model: group snapshottable ModelChecker members in struct
[c11tester.git] / model.cc
index 56723c7d5660077c3b1e27d484976d5092388bd7..43530fe12c25e2ecafa4af78cbb5eb3008b6190d 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <algorithm>
 
 #include "model.h"
 #include "action.h"
@@ -9,6 +10,7 @@
 #include "clockvector.h"
 #include "cyclegraph.h"
 #include "promise.h"
+#include "datarace.h"
 
 #define INITIAL_THREAD_ID      0
 
@@ -18,14 +20,9 @@ ModelChecker *model;
 ModelChecker::ModelChecker(struct model_params params) :
        /* Initialize default 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),
        params(params),
-       current_action(NULL),
        diverge(NULL),
-       nextThread(NULL),
        action_trace(new action_list_t()),
        thread_map(new HashTable<int, Thread *, int>()),
        obj_map(new HashTable<const void *, action_list_t, uintptr_t, 4>()),
@@ -34,10 +31,14 @@ ModelChecker::ModelChecker(struct model_params params) :
        lazy_sync_with_release(new HashTable<void *, std::list<ModelAction *>, uintptr_t, 4>()),
        thrd_last_action(new std::vector<ModelAction *>(1)),
        node_stack(new NodeStack()),
-       next_backtrack(NULL),
        mo_graph(new CycleGraph()),
-       failed_promise(false)
+       failed_promise(false),
+       asserted(false)
 {
+       /* Allocate this "size" on the snapshotting heap */
+       priv = (struct model_snapshot_members *)calloc(1, sizeof(*priv));
+       /* First thread created will have id INITIAL_THREAD_ID */
+       priv->next_thread_id = INITIAL_THREAD_ID;
 }
 
 /** @brief Destructor */
@@ -71,31 +72,27 @@ void ModelChecker::reset_to_initial_state()
 {
        DEBUG("+++ Resetting to initial state +++\n");
        node_stack->reset_execution();
-       current_action = NULL;
-       next_thread_id = INITIAL_THREAD_ID;
-       used_sequence_numbers = 0;
-       nextThread = NULL;
-       next_backtrack = NULL;
        failed_promise = false;
+       reset_asserted();
        snapshotObject->backTrackBeforeStep(0);
 }
 
 /** @returns a thread ID for a new Thread */
 thread_id_t ModelChecker::get_next_id()
 {
-       return next_thread_id++;
+       return priv->next_thread_id++;
 }
 
 /** @returns the number of user threads created during this execution */
 int ModelChecker::get_num_threads()
 {
-       return next_thread_id;
+       return priv->next_thread_id;
 }
 
 /** @returns a sequence number for a new ModelAction */
 modelclock_t ModelChecker::get_next_seq_num()
 {
-       return ++used_sequence_numbers;
+       return ++priv->used_sequence_numbers;
 }
 
 /**
@@ -163,7 +160,7 @@ bool ModelChecker::next_execution()
        if (isfinalfeasible() || DBG_ENABLED())
                print_summary();
 
-       if ((diverge = model->get_next_backtrack()) == NULL)
+       if ((diverge = get_next_backtrack()) == NULL)
                return false;
 
        if (DBG_ENABLED()) {
@@ -171,7 +168,7 @@ bool ModelChecker::next_execution()
                diverge->print();
        }
 
-       model->reset_to_initial_state();
+       reset_to_initial_state();
        return true;
 }
 
@@ -218,8 +215,8 @@ void ModelChecker::set_backtracking(ModelAction *act)
                return;
 
        /* Cache the latest backtracking point */
-       if (!next_backtrack || *prev > *next_backtrack)
-               next_backtrack = prev;
+       if (!priv->next_backtrack || *prev > *priv->next_backtrack)
+               priv->next_backtrack = prev;
 
        /* If this is a new backtracking point, mark the tree */
        if (!node->set_backtrack(t->get_id()))
@@ -239,8 +236,8 @@ void ModelChecker::set_backtracking(ModelAction *act)
  */
 ModelAction * ModelChecker::get_next_backtrack()
 {
-       ModelAction *next = next_backtrack;
-       next_backtrack = NULL;
+       ModelAction *next = priv->next_backtrack;
+       priv->next_backtrack = NULL;
        return next;
 }
 
@@ -339,7 +336,7 @@ Thread * ModelChecker::check_current_action(ModelAction *curr)
                }
        } else if (curr->is_write()) {
                if (w_modification_order(curr))
-                       updated = true;;
+                       updated = true;
                if (resolve_promises(curr))
                        updated = true;
        }
@@ -358,18 +355,28 @@ Thread * ModelChecker::check_current_action(ModelAction *curr)
 
        if (!parnode->backtrack_empty() || !currnode->read_from_empty() ||
                  !currnode->future_value_empty() || !currnode->promise_empty())
-               if (!next_backtrack || *curr > *next_backtrack)
-                       next_backtrack = curr;
+               if (!priv->next_backtrack || *curr > *priv->next_backtrack)
+                       priv->next_backtrack = curr;
 
        set_backtracking(curr);
 
        /* Do not split atomic actions. */
        if (curr->is_rmwr())
                return thread_current();
+       /* The THREAD_CREATE action points to the created Thread */
+       else if (curr->get_type() == THREAD_CREATE)
+               return (Thread *)curr->get_location();
        else
                return get_next_replay_thread();
 }
 
+/** @returns whether the current partial trace must be a prefix of a
+ * feasible trace. */
+
+bool ModelChecker::isfeasibleprefix() {
+       return promises->size()==0;
+}
+
 /** @returns whether the current partial trace is feasible. */
 bool ModelChecker::isfeasible() {
        return !mo_graph->checkForCycles() && !failed_promise;
@@ -517,8 +524,8 @@ bool ModelChecker::w_modification_order(ModelAction *curr)
                                   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;
+                                               (!priv->next_backtrack || *act > *priv->next_backtrack))
+                                       priv->next_backtrack = act;
                        }
                }
        }
@@ -573,9 +580,8 @@ bool ModelChecker::release_seq_head(const ModelAction *rf,
        action_list_t::const_reverse_iterator rit;
 
        /* Find rf in the thread list */
-       for (rit = list->rbegin(); rit != list->rend(); rit++)
-               if (*rit == rf)
-                       break;
+       rit = std::find(list->rbegin(), list->rend(), rf);
+       ASSERT(rit != list->rend());
 
        /* Find the last write/release */
        for (; rit != list->rend(); rit++)
@@ -594,6 +600,11 @@ bool ModelChecker::release_seq_head(const ModelAction *rf,
                if (id_to_int(rf->get_tid()) == (int)i)
                        continue;
                list = &(*thrd_lists)[i];
+
+               /* Can we ensure no future writes from this thread may break
+                * the release seq? */
+               bool future_ordered = false;
+
                for (rit = list->rbegin(); rit != list->rend(); rit++) {
                        const ModelAction *act = *rit;
                        if (!act->is_write())
@@ -601,13 +612,17 @@ bool ModelChecker::release_seq_head(const ModelAction *rf,
                        /* Reach synchronization -> this thread is complete */
                        if (act->happens_before(release))
                                break;
-                       if (rf->happens_before(act))
+                       if (rf->happens_before(act)) {
+                               future_ordered = true;
                                continue;
+                       }
 
                        /* Check modification order */
-                       if (mo_graph->checkReachable(rf, act))
+                       if (mo_graph->checkReachable(rf, act)) {
                                /* rf --mo--> act */
+                               future_ordered = true;
                                continue;
+                       }
                        if (mo_graph->checkReachable(act, release))
                                /* act --mo--> release */
                                break;
@@ -618,6 +633,8 @@ bool ModelChecker::release_seq_head(const ModelAction *rf,
                        }
                        certain = false;
                }
+               if (!future_ordered)
+                       return false; /* This thread is uncertain */
        }
 
        if (certain)
@@ -700,6 +717,11 @@ bool ModelChecker::resolve_release_sequences(void *location)
                        it++;
        }
 
+       // If we resolved promises or data races, see if we have realized a data race.
+       if (checkDataRaces()) {
+               set_assert();
+       }
+
        return updated;
 }
 
@@ -719,7 +741,7 @@ void ModelChecker::add_action_to_lists(ModelAction *act)
 
        std::vector<action_list_t> *vec = obj_thrd_map->get_safe_ptr(act->get_location());
        if (tid >= (int)vec->size())
-               vec->resize(next_thread_id);
+               vec->resize(priv->next_thread_id);
        (*vec)[tid].push_back(act);
 
        if ((int)thrd_last_action->size() <= tid)
@@ -791,6 +813,7 @@ bool ModelChecker::resolve_promises(ModelAction *write)
                } else
                        promise_index++;
        }
+
        return resolved;
 }
 
@@ -825,7 +848,7 @@ void ModelChecker::check_promises(ClockVector *old_cv, ClockVector *merge_cv)
                                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()) {
+                       if (num_synchronized_threads == get_num_threads()) {
                                //Promise has failed
                                failed_promise = true;
                                return;
@@ -973,19 +996,22 @@ int ModelChecker::switch_to_master(ModelAction *act)
 bool ModelChecker::take_step() {
        Thread *curr, *next;
 
+       if (has_asserted())
+               return false;
+
        curr = thread_current();
        if (curr) {
                if (curr->get_state() == THREAD_READY) {
-                       ASSERT(current_action);
-                       nextThread = check_current_action(current_action);
-                       current_action = NULL;
+                       ASSERT(priv->current_action);
+                       priv->nextThread = check_current_action(priv->current_action);
+                       priv->current_action = NULL;
                        if (!curr->is_blocked() && !curr->is_complete())
                                scheduler->add_thread(curr);
                } else {
                        ASSERT(false);
                }
        }
-       next = scheduler->next_thread(nextThread);
+       next = scheduler->next_thread(priv->nextThread);
 
        /* Infeasible -> don't take any more steps */
        if (!isfeasible())