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 = 0;
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)",
261 xbt_fifo_size(mc_stack_safety), state, state->num,
262 MC_state_interleave_size(state));
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 &&
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){
355 XBT_WARN("/!\\ Max depth reached ! /!\\ ");
357 /* Interleave enabled processes in the state in which they have been enabled for the first time */
358 xbt_swag_foreach(process, simix_global->process_list){
359 if(MC_process_is_enabled(process)){
360 char *key = bprintf("%lu", process->pid);
361 enabled = (int)strtoul(xbt_dict_get_or_null(first_enabled_state, key), 0, 10);
363 mc_state_t state_test = NULL;
364 xbt_fifo_item_t item = NULL;
365 int cursor = xbt_fifo_size(mc_stack_safety);
366 xbt_fifo_foreach(mc_stack_safety, item, state_test, mc_state_t){
367 if(cursor-- == enabled){
368 if(!MC_state_process_is_done(state_test, process)){
369 MC_state_interleave_process(state_test, process);
377 if(MC_state_interleave_size(state) > 0){
378 max_depth_reached = 1;
380 /* Trash the current state, no longer needed */
382 xbt_fifo_shift(mc_stack_safety);
383 MC_state_delete(state);
386 max_depth_reached = 0;
392 XBT_DEBUG("There are no more processes to interleave.");
394 /* Trash the current state, no longer needed */
396 xbt_fifo_shift(mc_stack_safety);
397 MC_state_delete(state);
400 max_depth_reached = 0;
403 /* Check for deadlocks */
404 if(MC_deadlock_check()){
405 MC_show_deadlock(NULL);
410 /* Traverse the stack backwards until a state with a non empty interleave
411 set is found, deleting all the states that have it empty in the way.
412 For each deleted state, check if the request that has generated it
413 (from it's predecesor state), depends on any other previous request
414 executed before it. If it does then add it to the interleave set of the
415 state that executed that previous request. */
417 while ((state = xbt_fifo_shift(mc_stack_safety)) != NULL) {
418 if(mc_reduce_kind != e_mc_reduce_none){
419 if((xbt_fifo_size(mc_stack_safety) == _sg_mc_max_depth) && max_depth_reached){
420 req = MC_state_get_request(state, &value);
421 MC_state_set_executed_request(state, req, value);
423 req = MC_state_get_internal_request(state);
424 xbt_fifo_foreach(mc_stack_safety, item, prev_state, mc_state_t) {
425 if(MC_request_depend(req, MC_state_get_internal_request(prev_state))){
426 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
427 XBT_DEBUG("Dependent Transitions:");
428 prev_req = MC_state_get_executed_request(prev_state, &value);
429 req_str = MC_request_to_string(prev_req, value);
430 XBT_DEBUG("%s (state=%p)", req_str, prev_state);
432 prev_req = MC_state_get_executed_request(state, &value);
433 req_str = MC_request_to_string(prev_req, value);
434 XBT_DEBUG("%s (state=%p)", req_str, state);
438 if(!MC_state_process_is_done(prev_state, req->issuer))
439 MC_state_interleave_process(prev_state, req->issuer);
441 XBT_DEBUG("Process %p is in done set", req->issuer);
445 }else if(req->issuer == MC_state_get_internal_request(prev_state)->issuer){
447 XBT_DEBUG("Simcall %d and %d with same issuer", req->call, MC_state_get_internal_request(prev_state)->call);
454 if (MC_state_interleave_size(state) && xbt_fifo_size(mc_stack_safety) < _sg_mc_max_depth) {
455 /* We found a back-tracking point, let's loop */
456 XBT_DEBUG("Back-tracking to depth %d", xbt_fifo_size(mc_stack_safety) + 1);
457 if(_sg_mc_checkpoint){
458 if(state->system_state != NULL){
459 MC_restore_snapshot(state->system_state);
460 xbt_fifo_unshift(mc_stack_safety, state);
463 pos = xbt_fifo_size(mc_stack_safety);
464 item = xbt_fifo_get_first_item(mc_stack_safety);
466 restore_state = (mc_state_t) xbt_fifo_get_item_content(item);
467 if(restore_state->system_state != NULL){
470 item = xbt_fifo_get_next_item(item);
474 MC_restore_snapshot(restore_state->system_state);
475 xbt_fifo_unshift(mc_stack_safety, state);
477 MC_replay(mc_stack_safety, pos);
480 xbt_fifo_unshift(mc_stack_safety, state);
482 MC_replay(mc_stack_safety, -1);
484 XBT_DEBUG("Back-tracking to depth %d", xbt_fifo_size(mc_stack_safety));
487 XBT_DEBUG("Delete state at depth %d",xbt_fifo_size(mc_stack_safety) + 1);
488 MC_state_delete(state);
494 MC_print_statistics(mc_stats);