model: schedule appropriate fence backtracking points

[c11tester.git] / promise.cc

diff --git a/promise.cc b/promise.cc
index 943a0f4f9ba09f1d7a7c67521b1c570ca6db0bf2..0f5ba4d1573d3ffc652ad28edb3bc69e62742248 100644 (file)
--- a/promise.cc
+++ b/promise.cc
@@ -1,6 +1,27 @@
+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
+
 #include "promise.h"
 #include "model.h"
 #include "schedule.h"
+#include "action.h"
+#include "threads-model.h"
+
+/**
+ * @brief Promise constructor
+ * @param read The read which reads from a promised future value
+ * @param fv The future value that is promised
+ */
+Promise::Promise(ModelAction *read, struct future_value fv) :
+       num_available_threads(0),
+       value(fv.value),
+       expiration(fv.expiration),
+       read(read),
+       write(NULL)
+{
+       add_thread(fv.tid);
+       eliminate_thread(read->get_tid());
+}
 
 /**
  * Eliminate a thread which no longer can satisfy this promise. Once all
@@ -13,29 +34,85 @@
 bool Promise::eliminate_thread(thread_id_t tid)
 {
        unsigned int id = id_to_int(tid);
-       if (id >= synced_thread.size())
-               synced_thread.resize(id + 1, false);
-       if (synced_thread[id])
+       if (!thread_is_available(tid))
                return false;
 
-       synced_thread[id] = true;
-       unsigned int sync_size = synced_thread.size();
-       int promise_tid = id_to_int(read->get_tid());
-       for (unsigned int i = 1; i < model->get_num_threads(); i++) {
-               if ((i >= sync_size || !synced_thread[i]) && ((int)i != promise_tid) && model->is_enabled(int_to_id(i))) {
-                       return false;
-               }
-       }
-       return true;
+       available_thread[id] = false;
+       num_available_threads--;
+       return has_failed();
 }
 
-bool Promise::check_promise() const
+/**
+ * Add a thread which may resolve this promise
+ *
+ * @param tid The thread ID
+ */
+void Promise::add_thread(thread_id_t tid)
 {
-       unsigned int sync_size = synced_thread.size();
-       for (unsigned int i = 1; i < model->get_num_threads(); i++) {
-               if ((i >= sync_size || !synced_thread[i]) && model->is_enabled(int_to_id(i))) {
-                       return false;
-               }
+       unsigned int id = id_to_int(tid);
+       if (id >= available_thread.size())
+               available_thread.resize(id + 1, false);
+       if (!available_thread[id]) {
+               available_thread[id] = true;
+               num_available_threads++;
        }
-       return true;
+}
+
+/**
+ * Check if a thread is available for resolving this promise. That is, the
+ * thread must have been previously marked for resolving this promise, and it
+ * cannot have been eliminated due to synchronization, etc.
+ *
+ * @param tid Thread ID of the thread to check
+ * @return True if the thread is available; false otherwise
+ */
+bool Promise::thread_is_available(thread_id_t tid) const
+{
+       unsigned int id = id_to_int(tid);
+       if (id >= available_thread.size())
+               return false;
+       return available_thread[id];
+}
+
+/** @brief Print debug info about the Promise */
+void Promise::print() const
+{
+       model_print("Promised value %#" PRIx64 ", read from thread %d, available threads to resolve: ", value, id_to_int(read->get_tid()));
+       for (unsigned int i = 0; i < available_thread.size(); i++)
+               if (available_thread[i])
+                       model_print("[%d]", i);
+       model_print("\n");
+}
+
+/**
+ * Check if this promise has failed. A promise can fail when all threads which
+ * could possibly satisfy the promise have been eliminated.
+ *
+ * @return True, if this promise has failed; false otherwise
+ */
+bool Promise::has_failed() const
+{
+       return num_available_threads == 0;
+}
+
+/**
+ * @brief Check if an action's thread and location are compatible for resolving
+ * this promise
+ * @param act The action to check against
+ * @return True if we are compatible; false otherwise
+ */
+bool Promise::is_compatible(const ModelAction *act) const
+{
+       return thread_is_available(act->get_tid()) && read->same_var(act);
+}
+
+/**
+ * @brief Check if an action's thread and location are compatible for resolving
+ * this promise, and that the promise is thread-exclusive
+ * @param act The action to check against
+ * @return True if we are compatible and exclusive; false otherwise
+ */
+bool Promise::is_compatible_exclusive(const ModelAction *act) const
+{
+       return get_num_available_threads() == 1 && is_compatible(act);
 }