diff options
Diffstat (limited to 'libguile/async.c')
-rw-r--r-- | libguile/async.c | 365 |
1 files changed, 92 insertions, 273 deletions
diff --git a/libguile/async.c b/libguile/async.c index f0a2b2eae..53edabda2 100644 --- a/libguile/async.c +++ b/libguile/async.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc. +/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002 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 @@ -49,6 +49,7 @@ #include "libguile/root.h" #include "libguile/smob.h" #include "libguile/lang.h" +#include "libguile/deprecation.h" #include "libguile/validate.h" #include "libguile/async.h" @@ -64,28 +65,30 @@ /* {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. * - * Async == thunk + mark. + * 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. * - * Setting the mark guarantees future execution of the thunk. More - * than one set may be satisfied by a single execution. + * 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. * - * 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. + * 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.) * - * 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. * + * 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. */ /* True between SCM_DEFER_INTS and SCM_ALLOW_INTS, and @@ -94,23 +97,11 @@ 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 scm_t_bits tc16_async; +/* User asyncs. */ - +static scm_t_bits tc16_async; /* cmm: this has SCM_ prefix because SCM_MAKE_VALIDATE expects it. this is ugly. */ @@ -121,169 +112,12 @@ static scm_t_bits tc16_async; #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) - - -#ifdef GUILE_OLD_ASYNC_CLICK -int -scm_asyncs_pending () -{ - SCM pos; - pos = scm_asyncs; - while (!SCM_NULL_OR_NIL_P (pos)) - { - SCM a = SCM_CAR (pos); - if (ASYNC_GOT_IT (a)) - return 1; - pos = SCM_CDR (pos); - } - return 0; -} - - -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; - } - } - - 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 -async_mark (SCM obj) +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}.") @@ -293,70 +127,22 @@ SCM_DEFINE (scm_async, "async", 1, 0, 0, } #undef FUNC_NAME -SCM_DEFINE (scm_system_async, "system-async", 1, 0, 0, - (SCM thunk), - "Create a new async for the procedure @var{thunk}. Also\n" - "add it to the system's list of active async objects.") -#define FUNC_NAME s_scm_system_async -{ - SCM it = scm_async (thunk); - scm_asyncs = scm_cons (it, scm_asyncs); - return it; -} -#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); -#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), - "Mark the async @var{a} for future execution.") -#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 - -void -scm_system_async_mark_from_signal_handler (SCM a) -{ - SET_ASYNC_GOT_IT (a, scm_asyncs_pending_p = 1); -} - 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 { -#ifdef GUILE_OLD_ASYNC_CLICK - if (scm_mask_ints) - return SCM_BOOL_F; -#else - scm_asyncs_pending_p = 0; -#endif while (! SCM_NULL_OR_NIL_P (list_of_a)) { SCM a; @@ -378,57 +164,90 @@ SCM_DEFINE (scm_run_asyncs, "run-asyncs", 1, 0, 0, +/* System asyncs. */ -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 +void +scm_async_click () { - SCM_VALIDATE_REST_ARGUMENT (args); - return (SCM_NULL_OR_NIL_P (args) ? SCM_BOOL_F : SCM_CAR (args)); + SCM asyncs; + + if (!scm_mask_ints) + { + while (!SCM_NULLP(asyncs = scm_active_asyncs)) + { + scm_active_asyncs = SCM_EOL; + do + { + SCM c = SCM_CDR (asyncs); + SCM_SETCDR (asyncs, SCM_EOL); + scm_call_0 (SCM_CAR (asyncs)); + asyncs = c; + } + while (!SCM_NULLP(asyncs)); + } + } } -#undef FUNC_NAME +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 a asnc 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 - +void +scm_i_queue_async_cell (SCM c, scm_root_state *root) +{ + if (SCM_CDR (c) == SCM_EOL) + { + SCM_SETCDR (c, root->active_asyncs); + root->active_asyncs = c; + } +} -#ifdef GUILE_OLD_ASYNC_CLICK +SCM_DEFINE (scm_system_async_mark_for_thread, "system-async-mark", 1, 1, 0, + (SCM proc, SCM thread), + "Register the procedure @var{proc} for future execution\n" + "in @var{thread}. When @var{thread} is not specified,\n" + "use the current thread.") +#define FUNC_NAME s_scm_system_async_mark_for_thread +{ + scm_i_queue_async_cell (scm_cons (proc, SCM_EOL), + (SCM_UNBNDP (thread) + ? scm_root + : scm_i_thread_root (thread))); + return SCM_UNSPECIFIED; +} +#undef FUNC_NAME -SCM_DEFINE (scm_set_tick_rate, "set-tick-rate", 1, 0, 0, - (SCM n), - "Set the rate of async ticks to @var{n}. Return the old rate\n" - "value.") -#define FUNC_NAME s_scm_set_tick_rate +SCM +scm_system_async_mark (SCM proc) +#define FUNC_NAME s_scm_system_async_mark_for_thread { - 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); + return scm_system_async_mark_for_thread (proc, SCM_UNDEFINED); } #undef FUNC_NAME -SCM_DEFINE (scm_set_switch_rate, "set-switch-rate", 1, 0, 0, - (SCM n), - "Set the async switch rate to @var{n}. Return the old value\n" - "of the switch rate.") -#define FUNC_NAME s_scm_set_switch_rate +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 { - 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); + SCM_VALIDATE_REST_ARGUMENT (args); + return (SCM_NULL_OR_NIL_P (args) ? SCM_BOOL_F : SCM_CAR (args)); } #undef FUNC_NAME -#endif @@ -460,7 +279,7 @@ scm_init_async () { scm_asyncs = SCM_EOL; tc16_async = scm_make_smob_type ("async", 0); - scm_set_smob_mark (tc16_async, async_mark); + scm_set_smob_mark (tc16_async, async_gc_mark); #include "libguile/async.x" } |