execution: bugfix - resolved promises should propagate synchronization

A new write ModelAction may resolve a Promise, completing a release
sequence and updating the read's clock vector. This update should be
propagated to any ModelAction later in the execution order which had
previously "happened after" the read.

diff --git a/execution.cc b/execution.cc
index 4e154275eac6b42cb4ea805ab9e86bf6a63cd2b5..4496b9c63deeca6fa8198ec086425ba8fa1d6932 100644 (file)
--- a/execution.cc
+++ b/execution.cc
@@ -817,9 +817,10 @@ 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;
@@ -832,7 +833,7 @@ 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;
 
@@ -1272,7 +1273,7 @@ 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))
@@ -2333,15 +2334,20 @@ 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 */

diff --git a/execution.h b/execution.h
index bb4ebb08f0b67cb3b30af855196c3b2b217b8013..ab4df362bcd89544402fafb701d2b982bb5c7be7 100644 (file)
--- a/execution.h
+++ b/execution.h
@@ -141,7 +141,7 @@ private:
        ModelAction * check_current_action(ModelAction *curr);
        bool initialize_curr_action(ModelAction **curr);
        bool process_read(ModelAction *curr);
-       bool process_write(ModelAction *curr);
+       bool process_write(ModelAction *curr, work_queue_t *work);
        bool process_fence(ModelAction *curr);
        bool process_mutex(ModelAction *curr);
        bool process_thread_action(ModelAction *curr);
@@ -160,7 +160,8 @@ private:
        void set_backtracking(ModelAction *act);
        bool set_latest_backtrack(ModelAction *act);
        Promise * pop_promise_to_resolve(const ModelAction *curr);
-       bool resolve_promise(ModelAction *curr, Promise *promise);
+       bool resolve_promise(ModelAction *curr, Promise *promise,
+                       work_queue_t *work);
        void compute_promises(ModelAction *curr);
        void compute_relseq_breakwrites(ModelAction *curr);