From 741d3d1160343d8545a783a2d05d3d0562b1c737 Mon Sep 17 00:00:00 2001
From: Brian Norris <banorris@uci.edu>
Date: Wed, 8 May 2013 10:09:52 -0700
Subject: [PATCH] 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.
---
execution.cc | 16 +++++++++++-----
execution.h | 5 +++--
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/execution.cc b/execution.cc
index 4e15427..4496b9c 100644
--- 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 bb4ebb0..ab4df36 100644
--- 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);
--
2.34.1