-/* 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
#include "libguile/root.h"
#include "libguile/smob.h"
#include "libguile/lang.h"
+#include "libguile/deprecation.h"
#include "libguile/validate.h"
#include "libguile/async.h"
\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.
*
- * 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
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
+\f
-static scm_t_bits tc16_async;
+/* User asyncs. */
-\f
+static scm_t_bits tc16_async;
/* cmm: this has SCM_ prefix because SCM_MAKE_VALIDATE expects it.
this is ugly. */
#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)
-\f
-
-#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
-
-
-\f
-
static SCM
-async_mark (SCM obj)
+async_gc_mark (SCM obj)
{
return ASYNC_THUNK (obj);
}
-\f
-
SCM_DEFINE (scm_async, "async", 1, 0, 0,
(SCM thunk),
"Create a new async for the procedure @var{thunk}.")
}
#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;
\f
+/* 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
-\f
+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
\f
-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
\f
{
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"
}
HCoop / bpt / guile.git / commitdiff