add support for pthread_mutex
[c11tester.git] / execution.cc
index e038961d211ca074c0b8deece5fe5fab7eccde51..887e2efa03df0f31832ff6ee260a1a8b1ed9794d 100644 (file)
@@ -17,6 +17,8 @@
 #include "threads-model.h"
 #include "bugmessage.h"
 
+#include <pthread.h>
+
 #define INITIAL_THREAD_ID      0
 
 /**
@@ -30,9 +32,11 @@ struct model_snapshot_members {
                next_backtrack(NULL),
                bugs(),
                failed_promise(false),
+               hard_failed_promise(false),
                too_many_reads(false),
                no_valid_reads(false),
                bad_synchronization(false),
+               bad_sc_read(false),
                asserted(false)
        { }
 
@@ -47,10 +51,12 @@ struct model_snapshot_members {
        ModelAction *next_backtrack;
        SnapVector<bug_message *> bugs;
        bool failed_promise;
+       bool hard_failed_promise;
        bool too_many_reads;
        bool no_valid_reads;
        /** @brief Incorrectly-ordered synchronization was made */
        bool bad_synchronization;
+       bool bad_sc_read;
        bool asserted;
 
        SNAPSHOTALLOC
@@ -58,15 +64,15 @@ struct model_snapshot_members {
 
 /** @brief Constructor */
 ModelExecution::ModelExecution(ModelChecker *m,
-               struct model_params *params,
+               const struct model_params *params,
                Scheduler *scheduler,
                NodeStack *node_stack) :
        model(m),
        params(params),
        scheduler(scheduler),
-       action_trace(new action_list_t()),
-       thread_map(),
-       obj_map(new HashTable<const void *, action_list_t *, uintptr_t, 4>()),
+       action_trace(),
+       thread_map(2), /* We'll always need at least 2 threads */
+       obj_map(),
        condvar_waiters_map(),
        obj_thrd_map(),
        promises(),
@@ -79,19 +85,17 @@ ModelExecution::ModelExecution(ModelChecker *m,
        mo_graph(new CycleGraph())
 {
        /* Initialize a model-checker thread, for special ModelActions */
-       model_thread = new Thread(get_next_id());
-       thread_map.put(id_to_int(model_thread->get_id()), model_thread);
+       model_thread = new Thread(get_next_id());       // L: Create model thread
+       add_thread(model_thread);                       // L: Add model thread to scheduler
        scheduler->register_engine(this);
+       node_stack->register_engine(this);
 }
 
 /** @brief Destructor */
 ModelExecution::~ModelExecution()
 {
        for (unsigned int i = 0; i < get_num_threads(); i++)
-               delete thread_map.get(i);
-
-       delete obj_map;
-       delete action_trace;
+               delete get_thread(int_to_id(i));
 
        for (unsigned int i = 0; i < promises.size(); i++)
                delete promises[i];
@@ -202,6 +206,13 @@ void ModelExecution::set_bad_synchronization()
        priv->bad_synchronization = true;
 }
 
+/** @brief Alert the model-checker that an incorrectly-ordered
+ * synchronization was made */
+void ModelExecution::set_bad_sc_read()
+{
+       priv->bad_sc_read = true;
+}
+
 bool ModelExecution::assert_bug(const char *msg)
 {
        priv->bugs.push_back(new bug_message(msg));
@@ -266,6 +277,28 @@ bool ModelExecution::is_deadlocked() const
        return blocking_threads;
 }
 
+/**
+ * @brief Check if we are yield-blocked
+ *
+ * A program can be "yield-blocked" if all threads are ready to execute a
+ * yield.
+ *
+ * @return True if the program is yield-blocked; false otherwise
+ */
+bool ModelExecution::is_yieldblocked() const
+{
+       if (!params->yieldblock)
+               return false;
+
+       for (unsigned int i = 0; i < get_num_threads(); i++) {
+               thread_id_t tid = int_to_id(i);
+               Thread *t = get_thread(tid);
+               if (t->get_pending() && t->get_pending()->is_yield())
+                       return true;
+       }
+       return false;
+}
+
 /**
  * Check if this is a complete execution. That is, have all thread completed
  * execution (rather than exiting because sleep sets have forced a redundant
@@ -275,6 +308,8 @@ bool ModelExecution::is_deadlocked() const
  */
 bool ModelExecution::is_complete_execution() const
 {
+       if (is_yieldblocked())
+               return false;
        for (unsigned int i = 0; i < get_num_threads(); i++)
                if (is_enabled(int_to_id(i)))
                        return false;
@@ -309,8 +344,8 @@ ModelAction * ModelExecution::get_last_fence_conflict(ModelAction *act) const
                return NULL;
 
        /* Skip past the release */
-       action_list_t *list = action_trace;
-       action_list_t::reverse_iterator rit;
+       const action_list_t *list = &action_trace;
+       action_list_t::const_reverse_iterator rit;
        for (rit = list->rbegin(); rit != list->rend(); rit++)
                if (*rit == last_release)
                        break;
@@ -368,17 +403,22 @@ ModelAction * ModelExecution::get_last_fence_conflict(ModelAction *act) const
 ModelAction * ModelExecution::get_last_conflict(ModelAction *act) const
 {
        switch (act->get_type()) {
-       /* case ATOMIC_FENCE: fences don't directly cause backtracking */
+       case ATOMIC_FENCE:
+               /* Only seq-cst fences can (directly) cause backtracking */
+               if (!act->is_seqcst())
+                       break;
        case ATOMIC_READ:
        case ATOMIC_WRITE:
        case ATOMIC_RMW: {
                ModelAction *ret = NULL;
 
                /* linear search: from most recent to oldest */
-               action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+               action_list_t *list = obj_map.get(act->get_location());
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        ModelAction *prev = *rit;
+                       if (prev == act)
+                               continue;
                        if (prev->could_synchronize_with(act)) {
                                ret = prev;
                                break;
@@ -397,7 +437,7 @@ ModelAction * ModelExecution::get_last_conflict(ModelAction *act) const
        case ATOMIC_LOCK:
        case ATOMIC_TRYLOCK: {
                /* linear search: from most recent to oldest */
-               action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+               action_list_t *list = obj_map.get(act->get_location());
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        ModelAction *prev = *rit;
@@ -408,7 +448,7 @@ ModelAction * ModelExecution::get_last_conflict(ModelAction *act) const
        }
        case ATOMIC_UNLOCK: {
                /* linear search: from most recent to oldest */
-               action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+               action_list_t *list = obj_map.get(act->get_location());
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        ModelAction *prev = *rit;
@@ -419,7 +459,7 @@ ModelAction * ModelExecution::get_last_conflict(ModelAction *act) const
        }
        case ATOMIC_WAIT: {
                /* linear search: from most recent to oldest */
-               action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+               action_list_t *list = obj_map.get(act->get_location());
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        ModelAction *prev = *rit;
@@ -434,7 +474,7 @@ ModelAction * ModelExecution::get_last_conflict(ModelAction *act) const
        case ATOMIC_NOTIFY_ALL:
        case ATOMIC_NOTIFY_ONE: {
                /* linear search: from most recent to oldest */
-               action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+               action_list_t *list = obj_map.get(act->get_location());
                action_list_t::reverse_iterator rit;
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        ModelAction *prev = *rit;
@@ -728,12 +768,13 @@ bool ModelExecution::process_mutex(ModelAction *curr)
 /**
  * @brief Check if the current pending promises allow a future value to be sent
  *
- * If one of the following is true:
- *  (a) there are no pending promises
- *  (b) the reader and writer do not cross any promises
- * Then, it is safe to pass a future value back now.
+ * It is unsafe to pass a future value back if there exists a pending promise Pr
+ * such that:
  *
- * Otherwise, we must save the pending future value until (a) or (b) is true
+ *    reader --exec-> Pr --exec-> writer
+ *
+ * If such Pr exists, we must save the pending future value until Pr is
+ * resolved.
  *
  * @param writer The operation which sends the future value. Must be a write.
  * @param reader The operation which will observe the value. Must be a read.
@@ -742,8 +783,6 @@ bool ModelExecution::process_mutex(ModelAction *curr)
 bool ModelExecution::promises_may_allow(const ModelAction *writer,
                const ModelAction *reader) const
 {
-       if (promises.empty())
-               return true;
        for (int i = promises.size() - 1; i >= 0; i--) {
                ModelAction *pr = promises[i]->get_reader(0);
                //reader is after promise...doesn't cross any promise
@@ -790,9 +829,10 @@ void ModelExecution::add_future_value(const ModelAction *writer, ModelAction *re
 /**
  * Process a write ModelAction
  * @param curr The ModelAction to process
+ * @param work The work queue, for adding fixup work
  * @return True if the mo_graph was updated or promises were resolved
  */
-bool ModelExecution::process_write(ModelAction *curr)
+bool ModelExecution::process_write(ModelAction *curr, work_queue_t *work)
 {
        /* Readers to which we may send our future value */
        ModelVector<ModelAction *> send_fv;
@@ -805,7 +845,7 @@ bool ModelExecution::process_write(ModelAction *curr)
 
        if (promise) {
                earliest_promise_reader = promise->get_reader(0);
-               updated_promises = resolve_promise(curr, promise);
+               updated_promises = resolve_promise(curr, promise, work);
        } else
                earliest_promise_reader = NULL;
 
@@ -856,7 +896,7 @@ bool ModelExecution::process_fence(ModelAction *curr)
         */
        bool updated = false;
        if (curr->is_acquire()) {
-               action_list_t *list = action_trace;
+               action_list_t *list = &action_trace;
                action_list_t::reverse_iterator rit;
                /* Find X : is_read(X) && X --sb-> curr */
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
@@ -909,6 +949,22 @@ bool ModelExecution::process_thread_action(ModelAction *curr)
                thrd_t *thrd = (thrd_t *)curr->get_location();
                struct thread_params *params = (struct thread_params *)curr->get_value();
                Thread *th = new Thread(get_next_id(), thrd, params->func, params->arg, get_thread(curr));
+               curr->set_thread_operand(th);
+               add_thread(th);
+               th->set_creation(curr);
+               /* Promises can be satisfied by children */
+               for (unsigned int i = 0; i < promises.size(); i++) {
+                       Promise *promise = promises[i];
+                       if (promise->thread_is_available(curr->get_tid()))
+                               promise->add_thread(th->get_id());
+               }
+               break;
+       }
+       case PTHREAD_CREATE: {
+               thrd_t *thrd = (thrd_t *)curr->get_location();
+               struct pthread_params *params = (struct pthread_params *)curr->get_value();
+               Thread *th = new Thread(get_next_id(), thrd, params->func, params->arg, get_thread(curr));
+               curr->set_thread_operand(th);
                add_thread(th);
                th->set_creation(curr);
                /* Promises can be satisfied by children */
@@ -926,6 +982,14 @@ bool ModelExecution::process_thread_action(ModelAction *curr)
                updated = true; /* trigger rel-seq checks */
                break;
        }
+       case PTHREAD_JOIN: {
+               Thread *blocking = curr->get_thread_operand();
+               ModelAction *act = get_last_action(blocking->get_id());
+               synchronize(act, curr);
+               updated = true; /* trigger rel-seq checks */
+               break; // WL: to be add (modified)
+       }
+
        case THREAD_FINISH: {
                Thread *th = get_thread(curr);
                /* Wake up any joining threads */
@@ -998,21 +1062,9 @@ void ModelExecution::process_relseq_fixup(ModelAction *curr, work_queue_t *work_
                /* Must synchronize */
                if (!synchronize(release, acquire))
                        return;
-               /* Re-check all pending release sequences */
-               work_queue->push_back(CheckRelSeqWorkEntry(NULL));
-               /* Re-check act for mo_graph edges */
-               work_queue->push_back(MOEdgeWorkEntry(acquire));
-
-               /* propagate synchronization to later actions */
-               action_list_t::reverse_iterator rit = action_trace->rbegin();
-               for (; (*rit) != acquire; rit++) {
-                       ModelAction *propagate = *rit;
-                       if (acquire->happens_before(propagate)) {
-                               synchronize(acquire, propagate);
-                               /* Re-check 'propagate' for mo_graph edges */
-                               work_queue->push_back(MOEdgeWorkEntry(propagate));
-                       }
-               }
+
+               /* Propagate the changed clock vector */
+               propagate_clockvector(acquire, work_queue);
        } else {
                /* Break release sequence with new edges:
                 *   release --mo--> write --mo--> rf */
@@ -1106,6 +1158,7 @@ bool ModelExecution::initialize_curr_action(ModelAction **curr)
  *
  * @return True if this read established synchronization
  */
+
 bool ModelExecution::read_from(ModelAction *act, const ModelAction *rf)
 {
        ASSERT(rf);
@@ -1178,9 +1231,10 @@ void ModelExecution::thread_blocking_check_promises(Thread *blocker, Thread *wai
 /**
  * @brief Check whether a model action is enabled.
  *
- * Checks whether a lock or join operation would be successful (i.e., is the
- * lock already locked, or is the joined thread already complete). If not, put
- * the action in a waiter list.
+ * Checks whether an operation would be successful (i.e., is a lock already
+ * locked, or is the joined thread already complete).
+ *
+ * For yield-blocking, yields are never enabled.
  *
  * @param curr is the ModelAction to check whether it is enabled.
  * @return a bool that indicates whether the action is enabled.
@@ -1197,6 +1251,8 @@ bool ModelExecution::check_action_enabled(ModelAction *curr) {
                        thread_blocking_check_promises(blocking, get_thread(curr));
                        return false;
                }
+       } else if (params->yieldblock && curr->is_yield()) {
+               return false;
        }
 
        return true;
@@ -1211,7 +1267,7 @@ bool ModelExecution::check_action_enabled(ModelAction *curr) {
  *
  * @param curr The current action to process
  * @return The ModelAction that is actually executed; may be different than
- * curr; may be NULL, if the current action is not enabled to run
+ * curr
  */
 ModelAction * ModelExecution::check_current_action(ModelAction *curr)
 {
@@ -1254,7 +1310,7 @@ ModelAction * ModelExecution::check_current_action(ModelAction *curr)
                        if (act->is_read() && !second_part_of_rmw && process_read(act))
                                update = true;
 
-                       if (act->is_write() && process_write(act))
+                       if (act->is_write() && process_write(act, &work_queue))
                                update = true;
 
                        if (act->is_fence() && process_fence(act))
@@ -1286,6 +1342,12 @@ ModelAction * ModelExecution::check_current_action(ModelAction *curr)
                                if (rf) {
                                        if (r_modification_order(act, rf))
                                                updated = true;
+                                       if (act->is_seqcst()) {
+                                               ModelAction *last_sc_write = get_last_seq_cst_write(act);
+                                               if (last_sc_write != NULL && rf->happens_before(last_sc_write)) {
+                                                       set_bad_sc_read();
+                                               }
+                                       }
                                } else if (promise) {
                                        if (r_modification_order(act, promise))
                                                updated = true;
@@ -1357,7 +1419,7 @@ void ModelExecution::print_infeasibility(const char *prefix) const
        char *ptr = buf;
        if (mo_graph->checkForCycles())
                ptr += sprintf(ptr, "[mo cycle]");
-       if (priv->failed_promise)
+       if (priv->failed_promise || priv->hard_failed_promise)
                ptr += sprintf(ptr, "[failed promise]");
        if (priv->too_many_reads)
                ptr += sprintf(ptr, "[too many reads]");
@@ -1365,12 +1427,14 @@ void ModelExecution::print_infeasibility(const char *prefix) const
                ptr += sprintf(ptr, "[no valid reads-from]");
        if (priv->bad_synchronization)
                ptr += sprintf(ptr, "[bad sw ordering]");
+       if (priv->bad_sc_read)
+               ptr += sprintf(ptr, "[bad sc read]");
        if (promises_expired())
                ptr += sprintf(ptr, "[promise expired]");
        if (promises.size() != 0)
                ptr += sprintf(ptr, "[unresolved promise]");
        if (ptr != buf)
-               model_print("%s: %s\n", prefix ? prefix : "Infeasible", buf);
+               model_print("%s: %s", prefix ? prefix : "Infeasible", buf);
 }
 
 /**
@@ -1379,7 +1443,8 @@ void ModelExecution::print_infeasibility(const char *prefix) const
  */
 bool ModelExecution::is_feasible_prefix_ignore_relseq() const
 {
-       return !is_infeasible() && promises.size() == 0;
+       return !is_infeasible() && promises.size() == 0 && ! priv->failed_promise;
+
 }
 
 /**
@@ -1392,9 +1457,10 @@ bool ModelExecution::is_infeasible() const
 {
        return mo_graph->checkForCycles() ||
                priv->no_valid_reads ||
-               priv->failed_promise ||
                priv->too_many_reads ||
                priv->bad_synchronization ||
+               priv->bad_sc_read ||
+               priv->hard_failed_promise ||
                promises_expired();
 }
 
@@ -1595,12 +1661,6 @@ bool ModelExecution::r_modification_order(ModelAction *curr, const rf_type *rf)
                                }
                        }
 
-                       /* C++, Section 29.3 statement 3 (second subpoint) */
-                       if (curr->is_seqcst() && last_sc_write && act == last_sc_write) {
-                               added = mo_graph->addEdge(act, rf) || added;
-                               break;
-                       }
-
                        /*
                         * Include at most one act per-thread that "happens
                         * before" curr
@@ -1732,9 +1792,10 @@ bool ModelExecution::w_modification_order(ModelAction *curr, ModelVector<ModelAc
                                        added = mo_graph->addEdge(act, curr) || added;
                                else if (act->is_read()) {
                                        //if previous read accessed a null, just keep going
-                                       if (act->get_reads_from() == NULL)
-                                               continue;
-                                       added = mo_graph->addEdge(act->get_reads_from(), curr) || added;
+                                       if (act->get_reads_from() == NULL) {
+                                               added = mo_graph->addEdge(act->get_reads_from_promise(), curr) || added;
+                                       } else
+                                               added = mo_graph->addEdge(act->get_reads_from(), curr) || added;
                                }
                                break;
                        } else if (act->is_read() && !act->could_synchronize_with(curr) &&
@@ -1751,7 +1812,8 @@ bool ModelExecution::w_modification_order(ModelAction *curr, ModelVector<ModelAc
                                   pendingfuturevalue.
 
                                 */
-                               if (send_fv && thin_air_constraint_may_allow(curr, act)) {
+
+                               if (send_fv && thin_air_constraint_may_allow(curr, act) && check_coherence_promise(curr, act)) {
                                        if (!is_infeasible())
                                                send_fv->push_back(act);
                                        else if (curr->is_rmw() && act->is_rmw() && curr->get_reads_from() && curr->get_reads_from() == act->get_reads_from())
@@ -1773,6 +1835,50 @@ bool ModelExecution::w_modification_order(ModelAction *curr, ModelVector<ModelAc
        return added;
 }
 
+//This procedure uses cohere to prune future values that are
+//guaranteed to generate a coherence violation.
+//
+//need to see if there is (1) a promise for thread write, (2)
+//the promise is sb before write, (3) the promise can only be
+//resolved by the thread read, and (4) the promise has same
+//location as read/write
+
+bool ModelExecution::check_coherence_promise(const ModelAction * write, const ModelAction *read) {
+       thread_id_t write_tid=write->get_tid();
+       for(unsigned int i = promises.size(); i>0; i--) {
+               Promise *pr=promises[i-1];
+               if (!pr->same_location(write))
+                       continue;
+               //the reading thread is the only thread that can resolve the promise
+               if (pr->get_num_was_available_threads()==1 && pr->thread_was_available(read->get_tid())) {
+                       for(unsigned int j=0;j<pr->get_num_readers();j++) {
+                               ModelAction *prreader=pr->get_reader(j);
+                               //the writing thread reads from the promise before the write
+                               if (prreader->get_tid()==write_tid &&
+                                               (*prreader)<(*write)) {
+                                       if ((*read)>(*prreader)) {
+                                               //check that we don't have a read between the read and promise
+                                               //from the same thread as read
+                                               bool okay=false;
+                                               for(const ModelAction *tmp=read;tmp!=prreader;) {
+                                                       tmp=tmp->get_node()->get_parent()->get_action();
+                                                       if (tmp->is_read() && tmp->same_thread(read)) {
+                                                               okay=true;
+                                                               break;
+                                                       }
+                                               }
+                                               if (okay)
+                                                       continue;
+                                       }
+                                       return false;
+                               }
+                       }
+               }
+       }
+       return true;
+}
+
+
 /** Arbitrary reads from the future are not allowed.  Section 29.3
  * part 9 places some constraints.  This method checks one result of constraint
  * constraint.  Others require compiler support. */
@@ -1801,6 +1907,7 @@ bool ModelExecution::thin_air_constraint_may_allow(const ModelAction *writer, co
  * require compiler support):
  *
  *   If X --hb-> Y --mo-> Z, then X should not read from Z.
+ *   If X --hb-> Y, A --rf-> Y, and A --mo-> Z, then X should not read from Z.
  */
 bool ModelExecution::mo_may_allow(const ModelAction *writer, const ModelAction *reader)
 {
@@ -2032,6 +2139,37 @@ void ModelExecution::get_release_seq_heads(ModelAction *acquire,
        }
 }
 
+/**
+ * @brief Propagate a modified clock vector to actions later in the execution
+ * order
+ *
+ * After an acquire operation lazily completes a release-sequence
+ * synchronization, we must update all clock vectors for operations later than
+ * the acquire in the execution order.
+ *
+ * @param acquire The ModelAction whose clock vector must be propagated
+ * @param work The work queue to which we can add work items, if this
+ * propagation triggers more updates (e.g., to the modification order)
+ */
+void ModelExecution::propagate_clockvector(ModelAction *acquire, work_queue_t *work)
+{
+       /* Re-check all pending release sequences */
+       work->push_back(CheckRelSeqWorkEntry(NULL));
+       /* Re-check read-acquire for mo_graph edges */
+       work->push_back(MOEdgeWorkEntry(acquire));
+
+       /* propagate synchronization to later actions */
+       action_list_t::reverse_iterator rit = action_trace.rbegin();
+       for (; (*rit) != acquire; rit++) {
+               ModelAction *propagate = *rit;
+               if (acquire->happens_before(propagate)) {
+                       synchronize(acquire, propagate);
+                       /* Re-check 'propagate' for mo_graph edges */
+                       work->push_back(MOEdgeWorkEntry(propagate));
+               }
+       }
+}
+
 /**
  * Attempt to resolve all stashed operations that might synchronize with a
  * release sequence for a given location. This implements the "lazy" portion of
@@ -2070,22 +2208,8 @@ bool ModelExecution::resolve_release_sequences(void *location, work_queue_t *wor
                                        updated = true;
 
                if (updated) {
-                       /* Re-check all pending release sequences */
-                       work_queue->push_back(CheckRelSeqWorkEntry(NULL));
-                       /* Re-check read-acquire for mo_graph edges */
-                       if (acquire->is_read())
-                               work_queue->push_back(MOEdgeWorkEntry(acquire));
-
-                       /* propagate synchronization to later actions */
-                       action_list_t::reverse_iterator rit = action_trace->rbegin();
-                       for (; (*rit) != acquire; rit++) {
-                               ModelAction *propagate = *rit;
-                               if (acquire->happens_before(propagate)) {
-                                       synchronize(acquire, propagate);
-                                       /* Re-check 'propagate' for mo_graph edges */
-                                       work_queue->push_back(MOEdgeWorkEntry(propagate));
-                               }
-                       }
+                       /* Propagate the changed clock vector */
+                       propagate_clockvector(acquire, work_queue);
                }
                if (complete) {
                        it = pending_rel_seqs.erase(it);
@@ -2113,7 +2237,7 @@ void ModelExecution::add_action_to_lists(ModelAction *act)
        int tid = id_to_int(act->get_tid());
        ModelAction *uninit = NULL;
        int uninit_id = -1;
-       action_list_t *list = get_safe_ptr_action(obj_map, act->get_location());
+       action_list_t *list = get_safe_ptr_action(&obj_map, act->get_location());
        if (list->empty() && act->is_atomic_var()) {
                uninit = get_uninitialized_action(act);
                uninit_id = id_to_int(uninit->get_tid());
@@ -2121,9 +2245,9 @@ void ModelExecution::add_action_to_lists(ModelAction *act)
        }
        list->push_back(act);
 
-       action_trace->push_back(act);
+       action_trace.push_back(act);
        if (uninit)
-               action_trace->push_front(uninit);
+               action_trace.push_front(uninit);
 
        SnapVector<action_list_t> *vec = get_safe_ptr_vect_action(&obj_thrd_map, act->get_location());
        if (tid >= (int)vec->size())
@@ -2146,7 +2270,7 @@ void ModelExecution::add_action_to_lists(ModelAction *act)
 
        if (act->is_wait()) {
                void *mutex_loc = (void *) act->get_value();
-               get_safe_ptr_action(obj_map, mutex_loc)->push_back(act);
+               get_safe_ptr_action(&obj_map, mutex_loc)->push_back(act);
 
                SnapVector<action_list_t> *vec = get_safe_ptr_vect_action(&obj_thrd_map, mutex_loc);
                if (tid >= (int)vec->size())
@@ -2194,7 +2318,7 @@ ModelAction * ModelExecution::get_last_fence_release(thread_id_t tid) const
 ModelAction * ModelExecution::get_last_seq_cst_write(ModelAction *curr) const
 {
        void *location = curr->get_location();
-       action_list_t *list = get_safe_ptr_action(obj_map, location);
+       action_list_t *list = obj_map.get(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) != curr; rit++)
@@ -2216,8 +2340,12 @@ ModelAction * ModelExecution::get_last_seq_cst_write(ModelAction *curr) const
  */
 ModelAction * ModelExecution::get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const
 {
-       /* All fences should have NULL location */
-       action_list_t *list = get_safe_ptr_action(obj_map, NULL);
+       /* All fences should have location FENCE_LOCATION */
+       action_list_t *list = obj_map.get(FENCE_LOCATION);
+
+       if (!list)
+               return NULL;
+
        action_list_t::reverse_iterator rit = list->rbegin();
 
        if (before_fence) {
@@ -2246,7 +2374,7 @@ ModelAction * ModelExecution::get_last_seq_cst_fence(thread_id_t tid, const Mode
 ModelAction * ModelExecution::get_last_unlock(ModelAction *curr) const
 {
        void *location = curr->get_location();
-       action_list_t *list = get_safe_ptr_action(obj_map, location);
+       action_list_t *list = obj_map.get(location);
        /* Find: max({i in dom(S) | isUnlock(t_i) && samevar(t_i, t)}) */
        action_list_t::reverse_iterator rit;
        for (rit = list->rbegin(); rit != list->rend(); rit++)
@@ -2294,21 +2422,26 @@ Promise * ModelExecution::pop_promise_to_resolve(const ModelAction *curr)
  * Resolve a Promise with a current write.
  * @param write The ModelAction that is fulfilling Promises
  * @param promise The Promise to resolve
+ * @param work The work queue, for adding new fixup work
  * @return True if the Promise was successfully resolved; false otherwise
  */
-bool ModelExecution::resolve_promise(ModelAction *write, Promise *promise)
+bool ModelExecution::resolve_promise(ModelAction *write, Promise *promise,
+               work_queue_t *work)
 {
        ModelVector<ModelAction *> actions_to_check;
 
        for (unsigned int i = 0; i < promise->get_num_readers(); i++) {
                ModelAction *read = promise->get_reader(i);
-               read_from(read, write);
+               if (read_from(read, write)) {
+                       /* Propagate the changed clock vector */
+                       propagate_clockvector(read, work);
+               }
                actions_to_check.push_back(read);
        }
        /* Make sure the promise's value matches the write's value */
        ASSERT(promise->is_compatible(write) && promise->same_value(write));
        if (!mo_graph->resolvePromise(promise, write))
-               priv->failed_promise = true;
+               priv->hard_failed_promise = true;
 
        /**
         * @todo  It is possible to end up in an inconsistent state, where a
@@ -2420,7 +2553,7 @@ void ModelExecution::mo_check_promises(const ModelAction *act, bool is_read_chec
                        if (!pread->happens_before(act))
                               continue;
                        if (mo_graph->checkPromise(write, promise)) {
-                               priv->failed_promise = true;
+                               priv->hard_failed_promise = true;
                                return;
                        }
                        break;
@@ -2432,7 +2565,7 @@ void ModelExecution::mo_check_promises(const ModelAction *act, bool is_read_chec
 
                if (mo_graph->checkReachable(promise, write)) {
                        if (mo_graph->checkPromise(write, promise)) {
-                               priv->failed_promise = true;
+                               priv->hard_failed_promise = true;
                                return;
                        }
                }
@@ -2581,11 +2714,13 @@ ModelAction * ModelExecution::get_uninitialized_action(const ModelAction *curr)
        return act;
 }
 
-static void print_list(action_list_t *list)
+static void print_list(const action_list_t *list)
 {
-       action_list_t::iterator it;
+       action_list_t::const_iterator it;
 
-       model_print("---------------------------------------------------------------------\n");
+       model_print("------------------------------------------------------------------------------------\n");
+       model_print("#    t     Action type     MO       Location         Value               Rf  CV\n");
+       model_print("------------------------------------------------------------------------------------\n");
 
        unsigned int hash = 0;
 
@@ -2596,7 +2731,7 @@ static void print_list(action_list_t *list)
                hash = hash^(hash<<3)^((*it)->hash());
        }
        model_print("HASH %u\n", hash);
-       model_print("---------------------------------------------------------------------\n");
+       model_print("------------------------------------------------------------------------------------\n");
 }
 
 #if SUPPORT_MOD_ORDER_DUMP
@@ -2609,7 +2744,7 @@ void ModelExecution::dumpGraph(char *filename) const
        mo_graph->dumpNodes(file);
        ModelAction **thread_array = (ModelAction **)model_calloc(1, sizeof(ModelAction *) * get_num_threads());
 
-       for (action_list_t::iterator it = action_trace->begin(); it != action_trace->end(); it++) {
+       for (action_list_t::const_iterator it = action_trace.begin(); it != action_trace.end(); it++) {
                ModelAction *act = *it;
                if (act->is_read()) {
                        mo_graph->dot_print_node(file, act);
@@ -2650,15 +2785,21 @@ void ModelExecution::print_summary() const
        dumpGraph(buffername);
 #endif
 
-       model_print("Execution %d:", get_execution_number());
+       model_print("Execution trace %d:", get_execution_number());
        if (isfeasibleprefix()) {
+               if (is_yieldblocked())
+                       model_print(" YIELD BLOCKED");
                if (scheduler->all_threads_sleeping())
                        model_print(" SLEEP-SET REDUNDANT");
-               model_print("\n");
+               if (have_bug_reports())
+                       model_print(" DETECTED BUG(S)");
        } else
                print_infeasibility(" INFEASIBLE");
-       print_list(action_trace);
        model_print("\n");
+
+       print_list(&action_trace);
+       model_print("\n");
+
        if (!promises.empty()) {
                model_print("Pending promises:\n");
                for (unsigned int i = 0; i < promises.size(); i++) {
@@ -2676,7 +2817,10 @@ void ModelExecution::print_summary() const
  */
 void ModelExecution::add_thread(Thread *t)
 {
-       thread_map.put(id_to_int(t->get_id()), t);
+       unsigned int i = id_to_int(t->get_id());
+       if (i >= thread_map.size())
+               thread_map.resize(i + 1);
+       thread_map[i] = t;
        if (!t->is_model_thread())
                scheduler->add_thread(t);
 }
@@ -2688,7 +2832,10 @@ void ModelExecution::add_thread(Thread *t)
  */
 Thread * ModelExecution::get_thread(thread_id_t tid) const
 {
-       return thread_map.get(id_to_int(tid));
+       unsigned int i = id_to_int(tid);
+       if (i < thread_map.size())
+               return thread_map[i];
+       return NULL;
 }
 
 /**
@@ -2757,9 +2904,26 @@ Thread * ModelExecution::action_select_next_thread(const ModelAction *curr) cons
        /* Do not split atomic RMW */
        if (curr->is_rmwr())
                return get_thread(curr);
+       if (curr->is_write()) {
+//             std::memory_order order = curr->get_mo(); 
+//             switch(order) {
+//                     case std::memory_order_relaxed: 
+//                             return get_thread(curr);
+//                     case std::memory_order_release:
+//                             return get_thread(curr);
+//                     defalut:
+//                             return NULL;
+//             }       
+               return NULL;
+       }
+
        /* Follow CREATE with the created thread */
+       /* which is not needed, because model.cc takes care of this */
        if (curr->get_type() == THREAD_CREATE)
+               return curr->get_thread_operand(); 
+       if (curr->get_type() == PTHREAD_CREATE) {
                return curr->get_thread_operand();
+       }
        return NULL;
 }
 
@@ -2803,7 +2967,7 @@ void ModelExecution::fixup_release_sequences()
 {
        while (!pending_rel_seqs.empty() &&
                        is_feasible_prefix_ignore_relseq() &&
-                       !unrealizedraces.empty()) {
+                       haveUnrealizedRaces()) {
                model_print("*** WARNING: release sequence fixup action "
                                "(%zu pending release seuqence(s)) ***\n",
                                pending_rel_seqs.size());