Commit | Line | Data |
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7dc6e754 | 1 | /* Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. |
0f2d19dd JB |
2 | * |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
0f2d19dd JB |
41 | \f |
42 | ||
43 | #include <stdio.h> | |
44 | #include <signal.h> | |
45 | #include "_scm.h" | |
20e6290e JB |
46 | #include "eval.h" |
47 | #include "throw.h" | |
48 | #include "smob.h" | |
49 | ||
50 | #include "async.h" | |
0f2d19dd | 51 | |
95b88819 GH |
52 | #ifdef HAVE_STRING_H |
53 | #include <string.h> | |
54 | #endif | |
0f2d19dd JB |
55 | #ifdef HAVE_UNISTD_H |
56 | #include <unistd.h> | |
57 | #endif | |
58 | ||
59 | ||
60 | \f | |
61 | /* {Asynchronous Events} | |
62 | * | |
63 | * | |
64 | * Async == thunk + mark. | |
65 | * | |
66 | * Setting the mark guarantees future execution of the thunk. More | |
67 | * than one set may be satisfied by a single execution. | |
68 | * | |
69 | * scm_tick_clock decremented once per SCM_ALLOW_INTS. | |
70 | * Async execution triggered by SCM_ALLOW_INTS when scm_tick_clock drops to 0. | |
71 | * Async execution prevented by scm_mask_ints != 0. | |
72 | * | |
73 | * If the clock reaches 0 when scm_mask_ints != 0, then reset the clock | |
74 | * to 1. | |
75 | * | |
76 | * If the clock reaches 0 any other time, run marked asyncs. | |
77 | * | |
78 | * From a unix signal handler, mark a corresponding async and set the clock | |
79 | * to 1. Do SCM_REDEFER_INTS;/SCM_REALLOW_INTS so that if the signal handler is not | |
80 | * called in the dynamic scope of a critical section, it is excecuted immediately. | |
81 | * | |
82 | * Overall, closely timed signals of a particular sort may be combined. Pending signals | |
83 | * are delivered in a fixed priority order, regardless of arrival order. | |
84 | * | |
85 | */ | |
86 | ||
a574455a GH |
87 | /* True between SCM_DEFER_INTS and SCM_ALLOW_INTS, and |
88 | * when the interpreter is not running at all. | |
89 | */ | |
90 | int scm_ints_disabled = 1; | |
0f2d19dd JB |
91 | |
92 | unsigned int scm_async_clock = 20; | |
93 | static unsigned int scm_async_rate = 20; | |
94 | unsigned int scm_mask_ints = 1; | |
95 | ||
96 | static unsigned int scm_tick_clock = 0; | |
97 | static unsigned int scm_tick_rate = 0; | |
98 | static unsigned int scm_desired_tick_rate = 0; | |
99 | static unsigned int scm_switch_clock = 0; | |
100 | static unsigned int scm_switch_rate = 0; | |
101 | static unsigned int scm_desired_switch_rate = 0; | |
102 | ||
0f2d19dd JB |
103 | static long scm_tc16_async; |
104 | ||
0f2d19dd JB |
105 | \f |
106 | ||
5e569ca8 MD |
107 | int |
108 | scm_asyncs_pending () | |
0f2d19dd JB |
109 | { |
110 | SCM pos; | |
111 | pos = scm_asyncs; | |
112 | while (pos != SCM_EOL) | |
113 | { | |
114 | SCM a; | |
115 | struct scm_async * it; | |
116 | a = SCM_CAR (pos); | |
117 | it = SCM_ASYNC (a); | |
118 | if (it->got_it) | |
119 | return 1; | |
120 | pos = SCM_CDR (pos); | |
121 | } | |
122 | return 0; | |
123 | } | |
124 | ||
9ea54cc6 GH |
125 | #if 0 |
126 | static SCM scm_sys_tick_async_thunk SCM_P ((void)); | |
127 | static SCM | |
128 | scm_sys_tick_async_thunk () | |
129 | { | |
130 | scm_deliver_signal (SCM_TICK_SIGNAL); | |
131 | return SCM_BOOL_F; | |
132 | } | |
133 | #endif | |
1cc91f1b | 134 | |
0f2d19dd JB |
135 | void |
136 | scm_async_click () | |
0f2d19dd JB |
137 | { |
138 | int owe_switch; | |
139 | int owe_tick; | |
140 | ||
141 | if (!scm_switch_rate) | |
142 | { | |
143 | owe_switch = 0; | |
144 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
145 | scm_desired_switch_rate = 0; | |
146 | } | |
147 | else | |
148 | { | |
149 | owe_switch = (scm_async_rate >= scm_switch_clock); | |
150 | if (owe_switch) | |
151 | { | |
152 | if (scm_desired_switch_rate) | |
153 | { | |
154 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
155 | scm_desired_switch_rate = 0; | |
156 | } | |
157 | else | |
158 | scm_switch_clock = scm_switch_rate; | |
159 | } | |
160 | else | |
161 | { | |
162 | if (scm_desired_switch_rate) | |
163 | { | |
164 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
165 | scm_desired_switch_rate = 0; | |
166 | } | |
167 | else | |
168 | scm_switch_clock -= scm_async_rate; | |
169 | } | |
170 | } | |
171 | ||
172 | if (scm_mask_ints) | |
173 | { | |
174 | if (owe_switch) | |
175 | scm_switch (); | |
176 | scm_async_clock = 1; | |
177 | return;; | |
178 | } | |
179 | ||
180 | if (!scm_tick_rate) | |
181 | { | |
182 | unsigned int r; | |
183 | owe_tick = 0; | |
184 | r = scm_desired_tick_rate; | |
185 | if (r) | |
186 | { | |
187 | scm_desired_tick_rate = 0; | |
188 | scm_tick_rate = r; | |
189 | scm_tick_clock = r; | |
190 | } | |
191 | } | |
192 | else | |
193 | { | |
194 | owe_tick = (scm_async_rate >= scm_tick_clock); | |
195 | if (owe_tick) | |
196 | { | |
197 | scm_tick_clock = scm_tick_rate = scm_desired_tick_rate; | |
198 | scm_desired_tick_rate = 0; | |
199 | } | |
200 | else | |
201 | { | |
202 | if (scm_desired_tick_rate) | |
203 | { | |
204 | scm_tick_clock = scm_tick_rate = scm_desired_tick_rate; | |
205 | scm_desired_tick_rate = 0; | |
206 | } | |
207 | else | |
208 | scm_tick_clock -= scm_async_rate; | |
209 | } | |
210 | } | |
211 | ||
9ea54cc6 GH |
212 | /* |
213 | if (owe_tick) | |
214 | scm_async_mark (system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)]); | |
215 | */ | |
0f2d19dd JB |
216 | |
217 | SCM_DEFER_INTS; | |
218 | if (scm_tick_rate && scm_switch_rate) | |
219 | { | |
220 | scm_async_rate = min (scm_tick_clock, scm_switch_clock); | |
221 | scm_async_clock = scm_async_rate; | |
222 | } | |
223 | else if (scm_tick_rate) | |
224 | { | |
225 | scm_async_clock = scm_async_rate = scm_tick_clock; | |
226 | } | |
227 | else if (scm_switch_rate) | |
228 | { | |
229 | scm_async_clock = scm_async_rate = scm_switch_clock; | |
230 | } | |
231 | else | |
232 | scm_async_clock = scm_async_rate = 1 << 16; | |
233 | SCM_ALLOW_INTS_ONLY; | |
234 | ||
235 | tail: | |
236 | scm_run_asyncs (scm_asyncs); | |
237 | ||
238 | SCM_DEFER_INTS; | |
5e569ca8 | 239 | if (scm_asyncs_pending ()) |
0f2d19dd JB |
240 | { |
241 | SCM_ALLOW_INTS_ONLY; | |
242 | goto tail; | |
243 | } | |
244 | SCM_ALLOW_INTS; | |
245 | ||
246 | if (owe_switch) | |
247 | scm_switch (); | |
248 | } | |
249 | ||
250 | ||
251 | \f | |
252 | ||
1cc91f1b | 253 | |
0f2d19dd JB |
254 | void |
255 | scm_switch () | |
7ad737b6 MD |
256 | { |
257 | #if 0 /* Thread switching code should probably reside here, but the | |
258 | async switching code doesn't seem to work, so it's put in the | |
259 | SCM_ASYNC_TICK macro instead. /mdj */ | |
260 | SCM_THREAD_SWITCHING_CODE; | |
261 | #endif | |
262 | } | |
0f2d19dd | 263 | |
0f2d19dd JB |
264 | \f |
265 | ||
1cc91f1b JB |
266 | static SCM mark_async SCM_P ((SCM obj)); |
267 | ||
0f2d19dd JB |
268 | static SCM |
269 | mark_async (obj) | |
270 | SCM obj; | |
0f2d19dd JB |
271 | { |
272 | struct scm_async * it; | |
0f2d19dd JB |
273 | it = SCM_ASYNC (obj); |
274 | return it->thunk; | |
275 | } | |
276 | ||
0f2d19dd JB |
277 | \f |
278 | ||
279 | SCM_PROC(s_async, "async", 1, 0, 0, scm_async); | |
1cc91f1b | 280 | |
0f2d19dd JB |
281 | SCM |
282 | scm_async (thunk) | |
283 | SCM thunk; | |
0f2d19dd | 284 | { |
4801c311 MD |
285 | struct scm_async * async |
286 | = (struct scm_async *) scm_must_malloc (sizeof (*async), s_async); | |
0f2d19dd JB |
287 | async->got_it = 0; |
288 | async->thunk = thunk; | |
23a62151 | 289 | SCM_RETURN_NEWSMOB (scm_tc16_async, async); |
0f2d19dd JB |
290 | } |
291 | ||
292 | SCM_PROC(s_system_async, "system-async", 1, 0, 0, scm_system_async); | |
1cc91f1b | 293 | |
0f2d19dd JB |
294 | SCM |
295 | scm_system_async (thunk) | |
296 | SCM thunk; | |
0f2d19dd JB |
297 | { |
298 | SCM it; | |
299 | SCM list; | |
300 | ||
301 | it = scm_async (thunk); | |
23a62151 | 302 | SCM_NEWSMOB (list, it, scm_asyncs); |
0f2d19dd | 303 | scm_asyncs = list; |
0f2d19dd JB |
304 | return it; |
305 | } | |
306 | ||
307 | SCM_PROC(s_async_mark, "async-mark", 1, 0, 0, scm_async_mark); | |
1cc91f1b | 308 | |
0f2d19dd JB |
309 | SCM |
310 | scm_async_mark (a) | |
311 | SCM a; | |
0f2d19dd JB |
312 | { |
313 | struct scm_async * it; | |
314 | SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_async_mark); | |
315 | it = SCM_ASYNC (a); | |
316 | it->got_it = 1; | |
317 | return SCM_UNSPECIFIED; | |
318 | } | |
319 | ||
320 | ||
321 | SCM_PROC(s_system_async_mark, "system-async-mark", 1, 0, 0, scm_system_async_mark); | |
1cc91f1b | 322 | |
0f2d19dd JB |
323 | SCM |
324 | scm_system_async_mark (a) | |
325 | SCM a; | |
0f2d19dd JB |
326 | { |
327 | struct scm_async * it; | |
328 | SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_async_mark); | |
329 | it = SCM_ASYNC (a); | |
330 | SCM_REDEFER_INTS; | |
331 | it->got_it = 1; | |
332 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
333 | scm_async_clock = 1; | |
334 | SCM_REALLOW_INTS; | |
335 | return SCM_UNSPECIFIED; | |
336 | } | |
337 | ||
338 | ||
339 | SCM_PROC(s_run_asyncs, "run-asyncs", 1, 0, 0, scm_run_asyncs); | |
1cc91f1b | 340 | |
0f2d19dd JB |
341 | SCM |
342 | scm_run_asyncs (list_of_a) | |
343 | SCM list_of_a; | |
0f2d19dd JB |
344 | { |
345 | SCM pos; | |
346 | ||
347 | if (scm_mask_ints) | |
348 | return SCM_BOOL_F; | |
349 | pos = list_of_a; | |
350 | while (pos != SCM_EOL) | |
351 | { | |
352 | SCM a; | |
353 | struct scm_async * it; | |
354 | SCM_ASSERT (SCM_NIMP (pos) && SCM_CONSP (pos), pos, SCM_ARG1, s_run_asyncs); | |
355 | a = SCM_CAR (pos); | |
356 | SCM_ASSERT (SCM_NIMP (a) && SCM_ASYNCP (a), a, SCM_ARG1, s_run_asyncs); | |
357 | it = SCM_ASYNC (a); | |
358 | scm_mask_ints = 1; | |
359 | if (it->got_it) | |
360 | { | |
361 | it->got_it = 0; | |
362 | scm_apply (it->thunk, SCM_EOL, SCM_EOL); | |
363 | } | |
364 | scm_mask_ints = 0; | |
365 | pos = SCM_CDR (pos); | |
366 | } | |
367 | return SCM_BOOL_T; | |
368 | } | |
369 | ||
370 | \f | |
371 | ||
372 | ||
373 | SCM_PROC(s_noop, "noop", 0, 0, 1, scm_noop); | |
1cc91f1b | 374 | |
0f2d19dd JB |
375 | SCM |
376 | scm_noop (args) | |
377 | SCM args; | |
0f2d19dd JB |
378 | { |
379 | return (SCM_NULLP (args) | |
380 | ? SCM_BOOL_F | |
381 | : SCM_CAR (args)); | |
382 | } | |
383 | ||
384 | ||
385 | \f | |
386 | ||
387 | SCM_PROC(s_set_tick_rate, "set-tick-rate", 1, 0, 0, scm_set_tick_rate); | |
1cc91f1b | 388 | |
0f2d19dd JB |
389 | SCM |
390 | scm_set_tick_rate (n) | |
391 | SCM n; | |
0f2d19dd JB |
392 | { |
393 | unsigned int old_n; | |
394 | SCM_ASSERT (SCM_INUMP (n), n, SCM_ARG1, s_set_tick_rate); | |
395 | old_n = scm_tick_rate; | |
396 | scm_desired_tick_rate = SCM_INUM (n); | |
397 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
398 | scm_async_clock = 1; | |
399 | return SCM_MAKINUM (old_n); | |
400 | } | |
401 | ||
402 | \f | |
403 | ||
404 | ||
405 | SCM_PROC(s_set_switch_rate, "set-switch-rate", 1, 0, 0, scm_set_switch_rate); | |
1cc91f1b | 406 | |
0f2d19dd JB |
407 | SCM |
408 | scm_set_switch_rate (n) | |
409 | SCM n; | |
0f2d19dd JB |
410 | { |
411 | unsigned int old_n; | |
412 | SCM_ASSERT (SCM_INUMP (n), n, SCM_ARG1, s_set_switch_rate); | |
413 | old_n = scm_switch_rate; | |
414 | scm_desired_switch_rate = SCM_INUM (n); | |
415 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
416 | scm_async_clock = 1; | |
417 | return SCM_MAKINUM (old_n); | |
418 | } | |
419 | ||
420 | \f | |
421 | ||
9ea54cc6 GH |
422 | /* points to the GC system-async, so that scm_gc_end can find it. */ |
423 | SCM scm_gc_async; | |
1cc91f1b | 424 | |
9ea54cc6 GH |
425 | /* the vcell for gc-thunk. */ |
426 | static SCM scm_gc_vcell; | |
1cc91f1b | 427 | |
9ea54cc6 GH |
428 | /* the thunk installed in the GC system-async, which is marked at the |
429 | end of garbage collection. */ | |
0f2d19dd | 430 | static SCM |
9ea54cc6 | 431 | scm_sys_gc_async_thunk (void) |
0f2d19dd | 432 | { |
9ea54cc6 GH |
433 | if (SCM_NFALSEP (scm_gc_vcell)) |
434 | { | |
435 | SCM proc = SCM_CDR (scm_gc_vcell); | |
1cc91f1b | 436 | |
9ea54cc6 GH |
437 | if (SCM_NFALSEP (proc) && !SCM_UNBNDP (proc)) |
438 | scm_apply (proc, SCM_EOL, SCM_EOL); | |
439 | } | |
440 | return SCM_UNSPECIFIED; | |
0f2d19dd JB |
441 | } |
442 | ||
0f2d19dd JB |
443 | \f |
444 | ||
0f2d19dd | 445 | SCM_PROC(s_unmask_signals, "unmask-signals", 0, 0, 0, scm_unmask_signals); |
1cc91f1b | 446 | |
0f2d19dd JB |
447 | SCM |
448 | scm_unmask_signals () | |
0f2d19dd JB |
449 | { |
450 | scm_mask_ints = 0; | |
451 | return SCM_UNSPECIFIED; | |
452 | } | |
453 | ||
454 | ||
455 | SCM_PROC(s_mask_signals, "mask-signals", 0, 0, 0, scm_mask_signals); | |
1cc91f1b | 456 | |
0f2d19dd JB |
457 | SCM |
458 | scm_mask_signals () | |
0f2d19dd JB |
459 | { |
460 | scm_mask_ints = 1; | |
461 | return SCM_UNSPECIFIED; | |
462 | } | |
463 | ||
464 | \f | |
465 | ||
0f2d19dd JB |
466 | void |
467 | scm_init_async () | |
0f2d19dd JB |
468 | { |
469 | SCM a_thunk; | |
23a62151 MD |
470 | scm_tc16_async = scm_make_smob_type_mfpe ("async", sizeof (struct scm_async), |
471 | mark_async, NULL, NULL, NULL); | |
9ea54cc6 | 472 | scm_gc_vcell = scm_sysintern ("gc-thunk", SCM_BOOL_F); |
0f2d19dd | 473 | a_thunk = scm_make_gsubr ("%gc-thunk", 0, 0, 0, scm_sys_gc_async_thunk); |
9ea54cc6 | 474 | scm_gc_async = scm_system_async (a_thunk); |
0f2d19dd | 475 | |
0f2d19dd JB |
476 | #include "async.x" |
477 | } |