/* NDFS dfs_blue */
void
ndfs_blue (run_t *run, wctx_t *ctx)
{
alg_local_t *loc = ctx->local;
transition_info_t ti = GB_NO_TRANSITION;
ndfs_blue_handle (ctx, ctx->initial, &ti, 0);
ctx->counters->trans = 0; //reset trans count
while ( !run_is_stopped(run) ) {
raw_data_t state_data = dfs_stack_top (loc->stack);
if (NULL != state_data) {
state_info_deserialize (ctx->state, state_data);
nndfs_color_t color = nn_get_color (&loc->color_map, ctx->state->ref);
if ( nn_color_eq(color, NNWHITE) ) {
if (all_red)
bitvector_set ( &loc->stackbits, ctx->counters->level_cur );
nn_set_color (&loc->color_map, ctx->state->ref, NNCYAN);
ndfs_explore_state_blue (ctx);
} else {
if ( all_red && ctx->counters->level_cur != 0 &&
!nn_color_eq(color, NNPINK) )
bitvector_unset ( &loc->stackbits, ctx->counters->level_cur - 1);
dfs_stack_pop (loc->stack);
}
} else { //backtrack
if (0 == dfs_stack_nframes (loc->stack))
return;
dfs_stack_leave (loc->stack);
ctx->counters->level_cur--;
state_data = dfs_stack_top (loc->stack);
state_info_deserialize (loc->seed, state_data);
if ( all_red && bitvector_is_set(&loc->stackbits, ctx->counters->level_cur) ) {
/* exit if backtrack hits seed, leave stack the way it was */
nn_set_color (&loc->color_map, loc->seed->ref, NNPINK);
loc->counters.allred++;
if ( GBbuchiIsAccepting(ctx->model, state_info_state(loc->seed)) )
loc->counters.accepting++;
} else if ( GBbuchiIsAccepting(ctx->model, state_info_state(loc->seed)) ) {
/* call red DFS for accepting states */
ndfs_red (ctx, loc->seed->ref);
nn_set_color (&loc->color_map, loc->seed->ref, NNPINK);
} else {
if (all_red && ctx->counters->level_cur > 0)
bitvector_unset (&loc->stackbits, ctx->counters->level_cur - 1);
nn_set_color (&loc->color_map, loc->seed->ref, NNBLUE);
}
dfs_stack_pop (loc->stack);
}
}
}
/**
* update lowlink for the parent (top of previous stackframe in search_stack)
*/
static void
update_parent (wctx_t *ctx, uint32_t low_child)
{
alg_local_t *loc = ctx->local;
raw_data_t state_data;
// the initial state has no parent
if (dfs_stack_nframes (loc->search_stack) == 0)
return;
// store the top of the previous stackframe to loc->target
state_data = dfs_stack_peek_top (loc->search_stack, 1);
state_info_deserialize (loc->target, state_data);
if (loc->target_tarjan.lowlink > low_child) {
Debug ("Updating %zu from low %d --> %d", loc->target->ref,
loc->target_tarjan.lowlink, low_child);
loc->target_tarjan.lowlink = low_child;
state_info_serialize (loc->target, state_data);
}
}
void
tarjan_run (run_t *run, wctx_t *ctx)
{
alg_local_t *loc = ctx->local;
raw_data_t *addr;
raw_data_t state_data;
bool on_stack;
hash32_t hash;
#ifdef HAVE_PROFILER
Warning (info, "Using the profiler");
ProfilerStart ("tarjan.perf");
#endif
#ifdef SEARCH_COMPLETE_GRAPH
int init_state = dlopen_get_worker_initial_state (ctx->id, W);
int inits = 0;
// loop until every state of the graph has been visited
while ( 1 )
{
inits ++;
// use loc->target as a dummy for the initial state
loc->target->ref = init_state;
#endif
tarjan_init (ctx);
// continue until we are done exploring the graph
while ( !run_is_stopped (run) ) {
state_data = dfs_stack_top (loc->search_stack);
if (state_data != NULL) {
// there is a state on the current stackframe ==> explore it
state_info_deserialize (ctx->state, state_data);
// pop the state and continue if it is part of a completed SCC
if (state_store_has_color (ctx->state->ref, SCC_STATE, 0)) {
dfs_stack_pop (loc->search_stack);
continue;
}
hash = ref_hash (ctx->state->ref);
on_stack = fset_find (loc->visited_states, &hash,
&ctx->state->ref, (void **) &addr, true);
if (!on_stack) {
// unseen state ==> initialize and explore
HREassert (loc->cnt.tarjan_counter != UINT32_MAX);
loc->cnt.tarjan_counter ++;
loc->state_tarjan.index = loc->cnt.tarjan_counter;
loc->state_tarjan.lowlink = loc->cnt.tarjan_counter;
// point visited_states data to stack
*addr = state_data;
explore_state (ctx);
state_info_serialize (ctx->state, state_data);
} else {
// previously visited state ==> update parent
// NB: state is on tarjan_stack
state_info_deserialize (ctx->state, *addr);
update_parent (ctx, loc->state_tarjan.lowlink);
dfs_stack_pop (loc->search_stack);
}
} else {
// there is no state on the current stackframe ==> backtrack
// we are done if we backtrack from the initial state
if (0 == dfs_stack_nframes (loc->search_stack))
break;
// leave the stackframe
dfs_stack_leave (loc->search_stack);
ctx->counters->level_cur--;
// retrieve the parent state from search_stack (to be removed)
state_data = dfs_stack_top (loc->search_stack);
state_info_deserialize (ctx->state, state_data);
Debug ("Backtracking %zu (%d, %d)", ctx->state->ref,
loc->state_tarjan.index, loc->state_tarjan.lowlink);
if (loc->state_tarjan.index == loc->state_tarjan.lowlink) {
// index == lowlink ==> root of the SCC ==> report the SCC
pop_scc (ctx, ctx->state->ref, loc->state_tarjan.lowlink);
} else {
// lowlink < index ==> LIVE SCC ==> move to tarjan_stack
move_tarjan (ctx, ctx->state, state_data);
update_parent (ctx, loc->state_tarjan.lowlink);
}
dfs_stack_pop (loc->search_stack);
}
}
#ifdef SEARCH_COMPLETE_GRAPH
init_state = dlopen_get_new_initial_state (init_state);
if (init_state == -1) {
Warning(info, "Number of inits : %d", inits);
break;
}
}
#endif
#ifdef HAVE_PROFILER
Warning(info, "Done profiling");
ProfilerStop();
#endif
if (!run_is_stopped(run) && dfs_stack_size(loc->tarjan_stack) != 0)
Warning (info, "Tarjan stack not empty: %zu (stack %zu)",
dfs_stack_size(loc->tarjan_stack),
dfs_stack_size(loc->search_stack));
if (!run_is_stopped(run) && fset_count(loc->visited_states) != 0)
Warning (info, "Stack-set not empty: %zu",
fset_count(loc->visited_states));
}
/* ENDFS dfs_blue */
void
endfs_blue (run_t *run, wctx_t *ctx)
{
HREassert (ecd, "CNDFS's correctness depends crucially on ECD");
alg_local_t *loc = ctx->local;
cndfs_alg_local_t *cloc = (cndfs_alg_local_t *) ctx->local;
transition_info_t ti = GB_NO_TRANSITION;
uint32_t global_color;
int accepting;
cloc->successors = NONEC;
endfs_handle_blue (ctx, ctx->initial, &ti, 0);
ctx->counters->trans = 0; //reset trans count
cloc->accepting_depth = 0;
alg_global_t *sm = ctx->global;
while ( !run_is_stopped(ctx->run) ) {
raw_data_t state_data = dfs_stack_top (loc->stack);
if (NULL != state_data) {
state_info_deserialize (ctx->state, state_data);
global_color = state_store_get_colors (ctx->state->ref);
if (global_color < CBLUE && !on_stack_accepting_up(ctx, &accepting)) {
if (global_color == CWHITE)
update_color (ctx, ctx->state->ref, CCYAN, 0);
if (all_red)
bitvector_set (&loc->stackbits, cur(ctx,REDALL));
bitvector_unset (&loc->stackbits, cur(ctx,INVOL));
endfs_explore_state_blue (ctx);
} else {
if ( all_red && ctx->counters->level_cur != 0 && global_color != CRED )
bitvector_unset (&loc->stackbits, pred(ctx,REDALL));
dfs_stack_pop (loc->stack);
}
} else { //backtrack
if (0 == dfs_stack_nframes(loc->stack))
break;
dfs_stack_leave (loc->stack);
ctx->counters->level_cur--;
/* call red DFS for accepting states */
state_data = dfs_stack_top (loc->stack);
state_info_deserialize (loc->seed, state_data);
if (check_cndfs_proviso(ctx)) {
reach_explore_all (ctx, loc->seed);
continue;
}
accepting = pins_state_is_accepting(ctx->model, state_info_state(loc->seed)) != 0;
/* Mark state GGREEN on backtrack */
update_color (ctx, loc->seed->ref, CBLUE, 1);
if ( all_red && bitvector_is_set(&loc->stackbits, cur(ctx,REDALL)) ) {
/* all successors are red */
//permute_trans (loc->permute, ctx->state, check, ctx);
set_all_red2 (ctx, loc->seed);
} else if ( accepting ) {
sm->work = loc->seed->ref;
endfs_red (ctx);
if (Strat_ENDFS == loc->strat)
endfs_handle_dangerous (ctx);
else
cndfs_handle_nonseed_accepting (ctx);
sm->work = SIZE_MAX;
} else if (all_red && ctx->counters->level_cur > 0 &&
state_store_get_colors (loc->seed->ref) != CRED) {
/* unset the all-red flag (only for non-initial nodes) */
bitvector_unset (&loc->stackbits, pred(ctx,REDALL));
}
accepting_down (ctx, loc->seed, accepting);
dfs_stack_pop (loc->stack);
}
}
HREassert (run_is_stopped(ctx->run) || fset_count(cloc->pink) == 0);
// if the recursive strategy uses global bits (global pruning)
// then do simple load balancing (only for the top-level strategy)
if ( Strat_ENDFS == loc->strat &&
run == run->shared->top_level &&
(Strat_LTLG & sm->rec->local->strat) ) {
endfs_lb (ctx);
}
if (global->exit_status == LTSMIN_EXIT_SUCCESS && ctx->id == 0) {
Warning(info," ");
Warning(info,"Empty product with LTL!");
Warning(info," ");
}
}
/* ENDFS dfs_red */
static void
endfs_red (wctx_t *ctx)
{
alg_local_t *loc = ctx->local;
cndfs_alg_local_t *cloc = (cndfs_alg_local_t *) ctx->local;
size_t seed_level = dfs_stack_nframes (loc->stack);
int accepting = 0;
int on_stack;
size_t count = fset_count(cloc->pink);
size_t *level;
while ( !run_is_stopped(ctx->run) ) {
raw_data_t state_data = dfs_stack_top (loc->stack);
if (NULL != state_data) {
state_info_deserialize (ctx->state, state_data);
// seed is only state on both cyan and pink stack
on_stack = ctx->state->ref == loc->seed->ref;
if (!on_stack) {
on_stack = fset_find (cloc->pink, NULL, &ctx->state->ref, (void**)&level, false);
HREassert (on_stack != FSET_FULL);
}
if (!on_stack && state_store_get_colors(ctx->state->ref) != CRED) {
on_stack_accepting_up (ctx, &accepting); //add to stack
bitvector_unset (&loc->stackbits, cur(ctx,INVOL));
dfs_stack_push (cloc->in_stack, state_data);
if ( Strat_CNDFS == loc->strat && ctx->state->ref != loc->seed->ref && accepting)
dfs_stack_push (cloc->out_stack, state_data);
endfs_explore_state_red (ctx);
} else {
if (seed_level == dfs_stack_nframes (loc->stack))
break;
dfs_stack_pop (loc->stack);
}
} else { //backtrack
dfs_stack_leave (loc->stack);
ctx->counters->level_cur--;
/* exit search if backtrack hits seed, leave stack the way it was */
if (seed_level == dfs_stack_nframes(loc->stack))
break;
state_data = dfs_stack_top (loc->stack);
state_info_deserialize (ctx->state, state_data);
if (check_cndfs_proviso(ctx)) {
reach_explore_all (ctx, ctx->state);
continue;
}
accepting = pins_state_is_accepting (ctx->model, state_info_state(ctx->state)) != 0;
accepting_down (ctx, ctx->state, accepting);
dfs_stack_pop (loc->stack);
}
}
if (!run_is_stopped(ctx->run)) {
HREassert (fset_count(cloc->pink) == count);
}
}