1 /* Copyright (c) 2008 Martin Quinson, Cristian Rosa.
2 All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
9 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dpor, mc,
10 "Logging specific to MC DPOR exploration");
13 * \brief Initialize the DPOR exploration algorithm
17 mc_state_t initial_state = NULL;
18 mc_transition_t trans, trans_tmp = NULL;
19 xbt_setset_cursor_t cursor = NULL;
21 /* Create the initial state and push it into the exploration stack */
23 initial_state = MC_state_new();
24 xbt_fifo_unshift(mc_stack, initial_state);
27 /* Schedule all the processes to detect the transitions of the initial state */
28 DEBUG0("**************************************************");
29 DEBUG0("Initial state");
30 MC_schedule_enabled_processes();
33 MC_trans_compute_enabled(initial_state->enabled_transitions,
34 initial_state->transitions);
36 /* Fill the interleave set of the initial state with an enabled process */
37 trans = xbt_setset_set_choose(initial_state->enabled_transitions);
39 DEBUG1("Choosing process %s for next interleave", trans->process->name);
40 xbt_setset_foreach(initial_state->enabled_transitions, cursor, trans_tmp){
41 if(trans_tmp->process == trans->process)
42 xbt_setset_set_insert(initial_state->interleave, trans_tmp);
47 /* Update Statistics */
48 mc_stats->state_size += xbt_setset_set_size(initial_state->enabled_transitions);
53 * \brief Perform the model-checking operation using a depth-first search exploration
54 * with Dynamic Partial Order Reductions
58 mc_transition_t trans, trans_tmp = NULL;
59 mc_state_t next_state = NULL;
60 xbt_setset_cursor_t cursor = NULL;
62 while(xbt_fifo_size(mc_stack) > 0){
64 DEBUG0("**************************************************");
66 /* FIXME: Think about what happen if there are no transitions but there are
67 some actions on the models. (ex. all the processes do a sleep(0) in a round). */
69 /* Get current state */
70 mc_current_state = (mc_state_t) xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack));
72 /* If there are transitions to execute and the maximun depth has not been reached
73 then perform one step of the exploration algorithm */
74 if(xbt_setset_set_size(mc_current_state->interleave) > 0 && xbt_fifo_size(mc_stack) < MAX_DEPTH){
76 DEBUG4("Exploration detph=%d (state=%p)(%d interleave) (%d enabled)", xbt_fifo_size(mc_stack),
77 mc_current_state, xbt_setset_set_size(mc_current_state->interleave),
78 xbt_setset_set_size(mc_current_state->enabled_transitions));
80 /* Update statistics */
81 mc_stats->visited_states++;
82 mc_stats->executed_transitions++;
84 /* Choose a transition to execute from the interleave set of the current
85 state, and create the data structures for the new expanded state in the
88 trans = xbt_setset_set_extract(mc_current_state->interleave);
90 /* Add the transition in the done set of the current state */
91 xbt_setset_set_insert(mc_current_state->done, trans);
93 next_state = MC_state_new();
94 xbt_fifo_unshift(mc_stack, next_state);
96 /* Set it as the executed transition of the current state */
97 mc_current_state->executed_transition = trans;
100 /* Execute the selected transition by scheduling it's associated process.
101 Then schedule every process that got ready to run due to the execution
103 DEBUG1("Executing transition %s", trans->name);
104 SIMIX_process_schedule(trans->process);
105 MC_execute_surf_actions(); /* Do surf's related black magic */
106 MC_schedule_enabled_processes();
108 /* Calculate the enabled transitions set of the next state */
111 xbt_setset_foreach(mc_current_state->transitions, cursor, trans_tmp){
112 if(trans_tmp->process != trans->process){
113 xbt_setset_set_insert(next_state->transitions, trans_tmp);
117 MC_trans_compute_enabled(next_state->enabled_transitions, next_state->transitions);
119 /* Choose one transition to interleave from the enabled transition set */
120 trans = xbt_setset_set_choose(next_state->enabled_transitions);
122 DEBUG1("Choosing process %s for next interleave", trans->process->name);
123 xbt_setset_foreach(next_state->enabled_transitions, cursor, trans_tmp){
124 if(trans_tmp->process == trans->process)
125 xbt_setset_set_insert(next_state->interleave, trans_tmp);
130 /* Update Statistics */
131 mc_stats->state_size += xbt_setset_set_size(next_state->enabled_transitions);
133 /* Let's loop again */
135 /* The interleave set is empty or the maximum depth is reached, let's back-track */
137 DEBUG0("There are no more transitions to interleave.");
140 /* Check for deadlocks */
141 xbt_setset_substract(mc_current_state->transitions, mc_current_state->done);
142 if(xbt_setset_set_size(mc_current_state->transitions) > 0){
143 INFO0("**************************");
144 INFO0("*** DEAD-LOCK DETECTED ***");
145 INFO0("**************************");
146 INFO0("Locked transitions:");
147 xbt_setset_foreach(mc_current_state->transitions, cursor, trans){
148 INFO1("%s", trans->name);
151 INFO0("Counter-example execution trace:");
152 MC_dump_stack(mc_stack);
154 MC_print_statistics(mc_stats);
158 mc_transition_t q = NULL;
159 xbt_fifo_item_t item = NULL;
160 mc_state_t state = NULL;
162 //MC_show_stack(mc_stack);
164 /* Trash the current state, no longer needed */
166 xbt_fifo_shift(mc_stack);
167 MC_state_delete(mc_current_state);
169 /* Traverse the stack backwards until a state with a non empty interleave
170 set is found, deleting all the states that have it empty in the way.
171 For each deleted state, check if the transition that has generated it
172 (from it's predecesor state), depends on any other previous transition
173 executed before it. If it does then add it to the interleave set of the
174 state that executed that previous transition. */
175 while((mc_current_state = xbt_fifo_shift(mc_stack)) != NULL){
176 q = mc_current_state->executed_transition;
177 xbt_fifo_foreach(mc_stack, item, state, mc_state_t){
178 if(MC_transition_depend(q, state->executed_transition)){
179 DEBUG3("Dependence found at state %p (%p,%p)", state, state->executed_transition, q);
180 xbt_setset_foreach(state->enabled_transitions, cursor, trans){
181 if((trans->process == q->process) && !xbt_setset_set_belongs(state->done, trans)){
182 DEBUG2("Unexplored interleaving found at state %p (%p)", state, trans);
184 xbt_setset_foreach(state->enabled_transitions, cursor, trans){
185 if(trans->process == q->process)
186 xbt_setset_set_insert(state->interleave, trans);
188 /* FIXME: hack to make it work*/
197 if(xbt_setset_set_size(mc_current_state->interleave) > 0){
198 /* We found a back-tracking point, let's loop */
199 xbt_fifo_unshift(mc_stack, mc_current_state);
200 DEBUG1("Back-tracking to depth %d", xbt_fifo_size(mc_stack));
205 MC_state_delete(mc_current_state);
210 DEBUG0("We are done");
211 /* We are done, show the statistics and return */
212 MC_print_statistics(mc_stats);