1 /* Copyright (c) 2008-2013. Da SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "mc_private.h"
8 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dpor, mc,
9 "Logging specific to MC DPOR exploration");
11 xbt_dynar_t visited_states;
12 xbt_dict_t first_enabled_state;
14 static void visited_state_free(mc_visited_state_t state){
16 MC_free_snapshot(state->system_state);
21 static void visited_state_free_voidp(void *s){
22 visited_state_free((mc_visited_state_t) * (void **) s);
25 static mc_visited_state_t visited_state_new(){
27 mc_visited_state_t new_state = NULL;
28 new_state = xbt_new0(s_mc_visited_state_t, 1);
29 new_state->heap_bytes_used = mmalloc_get_bytes_used(std_heap);
30 new_state->nb_processes = xbt_swag_size(simix_global->process_list);
31 new_state->system_state = MC_take_snapshot();
32 new_state->num = mc_stats->expanded_states;
38 /* Dichotomic search in visited_states dynar.
39 * States are ordered by the number of processes then the number of bytes used in std_heap */
41 static int is_visited_state(){
43 if(_sg_mc_visited == 0)
46 int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
49 mc_visited_state_t new_state = visited_state_new();
52 if(xbt_dynar_is_empty(visited_states)){
55 xbt_dynar_push(visited_states, &new_state);
67 size_t current_bytes_used = new_state->heap_bytes_used;
68 int current_nb_processes = new_state->nb_processes;
70 unsigned int cursor = 0;
71 int previous_cursor = 0, next_cursor = 0;
73 int end = xbt_dynar_length(visited_states) - 1;
75 mc_visited_state_t state_test = NULL;
76 size_t bytes_used_test;
77 int nb_processes_test;
78 int same_processes_and_bytes_not_found = 1;
80 while(start <= end && same_processes_and_bytes_not_found){
81 cursor = (start + end) / 2;
82 state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, cursor, mc_visited_state_t);
83 bytes_used_test = state_test->heap_bytes_used;
84 nb_processes_test = state_test->nb_processes;
85 if(nb_processes_test < current_nb_processes){
87 }else if(nb_processes_test > current_nb_processes){
89 }else if(nb_processes_test == current_nb_processes){
90 if(bytes_used_test < current_bytes_used)
92 if(bytes_used_test > current_bytes_used)
94 if(bytes_used_test == current_bytes_used){
95 same_processes_and_bytes_not_found = 0;
96 if(snapshot_compare(new_state->system_state, state_test->system_state) == 0){
97 XBT_DEBUG("State %d already visited ! (equal to state %d)", new_state->num, state_test->num);
102 return state_test->num;
104 /* Search another state with same number of bytes used in std_heap */
105 previous_cursor = cursor - 1;
106 while(previous_cursor >= 0){
107 state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, previous_cursor, mc_visited_state_t);
108 bytes_used_test = state_test->system_state->heap_bytes_used;
109 if(bytes_used_test != current_bytes_used)
111 if(snapshot_compare(new_state->system_state, state_test->system_state) == 0){
112 XBT_DEBUG("State %d already visited ! (equal to state %d)", new_state->num, state_test->num);
117 return state_test->num;
121 next_cursor = cursor + 1;
122 while(next_cursor < xbt_dynar_length(visited_states)){
123 state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, next_cursor, mc_visited_state_t);
124 bytes_used_test = state_test->system_state->heap_bytes_used;
125 if(bytes_used_test != current_bytes_used)
127 if(snapshot_compare(new_state->system_state, state_test->system_state) == 0){
128 XBT_DEBUG("State %d already visited ! (equal to state %d)", new_state->num, state_test->num);
133 return state_test->num;
142 state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, cursor, mc_visited_state_t);
143 bytes_used_test = state_test->heap_bytes_used;
145 if(bytes_used_test < current_bytes_used)
146 xbt_dynar_insert_at(visited_states, cursor + 1, &new_state);
148 xbt_dynar_insert_at(visited_states, cursor, &new_state);
150 if(xbt_dynar_length(visited_states) > _sg_mc_visited){
151 int min = mc_stats->expanded_states;
152 unsigned int cursor2 = 0;
153 unsigned int index = 0;
154 xbt_dynar_foreach(visited_states, cursor2, state_test){
155 if(state_test->num < min){
157 min = state_test->num;
160 xbt_dynar_remove_at(visited_states, index, NULL);
174 * \brief Initialize the DPOR exploration algorithm
179 int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
181 mc_state_t initial_state = NULL;
182 smx_process_t process;
184 /* Create the initial state and push it into the exploration stack */
187 initial_state = MC_state_new();
188 visited_states = xbt_dynar_new(sizeof(mc_visited_state_t), visited_state_free_voidp);
190 first_enabled_state = xbt_dict_new_homogeneous(&xbt_free_f);
194 XBT_DEBUG("**************************************************");
195 XBT_DEBUG("Initial state");
197 /* Wait for requests (schedules processes) */
198 MC_wait_for_requests();
202 /* Get an enabled process and insert it in the interleave set of the initial state */
203 xbt_swag_foreach(process, simix_global->process_list){
204 if(MC_process_is_enabled(process)){
205 MC_state_interleave_process(initial_state, process);
206 if(mc_reduce_kind != e_mc_reduce_none)
211 xbt_fifo_unshift(mc_stack_safety, initial_state);
213 /* To ensure the soundness of DPOR, we have to keep a list of
214 processes which are still enabled at each step of the exploration.
215 If max depth is reached, we interleave them in the state in which they have
216 been enabled for the first time. */
217 xbt_swag_foreach(process, simix_global->process_list){
218 if(MC_process_is_enabled(process)){
219 char *key = bprintf("%lu", process->pid);
220 char *data = bprintf("%d", xbt_fifo_size(mc_stack_safety));
221 xbt_dict_set(first_enabled_state, key, data, NULL);
237 * \brief Perform the model-checking operation using a depth-first search exploration
238 * with Dynamic Partial Order Reductions
243 char *req_str = NULL;
245 smx_simcall_t req = NULL, prev_req = NULL;
246 mc_state_t state = NULL, prev_state = NULL, next_state = NULL, restore_state=NULL;
247 smx_process_t process = NULL;
248 xbt_fifo_item_t item = NULL;
251 int enabled = 0, max_depth_reached;
253 while (xbt_fifo_size(mc_stack_safety) > 0) {
255 /* Get current state */
257 xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack_safety));
259 XBT_DEBUG("**************************************************");
260 XBT_DEBUG("Exploration depth=%d (state=%p, num %d)(%u interleave, user_max_depth %d)",
261 xbt_fifo_size(mc_stack_safety), state, state->num,
262 MC_state_interleave_size(state), user_max_depth_reached);
264 /* Update statistics */
265 mc_stats->visited_states++;
267 /* If there are processes to interleave and the maximum depth has not been reached
268 then perform one step of the exploration algorithm */
269 if (xbt_fifo_size(mc_stack_safety) <= _sg_mc_max_depth && !user_max_depth_reached &&
270 (req = MC_state_get_request(state, &value))) {
272 /* Debug information */
273 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
274 req_str = MC_request_to_string(req, value);
275 XBT_DEBUG("Execute: %s", req_str);
280 if(dot_output != NULL)
281 req_str = MC_request_get_dot_output(req, value);
284 MC_state_set_executed_request(state, req, value);
285 mc_stats->executed_transitions++;
288 char *key = bprintf("%lu", req->issuer->pid);
289 xbt_dict_remove(first_enabled_state, key);
293 /* Answer the request */
294 SIMIX_simcall_pre(req, value); /* After this call req is no longer usefull */
296 /* Wait for requests (schedules processes) */
297 MC_wait_for_requests();
299 /* Create the new expanded state */
302 next_state = MC_state_new();
304 if((visited_state = is_visited_state()) == -1){
306 /* Get an enabled process and insert it in the interleave set of the next state */
307 xbt_swag_foreach(process, simix_global->process_list){
308 if(MC_process_is_enabled(process)){
309 MC_state_interleave_process(next_state, process);
310 if(mc_reduce_kind != e_mc_reduce_none)
315 if(_sg_mc_checkpoint && ((xbt_fifo_size(mc_stack_safety) + 1) % _sg_mc_checkpoint == 0)){
316 next_state->system_state = MC_take_snapshot();
319 if(dot_output != NULL)
320 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num, next_state->num, req_str);
324 if(dot_output != NULL)
325 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num, visited_state, req_str);
329 xbt_fifo_unshift(mc_stack_safety, next_state);
331 /* Insert in dict all enabled processes, if not included yet */
332 xbt_swag_foreach(process, simix_global->process_list){
333 if(MC_process_is_enabled(process)){
334 char *key = bprintf("%lu", process->pid);
335 if(xbt_dict_get_or_null(first_enabled_state, key) == NULL){
336 char *data = bprintf("%d", xbt_fifo_size(mc_stack_safety));
337 xbt_dict_set(first_enabled_state, key, data, NULL);
343 if(dot_output != NULL)
348 /* Let's loop again */
350 /* The interleave set is empty or the maximum depth is reached, let's back-track */
353 if((xbt_fifo_size(mc_stack_safety) > _sg_mc_max_depth) || user_max_depth_reached){
355 if(user_max_depth_reached)
356 XBT_WARN("User max depth reached !");
358 XBT_WARN("/!\\ Max depth reached ! /!\\ ");
360 /* Interleave enabled processes in the state in which they have been enabled for the first time */
361 xbt_swag_foreach(process, simix_global->process_list){
362 if(MC_process_is_enabled(process)){
363 char *key = bprintf("%lu", process->pid);
364 enabled = (int)strtoul(xbt_dict_get_or_null(first_enabled_state, key), 0, 10);
366 mc_state_t state_test = NULL;
367 xbt_fifo_item_t item = NULL;
368 int cursor = xbt_fifo_size(mc_stack_safety);
369 xbt_fifo_foreach(mc_stack_safety, item, state_test, mc_state_t){
370 if(cursor-- == enabled){
371 if(!MC_state_process_is_done(state_test, process)){
372 MC_state_interleave_process(state_test, process);
380 if(MC_state_interleave_size(state) > 0){
381 max_depth_reached = 1;
383 /* Trash the current state, no longer needed */
385 xbt_fifo_shift(mc_stack_safety);
386 MC_state_delete(state);
389 max_depth_reached = 0;
395 XBT_DEBUG("There are no more processes to interleave.");
397 /* Trash the current state, no longer needed */
399 xbt_fifo_shift(mc_stack_safety);
400 MC_state_delete(state);
401 XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
404 max_depth_reached = 0;
407 /* Check for deadlocks */
408 if(MC_deadlock_check()){
409 MC_show_deadlock(NULL);
414 /* Traverse the stack backwards until a state with a non empty interleave
415 set is found, deleting all the states that have it empty in the way.
416 For each deleted state, check if the request that has generated it
417 (from it's predecesor state), depends on any other previous request
418 executed before it. If it does then add it to the interleave set of the
419 state that executed that previous request. */
421 while ((state = xbt_fifo_shift(mc_stack_safety)) != NULL) {
422 if(mc_reduce_kind != e_mc_reduce_none){
423 if(((xbt_fifo_size(mc_stack_safety) == _sg_mc_max_depth) && max_depth_reached) || user_max_depth_reached){
424 req = MC_state_get_request(state, &value);
425 MC_state_set_executed_request(state, req, value);
426 user_max_depth_reached = 0;
428 req = MC_state_get_internal_request(state);
429 xbt_fifo_foreach(mc_stack_safety, item, prev_state, mc_state_t) {
430 if(MC_request_depend(req, MC_state_get_internal_request(prev_state))){
431 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
432 XBT_DEBUG("Dependent Transitions:");
433 prev_req = MC_state_get_executed_request(prev_state, &value);
434 req_str = MC_request_to_string(prev_req, value);
435 XBT_DEBUG("%s (state=%d)", req_str, prev_state->num);
437 prev_req = MC_state_get_executed_request(state, &value);
438 req_str = MC_request_to_string(prev_req, value);
439 XBT_DEBUG("%s (state=%d)", req_str, state->num);
443 if(!MC_state_process_is_done(prev_state, req->issuer))
444 MC_state_interleave_process(prev_state, req->issuer);
446 XBT_DEBUG("Process %p is in done set", req->issuer);
450 }else if(req->issuer == MC_state_get_internal_request(prev_state)->issuer){
452 XBT_DEBUG("Simcall %d and %d with same issuer", req->call, MC_state_get_internal_request(prev_state)->call);
457 XBT_DEBUG("Simcall %d, process %lu (state %d) and simcall %d, process %lu (state %d) are independant", req->call, req->issuer->pid, state->num, MC_state_get_internal_request(prev_state)->call, MC_state_get_internal_request(prev_state)->issuer->pid, prev_state->num);
463 if (MC_state_interleave_size(state) && xbt_fifo_size(mc_stack_safety) < _sg_mc_max_depth) {
464 /* We found a back-tracking point, let's loop */
465 XBT_DEBUG("Back-tracking to state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
466 if(_sg_mc_checkpoint){
467 if(state->system_state != NULL){
468 MC_restore_snapshot(state->system_state);
469 xbt_fifo_unshift(mc_stack_safety, state);
472 pos = xbt_fifo_size(mc_stack_safety);
473 item = xbt_fifo_get_first_item(mc_stack_safety);
475 restore_state = (mc_state_t) xbt_fifo_get_item_content(item);
476 if(restore_state->system_state != NULL){
479 item = xbt_fifo_get_next_item(item);
483 MC_restore_snapshot(restore_state->system_state);
484 xbt_fifo_unshift(mc_stack_safety, state);
486 MC_replay(mc_stack_safety, pos);
489 xbt_fifo_unshift(mc_stack_safety, state);
491 MC_replay(mc_stack_safety, -1);
493 XBT_DEBUG("Back-tracking to state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety));
496 XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
497 MC_state_delete(state);
503 MC_print_statistics(mc_stats);