X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/e94e3f21d68575cded1b03fb07a66ae622b321e6..c9d15b05833feccf1cbc644ab534b9beeaa5b744:/libguile/async.c diff --git a/libguile/async.c b/libguile/async.c dissimilarity index 81% index 718a9a126..63708b633 100644 --- a/libguile/async.c +++ b/libguile/async.c @@ -1,508 +1,486 @@ -/* Copyright (C) 1995, 96, 97, 98, 2000 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. */ - -/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, - gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ - - - -#include -#include -#include "_scm.h" -#include "eval.h" -#include "throw.h" -#include "root.h" -#include "smob.h" - -#include "validate.h" -#include "async.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. - * - */ - -/* True between SCM_DEFER_INTS and SCM_ALLOW_INTS, and - * when the interpreter is not running at all. - */ -int scm_ints_disabled = 1; -unsigned int scm_mask_ints = 1; - -#ifdef GUILE_OLD_ASYNC_CLICK -unsigned int scm_async_clock = 20; -static unsigned int scm_async_rate = 20; - -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; -#else -int scm_asyncs_pending_p = 0; -#endif - -static long tc16_async; - - - -/* cmm: this has SCM_ prefix because SCM_MAKE_VALIDATE expects it. - this is ugly. */ -#define SCM_ASYNCP(X) (SCM_NIMP(X) && (tc16_async == SCM_GCTYP16 (X))) - -#define VALIDATE_ASYNC(pos,a) SCM_MAKE_VALIDATE(pos, a, ASYNCP) - -#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_CELL_WORD_0 (X) & ((1 << 16) - 1)) | ((V) << 16))) -#define ASYNC_THUNK(X) SCM_CELL_OBJECT_1 (X) - - - -#ifdef GUILE_OLD_ASYNC_CLICK -int -scm_asyncs_pending () -{ - SCM pos; - pos = scm_asyncs; - while (pos != SCM_EOL) - { - SCM a = SCM_CAR (pos); - if (ASYNC_GOT_IT (a)) - return 1; - pos = SCM_CDR (pos); - } - return 0; -} - -#if 0 -static SCM -scm_sys_tick_async_thunk (void) -{ - scm_deliver_signal (SCM_TICK_SIGNAL); - return SCM_BOOL_F; -} -#endif - -void -scm_async_click () -{ - 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 (scm_asyncs_pending ()) - { - SCM_ALLOW_INTS_ONLY; - goto tail; - } - SCM_ALLOW_INTS; - - if (owe_switch) - scm_switch (); -} - -void -scm_switch () -{ -#if 0 /* Thread switching code should probably reside here, but the - async switching code doesn't seem to work, so it's put in the - SCM_DEFER_INTS macro instead. /mdj */ - SCM_THREAD_SWITCHING_CODE; -#endif -} - -#else - -void -scm_async_click () -{ - if (!scm_mask_ints) - do - scm_run_asyncs (scm_asyncs); - while (scm_asyncs_pending_p); -} - -#endif - - - - -static SCM -mark_async (SCM obj) -{ - return ASYNC_THUNK (obj); -} - - - -SCM_DEFINE (scm_async, "async", 1, 0, 0, - (SCM thunk), -"") -#define FUNC_NAME s_scm_async -{ - SCM_RETURN_NEWSMOB (tc16_async, SCM_UNPACK (thunk)); -} -#undef FUNC_NAME - -SCM_DEFINE (scm_system_async, "system-async", 1, 0, 0, - (SCM thunk), -"") -#define FUNC_NAME s_scm_system_async -{ - SCM it; - SCM list; - - it = scm_async (thunk); - SCM_NEWCELL (list); - SCM_SETCAR (list, it); - SCM_SETCDR (list, scm_asyncs); - scm_asyncs = list; - return it; -} -#undef FUNC_NAME - -SCM_DEFINE (scm_async_mark, "async-mark", 1, 0, 0, - (SCM a), -"") -#define FUNC_NAME s_scm_async_mark -{ - VALIDATE_ASYNC (1, a); -#ifdef GUILE_OLD_ASYNC_CLICK - SET_ASYNC_GOT_IT (a, 1); -#else - SET_ASYNC_GOT_IT (a, scm_asyncs_pending_p = 1); -#endif - return SCM_UNSPECIFIED; -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_system_async_mark, "system-async-mark", 1, 0, 0, - (SCM a), -"") -#define FUNC_NAME s_scm_system_async_mark -{ - VALIDATE_ASYNC (1, a); - SCM_REDEFER_INTS; -#ifdef GUILE_OLD_ASYNC_CLICK - SET_ASYNC_GOT_IT (a, 1); - scm_async_rate = 1 + scm_async_rate - scm_async_clock; - scm_async_clock = 1; -#else - SET_ASYNC_GOT_IT (a, scm_asyncs_pending_p = 1); -#endif - SCM_REALLOW_INTS; - return SCM_UNSPECIFIED; -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_run_asyncs, "run-asyncs", 1, 0, 0, - (SCM list_of_a), -"") -#define FUNC_NAME s_scm_run_asyncs -{ -#ifdef GUILE_OLD_ASYNC_CLICK - if (scm_mask_ints) - return SCM_BOOL_F; -#else - scm_asyncs_pending_p = 0; -#endif - while (! SCM_NULLP (list_of_a)) - { - SCM a; - SCM_VALIDATE_CONS (1, list_of_a); - a = SCM_CAR (list_of_a); - VALIDATE_ASYNC (SCM_ARG1, a); - scm_mask_ints = 1; - if (ASYNC_GOT_IT (a)) - { - SET_ASYNC_GOT_IT (a, 0); - scm_apply (ASYNC_THUNK (a), SCM_EOL, SCM_EOL); - } - scm_mask_ints = 0; - list_of_a = SCM_CDR (list_of_a); - } - return SCM_BOOL_T; -} -#undef FUNC_NAME - - - - -SCM_DEFINE (scm_noop, "noop", 0, 0, 1, - (SCM args), -"") -#define FUNC_NAME s_scm_noop -{ - return (SCM_NULLP (args) ? SCM_BOOL_F : SCM_CAR (args)); -} -#undef FUNC_NAME - - - - -#ifdef GUILE_OLD_ASYNC_CLICK - -SCM_DEFINE (scm_set_tick_rate, "set-tick-rate", 1, 0, 0, - (SCM n), -"") -#define FUNC_NAME s_scm_set_tick_rate -{ - unsigned int old_n = scm_tick_rate; - SCM_VALIDATE_INUM (1, n); - 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); -} -#undef FUNC_NAME - - - - -SCM_DEFINE (scm_set_switch_rate, "set-switch-rate", 1, 0, 0, - (SCM n), -"") -#define FUNC_NAME s_scm_set_switch_rate -{ - unsigned int old_n = scm_switch_rate; - SCM_VALIDATE_INUM (1, n); - 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); -} -#undef FUNC_NAME - -#endif - - -/* points to the GC system-async, so that scm_gc_end can find it. */ -SCM scm_gc_async; - -/* the vcell for gc-thunk. */ -static SCM scm_gc_vcell; - -/* the thunk installed in the GC system-async, which is marked at the - end of garbage collection. */ -static SCM -scm_sys_gc_async_thunk (void) -{ - if (SCM_NFALSEP (scm_gc_vcell)) - { - SCM proc = SCM_CDR (scm_gc_vcell); - - if (SCM_NFALSEP (proc) && !SCM_UNBNDP (proc)) - scm_apply (proc, SCM_EOL, SCM_EOL); - } - return SCM_UNSPECIFIED; -} - - - -SCM_DEFINE (scm_unmask_signals, "unmask-signals", 0, 0, 0, - (), -"") -#define FUNC_NAME s_scm_unmask_signals -{ - scm_mask_ints = 0; - return SCM_UNSPECIFIED; -} -#undef FUNC_NAME - - -SCM_DEFINE (scm_mask_signals, "mask-signals", 0, 0, 0, - (), -"") -#define FUNC_NAME s_scm_mask_signals -{ - scm_mask_ints = 1; - return SCM_UNSPECIFIED; -} -#undef FUNC_NAME - - - -void -scm_init_async () -{ - SCM a_thunk; - tc16_async = scm_make_smob_type_mfpe ("async", 0, - mark_async, NULL, NULL, NULL); - scm_gc_vcell = scm_sysintern ("gc-thunk", SCM_BOOL_F); - a_thunk = scm_make_gsubr ("%gc-thunk", 0, 0, 0, scm_sys_gc_async_thunk); - scm_gc_async = scm_system_async (a_thunk); - -#include "async.x" -} - -/* - Local Variables: - c-file-style: "gnu" - End: -*/ +/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002, 2004, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + + + +#ifdef 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) + + +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 + + + +static scm_i_pthread_mutex_t async_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; + +/* System asyncs. */ + +void +scm_async_click () +{ + scm_i_thread *t = SCM_I_CURRENT_THREAD; + SCM asyncs; + + /* Reset pending_asyncs even when asyncs are blocked and not really + executed since this will avoid future futile calls to this + function. When asyncs are unblocked again, this function is + invoked even when pending_asyncs is zero. + */ + + scm_i_scm_pthread_mutex_lock (&async_mutex); + t->pending_asyncs = 0; + if (t->block_asyncs == 0) + { + asyncs = t->active_asyncs; + t->active_asyncs = SCM_EOL; + } + else + asyncs = SCM_EOL; + scm_i_pthread_mutex_unlock (&async_mutex); + + while (scm_is_pair (asyncs)) + { + SCM next = SCM_CDR (asyncs); + SCM_SETCDR (asyncs, SCM_BOOL_F); + scm_call_0 (SCM_CAR (asyncs)); + asyncs = next; + } +} + +#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_i_thread *t) +{ + SCM sleep_object; + scm_i_pthread_mutex_t *sleep_mutex; + int sleep_fd; + SCM p; + + scm_i_scm_pthread_mutex_lock (&async_mutex); + p = t->active_asyncs; + SCM_SETCDR (c, SCM_EOL); + if (!scm_is_pair (p)) + t->active_asyncs = c; + else + { + SCM pp; + while (scm_is_pair (pp = SCM_CDR (p))) + { + if (scm_is_eq (SCM_CAR (p), SCM_CAR (c))) + { + scm_i_pthread_mutex_unlock (&async_mutex); + return; + } + p = pp; + } + SCM_SETCDR (p, c); + } + t->pending_asyncs = 1; + sleep_object = t->sleep_object; + sleep_mutex = t->sleep_mutex; + sleep_fd = t->sleep_fd; + scm_i_pthread_mutex_unlock (&async_mutex); + + if (sleep_mutex) + { + /* By now, the thread T might be out of its sleep already, or + might even be in the next, unrelated sleep. Interrupting it + anyway does no harm, however. + + The important thing to prevent here is to signal sleep_cond + before T waits on it. This can not happen since T has + sleep_mutex locked while setting t->sleep_mutex and will only + unlock it again while waiting on sleep_cond. + */ + scm_i_scm_pthread_mutex_lock (sleep_mutex); + scm_i_pthread_cond_signal (&t->sleep_cond); + scm_i_pthread_mutex_unlock (sleep_mutex); + } + + if (sleep_fd >= 0) + { + char dummy = 0; + /* Likewise, T might already been done with sleeping here, but + interrupting it once too often does no harm. T might also + not yet have started sleeping, but this is no problem either + since the data written to a pipe will not be lost, unlike a + condition variable signal. + */ + write (sleep_fd, &dummy, 1); + } + + /* This is needed to protect sleep_mutex. + */ + scm_remember_upto_here_1 (sleep_object); +} + +int +scm_i_setup_sleep (scm_i_thread *t, + SCM sleep_object, scm_i_pthread_mutex_t *sleep_mutex, + int sleep_fd) +{ + int pending; + + scm_i_scm_pthread_mutex_lock (&async_mutex); + pending = t->pending_asyncs; + if (!pending) + { + t->sleep_object = sleep_object; + t->sleep_mutex = sleep_mutex; + t->sleep_fd = sleep_fd; + } + scm_i_pthread_mutex_unlock (&async_mutex); + return pending; +} + +void +scm_i_reset_sleep (scm_i_thread *t) +{ + scm_i_scm_pthread_mutex_lock (&async_mutex); + t->sleep_object = SCM_BOOL_F; + t->sleep_mutex = NULL; + t->sleep_fd = -1; + scm_i_pthread_mutex_unlock (&async_mutex); +} + +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 +{ + /* The current thread might not have a handle yet. This can happen + when the GC runs immediately before allocating the handle. At + the end of that GC, a system async might be marked. Thus, we can + not use scm_current_thread here. + */ + + scm_i_thread *t; + + if (SCM_UNBNDP (thread)) + t = SCM_I_CURRENT_THREAD; + else + { + SCM_VALIDATE_THREAD (2, thread); + if (scm_c_thread_exited_p (thread)) + SCM_MISC_ERROR ("thread has already exited", SCM_EOL); + t = SCM_I_THREAD_DATA (thread); + } + scm_i_queue_async_cell (scm_cons (proc, SCM_BOOL_F), t); + 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_i_thread *t = SCM_I_CURRENT_THREAD; + + scm_c_issue_deprecation_warning + ("'unmask-signals' is deprecated. " + "Use 'call-with-blocked-asyncs' instead."); + + if (t->block_asyncs == 0) + SCM_MISC_ERROR ("signals already unmasked", SCM_EOL); + t->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_i_thread *t = SCM_I_CURRENT_THREAD; + + scm_c_issue_deprecation_warning + ("'mask-signals' is deprecated. Use 'call-with-blocked-asyncs' instead."); + + if (t->block_asyncs > 0) + SCM_MISC_ERROR ("signals already masked", SCM_EOL); + t->block_asyncs = 1; + return SCM_UNSPECIFIED; +} +#undef FUNC_NAME + +#endif /* SCM_ENABLE_DEPRECATED == 1 */ + +static void +increase_block (void *data) +{ + ((scm_i_thread *)data)->block_asyncs++; +} + +static void +decrease_block (void *data) +{ + if (--((scm_i_thread *)data)->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, + SCM_I_CURRENT_THREAD); +} +#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, + SCM_I_CURRENT_THREAD); +} + + +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_I_CURRENT_THREAD->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, + SCM_I_CURRENT_THREAD); +} +#undef FUNC_NAME + +void * +scm_c_call_with_unblocked_asyncs (void *(*proc) (void *data), void *data) +{ + if (SCM_I_CURRENT_THREAD->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, + SCM_I_CURRENT_THREAD); +} + +void +scm_dynwind_block_asyncs () +{ + scm_i_thread *t = SCM_I_CURRENT_THREAD; + scm_dynwind_rewind_handler (increase_block, t, SCM_F_WIND_EXPLICITLY); + scm_dynwind_unwind_handler (decrease_block, t, SCM_F_WIND_EXPLICITLY); +} + +void +scm_dynwind_unblock_asyncs () +{ + scm_i_thread *t = SCM_I_CURRENT_THREAD; + if (t->block_asyncs == 0) + scm_misc_error ("scm_with_unblocked_asyncs", + "asyncs already unblocked", SCM_EOL); + scm_dynwind_rewind_handler (decrease_block, t, SCM_F_WIND_EXPLICITLY); + scm_dynwind_unwind_handler (increase_block, t, SCM_F_WIND_EXPLICITLY); +} + + + + +void +scm_init_async () +{ + scm_asyncs = SCM_EOL; + tc16_async = scm_make_smob_type ("async", 0); + +#include "libguile/async.x" +} + +/* + Local Variables: + c-file-style: "gnu" + End: +*/