execution: remove redundant condition, reword doc for promises_may_allow

[model-checker.git] / execution.cc

diff --git a/execution.cc b/execution.cc
index e04b672a28d1a08e9e5991bacc3aa25826d3dbc9..53aa5212f0b017622d0c284f1cbc765e0620fddd 100644 (file)
--- a/execution.cc
+++ b/execution.cc
@@ -755,12 +755,13 @@ bool ModelExecution::process_mutex(ModelAction *curr)
 /**
  * @brief Check if the current pending promises allow a future value to be sent
  *
 /**
  * @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.
  *
  * @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.


@@ -769,8 +770,6 @@ bool ModelExecution::process_mutex(ModelAction *curr)
 bool ModelExecution::promises_may_allow(const ModelAction *writer,
                const ModelAction *reader) const
 {
 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
        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