Commit | Line | Data |
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8c108c1c | 1 | #include <glib.h> |
b1d18041 | 2 | #include <stdio.h> |
8c108c1c PMF |
3 | |
4 | #include "sstack.h" | |
5 | ||
6 | /* This is the implementation of sstack, a data structure that holds | |
7 | * operations done on a stack in order to play them on a stack a short | |
8 | * while later. They are played when dependencies are fulfilled. The | |
9 | * operations are held in a queue. | |
10 | * | |
11 | * Operations include PUSH of data, POP, as well as other special markers. | |
12 | * | |
13 | * Stack operations are defined by a struct sstack_item. Each struct | |
14 | * sstack_item has 3 flags: | |
15 | * - finished | |
16 | * - processable | |
17 | * - deletable | |
18 | * | |
19 | * Finished is raised when all the dependencies of the operation are | |
20 | * fulfilled. POPs are always created finished because they have no | |
21 | * dependencies. PUSHes are marked finished when their corresponding | |
22 | * POP is added to the queueit is the PUSHes | |
23 | * that contain the and EVENTs are always created finished. | |
24 | * | |
25 | * Once an operation is finished | |
26 | */ | |
27 | ||
28 | void (*print_sstack_item_data)(struct sstack_item *); | |
29 | ||
30 | /* Debugging function: print a queue item */ | |
31 | ||
32 | static void print_item(struct sstack_item *item) | |
33 | { | |
34 | char *label; | |
35 | ||
36 | if(item->data_type == SSTACK_TYPE_PUSH) { | |
37 | label = "PUSH"; | |
38 | } | |
39 | else if(item->data_type == SSTACK_TYPE_POP) { | |
40 | label = "POP"; | |
41 | } | |
42 | else { | |
43 | label = "UNKNOWN"; | |
44 | } | |
45 | ||
46 | printf("%-10s %-2u%-2u%-2u", label, item->finished, item->processable, item->deletable); | |
47 | /* hack: call this external, application-dependant function to show the private data in the item */ | |
48 | print_sstack_item_data(item); | |
49 | } | |
50 | ||
51 | /* Debugging function: print the queue as it is now */ | |
52 | ||
53 | void print_stack(struct sstack *stack) | |
54 | { | |
55 | int i; | |
56 | ||
57 | printf("************************\n"); | |
58 | printf("** %-10s F P D\n", "label"); | |
59 | for(i=0; i<stack->array->len; i++) { | |
60 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, i); | |
61 | ||
62 | printf("** %-3d- ", i); | |
63 | print_item(item); | |
64 | } | |
65 | printf("\n"); | |
66 | } | |
67 | ||
68 | static void try_start_deleting(struct sstack *stack) | |
69 | { | |
70 | int index = stack->array->len-1; | |
71 | ||
72 | while(index >= 0 && g_array_index(stack->array, struct sstack_item *, index)->deletable) { | |
73 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, index); | |
74 | ||
75 | if(item->delete_data_val) | |
76 | item->delete_data_val(item->data_val); | |
77 | ||
78 | //g_array_free(item->depends, FALSE); | |
79 | //g_array_free(item->rev_depends, FALSE); | |
80 | g_free(item); | |
81 | ||
82 | g_array_remove_index(stack->array, index); | |
83 | index--; | |
84 | } | |
85 | ||
86 | if(stack->proc_index > stack->array->len) | |
87 | stack->proc_index = stack->array->len; | |
88 | } | |
89 | ||
90 | /* An item is deletable as soon as it is processed. However, all the items after it | |
91 | * in the list must be deleted before it can be deleted. | |
92 | * | |
93 | * After this function, try_start_deleting must be called. | |
94 | */ | |
95 | ||
96 | static void mark_deletable(struct sstack *stack, int index) | |
97 | { | |
98 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, index); | |
99 | ||
100 | item->deletable = 1; | |
101 | ||
102 | // if(index == stack->array->len - 1) { | |
103 | // start_deleting(stack); | |
104 | // } | |
105 | } | |
106 | ||
107 | #if 0 | |
108 | /* Called to process an index of the queue */ | |
109 | ||
110 | static void process(struct sstack *stack, int index) | |
111 | { | |
112 | g_assert(stack->proc_index == index); | |
113 | ||
114 | //printf("sstack: starting to process\n"); | |
115 | while(stack->proc_index < stack->array->len) { | |
116 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, stack->proc_index); | |
117 | ||
118 | if(!item->processable) | |
119 | break; | |
120 | ||
121 | //printf("sstack: processing "); | |
122 | //print_item(item); | |
123 | ||
124 | if(stack->process_func) { | |
125 | stack->process_func(stack->process_func_arg, item); | |
126 | } | |
127 | else { | |
128 | printf("warning: no process func\n"); | |
129 | } | |
130 | ||
131 | stack->proc_index++; | |
132 | ||
133 | mark_deletable(stack, stack->proc_index-1); | |
134 | if(item->pushpop >= 0 && item->pushpop < stack->proc_index-1) { | |
135 | mark_deletable(stack, item->pushpop); | |
136 | } | |
137 | try_start_deleting(stack); | |
138 | } | |
139 | //printf("sstack: stopping processing\n"); | |
140 | } | |
141 | ||
142 | /* Called to mark an index of the queue as processable */ | |
143 | ||
144 | static void mark_processable(struct sstack *stack, int index) | |
145 | { | |
146 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, index); | |
147 | ||
148 | item->processable = 1; | |
149 | ||
150 | if(stack->proc_index <= stack->array->len && stack->proc_index == index) { | |
151 | process(stack, index); | |
152 | } | |
153 | } | |
154 | ||
155 | /* Called to check whether an index of the queue could be marked processable. If so, | |
156 | * mark it processable. | |
157 | * | |
158 | * To be processable, an item must: | |
159 | * - be finished | |
160 | * - have its push/pop dependency fulfilled | |
161 | * - have its other dependencies fulfilled | |
162 | */ | |
163 | ||
164 | static void try_mark_processable(struct sstack *stack, int index) | |
165 | { | |
166 | int i; | |
167 | int all_finished = 1; | |
168 | ||
169 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, index); | |
170 | ||
171 | //for(i=0; i<stack->array->len; i++) { | |
172 | // if(!g_array_index(stack->array, struct sstack_item *, index)->finished) { | |
173 | // all_finished = 0; | |
174 | // break; | |
175 | // } | |
176 | //} | |
177 | ||
178 | /* Theoritically, we should confirm that the push/pop dependency is | |
179 | * finished, but in practice, it's not necessary. If we are a push, the | |
180 | * corresponding pop is always finished. If we are a pop and we exist, | |
181 | * the corresponding push is necessarily finished. | |
182 | */ | |
183 | ||
184 | //if(all_finished) { | |
185 | if(item->finished) { | |
186 | mark_processable(stack, index); | |
187 | } | |
188 | //} | |
189 | } | |
190 | ||
191 | /* Called to mark an index of the queue as finished */ | |
192 | ||
193 | static void mark_finished(struct sstack *stack, int index) | |
194 | { | |
195 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, index); | |
196 | ||
197 | item->finished = 1; | |
198 | ||
199 | try_mark_processable(stack, index); | |
200 | } | |
201 | ||
202 | #endif | |
203 | /* --------------------- */ | |
204 | ||
205 | static void try_advance_processing(struct sstack *stack) | |
206 | { | |
207 | //g_assert(stack->proc_index == index); | |
208 | ||
209 | //printf("sstack: starting to process\n"); | |
210 | while(stack->proc_index < stack->array->len) { | |
211 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, stack->proc_index); | |
212 | ||
213 | //if(!item->finished) { | |
214 | // break; | |
215 | //} | |
216 | ||
217 | //printf("sstack: processing "); | |
218 | //print_item(item); | |
219 | ||
220 | if(stack->process_func) { | |
221 | stack->process_func(stack->process_func_arg, item); | |
222 | } | |
223 | else { | |
224 | printf("warning: no process func\n"); | |
225 | } | |
226 | ||
227 | stack->proc_index++; | |
228 | ||
229 | if(item->data_type == SSTACK_TYPE_POP) | |
230 | mark_deletable(stack, stack->proc_index-1); | |
231 | if(item->pushpop >= 0 && item->pushpop < stack->proc_index-1) { | |
232 | mark_deletable(stack, item->pushpop); | |
233 | } | |
234 | } | |
235 | try_start_deleting(stack); | |
236 | //printf("sstack: stopping processing\n"); | |
237 | } | |
238 | ||
239 | ||
240 | /* Add an item to the queue */ | |
241 | ||
242 | void sstack_add_item(struct sstack *stack, struct sstack_item *item) | |
243 | { | |
244 | int index; | |
245 | ||
246 | g_array_append_val(stack->array, item); | |
247 | ||
248 | //printf("stack after adding\n"); | |
249 | //print_stack(stack); | |
250 | ||
251 | index = stack->array->len-1; | |
252 | ||
253 | if(item->data_type == SSTACK_TYPE_PUSH) { | |
254 | int top_of_wait_pop_stack; | |
255 | ||
256 | if(stack->wait_pop_stack->len && g_array_index(stack->wait_pop_stack, int, stack->wait_pop_stack->len-1)) { | |
257 | /* if the preceding is a wait_for_pop (and there is a preceding), push a wait_for_pop */ | |
258 | const int one=1; | |
259 | g_array_append_val(stack->wait_pop_stack, one); | |
260 | } | |
261 | else { | |
262 | /* otherwise, push what the item wants */ | |
263 | g_array_append_val(stack->wait_pop_stack, item->wait_pop); | |
264 | } | |
265 | ||
266 | top_of_wait_pop_stack = g_array_index(stack->wait_pop_stack, int, stack->wait_pop_stack->len-1); | |
267 | ||
268 | g_array_append_val(stack->pushes, index); | |
269 | ||
270 | //printf("after pushing:\n"); | |
271 | //print_stack(stack); | |
272 | if(top_of_wait_pop_stack == 0) { | |
273 | try_advance_processing(stack); | |
274 | /* ASSERT that we processed the whole sstack */ | |
275 | } | |
276 | //printf("after processing:\n"); | |
277 | //print_stack(stack); | |
278 | } | |
279 | else if(item->data_type == SSTACK_TYPE_POP) { | |
280 | item->finished = 1; | |
281 | ||
282 | if(stack->pushes->len > 0) { | |
283 | /* FIXME: confirm we are popping what we expected to pop */ | |
284 | item->pushpop = g_array_index(stack->pushes, int, stack->pushes->len-1); | |
285 | g_array_index(stack->array, struct sstack_item *, item->pushpop)->pushpop = index; | |
286 | g_array_index(stack->array, struct sstack_item *, item->pushpop)->finished = 1; | |
287 | ||
288 | g_array_remove_index(stack->pushes, stack->pushes->len-1); | |
289 | } | |
290 | ||
291 | if(stack->wait_pop_stack->len > 0) { | |
292 | int top_of_wait_pop_stack; | |
293 | ||
294 | g_array_remove_index(stack->wait_pop_stack, stack->wait_pop_stack->len-1); | |
295 | ||
296 | if(stack->wait_pop_stack->len > 0) { | |
297 | top_of_wait_pop_stack = g_array_index(stack->wait_pop_stack, int, stack->wait_pop_stack->len-1); | |
298 | ||
299 | if(top_of_wait_pop_stack == 0) | |
300 | try_advance_processing(stack); | |
301 | } | |
302 | else { | |
303 | try_advance_processing(stack); | |
304 | } | |
305 | } | |
306 | else { | |
307 | try_advance_processing(stack); | |
308 | } | |
309 | } | |
310 | ||
311 | //printf("stack after processing\n"); | |
312 | //print_stack(stack); | |
313 | } | |
314 | ||
315 | /* Force processing of all items */ | |
316 | ||
317 | void sstack_force_flush(struct sstack *stack) | |
318 | { | |
319 | int i; | |
320 | ||
321 | for(i=0; i<stack->array->len; i++) { | |
322 | struct sstack_item *item = g_array_index(stack->array, struct sstack_item *, i); | |
323 | ||
324 | if(!item->finished) { | |
325 | item->finished = 1; | |
326 | } | |
327 | } | |
328 | ||
329 | try_advance_processing(stack); | |
330 | } | |
331 | ||
332 | /* Create a new sstack */ | |
333 | ||
334 | struct sstack *sstack_new(void) | |
335 | { | |
336 | struct sstack *retval; | |
337 | ||
338 | retval = (struct sstack *) g_malloc(sizeof(struct sstack)); | |
339 | ||
340 | retval->array = g_array_new(FALSE, FALSE, sizeof(struct sstack_item *)); | |
341 | retval->pushes = g_array_new(FALSE, FALSE, sizeof(int)); | |
342 | retval->wait_pop_stack = g_array_new(FALSE, FALSE, sizeof(int)); | |
343 | retval->proc_index = 0; | |
344 | retval->process_func = NULL; | |
345 | ||
346 | return retval; | |
347 | } | |
348 | ||
349 | /* Create a new sstack_item. Normally not invoked directly. See other functions below. */ | |
350 | ||
351 | struct sstack_item *sstack_item_new(void) | |
352 | { | |
353 | struct sstack_item *retval; | |
354 | ||
355 | retval = (struct sstack_item *) g_malloc(sizeof(struct sstack_item)); | |
356 | retval->finished = 0; | |
357 | retval->processable = 0; | |
358 | retval->deletable = 0; | |
359 | retval->data_type = 0; | |
360 | retval->data_val = NULL; | |
361 | retval->delete_data_val = NULL; | |
362 | retval->pushpop = -1; | |
363 | retval->wait_pop = 0; | |
364 | //retval->depends = g_array_new(FALSE, FALSE, sizeof(int)); | |
365 | //retval->rev_depends = g_array_new(FALSE, FALSE, sizeof(int)); | |
366 | ||
367 | return retval; | |
368 | } | |
369 | ||
370 | /* Create a new sstack_item that will represent a PUSH operation */ | |
371 | ||
372 | struct sstack_item *sstack_item_new_push(unsigned char wait_pop) | |
373 | { | |
374 | struct sstack_item *retval = sstack_item_new(); | |
375 | ||
376 | retval->data_type = SSTACK_TYPE_PUSH; | |
377 | retval->wait_pop = wait_pop; | |
378 | ||
379 | return retval; | |
380 | } | |
381 | ||
382 | /* Create a new sstack_item that will represent a POP operation */ | |
383 | ||
384 | struct sstack_item *sstack_item_new_pop(void) | |
385 | { | |
386 | struct sstack_item *retval = sstack_item_new(); | |
387 | ||
388 | retval->data_type = SSTACK_TYPE_POP; | |
389 | retval->finished = 1; | |
390 | ||
391 | return retval; | |
392 | } | |
393 | ||
394 | /* Create a new sstack_item that will represent an EVENT operation */ | |
395 | ||
396 | struct sstack_item *sstack_item_new_event(void) | |
397 | { | |
398 | struct sstack_item *retval = sstack_item_new(); | |
399 | ||
400 | retval->data_type = SSTACK_TYPE_EVENT; | |
401 | retval->finished = 1; | |
402 | retval->processable = 1; | |
403 | retval->deletable = 1; | |
404 | ||
405 | return retval; | |
406 | } |