X-Git-Url: https://git.hcoop.net/bpt/guile.git/blobdiff_plain/95b8881908aace933729d5242f4ce6e4d031360a..f160e709073df53cbb360166e07f815c15694429:/libguile/async.c diff --git a/libguile/async.c b/libguile/async.c dissimilarity index 94% index 2658ca3d3..35e8a5a66 100644 --- a/libguile/async.c +++ b/libguile/async.c @@ -1,740 +1,401 @@ -/* 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. - */ - - -#include -#include -#include "_scm.h" - -#ifdef HAVE_STRING_H -#include -#endif -#ifdef HAVE_UNISTD_H -#include -#endif - - - -/* {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)) - - - - - - -#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 (); -} - - - - -#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)); - } -} - - - - -#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, "#', 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 -}; - - - - -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; -} - - - - -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)); -} - - - - -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); -} - - - - -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); -} - - - -#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; -} - - - - - -#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; -} - - - -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; -} - - - -#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", strlen ("signal"))); - 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", strlen ("signal")); - 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 + */ + + + +#if HAVE_CONFIG_H +# include +#endif + +#include +#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 +#endif +#ifdef HAVE_UNISTD_H +#include +#endif + + +/* {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. + */ + + + + +/* 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 + + + +/* 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 + + + + +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 + + + + +#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); +} + + + + +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: +*/