#include "common.h"
#include "clockvector.h"
#include "cyclegraph.h"
+#include "promise.h"
#define INITIAL_THREAD_ID 0
/* 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()),
- thread_map(new std::map<int, Thread *>),
- obj_map(new std::map<const void *, action_list_t>()),
- obj_thrd_map(new std::map<void *, std::vector<action_list_t> >()),
+ thread_map(new HashTable<int, Thread *, int>()),
+ obj_map(new HashTable<const void *, action_list_t, uintptr_t, 4>()),
+ obj_thrd_map(new HashTable<void *, std::vector<action_list_t>, uintptr_t, 4 >()),
+ promises(new std::vector<Promise *>()),
thrd_last_action(new std::vector<ModelAction *>(1)),
node_stack(new NodeStack()),
next_backtrack(NULL),
- cyclegraph(new CycleGraph())
+ cyclegraph(new CycleGraph()),
+ failed_promise(false)
{
}
/** @brief Destructor */
ModelChecker::~ModelChecker()
{
- std::map<int, Thread *>::iterator it;
+ /* std::map<int, Thread *>::iterator it;
for (it = thread_map->begin(); it != thread_map->end(); it++)
- delete (*it).second;
+ delete (*it).second;*/
delete thread_map;
delete obj_thrd_map;
used_sequence_numbers = 0;
nextThread = 0;
next_backtrack = NULL;
+ failed_promise = false;
snapshotObject->backTrackBeforeStep(0);
}
Thread *t;
if (nextThread == THREAD_ID_T_NONE)
return NULL;
- t = (*thread_map)[id_to_int(nextThread)];
+ t = thread_map->get(id_to_int(nextThread));
ASSERT(t != NULL);
*/
thread_id_t ModelChecker::get_next_replay_thread()
{
- ModelAction *next;
thread_id_t tid;
/* Have we completed exploring the preselected path? */
return THREAD_ID_T_NONE;
/* Else, we are trying to replay an execution */
- next = node_stack->get_next()->get_action();
+ ModelAction * next = node_stack->get_next()->get_action();
if (next == diverge) {
Node *nextnode = next->get_node();
/* Reached divergence point */
- if (nextnode->increment_read_from()) {
- /* The next node will read from a different value */
+ if (nextnode->increment_promises()) {
+ /* The next node will try to satisfy a different set of promises. */
+ tid = next->get_tid();
+ node_stack->pop_restofstack(2);
+ } else if (nextnode->increment_read_from()) {
+ /* The next node will read from a different value. */
+ tid = next->get_tid();
+ node_stack->pop_restofstack(2);
+ } else if (nextnode->increment_future_values()) {
+ /* The next node will try to read from a different future value. */
tid = next->get_tid();
node_stack->pop_restofstack(2);
} else {
return NULL;
}
/* linear search: from most recent to oldest */
- action_list_t *list = &(*obj_map)[act->get_location()];
+ action_list_t *list = obj_map->ensureptr(act->get_location());
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *prev = *rit;
}
}
+/**
+ * Returns last backtracking point. The model checker will explore a different
+ * path for this point in the next execution.
+ * @return The ModelAction at which the next execution should diverge.
+ */
ModelAction * ModelChecker::get_next_backtrack()
{
ModelAction *next = next_backtrack;
void ModelChecker::check_current_action(void)
{
ModelAction *curr = this->current_action;
- ModelAction *tmp;
- current_action = NULL;
+ bool already_added = false;
+ this->current_action = NULL;
if (!curr) {
DEBUG("trying to push NULL action...\n");
return;
}
- if (curr->is_rmw()) {
- //We have a RMW action
- process_rmw(curr);
- //Force the current thread to continue since the RMW should be atomic
- nextThread = thread_current()->get_id();
+ if (curr->is_rmwc()||curr->is_rmw()) {
+ ModelAction *tmp=process_rmw(curr);
+ already_added = true;
delete curr;
- return;
- }
-
- tmp = node_stack->explore_action(curr);
- if (tmp) {
- /* Discard duplicate ModelAction; use action from NodeStack */
- delete curr;
- curr = tmp;
+ curr=tmp;
} else {
- /*
- * Perform one-time actions when pushing new ModelAction onto
- * NodeStack
- */
- curr->create_cv(get_parent_action(curr->get_tid()));
- /* Build may_read_from set */
- if (curr->is_read())
- build_reads_from_past(curr);
+ ModelAction * tmp = node_stack->explore_action(curr);
+ if (tmp) {
+ /* Discard duplicate ModelAction; use action from NodeStack */
+ /* First restore type and order in case of RMW operation */
+ if (curr->is_rmwr())
+ tmp->copy_typeandorder(curr);
+ delete curr;
+ curr = tmp;
+ } else {
+ /*
+ * Perform one-time actions when pushing new ModelAction onto
+ * NodeStack
+ */
+ curr->create_cv(get_parent_action(curr->get_tid()));
+ /* Build may_read_from set */
+ if (curr->is_read())
+ build_reads_from_past(curr);
+ if (curr->is_write())
+ compute_promises(curr);
+ }
}
/* Assign 'creation' parent */
th->set_creation(curr);
}
- /* Is there a better interface for setting the next thread rather
- than this field/convoluted approach? Perhaps like just returning
- it or something? */
-
- nextThread = get_next_replay_thread();
-
- Node *currnode = curr->get_node();
- Node *parnode = currnode->get_parent();
-
- if (!parnode->backtrack_empty()||!currnode->readsfrom_empty())
- if (!next_backtrack || *curr > *next_backtrack)
- next_backtrack = curr;
-
- set_backtracking(curr);
+ /* Deal with new thread */
+ if (curr->get_type() == THREAD_START) {
+ check_promises(NULL, curr->get_cv());
+ }
/* Assign reads_from values */
- /* TODO: perform release/acquire synchronization here; include
- * reads_from as ModelAction member? */
Thread *th = get_thread(curr->get_tid());
uint64_t value = VALUE_NONE;
if (curr->is_read()) {
const ModelAction *reads_from = curr->get_node()->get_read_from();
- value = reads_from->get_value();
- /* Assign reads_from, perform release/acquire synchronization */
- curr->read_from(reads_from);
- r_modification_order(curr,reads_from);
+ if (reads_from!=NULL) {
+ value = reads_from->get_value();
+ /* Assign reads_from, perform release/acquire synchronization */
+ curr->read_from(reads_from);
+ r_modification_order(curr,reads_from);
+ } else {
+ /* Read from future value */
+ value = curr->get_node()->get_future_value();
+ curr->read_from(NULL);
+ Promise * valuepromise=new Promise(curr, value);
+ promises->push_back(valuepromise);
+ }
} else if (curr->is_write()) {
w_modification_order(curr);
+ resolve_promises(curr);
}
th->set_return_value(value);
- /* Add action to list last. */
- add_action_to_lists(curr);
+ /* Add action to list. */
+ if (!already_added)
+ add_action_to_lists(curr);
+
+ /* Is there a better interface for setting the next thread rather
+ than this field/convoluted approach? Perhaps like just returning
+ it or something? */
+
+ /* Do not split atomic actions. */
+ if (curr->is_rmwr()) {
+ nextThread = thread_current()->get_id();
+ } else {
+ nextThread = get_next_replay_thread();
+ }
+
+ Node *currnode = curr->get_node();
+ Node *parnode = currnode->get_parent();
+
+ if (!parnode->backtrack_empty()||!currnode->readsfrom_empty()||!currnode->futurevalues_empty()||!currnode->promises_empty())
+ if (!next_backtrack || *curr > *next_backtrack)
+ next_backtrack = curr;
+
+ set_backtracking(curr);
}
+/** @returns whether the current trace is feasible. */
bool ModelChecker::isfeasible() {
- return !cyclegraph->checkForCycles();
+ return !cyclegraph->checkForCycles() && !failed_promise;
}
-/** Process a RMW by converting previous read into a RMW. */
-void ModelChecker::process_rmw(ModelAction * act) {
+/** Close out a RMWR by converting previous RMWR into a RMW or READ. */
+ModelAction * ModelChecker::process_rmw(ModelAction * act) {
int tid = id_to_int(act->get_tid());
- std::vector<action_list_t> *vec = &(*obj_thrd_map)[act->get_location()];
- ASSERT(tid < (int) vec->size());
- ModelAction *lastread=(*vec)[tid].back();
- lastread->upgrade_rmw(act);
+ ModelAction *lastread=get_last_action(tid);
+ lastread->process_rmw(act);
+ if (act->is_rmw())
+ cyclegraph->addRMWEdge(lastread, lastread->get_reads_from());
+ return lastread;
}
+/**
+ * Updates the cyclegraph with the constraints imposed from the current read.
+ * @param curr The current action. Must be a read.
+ * @param rf The action that curr reads from. Must be a write.
+ */
void ModelChecker::r_modification_order(ModelAction * curr, const ModelAction *rf) {
- std::vector<action_list_t> *thrd_lists = &(*obj_thrd_map)[curr->get_location()];
+ std::vector<action_list_t> *thrd_lists = obj_thrd_map->ensureptr(curr->get_location());
unsigned int i;
ASSERT(curr->is_read());
}
}
+/**
+ * Updates the cyclegraph with the constraints imposed from the current write.
+ * @param curr The current action. Must be a write.
+ */
void ModelChecker::w_modification_order(ModelAction * curr) {
- std::vector<action_list_t> *thrd_lists = &(*obj_thrd_map)[curr->get_location()];
+ std::vector<action_list_t> *thrd_lists = obj_thrd_map->ensureptr(curr->get_location());
unsigned int i;
ASSERT(curr->is_write());
} else
cyclegraph->addEdge(curr, act);
break;
+ } else {
+ if (act->is_read()&&!act->is_synchronizing(curr)&&!act->same_thread(curr)) {
+ /* We have an action that:
+ (1) did not happen before us
+ (2) is a read and we are a write
+ (3) cannot synchronize with us
+ (4) is in a different thread
+ =>
+ that read could potentially read from our write.
+ */
+
+ if (act->get_node()->add_future_value(curr->get_value())&&
+ (!next_backtrack || *act > * next_backtrack))
+ next_backtrack = act;
+ }
}
}
}
int tid = id_to_int(act->get_tid());
action_trace->push_back(act);
- (*obj_map)[act->get_location()].push_back(act);
+ obj_map->ensureptr(act->get_location())->push_back(act);
- std::vector<action_list_t> *vec = &(*obj_thrd_map)[act->get_location()];
+ std::vector<action_list_t> *vec = obj_thrd_map->ensureptr(act->get_location());
if (tid >= (int)vec->size())
vec->resize(next_thread_id);
(*vec)[tid].push_back(act);
*/
ModelAction * ModelChecker::get_last_seq_cst(const void *location)
{
- action_list_t *list = &(*obj_map)[location];
+ action_list_t *list = obj_map->ensureptr(location);
/* Find: max({i in dom(S) | seq_cst(t_i) && isWrite(t_i) && samevar(t_i, t)}) */
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++)
return parent;
}
+/**
+ * Returns the clock vector for a given thread.
+ * @param tid The thread whose clock vector we want
+ * @return Desired clock vector
+ */
ClockVector * ModelChecker::get_cv(thread_id_t tid) {
return get_parent_action(tid)->get_cv();
}
+
+/** Resolve promises. */
+
+void ModelChecker::resolve_promises(ModelAction *write) {
+ for(unsigned int i=0;i<promises->size();i++) {
+ Promise * promise=(*promises)[i];
+ if (write->get_node()->get_promise(i)) {
+ ModelAction * read=promise->get_action();
+ read->read_from(write);
+ r_modification_order(read, write);
+ }
+ }
+}
+
+void ModelChecker::compute_promises(ModelAction *curr) {
+ for(unsigned int i=0;i<promises->size();i++) {
+ Promise * promise=(*promises)[i];
+ const ModelAction * act=promise->get_action();
+ if (!act->happens_before(curr)&&
+ act->is_read()&&
+ !act->is_synchronizing(curr)&&
+ !act->same_thread(curr)&&
+ promise->get_value()==curr->get_value()) {
+ curr->get_node()->set_promise(i);
+ }
+ }
+}
+
+/** Checks promises in response to change in ClockVector Threads. */
+
+void ModelChecker::check_promises(ClockVector *old_cv, ClockVector * merge_cv) {
+ for(unsigned int i=0;i<promises->size();i++) {
+ Promise * promise=(*promises)[i];
+ const ModelAction * act=promise->get_action();
+ if ((old_cv==NULL||!old_cv->synchronized_since(act))&&
+ merge_cv->synchronized_since(act)) {
+ //This thread is no longer able to send values back to satisfy the promise
+ int num_synchronized_threads=promise->increment_threads();
+ if (num_synchronized_threads==model->get_num_threads()) {
+ //Promise has failed
+ failed_promise = true;
+ return;
+ }
+ }
+ }
+}
+
/**
* Build up an initial set of all past writes that this 'read' action may read
* from. This set is determined by the clock vector's "happens before"
*/
void ModelChecker::build_reads_from_past(ModelAction *curr)
{
- std::vector<action_list_t> *thrd_lists = &(*obj_thrd_map)[curr->get_location()];
+ std::vector<action_list_t> *thrd_lists = obj_thrd_map->ensureptr(curr->get_location());
unsigned int i;
ASSERT(curr->is_read());
action_list_t::reverse_iterator rit;
for (rit = list->rbegin(); rit != list->rend(); rit++) {
ModelAction *act = *rit;
-
+
/* Only consider 'write' actions */
if (!act->is_write())
continue;
}
if (!initialized) {
- /* TODO: need a more informative way of reporting errors */
+ /** @todo Need a more informative way of reporting errors. */
printf("ERROR: may read from uninitialized atomic\n");
}
-
+
if (DBG_ENABLED() || !initialized) {
printf("Reached read action:\n");
curr->print();
curr->get_node()->print_may_read_from();
printf("End printing may_read_from\n");
}
-
+
ASSERT(initialized);
}
int ModelChecker::add_thread(Thread *t)
{
- (*thread_map)[id_to_int(t->get_id())] = t;
+ thread_map->put(id_to_int(t->get_id()), t);
scheduler->add_thread(t);
return 0;
}
*/
int ModelChecker::switch_to_master(ModelAction *act)
{
- Thread *old;
-
DBG();
- old = thread_current();
+ Thread * old = thread_current();
set_current_action(act);
old->set_state(THREAD_READY);
return Thread::swap(old, get_system_context());
projects / c11tester.git / blobdiff