rate = scm_desired_tick_rate;
- scm_desired_tick_rate = 0;
- }
- else
- {
- if (scm_desired_tick_rate)
- {
- scm_tick_clock = scm_tick_rate = scm_desired_tick_rate;
- scm_desired_tick_rate = 0;
- }
- else
- scm_tick_clock -= scm_async_rate;
- }
- }
-
- if (owe_tick)
- scm_async_mark (system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)]);
-
- SCM_DEFER_INTS;
- if (scm_tick_rate && scm_switch_rate)
- {
- scm_async_rate = min (scm_tick_clock, scm_switch_clock);
- scm_async_clock = scm_async_rate;
- }
- else if (scm_tick_rate)
- {
- scm_async_clock = scm_async_rate = scm_tick_clock;
- }
- else if (scm_switch_rate)
- {
- scm_async_clock = scm_async_rate = scm_switch_clock;
- }
- else
- scm_async_clock = scm_async_rate = 1 << 16;
- SCM_ALLOW_INTS_ONLY;
-
- tail:
- scm_run_asyncs (scm_asyncs);
-
- SCM_DEFER_INTS;
- if (asyncs_pending ())
- {
- SCM_ALLOW_INTS_ONLY;
- goto tail;
- }
- SCM_ALLOW_INTS;
-
- if (owe_switch)
- scm_switch ();
-}
-
-
-\f
-
-#ifdef __STDC__
-void
-scm_switch (void)
-#else
-void
-scm_switch ()
-#endif
-{}
-
-
-#ifdef __STDC__
-static void
-scm_deliver_signal (int num)
-#else
-static void
-scm_deliver_signal (num)
- int num;
-#endif
-{
- SCM handler;
- handler = SCM_CDR (handler_var);
- if (handler != SCM_BOOL_F)
- scm_apply (handler, SCM_MAKINUM (num), scm_listofnull);
- else
- {
- scm_mask_ints = 0;
- scm_throw (symbol_signal,
- scm_listify (SCM_MAKINUM (num), SCM_UNDEFINED));
- }
-}
-
-
-\f
-
-#ifdef __STDC__
-static int
-print_async (SCM exp, SCM port, int writing)
-#else
-static int
-print_async (exp, port, writing)
- SCM exp;
- SCM port;
- int writing;
-#endif
-{
- scm_gen_puts (scm_regular_string, "#<async ", port);
- scm_intprint(exp, 16, port);
- scm_gen_putc('>', port);
- return 1;
-}
-
-#ifdef __STDC__
-static SCM
-mark_async (SCM obj)
-#else
-static SCM
-mark_async (obj)
- SCM obj;
-#endif
-{
- struct scm_async * it;
- if (SCM_GC8MARKP (obj))
- return SCM_BOOL_F;
- SCM_SETGC8MARK (obj);
- it = SCM_ASYNC (obj);
- return it->thunk;
-}
-
-#ifdef __STDC__
-static scm_sizet
-free_async (SCM obj)
-#else
-static scm_sizet
-free_async (SCM obj)
- SCM obj;
-#endif
-{
- struct scm_async * it;
- it = SCM_ASYNC (obj);
- scm_must_free ((char *)it);
- return (sizeof (*it));
-}
-
-
-static scm_smobfuns async_smob =
-{
- mark_async,
- free_async,
- print_async,
- 0
-};
-
-
-\f
-
-SCM_PROC(s_async, "async", 1, 0, 0, scm_async);
-#ifdef __STDC__
-SCM
-scm_async (SCM thunk)
-#else
-SCM
-scm_async (thunk)
- SCM thunk;
-#endif
-{
- SCM it;
- struct scm_async * async;
-
- SCM_NEWCELL (it);
- SCM_DEFER_INTS;
- SCM_SETCDR (it, SCM_EOL);
- async = (struct scm_async *)scm_must_malloc (sizeof (*async), s_async);
- async->got_it = 0;
- async->thunk = thunk;
- SCM_SETCDR (it, (SCM)async);
- SCM_SETCAR (it, (SCM)scm_tc16_async);
- SCM_ALLOW_INTS;
- return it;
-}
-
-SCM_PROC(s_system_async, "system-async", 1, 0, 0, scm_system_async);
-#ifdef __STDC__
-SCM
-scm_system_async (SCM thunk)
-#else
-SCM
-scm_system_async (thunk)
- SCM thunk;
-#endif
-{
- SCM it;
- SCM list;
-
- it = scm_async (thunk);
- SCM_NEWCELL (list);
- SCM_DEFER_INTS;
- SCM_SETCAR (list, it);
- SCM_SETCDR (list, scm_asyncs);
- scm_asyncs = list;
- SCM_ALLOW_INTS;
- return it;
-}
-
-SCM_PROC(s_async_mark, "async-mark", 1, 0, 0, scm_async_mark);
-#ifdef __STDC__
-SCM
-scm_async_mark (SCM a)
-#else
-SCM
-scm_async_mark (a)
- SCM a;
-#endif
-{
- struct scm_async * it;
- SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_async_mark);
- it = SCM_ASYNC (a);
- it->got_it = 1;
- return SCM_UNSPECIFIED;
-}
-
-
-SCM_PROC(s_system_async_mark, "system-async-mark", 1, 0, 0, scm_system_async_mark);
-#ifdef __STDC__
-SCM
-scm_system_async_mark (SCM a)
-#else
-SCM
-scm_system_async_mark (a)
- SCM a;
-#endif
-{
- struct scm_async * it;
- SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_async_mark);
- it = SCM_ASYNC (a);
- SCM_REDEFER_INTS;
- it->got_it = 1;
- scm_async_rate = 1 + scm_async_rate - scm_async_clock;
- scm_async_clock = 1;
- SCM_REALLOW_INTS;
- return SCM_UNSPECIFIED;
-}
-
-
-SCM_PROC(s_run_asyncs, "run-asyncs", 1, 0, 0, scm_run_asyncs);
-#ifdef __STDC__
-SCM
-scm_run_asyncs (SCM list_of_a)
-#else
-SCM
-scm_run_asyncs (list_of_a)
- SCM list_of_a;
-#endif
-{
- SCM pos;
-
- if (scm_mask_ints)
- return SCM_BOOL_F;
- pos = list_of_a;
- while (pos != SCM_EOL)
- {
- SCM a;
- struct scm_async * it;
- SCM_ASSERT (SCM_NIMP (pos) && SCM_CONSP (pos), pos, SCM_ARG1, s_run_asyncs);
- a = SCM_CAR (pos);
- SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_run_asyncs);
- it = SCM_ASYNC (a);
- scm_mask_ints = 1;
- if (it->got_it)
- {
- it->got_it = 0;
- scm_apply (it->thunk, SCM_EOL, SCM_EOL);
- }
- scm_mask_ints = 0;
- pos = SCM_CDR (pos);
- }
- return SCM_BOOL_T;
-}
-
-\f
-
-
-SCM_PROC(s_noop, "noop", 0, 0, 1, scm_noop);
-#ifdef __STDC__
-SCM
-scm_noop (SCM args)
-#else
-SCM
-scm_noop (args)
- SCM args;
-#endif
-{
- return (SCM_NULLP (args)
- ? SCM_BOOL_F
- : SCM_CAR (args));
-}
-
-
-\f
-
-SCM_PROC(s_set_tick_rate, "set-tick-rate", 1, 0, 0, scm_set_tick_rate);
-#ifdef __STDC__
-SCM
-scm_set_tick_rate (SCM n)
-#else
-SCM
-scm_set_tick_rate (n)
- SCM n;
-#endif
-{
- unsigned int old_n;
- SCM_ASSERT (SCM_INUMP (n), n, SCM_ARG1, s_set_tick_rate);
- old_n = scm_tick_rate;
- scm_desired_tick_rate = SCM_INUM (n);
- scm_async_rate = 1 + scm_async_rate - scm_async_clock;
- scm_async_clock = 1;
- return SCM_MAKINUM (old_n);
-}
-
-\f
-
-
-SCM_PROC(s_set_switch_rate, "set-switch-rate", 1, 0, 0, scm_set_switch_rate);
-#ifdef __STDC__
-SCM
-scm_set_switch_rate (SCM n)
-#else
-SCM
-scm_set_switch_rate (n)
- SCM n;
-#endif
-{
- unsigned int old_n;
- SCM_ASSERT (SCM_INUMP (n), n, SCM_ARG1, s_set_switch_rate);
- old_n = scm_switch_rate;
- scm_desired_switch_rate = SCM_INUM (n);
- scm_async_rate = 1 + scm_async_rate - scm_async_clock;
- scm_async_clock = 1;
- return SCM_MAKINUM (old_n);
-}
-
-\f
-
-#ifdef __STDC__
-static SCM
-scm_sys_hup_async_thunk (void)
-#else
-static SCM
-scm_sys_hup_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_HUP_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_int_async_thunk (void)
-#else
-static SCM
-scm_sys_int_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_INT_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_fpe_async_thunk (void)
-#else
-static SCM
-scm_sys_fpe_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_FPE_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_bus_async_thunk (void)
-#else
-static SCM
-scm_sys_bus_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_BUS_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_segv_async_thunk (void)
-#else
-static SCM
-scm_sys_segv_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_SEGV_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_alrm_async_thunk (void)
-#else
-static SCM
-scm_sys_alrm_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_ALRM_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_gc_async_thunk (void)
-#else
-static SCM
-scm_sys_gc_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_GC_SIGNAL);
- return SCM_BOOL_F;
-}
-
-#ifdef __STDC__
-static SCM
-scm_sys_tick_async_thunk (void)
-#else
-static SCM
-scm_sys_tick_async_thunk ()
-#endif
-{
- scm_deliver_signal (SCM_TICK_SIGNAL);
- return SCM_BOOL_F;
-}
-
-
-
-\f
-
-#ifdef __STDC__
-SCM
-scm_take_signal (int n)
-#else
-SCM
-scm_take_signal (n)
- int n;
-#endif
-{
- SCM ignored;
- if (!scm_ints_disabled)
- {
- SCM_NEWCELL (ignored); /* In case we interrupted SCM_NEWCELL,
- * throw out the possibly already allocated
- * free cell.
- */
- }
- scm_system_async_mark (system_signal_asyncs[SCM_SIG_ORD(n)]);
- return SCM_BOOL_F;
-}
-
-\f
-
-SCM_PROC(s_unmask_signals, "unmask-signals", 0, 0, 0, scm_unmask_signals);
-#ifdef __STDC__
-SCM
-scm_unmask_signals (void)
-#else
-SCM
-scm_unmask_signals ()
-#endif
-{
- scm_mask_ints = 0;
- return SCM_UNSPECIFIED;
-}
-
-
-SCM_PROC(s_mask_signals, "mask-signals", 0, 0, 0, scm_mask_signals);
-#ifdef __STDC__
-SCM
-scm_mask_signals (void)
-#else
-SCM
-scm_mask_signals ()
-#endif
-{
- scm_mask_ints = 1;
- return SCM_UNSPECIFIED;
-}
-
-\f
-
-#ifdef __STDC__
-void
-scm_init_async (void)
-#else
-void
-scm_init_async ()
-#endif
-{
- SCM a_thunk;
- scm_tc16_async = scm_newsmob (&async_smob);
- symbol_signal = SCM_CAR (scm_sysintern ("signal", SCM_UNDEFINED));
- scm_permanent_object (symbol_signal);
-
- /* These are in the opposite order of delivery priortity.
- *
- * Error conditions are given low priority:
- */
- a_thunk = scm_make_gsubr ("%hup-thunk", 0, 0, 0, scm_sys_hup_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_HUP_SIGNAL)] = scm_system_async (a_thunk);
- a_thunk = scm_make_gsubr ("%int-thunk", 0, 0, 0, scm_sys_int_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_INT_SIGNAL)] = scm_system_async (a_thunk);
- a_thunk = scm_make_gsubr ("%fpe-thunk", 0, 0, 0, scm_sys_fpe_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_FPE_SIGNAL)] = scm_system_async (a_thunk);
- a_thunk = scm_make_gsubr ("%bus-thunk", 0, 0, 0, scm_sys_bus_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_BUS_SIGNAL)] = scm_system_async (a_thunk);
- a_thunk = scm_make_gsubr ("%segv-thunk", 0, 0, 0, scm_sys_segv_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_SEGV_SIGNAL)] = scm_system_async (a_thunk);
-
-
- a_thunk = scm_make_gsubr ("%gc-thunk", 0, 0, 0, scm_sys_gc_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_GC_SIGNAL)] = scm_system_async (a_thunk);
-
- /* Clock and PC driven conditions are given highest priority. */
- a_thunk = scm_make_gsubr ("%tick-thunk", 0, 0, 0, scm_sys_tick_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)] = scm_system_async (a_thunk);
- a_thunk = scm_make_gsubr ("%alrm-thunk", 0, 0, 0, scm_sys_alrm_async_thunk);
- system_signal_asyncs[SCM_SIG_ORD(SCM_ALRM_SIGNAL)] = scm_system_async (a_thunk);
-
- handler_var = scm_sysintern ("signal-handler", SCM_UNDEFINED);
- SCM_SETCDR (handler_var, SCM_BOOL_F);
- scm_permanent_object (handler_var);
-#include "async.x"
-}
+/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002, 2004 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 2.1 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+\f
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <signal.h>
+#include "libguile/_scm.h"
+#include "libguile/eval.h"
+#include "libguile/throw.h"
+#include "libguile/root.h"
+#include "libguile/smob.h"
+#include "libguile/lang.h"
+#include "libguile/dynwind.h"
+#include "libguile/deprecation.h"
+
+#include "libguile/validate.h"
+#include "libguile/async.h"
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+\f
+/* {Asynchronous Events}
+ *
+ * There are two kinds of asyncs: system asyncs and user asyncs. The
+ * two kinds have some concepts in commen but work slightly
+ * differently and are not interchangeable.
+ *
+ * System asyncs are used to run arbitrary code at the next safe point
+ * in a specified thread. You can use them to trigger execution of
+ * Scheme code from signal handlers or to interrupt a thread, for
+ * example.
+ *
+ * Each thread has a list of 'activated asyncs', which is a normal
+ * Scheme list of procedures with zero arguments. When a thread
+ * executes a SCM_ASYNC_TICK statement (which is included in
+ * SCM_TICK), it will call all procedures on this list.
+ *
+ * Also, a thread will wake up when a procedure is added to its list
+ * of active asyncs and call them. After that, it will go to sleep
+ * again. (Not implemented yet.)
+ *
+ *
+ * User asyncs are a little data structure that consists of a
+ * procedure of zero arguments and a mark. There are functions for
+ * setting the mark of a user async and for calling all procedures of
+ * marked asyncs in a given list. Nothing you couldn't quickly
+ * implement yourself.
+ */
+
+
+\f
+
+/* User asyncs. */
+
+static scm_t_bits tc16_async;
+
+/* cmm: this has SCM_ prefix because SCM_MAKE_VALIDATE expects it.
+ this is ugly. */
+#define SCM_ASYNCP(X) SCM_TYP16_PREDICATE (tc16_async, X)
+#define VALIDATE_ASYNC(pos, a) SCM_MAKE_VALIDATE_MSG(pos, a, ASYNCP, "user async")
+
+#define ASYNC_GOT_IT(X) (SCM_CELL_WORD_0 (X) >> 16)
+#define SET_ASYNC_GOT_IT(X, V) (SCM_SET_CELL_WORD_0 ((X), SCM_TYP16 (X) | ((V) << 16)))
+#define ASYNC_THUNK(X) SCM_CELL_OBJECT_1 (X)
+
+static SCM
+async_gc_mark (SCM obj)
+{
+ return ASYNC_THUNK (obj);
+}
+
+SCM_DEFINE (scm_async, "async", 1, 0, 0,
+ (SCM thunk),
+ "Create a new async for the procedure @var{thunk}.")
+#define FUNC_NAME s_scm_async
+{
+ SCM_RETURN_NEWSMOB (tc16_async, SCM_UNPACK (thunk));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_async_mark, "async-mark", 1, 0, 0,
+ (SCM a),
+ "Mark the async @var{a} for future execution.")
+#define FUNC_NAME s_scm_async_mark
+{
+ VALIDATE_ASYNC (1, a);
+ SET_ASYNC_GOT_IT (a, 1);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_run_asyncs, "run-asyncs", 1, 0, 0,
+ (SCM list_of_a),
+ "Execute all thunks from the asyncs of the list @var{list_of_a}.")
+#define FUNC_NAME s_scm_run_asyncs
+{
+ while (! SCM_NULL_OR_NIL_P (list_of_a))
+ {
+ SCM a;
+ SCM_VALIDATE_CONS (1, list_of_a);
+ a = SCM_CAR (list_of_a);
+ VALIDATE_ASYNC (SCM_ARG1, a);
+ if (ASYNC_GOT_IT (a))
+ {
+ SET_ASYNC_GOT_IT (a, 0);
+ scm_call_0 (ASYNC_THUNK (a));
+ }
+ list_of_a = SCM_CDR (list_of_a);
+ }
+ return SCM_BOOL_T;
+}
+#undef FUNC_NAME
+
+\f
+
+/* System asyncs. */
+
+void
+scm_async_click ()
+{
+ /* Reset pending_asyncs even when asyncs are blocked and not really
+ executed.
+ */
+
+ scm_root->pending_asyncs = 0;
+ if (scm_root->block_asyncs == 0)
+ {
+ SCM asyncs;
+ while (!scm_is_null(asyncs = scm_root->active_asyncs))
+ {
+ scm_root->active_asyncs = SCM_EOL;
+ do
+ {
+ scm_call_0 (SCM_CAR (asyncs));
+ asyncs = SCM_CDR (asyncs);
+ }
+ while (!scm_is_null(asyncs));
+ }
+ for (asyncs = scm_root->signal_asyncs; !scm_is_null(asyncs);
+ asyncs = SCM_CDR (asyncs))
+ {
+ if (scm_is_true (SCM_CAR (asyncs)))
+ {
+ SCM proc = SCM_CAR (asyncs);
+ SCM_SETCAR (asyncs, SCM_BOOL_F);
+ scm_call_0 (proc);
+ }
+ }
+ }
+}
+
+#if (SCM_ENABLE_DEPRECATED == 1)
+
+SCM_DEFINE (scm_system_async, "system-async", 1, 0, 0,
+ (SCM thunk),
+ "This function is deprecated. You can use @var{thunk} directly\n"
+ "instead of explicitely creating an async object.\n")
+#define FUNC_NAME s_scm_system_async
+{
+ scm_c_issue_deprecation_warning
+ ("'system-async' is deprecated. "
+ "Use the procedure directly with 'system-async-mark'.");
+ return thunk;
+}
+#undef FUNC_NAME
+
+#endif /* SCM_ENABLE_DEPRECATED == 1 */
+
+void
+scm_i_queue_async_cell (SCM c, scm_root_state *root)
+{
+ SCM p = root->active_asyncs;
+ SCM_SETCDR (c, SCM_EOL);
+ if (p == SCM_EOL)
+ root->active_asyncs = c;
+ else
+ {
+ SCM pp;
+ while ((pp = SCM_CDR(p)) != SCM_EOL)
+ {
+ if (SCM_CAR (p) == SCM_CAR (c))
+ return;
+ p = pp;
+ }
+ SCM_SETCDR (p, c);
+ }
+ root->pending_asyncs = 1;
+}
+
+SCM_DEFINE (scm_system_async_mark_for_thread, "system-async-mark", 1, 1, 0,
+ (SCM proc, SCM thread),
+ "Mark @var{proc} (a procedure with zero arguments) for future execution\n"
+ "in @var{thread}. If @var{proc} has already been marked for\n"
+ "@var{thread} but has not been executed yet, this call has no effect.\n"
+ "If @var{thread} is omitted, the thread that called\n"
+ "@code{system-async-mark} is used.\n\n"
+ "This procedure is not safe to be called from C signal handlers. Use\n"
+ "@code{scm_sigaction} or @code{scm_sigaction_for_thread} to install\n"
+ "signal handlers.")
+#define FUNC_NAME s_scm_system_async_mark_for_thread
+{
+ if (SCM_UNBNDP (thread))
+ thread = scm_current_thread ();
+ else
+ {
+ SCM_VALIDATE_THREAD (2, thread);
+ if (scm_c_thread_exited_p (thread))
+ SCM_MISC_ERROR ("thread has already exited", SCM_EOL);
+ }
+ scm_i_queue_async_cell (scm_cons (proc, SCM_BOOL_F),
+ scm_i_thread_root (thread));
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM
+scm_system_async_mark (SCM proc)
+#define FUNC_NAME s_scm_system_async_mark_for_thread
+{
+ return scm_system_async_mark_for_thread (proc, SCM_UNDEFINED);
+}
+#undef FUNC_NAME
+
+\f
+
+
+SCM_DEFINE (scm_noop, "noop", 0, 0, 1,
+ (SCM args),
+ "Do nothing. When called without arguments, return @code{#f},\n"
+ "otherwise return the first argument.")
+#define FUNC_NAME s_scm_noop
+{
+ SCM_VALIDATE_REST_ARGUMENT (args);
+ return (SCM_NULL_OR_NIL_P (args) ? SCM_BOOL_F : SCM_CAR (args));
+}
+#undef FUNC_NAME
+
+
+\f
+
+#if (SCM_ENABLE_DEPRECATED == 1)
+
+SCM_DEFINE (scm_unmask_signals, "unmask-signals", 0, 0, 0,
+ (),
+ "Unmask signals. The returned value is not specified.")
+#define FUNC_NAME s_scm_unmask_signals
+{
+ scm_c_issue_deprecation_warning
+ ("'unmask-signals' is deprecated. "
+ "Use 'call-with-blocked-asyncs' instead.");
+
+ if (scm_root->block_asyncs == 0)
+ SCM_MISC_ERROR ("signals already unmasked", SCM_EOL);
+ scm_root->block_asyncs = 0;
+ scm_async_click ();
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_mask_signals, "mask-signals", 0, 0, 0,
+ (),
+ "Mask signals. The returned value is not specified.")
+#define FUNC_NAME s_scm_mask_signals
+{
+ scm_c_issue_deprecation_warning
+ ("'mask-signals' is deprecated. Use 'call-with-blocked-asyncs' instead.");
+
+ if (scm_root->block_asyncs > 0)
+ SCM_MISC_ERROR ("signals already masked", SCM_EOL);
+ scm_root->block_asyncs = 1;
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+#endif /* SCM_ENABLE_DEPRECATED == 1 */
+
+static void
+increase_block (void *unused)
+{
+ scm_root->block_asyncs++;
+}
+
+static void
+decrease_block (void *unused)
+{
+ scm_root->block_asyncs--;
+ if (scm_root->block_asyncs == 0)
+ scm_async_click ();
+}
+
+SCM_DEFINE (scm_call_with_blocked_asyncs, "call-with-blocked-asyncs", 1, 0, 0,
+ (SCM proc),
+ "Call @var{proc} with no arguments and block the execution\n"
+ "of system asyncs by one level for the current thread while\n"
+ "it is running. Return the value returned by @var{proc}.\n")
+#define FUNC_NAME s_scm_call_with_blocked_asyncs
+{
+ return scm_internal_dynamic_wind (increase_block,
+ (scm_t_inner) scm_call_0,
+ decrease_block,
+ (void *)proc, NULL);
+}
+#undef FUNC_NAME
+
+void *
+scm_c_call_with_blocked_asyncs (void *(*proc) (void *data), void *data)
+{
+ return (void *)scm_internal_dynamic_wind (increase_block,
+ (scm_t_inner) proc,
+ decrease_block,
+ data, NULL);
+}
+
+
+SCM_DEFINE (scm_call_with_unblocked_asyncs, "call-with-unblocked-asyncs", 1, 0, 0,
+ (SCM proc),
+ "Call @var{proc} with no arguments and unblock the execution\n"
+ "of system asyncs by one level for the current thread while\n"
+ "it is running. Return the value returned by @var{proc}.\n")
+#define FUNC_NAME s_scm_call_with_unblocked_asyncs
+{
+ if (scm_root->block_asyncs == 0)
+ SCM_MISC_ERROR ("asyncs already unblocked", SCM_EOL);
+ return scm_internal_dynamic_wind (decrease_block,
+ (scm_t_inner) scm_call_0,
+ increase_block,
+ (void *)proc, NULL);
+}
+#undef FUNC_NAME
+
+void *
+scm_c_call_with_unblocked_asyncs (void *(*proc) (void *data), void *data)
+{
+ if (scm_root->block_asyncs == 0)
+ scm_misc_error ("scm_c_call_with_unblocked_asyncs",
+ "asyncs already unblocked", SCM_EOL);
+ return (void *)scm_internal_dynamic_wind (decrease_block,
+ (scm_t_inner) proc,
+ increase_block,
+ data, NULL);
+}
+
+void
+scm_frame_block_asyncs ()
+{
+ scm_frame_rewind_handler (increase_block, NULL, SCM_F_WIND_EXPLICITLY);
+ scm_frame_unwind_handler (decrease_block, NULL, SCM_F_WIND_EXPLICITLY);
+}
+
+void
+scm_frame_unblock_asyncs ()
+{
+ if (scm_root->block_asyncs == 0)
+ scm_misc_error ("scm_with_unblocked_asyncs",
+ "asyncs already unblocked", SCM_EOL);
+ scm_frame_rewind_handler (decrease_block, NULL, SCM_F_WIND_EXPLICITLY);
+ scm_frame_unwind_handler (increase_block, NULL, SCM_F_WIND_EXPLICITLY);
+}
+
+
+\f
+
+void
+scm_init_async ()
+{
+ scm_asyncs = SCM_EOL;
+ tc16_async = scm_make_smob_type ("async", 0);
+ scm_set_smob_mark (tc16_async, async_gc_mark);
+
+#include "libguile/async.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/