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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. */ |
1bbd0b84 GB |
41 | |
42 | /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, | |
43 | gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ | |
44 | ||
0f2d19dd JB |
45 | \f |
46 | ||
47 | #include <stdio.h> | |
48 | #include <signal.h> | |
49 | #include "_scm.h" | |
20e6290e JB |
50 | #include "eval.h" |
51 | #include "throw.h" | |
52 | #include "smob.h" | |
53 | ||
1bbd0b84 | 54 | #include "scm_validate.h" |
20e6290e | 55 | #include "async.h" |
0f2d19dd | 56 | |
95b88819 GH |
57 | #ifdef HAVE_STRING_H |
58 | #include <string.h> | |
59 | #endif | |
0f2d19dd JB |
60 | #ifdef HAVE_UNISTD_H |
61 | #include <unistd.h> | |
62 | #endif | |
63 | ||
64 | ||
65 | \f | |
66 | /* {Asynchronous Events} | |
67 | * | |
68 | * | |
69 | * Async == thunk + mark. | |
70 | * | |
71 | * Setting the mark guarantees future execution of the thunk. More | |
72 | * than one set may be satisfied by a single execution. | |
73 | * | |
74 | * scm_tick_clock decremented once per SCM_ALLOW_INTS. | |
75 | * Async execution triggered by SCM_ALLOW_INTS when scm_tick_clock drops to 0. | |
76 | * Async execution prevented by scm_mask_ints != 0. | |
77 | * | |
78 | * If the clock reaches 0 when scm_mask_ints != 0, then reset the clock | |
79 | * to 1. | |
80 | * | |
81 | * If the clock reaches 0 any other time, run marked asyncs. | |
82 | * | |
83 | * From a unix signal handler, mark a corresponding async and set the clock | |
84 | * to 1. Do SCM_REDEFER_INTS;/SCM_REALLOW_INTS so that if the signal handler is not | |
85 | * called in the dynamic scope of a critical section, it is excecuted immediately. | |
86 | * | |
87 | * Overall, closely timed signals of a particular sort may be combined. Pending signals | |
88 | * are delivered in a fixed priority order, regardless of arrival order. | |
89 | * | |
90 | */ | |
91 | ||
a574455a GH |
92 | /* True between SCM_DEFER_INTS and SCM_ALLOW_INTS, and |
93 | * when the interpreter is not running at all. | |
94 | */ | |
95 | int scm_ints_disabled = 1; | |
0f2d19dd JB |
96 | |
97 | unsigned int scm_async_clock = 20; | |
98 | static unsigned int scm_async_rate = 20; | |
99 | unsigned int scm_mask_ints = 1; | |
100 | ||
101 | static unsigned int scm_tick_clock = 0; | |
102 | static unsigned int scm_tick_rate = 0; | |
103 | static unsigned int scm_desired_tick_rate = 0; | |
104 | static unsigned int scm_switch_clock = 0; | |
105 | static unsigned int scm_switch_rate = 0; | |
106 | static unsigned int scm_desired_switch_rate = 0; | |
107 | ||
0f2d19dd JB |
108 | static long scm_tc16_async; |
109 | ||
0f2d19dd JB |
110 | \f |
111 | ||
5e569ca8 MD |
112 | int |
113 | scm_asyncs_pending () | |
0f2d19dd JB |
114 | { |
115 | SCM pos; | |
116 | pos = scm_asyncs; | |
117 | while (pos != SCM_EOL) | |
118 | { | |
119 | SCM a; | |
120 | struct scm_async * it; | |
121 | a = SCM_CAR (pos); | |
122 | it = SCM_ASYNC (a); | |
123 | if (it->got_it) | |
124 | return 1; | |
125 | pos = SCM_CDR (pos); | |
126 | } | |
127 | return 0; | |
128 | } | |
129 | ||
9ea54cc6 | 130 | #if 0 |
9ea54cc6 | 131 | static SCM |
1bbd0b84 | 132 | scm_sys_tick_async_thunk (void) |
9ea54cc6 GH |
133 | { |
134 | scm_deliver_signal (SCM_TICK_SIGNAL); | |
135 | return SCM_BOOL_F; | |
136 | } | |
137 | #endif | |
1cc91f1b | 138 | |
0f2d19dd JB |
139 | void |
140 | scm_async_click () | |
0f2d19dd JB |
141 | { |
142 | int owe_switch; | |
143 | int owe_tick; | |
144 | ||
145 | if (!scm_switch_rate) | |
146 | { | |
147 | owe_switch = 0; | |
148 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
149 | scm_desired_switch_rate = 0; | |
150 | } | |
151 | else | |
152 | { | |
153 | owe_switch = (scm_async_rate >= scm_switch_clock); | |
154 | if (owe_switch) | |
155 | { | |
156 | if (scm_desired_switch_rate) | |
157 | { | |
158 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
159 | scm_desired_switch_rate = 0; | |
160 | } | |
161 | else | |
162 | scm_switch_clock = scm_switch_rate; | |
163 | } | |
164 | else | |
165 | { | |
166 | if (scm_desired_switch_rate) | |
167 | { | |
168 | scm_switch_clock = scm_switch_rate = scm_desired_switch_rate; | |
169 | scm_desired_switch_rate = 0; | |
170 | } | |
171 | else | |
172 | scm_switch_clock -= scm_async_rate; | |
173 | } | |
174 | } | |
175 | ||
176 | if (scm_mask_ints) | |
177 | { | |
178 | if (owe_switch) | |
179 | scm_switch (); | |
180 | scm_async_clock = 1; | |
181 | return;; | |
182 | } | |
183 | ||
184 | if (!scm_tick_rate) | |
185 | { | |
186 | unsigned int r; | |
187 | owe_tick = 0; | |
188 | r = scm_desired_tick_rate; | |
189 | if (r) | |
190 | { | |
191 | scm_desired_tick_rate = 0; | |
192 | scm_tick_rate = r; | |
193 | scm_tick_clock = r; | |
194 | } | |
195 | } | |
196 | else | |
197 | { | |
198 | owe_tick = (scm_async_rate >= scm_tick_clock); | |
199 | if (owe_tick) | |
200 | { | |
201 | scm_tick_clock = scm_tick_rate = scm_desired_tick_rate; | |
202 | scm_desired_tick_rate = 0; | |
203 | } | |
204 | else | |
205 | { | |
206 | if (scm_desired_tick_rate) | |
207 | { | |
208 | scm_tick_clock = scm_tick_rate = scm_desired_tick_rate; | |
209 | scm_desired_tick_rate = 0; | |
210 | } | |
211 | else | |
212 | scm_tick_clock -= scm_async_rate; | |
213 | } | |
214 | } | |
215 | ||
9ea54cc6 GH |
216 | /* |
217 | if (owe_tick) | |
218 | scm_async_mark (system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)]); | |
219 | */ | |
0f2d19dd JB |
220 | |
221 | SCM_DEFER_INTS; | |
222 | if (scm_tick_rate && scm_switch_rate) | |
223 | { | |
224 | scm_async_rate = min (scm_tick_clock, scm_switch_clock); | |
225 | scm_async_clock = scm_async_rate; | |
226 | } | |
227 | else if (scm_tick_rate) | |
228 | { | |
229 | scm_async_clock = scm_async_rate = scm_tick_clock; | |
230 | } | |
231 | else if (scm_switch_rate) | |
232 | { | |
233 | scm_async_clock = scm_async_rate = scm_switch_clock; | |
234 | } | |
235 | else | |
236 | scm_async_clock = scm_async_rate = 1 << 16; | |
237 | SCM_ALLOW_INTS_ONLY; | |
238 | ||
239 | tail: | |
240 | scm_run_asyncs (scm_asyncs); | |
241 | ||
242 | SCM_DEFER_INTS; | |
5e569ca8 | 243 | if (scm_asyncs_pending ()) |
0f2d19dd JB |
244 | { |
245 | SCM_ALLOW_INTS_ONLY; | |
246 | goto tail; | |
247 | } | |
248 | SCM_ALLOW_INTS; | |
249 | ||
250 | if (owe_switch) | |
251 | scm_switch (); | |
252 | } | |
253 | ||
254 | ||
255 | \f | |
256 | ||
1cc91f1b | 257 | |
0f2d19dd JB |
258 | void |
259 | scm_switch () | |
7ad737b6 MD |
260 | { |
261 | #if 0 /* Thread switching code should probably reside here, but the | |
262 | async switching code doesn't seem to work, so it's put in the | |
263 | SCM_ASYNC_TICK macro instead. /mdj */ | |
264 | SCM_THREAD_SWITCHING_CODE; | |
265 | #endif | |
266 | } | |
0f2d19dd | 267 | |
0f2d19dd JB |
268 | \f |
269 | ||
0f2d19dd | 270 | static SCM |
1bbd0b84 | 271 | mark_async (SCM obj) |
0f2d19dd JB |
272 | { |
273 | struct scm_async * it; | |
0f2d19dd JB |
274 | it = SCM_ASYNC (obj); |
275 | return it->thunk; | |
276 | } | |
277 | ||
0f2d19dd JB |
278 | \f |
279 | ||
a1ec6916 | 280 | SCM_DEFINE(scm_async, "async", 1, 0, 0, |
1bbd0b84 GB |
281 | (SCM thunk), |
282 | "") | |
283 | #define FUNC_NAME s_scm_async | |
0f2d19dd | 284 | { |
4801c311 | 285 | struct scm_async * async |
1bbd0b84 | 286 | = (struct scm_async *) scm_must_malloc (sizeof (*async), FUNC_NAME); |
0f2d19dd JB |
287 | async->got_it = 0; |
288 | async->thunk = thunk; | |
23a62151 | 289 | SCM_RETURN_NEWSMOB (scm_tc16_async, async); |
0f2d19dd | 290 | } |
1bbd0b84 | 291 | #undef FUNC_NAME |
0f2d19dd | 292 | |
a1ec6916 | 293 | SCM_DEFINE(scm_system_async, "system-async", 1, 0, 0, |
1bbd0b84 GB |
294 | (SCM thunk), |
295 | "") | |
296 | #define FUNC_NAME s_scm_system_async | |
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 | } | |
1bbd0b84 | 306 | #undef FUNC_NAME |
0f2d19dd | 307 | |
a1ec6916 | 308 | SCM_DEFINE(scm_async_mark, "async-mark", 1, 0, 0, |
1bbd0b84 GB |
309 | (SCM a), |
310 | "") | |
311 | #define FUNC_NAME s_scm_async_mark | |
0f2d19dd JB |
312 | { |
313 | struct scm_async * it; | |
1bbd0b84 | 314 | SCM_VALIDATE_ASYNC_COPY(1,a,it); |
0f2d19dd JB |
315 | it->got_it = 1; |
316 | return SCM_UNSPECIFIED; | |
317 | } | |
1bbd0b84 | 318 | #undef FUNC_NAME |
0f2d19dd JB |
319 | |
320 | ||
a1ec6916 | 321 | SCM_DEFINE(scm_system_async_mark, "system-async-mark", 1, 0, 0, |
1bbd0b84 GB |
322 | (SCM a), |
323 | "") | |
324 | #define FUNC_NAME s_scm_system_async_mark | |
0f2d19dd JB |
325 | { |
326 | struct scm_async * it; | |
1bbd0b84 | 327 | SCM_VALIDATE_ASYNC_COPY(1,a,it); |
0f2d19dd JB |
328 | SCM_REDEFER_INTS; |
329 | it->got_it = 1; | |
330 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
331 | scm_async_clock = 1; | |
332 | SCM_REALLOW_INTS; | |
333 | return SCM_UNSPECIFIED; | |
334 | } | |
1bbd0b84 | 335 | #undef FUNC_NAME |
0f2d19dd JB |
336 | |
337 | ||
a1ec6916 | 338 | SCM_DEFINE(scm_run_asyncs, "run-asyncs", 1, 0, 0, |
1bbd0b84 GB |
339 | (SCM list_of_a), |
340 | "") | |
341 | #define FUNC_NAME s_scm_run_asyncs | |
0f2d19dd | 342 | { |
0f2d19dd JB |
343 | if (scm_mask_ints) |
344 | return SCM_BOOL_F; | |
1bbd0b84 | 345 | while (list_of_a != SCM_EOL) |
0f2d19dd JB |
346 | { |
347 | SCM a; | |
348 | struct scm_async * it; | |
30939477 | 349 | SCM_VALIDATE_CONS(1,list_of_a); |
1bbd0b84 | 350 | a = SCM_CAR (list_of_a); |
0c95b57d | 351 | SCM_ASSERT (SCM_ASYNCP (a), a, SCM_ARG1, FUNC_NAME); |
0f2d19dd JB |
352 | it = SCM_ASYNC (a); |
353 | scm_mask_ints = 1; | |
354 | if (it->got_it) | |
355 | { | |
356 | it->got_it = 0; | |
357 | scm_apply (it->thunk, SCM_EOL, SCM_EOL); | |
358 | } | |
359 | scm_mask_ints = 0; | |
1bbd0b84 | 360 | list_of_a = SCM_CDR (list_of_a); |
0f2d19dd JB |
361 | } |
362 | return SCM_BOOL_T; | |
363 | } | |
1bbd0b84 | 364 | #undef FUNC_NAME |
0f2d19dd JB |
365 | |
366 | \f | |
367 | ||
368 | ||
a1ec6916 | 369 | SCM_DEFINE(scm_noop, "noop", 0, 0, 1, |
1bbd0b84 GB |
370 | (SCM args), |
371 | "") | |
372 | #define FUNC_NAME s_scm_noop | |
0f2d19dd JB |
373 | { |
374 | return (SCM_NULLP (args) | |
375 | ? SCM_BOOL_F | |
376 | : SCM_CAR (args)); | |
377 | } | |
1bbd0b84 | 378 | #undef FUNC_NAME |
0f2d19dd JB |
379 | |
380 | ||
381 | \f | |
382 | ||
a1ec6916 | 383 | SCM_DEFINE(scm_set_tick_rate, "set-tick-rate", 1, 0, 0, |
1bbd0b84 GB |
384 | (SCM n), |
385 | "") | |
386 | #define FUNC_NAME s_scm_set_tick_rate | |
0f2d19dd JB |
387 | { |
388 | unsigned int old_n; | |
47c6b75e | 389 | SCM_VALIDATE_INUM(1,n); |
0f2d19dd JB |
390 | old_n = scm_tick_rate; |
391 | scm_desired_tick_rate = SCM_INUM (n); | |
392 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
393 | scm_async_clock = 1; | |
394 | return SCM_MAKINUM (old_n); | |
395 | } | |
1bbd0b84 | 396 | #undef FUNC_NAME |
0f2d19dd JB |
397 | |
398 | \f | |
399 | ||
400 | ||
a1ec6916 | 401 | SCM_DEFINE(scm_set_switch_rate, "set-switch-rate", 1, 0, 0, |
1bbd0b84 GB |
402 | (SCM n), |
403 | "") | |
404 | #define FUNC_NAME s_scm_set_switch_rate | |
0f2d19dd JB |
405 | { |
406 | unsigned int old_n; | |
47c6b75e | 407 | SCM_VALIDATE_INUM(1,n); |
0f2d19dd JB |
408 | old_n = scm_switch_rate; |
409 | scm_desired_switch_rate = SCM_INUM (n); | |
410 | scm_async_rate = 1 + scm_async_rate - scm_async_clock; | |
411 | scm_async_clock = 1; | |
412 | return SCM_MAKINUM (old_n); | |
413 | } | |
1bbd0b84 | 414 | #undef FUNC_NAME |
0f2d19dd JB |
415 | |
416 | \f | |
417 | ||
9ea54cc6 GH |
418 | /* points to the GC system-async, so that scm_gc_end can find it. */ |
419 | SCM scm_gc_async; | |
1cc91f1b | 420 | |
9ea54cc6 GH |
421 | /* the vcell for gc-thunk. */ |
422 | static SCM scm_gc_vcell; | |
1cc91f1b | 423 | |
9ea54cc6 GH |
424 | /* the thunk installed in the GC system-async, which is marked at the |
425 | end of garbage collection. */ | |
0f2d19dd | 426 | static SCM |
9ea54cc6 | 427 | scm_sys_gc_async_thunk (void) |
0f2d19dd | 428 | { |
9ea54cc6 GH |
429 | if (SCM_NFALSEP (scm_gc_vcell)) |
430 | { | |
431 | SCM proc = SCM_CDR (scm_gc_vcell); | |
1cc91f1b | 432 | |
9ea54cc6 GH |
433 | if (SCM_NFALSEP (proc) && !SCM_UNBNDP (proc)) |
434 | scm_apply (proc, SCM_EOL, SCM_EOL); | |
435 | } | |
436 | return SCM_UNSPECIFIED; | |
0f2d19dd JB |
437 | } |
438 | ||
0f2d19dd JB |
439 | \f |
440 | ||
a1ec6916 | 441 | SCM_DEFINE(scm_unmask_signals, "unmask-signals", 0, 0, 0, |
1bbd0b84 GB |
442 | (), |
443 | "") | |
444 | #define FUNC_NAME s_scm_unmask_signals | |
0f2d19dd JB |
445 | { |
446 | scm_mask_ints = 0; | |
447 | return SCM_UNSPECIFIED; | |
448 | } | |
1bbd0b84 | 449 | #undef FUNC_NAME |
0f2d19dd JB |
450 | |
451 | ||
a1ec6916 | 452 | SCM_DEFINE(scm_mask_signals, "mask-signals", 0, 0, 0, |
1bbd0b84 GB |
453 | (), |
454 | "") | |
455 | #define FUNC_NAME s_scm_mask_signals | |
0f2d19dd JB |
456 | { |
457 | scm_mask_ints = 1; | |
458 | return SCM_UNSPECIFIED; | |
459 | } | |
1bbd0b84 | 460 | #undef FUNC_NAME |
0f2d19dd JB |
461 | |
462 | \f | |
463 | ||
0f2d19dd JB |
464 | void |
465 | scm_init_async () | |
0f2d19dd JB |
466 | { |
467 | SCM a_thunk; | |
23a62151 MD |
468 | scm_tc16_async = scm_make_smob_type_mfpe ("async", sizeof (struct scm_async), |
469 | mark_async, NULL, NULL, NULL); | |
9ea54cc6 | 470 | scm_gc_vcell = scm_sysintern ("gc-thunk", SCM_BOOL_F); |
0f2d19dd | 471 | a_thunk = scm_make_gsubr ("%gc-thunk", 0, 0, 0, scm_sys_gc_async_thunk); |
9ea54cc6 | 472 | scm_gc_async = scm_system_async (a_thunk); |
0f2d19dd | 473 | |
0f2d19dd JB |
474 | #include "async.x" |
475 | } |