1 /* Copyright (c) 2008-2012. 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;
13 static int is_visited_state(void);
15 static int is_visited_state(){
17 if(_surf_mc_stateful == 0)
20 int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
24 mc_snapshot_t new_state = NULL;
25 new_state = MC_take_snapshot();
29 if(xbt_dynar_is_empty(visited_states)){
32 xbt_dynar_push(visited_states, &new_state);
44 unsigned int cursor = 0;
45 mc_snapshot_t state_test = NULL;
47 xbt_dynar_foreach(visited_states, cursor, state_test){
48 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug))
49 XBT_DEBUG("****** Pair visited #%d ******", cursor + 1);
50 if(snapshot_compare(new_state, state_test, NULL, NULL) == 0){
60 if(xbt_dynar_length(visited_states) == _surf_mc_stateful){
61 mc_snapshot_t state_to_remove = NULL;
62 xbt_dynar_shift(visited_states, &state_to_remove);
63 MC_free_snapshot(state_to_remove);
66 xbt_dynar_push(visited_states, &new_state);
79 * \brief Initialize the DPOR exploration algorithm
84 int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
86 mc_state_t initial_state = NULL;
87 smx_process_t process;
89 /* Create the initial state and push it into the exploration stack */
92 initial_state = MC_state_new();
93 visited_states = xbt_dynar_new(sizeof(mc_snapshot_t), NULL);
97 XBT_DEBUG("**************************************************");
98 XBT_DEBUG("Initial state");
100 /* Wait for requests (schedules processes) */
101 MC_wait_for_requests();
105 xbt_swag_foreach(process, simix_global->process_list){
106 if(MC_process_is_enabled(process)){
107 XBT_DEBUG("Process %lu enabled with simcall : %d", process->pid, (&process->simcall)->call);
111 /* Get an enabled process and insert it in the interleave set of the initial state */
112 xbt_swag_foreach(process, simix_global->process_list){
113 if(MC_process_is_enabled(process)){
114 MC_state_interleave_process(initial_state, process);
119 xbt_fifo_unshift(mc_stack_safety, initial_state);
129 /* FIXME: Update Statistics
130 mc_stats->state_size +=
131 xbt_setset_set_size(initial_state->enabled_transitions); */
136 * \brief Perform the model-checking operation using a depth-first search exploration
137 * with Dynamic Partial Order Reductions
144 smx_simcall_t req = NULL, prev_req = NULL;
145 mc_state_t state = NULL, prev_state = NULL, next_state = NULL, restore_state=NULL;
146 smx_process_t process = NULL;
147 xbt_fifo_item_t item = NULL;
150 while (xbt_fifo_size(mc_stack_safety) > 0) {
152 /* Get current state */
154 xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack_safety));
156 XBT_DEBUG("**************************************************");
157 XBT_DEBUG("Exploration depth=%d (state=%p)(%u interleave)",
158 xbt_fifo_size(mc_stack_safety), state,
159 MC_state_interleave_size(state));
161 /* Update statistics */
162 mc_stats->visited_states++;
164 /* If there are processes to interleave and the maximum depth has not been reached
165 then perform one step of the exploration algorithm */
166 if (xbt_fifo_size(mc_stack_safety) < _surf_mc_max_depth &&
167 (req = MC_state_get_request(state, &value))) {
169 /* Debug information */
170 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
171 req_str = MC_request_to_string(req, value);
172 XBT_DEBUG("Execute: %s", req_str);
176 MC_state_set_executed_request(state, req, value);
177 mc_stats->executed_transitions++;
179 /* Answer the request */
180 SIMIX_simcall_pre(req, value); /* After this call req is no longer usefull */
182 /* Wait for requests (schedules processes) */
183 MC_wait_for_requests();
185 /* Create the new expanded state */
188 next_state = MC_state_new();
190 if(!is_visited_state()){
192 xbt_swag_foreach(process, simix_global->process_list){
193 if(MC_process_is_enabled(process)){
194 XBT_DEBUG("Process %lu enabled with simcall : %d", process->pid, (&process->simcall)->call);
198 /* Get an enabled process and insert it in the interleave set of the next state */
199 xbt_swag_foreach(process, simix_global->process_list){
200 if(MC_process_is_enabled(process)){
201 MC_state_interleave_process(next_state, process);
206 if(_surf_mc_checkpoint && ((xbt_fifo_size(mc_stack_safety) + 1) % _surf_mc_checkpoint == 0)){
207 next_state->system_state = MC_take_snapshot();
212 xbt_fifo_unshift(mc_stack_safety, next_state);
215 /* FIXME: Update Statistics
216 mc_stats->state_size +=
217 xbt_setset_set_size(next_state->enabled_transitions);*/
219 /* Let's loop again */
221 /* The interleave set is empty or the maximum depth is reached, let's back-track */
224 if(xbt_fifo_size(mc_stack_safety) == _surf_mc_max_depth){
226 XBT_WARN("/!\\ Max depth reached ! /!\\ ");
228 XBT_WARN("/!\\ But, there are still processes to interleave. Model-checker will not be able to ensure the soundness of the verification from now. /!\\ ");
229 XBT_WARN("Notice : the default value of max depth is 1000 but you can change it with cfg=model-check/max_depth:value.");
234 XBT_DEBUG("There are no more processes to interleave.");
238 /* Trash the current state, no longer needed */
240 xbt_fifo_shift(mc_stack_safety);
241 MC_state_delete(state);
244 /* Check for deadlocks */
245 if(MC_deadlock_check()){
246 MC_show_deadlock(NULL);
251 /* Traverse the stack backwards until a state with a non empty interleave
252 set is found, deleting all the states that have it empty in the way.
253 For each deleted state, check if the request that has generated it
254 (from it's predecesor state), depends on any other previous request
255 executed before it. If it does then add it to the interleave set of the
256 state that executed that previous request. */
257 while ((state = xbt_fifo_shift(mc_stack_safety)) != NULL) {
258 req = MC_state_get_internal_request(state);
259 xbt_fifo_foreach(mc_stack_safety, item, prev_state, mc_state_t) {
260 if(MC_request_depend(req, MC_state_get_internal_request(prev_state))){
261 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
262 XBT_DEBUG("Dependent Transitions:");
263 prev_req = MC_state_get_executed_request(prev_state, &value);
264 req_str = MC_request_to_string(prev_req, value);
265 XBT_DEBUG("%s (state=%p)", req_str, prev_state);
267 prev_req = MC_state_get_executed_request(state, &value);
268 req_str = MC_request_to_string(prev_req, value);
269 XBT_DEBUG("%s (state=%p)", req_str, state);
273 if(!MC_state_process_is_done(prev_state, req->issuer))
274 MC_state_interleave_process(prev_state, req->issuer);
276 XBT_DEBUG("Process %p is in done set", req->issuer);
281 if (MC_state_interleave_size(state)) {
282 /* We found a back-tracking point, let's loop */
283 if(_surf_mc_checkpoint){
284 if(state->system_state != NULL){
285 MC_restore_snapshot(state->system_state);
286 xbt_fifo_unshift(mc_stack_safety, state);
287 XBT_DEBUG("Back-tracking to depth %d", xbt_fifo_size(mc_stack_safety));
290 pos = xbt_fifo_size(mc_stack_safety);
291 item = xbt_fifo_get_first_item(mc_stack_safety);
293 restore_state = (mc_state_t) xbt_fifo_get_item_content(item);
294 if(restore_state->system_state != NULL){
297 item = xbt_fifo_get_next_item(item);
301 MC_restore_snapshot(restore_state->system_state);
302 xbt_fifo_unshift(mc_stack_safety, state);
303 XBT_DEBUG("Back-tracking to depth %d", xbt_fifo_size(mc_stack_safety));
305 MC_replay(mc_stack_safety, pos);
308 xbt_fifo_unshift(mc_stack_safety, state);
309 XBT_DEBUG("Back-tracking to depth %d", xbt_fifo_size(mc_stack_safety));
311 MC_replay(mc_stack_safety, -1);
315 MC_state_delete(state);
321 MC_print_statistics(mc_stats);