#include <stdio.h>
#include "model.h"
+#include "action.h"
+#include "nodestack.h"
#include "schedule.h"
+#include "snapshot-interface.h"
+#undef DEBUG
#include "common.h"
+#define INITIAL_THREAD_ID 0
+
ModelChecker *model;
ModelChecker::ModelChecker()
-{
- /* First thread created (system_thread) will have id 1 */
- this->used_thread_id = 0;
+ :
/* Initialize default scheduler */
- this->scheduler = new Scheduler();
+ scheduler(new Scheduler()),
+ /* First thread created will have id INITIAL_THREAD_ID */
+ next_thread_id(INITIAL_THREAD_ID),
+ used_sequence_numbers(0),
+
+ num_executions(0),
+ current_action(NULL),
+ diverge(NULL),
+ nextThread(THREAD_ID_T_NONE),
+ action_trace(new action_list_t()),
+ node_stack(new NodeStack()),
+ next_backtrack(NULL)
+{
+}
- num_executions = 0;
- this->current_action = NULL;
- this->exploring = NULL;
- this->nextThread = THREAD_ID_T_NONE;
+ModelChecker::~ModelChecker()
+{
+ std::map<int, class Thread *, std::less< int >, MyAlloc< std::pair< int, class Thread * > > >::iterator it;
+ for (it = thread_map.begin(); it != thread_map.end(); it++)
+ delete (*it).second;
+ thread_map.clear();
- rootNode = new TreeNode(NULL);
- currentNode = rootNode;
- action_trace = new action_list_t();
+ delete action_trace;
+
+ delete node_stack;
+ delete scheduler;
}
-ModelChecker::~ModelChecker()
+void ModelChecker::reset_to_initial_state()
{
+ DEBUG("+++ Resetting to initial state +++\n");
+ std::map<int, class Thread *, std::less< int >, MyAlloc< std::pair< int, class Thread * > > >::iterator it;
+ for (it = thread_map.begin(); it != thread_map.end(); it++)
+ delete (*it).second;
+ thread_map.clear();
delete action_trace;
- delete this->scheduler;
- delete rootNode;
+ action_trace = new action_list_t();
+ node_stack->reset_execution();
+ current_action = NULL;
+ next_thread_id = INITIAL_THREAD_ID;
+ used_sequence_numbers = 0;
+ nextThread = 0;
+ next_backtrack = NULL;
+ /* scheduler reset ? */
}
-int ModelChecker::get_next_id()
+thread_id_t ModelChecker::get_next_id()
{
- return ++used_thread_id;
+ return next_thread_id++;
}
-void ModelChecker::add_system_thread(Thread *t)
+int ModelChecker::get_next_seq_num()
{
- this->system_thread = t;
+ return ++used_sequence_numbers;
}
Thread * ModelChecker::schedule_next_thread()
Thread *t;
if (nextThread == THREAD_ID_T_NONE)
return NULL;
- t = thread_map[nextThread];
- if (t == NULL)
- DEBUG("*** error: thread not in thread_map: id = %d\n", nextThread);
+ t = thread_map[id_to_int(nextThread)];
+
+ ASSERT(t != NULL);
+
return t;
}
ModelAction *next;
thread_id_t tid;
- next = exploring->get_state();
+ /* Have we completed exploring the preselected path? */
+ if (diverge == NULL)
+ return THREAD_ID_T_NONE;
- if (next == exploring->get_diverge()) {
- TreeNode *node = next->get_node();
+ /* Else, we are trying to replay an execution */
+ next = node_stack->get_next()->get_action();
- /* Reached divergence point; discard our current 'exploring' */
- DEBUG("*** Discard 'Backtrack' object ***\n");
- tid = node->getNextBacktrack();
- delete exploring;
- exploring = NULL;
+ if (next == diverge) {
+ Node *node = next->get_node();
+
+ /* Reached divergence point */
+ DEBUG("*** Divergence point ***\n");
+ tid = node->get_next_backtrack();
+ diverge = NULL;
} else {
tid = next->get_tid();
}
return tid;
}
-thread_id_t ModelChecker::advance_backtracking_state()
-{
- /* Have we completed exploring the preselected path? */
- if (exploring == NULL)
- return THREAD_ID_T_NONE;
-
- /* Else, we are trying to replay an execution */
- exploring->advance_state();
- if (exploring->get_state() == NULL)
- DEBUG("*** error: reached end of backtrack trace\n");
-
- return get_next_replay_thread();
-}
-
bool ModelChecker::next_execution()
{
+ DBG();
+
num_executions++;
- if ((exploring = model->get_next_backtrack()) == NULL)
+ print_summary();
+ if ((diverge = model->get_next_backtrack()) == NULL)
return false;
+
+ if (DBG_ENABLED()) {
+ printf("Next execution will diverge at:\n");
+ diverge->print();
+ }
+
model->reset_to_initial_state();
- nextThread = get_next_replay_thread();
return true;
}
ModelAction * ModelChecker::get_last_conflict(ModelAction *act)
{
- void *loc = act->get_location();
action_type type = act->get_type();
- thread_id_t id = act->get_tid();
switch (type) {
case THREAD_CREATE:
action_list_t::reverse_iterator rit;
for (rit = action_trace->rbegin(); rit != action_trace->rend(); rit++) {
ModelAction *prev = *rit;
- if (prev->get_location() != loc)
- continue;
- if (type == ATOMIC_READ && prev->get_type() != ATOMIC_WRITE)
- continue;
- /* Conflict from the same thread is not really a conflict */
- if (id == prev->get_tid())
- return NULL;
- return prev;
+ if (act->is_dependent(prev))
+ return prev;
}
return NULL;
}
void ModelChecker::set_backtracking(ModelAction *act)
{
ModelAction *prev;
- TreeNode *node;
+ Node *node;
+ Thread *t = get_thread(act->get_tid());
prev = get_last_conflict(act);
if (prev == NULL)
node = prev->get_node();
+ while (!node->is_enabled(t))
+ t = t->get_parent();
+
/* Check if this has been explored already */
- if (node->hasBeenExplored(act->get_tid()))
+ if (node->has_been_explored(t->get_id()))
return;
+
+ if (!next_backtrack || *prev > *next_backtrack)
+ next_backtrack = prev;
+
/* If this is a new backtracking point, mark the tree */
- if (node->setBacktrack(act->get_tid()) != 0)
+ if (!node->set_backtrack(t->get_id()))
return;
+ DEBUG("Setting backtrack: conflict = %d, instead tid = %d\n",
+ prev->get_tid(), t->get_id());
+ if (DBG_ENABLED()) {
+ prev->print();
+ act->print();
+ }
+}
- printf("Setting backtrack: conflict = %d, instead tid = %d\n",
- prev->get_tid(), act->get_tid());
- prev->print();
- act->print();
-
- Backtrack *back = new Backtrack(prev, action_trace);
- backtrack_list.push_back(back);
+ModelAction * ModelChecker::get_next_backtrack()
+{
+ ModelAction *next = next_backtrack;
+ next_backtrack = NULL;
+ return next;
}
void ModelChecker::check_current_action(void)
{
- ModelAction *next = this->current_action;
+ Node *currnode;
- if (!next) {
+ ModelAction *curr = this->current_action;
+ current_action = NULL;
+ if (!curr) {
DEBUG("trying to push NULL action...\n");
return;
}
- nextThread = advance_backtracking_state();
- next->set_node(currentNode);
- set_backtracking(next);
- currentNode = currentNode->exploreChild(next->get_tid());
- this->action_trace->push_back(next);
+
+ curr = node_stack->explore_action(curr);
+ nextThread = get_next_replay_thread();
+
+ currnode = curr->get_node();
+
+ if (!currnode->backtrack_empty())
+ if (!next_backtrack || *curr > *next_backtrack)
+ next_backtrack = curr;
+
+ set_backtracking(curr);
+ this->action_trace->push_back(curr);
}
-void ModelChecker::print_trace(void)
+void ModelChecker::print_summary(void)
{
- action_list_t::iterator it;
-
printf("\n");
- printf("---------------------------------------------------------------------\n");
printf("Number of executions: %d\n", num_executions);
- printf("Total nodes created: %d\n\n", TreeNode::getTotalNodes());
+ printf("Total nodes created: %d\n", Node::get_total_nodes());
scheduler->print();
- printf("\nTrace:\n\n");
+ print_list(action_trace);
+ printf("\n");
+}
+
+void ModelChecker::print_list(action_list_t *list)
+{
+ action_list_t::iterator it;
+
+ printf("---------------------------------------------------------------------\n");
+ printf("Trace:\n");
- for (it = action_trace->begin(); it != action_trace->end(); it++) {
- DBG();
+ for (it = list->begin(); it != list->end(); it++) {
(*it)->print();
}
printf("---------------------------------------------------------------------\n");
int ModelChecker::add_thread(Thread *t)
{
- thread_map[t->get_id()] = t;
+ thread_map[id_to_int(t->get_id())] = t;
scheduler->add_thread(t);
return 0;
}
int ModelChecker::switch_to_master(ModelAction *act)
{
- Thread *old, *next;
+ Thread *old;
DBG();
old = thread_current();
set_current_action(act);
old->set_state(THREAD_READY);
- next = system_thread;
- return old->swap(next);
-}
-
-ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, int value)
-{
- Thread *t = thread_current();
- ModelAction *act = this;
-
- act->type = type;
- act->order = order;
- act->location = loc;
- act->tid = t->get_id();
- act->value = value;
-}
-
-void ModelAction::print(void)
-{
- const char *type_str;
- switch (this->type) {
- case THREAD_CREATE:
- type_str = "thread create";
- break;
- case THREAD_YIELD:
- type_str = "thread yield";
- break;
- case THREAD_JOIN:
- type_str = "thread join";
- break;
- case ATOMIC_READ:
- type_str = "atomic read";
- break;
- case ATOMIC_WRITE:
- type_str = "atomic write";
- break;
- default:
- type_str = "unknown type";
- }
-
- printf("Thread: %d\tAction: %s\tMO: %d\tLoc: %#014zx\tValue: %d\n", tid, type_str, order, (size_t)location, value);
+ return Thread::swap(old, get_system_context());
}