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 smx_process_t process;
20 /* Create the initial state and push it into the exploration stack */
22 initial_state = MC_state_new();
23 xbt_fifo_unshift(mc_stack, initial_state);
26 DEBUG0("**************************************************");
27 DEBUG0("Initial state");
29 /* Wait for requests (schedules processes) */
30 MC_wait_for_requests();
33 /* Get an enabled process and insert it in the interleave set of the initial state */
34 xbt_swag_foreach(process, simix_global->process_list){
35 if(SIMIX_process_is_enabled(process)){
36 MC_state_interleave_process(initial_state, process);
42 /* FIXME: Update Statistics
43 mc_stats->state_size +=
44 xbt_setset_set_size(initial_state->enabled_transitions); */
49 * \brief Perform the model-checking operation using a depth-first search exploration
50 * with Dynamic Partial Order Reductions
57 mc_state_t state = NULL, prev_state = NULL, next_state = NULL;
58 smx_process_t process = NULL;
59 xbt_fifo_item_t item = NULL;
61 while (xbt_fifo_size(mc_stack) > 0) {
63 /* Get current state */
65 xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack));
67 DEBUG0("**************************************************");
68 DEBUG3("Exploration detph=%d (state=%p)(%u interleave)",
69 xbt_fifo_size(mc_stack), state,
70 MC_state_interleave_size(state));
72 /* Update statistics */
73 mc_stats->visited_states++;
75 /* If there are processes to interleave and the maximum depth has not been reached
76 then perform one step of the exploration algorithm */
77 if (xbt_fifo_size(mc_stack) < MAX_DEPTH &&
78 (req = MC_state_get_request(state, &value))) {
80 /* Debug information */
81 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
82 req_str = MC_request_to_string(req);
83 DEBUG2("Execute: %s (%u)", req_str, value);
87 MC_state_set_executed_request(state, req, value);
88 mc_stats->executed_transitions++;
90 /* Answer the request */
91 SIMIX_request_pre(req, value); /* After this call req is no longer usefull */
93 /* Wait for requests (schedules processes) */
94 MC_wait_for_requests();
96 /* Create the new expanded state */
98 next_state = MC_state_new();
99 xbt_fifo_unshift(mc_stack, next_state);
102 /* Get an enabled process and insert it in the interleave set of the next state */
103 xbt_swag_foreach(process, simix_global->process_list){
104 if(SIMIX_process_is_enabled(process)){
105 MC_state_interleave_process(next_state, process);
111 /* FIXME: Update Statistics
112 mc_stats->state_size +=
113 xbt_setset_set_size(next_state->enabled_transitions);*/
115 /* Let's loop again */
117 /* The interleave set is empty or the maximum depth is reached, let's back-track */
119 DEBUG0("There are no more processes to interleave.");
121 /* Trash the current state, no longer needed */
123 xbt_fifo_shift(mc_stack);
124 MC_state_delete(state);
127 /* Check for deadlocks */
128 if(MC_deadlock_check()){
129 MC_show_deadlock(NULL);
134 /* Traverse the stack backwards until a state with a non empty interleave
135 set is found, deleting all the states that have it empty in the way.
136 For each deleted state, check if the request that has generated it
137 (from it's predecesor state), depends on any other previous request
138 executed before it. If it does then add it to the interleave set of the
139 state that executed that previous request. */
140 while ((state = xbt_fifo_shift(mc_stack)) != NULL) {
141 req = MC_state_get_executed_request(state, &value);
142 xbt_fifo_foreach(mc_stack, item, prev_state, mc_state_t) {
143 if(MC_request_depend(req, MC_state_get_executed_request(prev_state, &value))){
144 if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
145 DEBUG0("Dependent Transitions:");
146 req_str = MC_request_to_string(MC_state_get_executed_request(prev_state, &value));
147 DEBUG2("%s (state=%p)", req_str, prev_state);
149 req_str = MC_request_to_string(req);
150 DEBUG2("%s (state=%p)", req_str, state);
154 if(!MC_state_process_is_done(prev_state, req->issuer))
155 MC_state_interleave_process(prev_state, req->issuer);
157 DEBUG1("Process %p is in done set", req->issuer);
162 if (MC_state_interleave_size(state)) {
163 /* We found a back-tracking point, let's loop */
164 xbt_fifo_unshift(mc_stack, state);
165 DEBUG1("Back-tracking to depth %d", xbt_fifo_size(mc_stack));
170 MC_state_delete(state);