From: Brian Norris <banorris@uci.edu>
Date: Wed, 27 Feb 2013 02:42:51 +0000 (-0800)
Subject: nodestack: rewrite promise-resolution "counting"
X-Git-Tag: oopsla2013~206
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e356dc963edf27f8a97b1ae3d39e276723aa5968;p=model-checker.git
nodestack: rewrite promise-resolution "counting"
We don't need to perform a full check of all possible combinations of
Promises to resolve; we only perform 0 or 1 resolution.
---
diff --git a/model.cc b/model.cc
index d3ebf4d..cb53e11 100644
--- a/model.cc
+++ b/model.cc
@@ -2500,7 +2500,7 @@ void ModelChecker::compute_promises(ModelAction *curr)
!act->could_synchronize_with(curr) &&
promise->is_compatible(curr) &&
promise->get_value() == curr->get_value()) {
- curr->get_node()->set_promise(i, act->is_rmw());
+ curr->get_node()->set_promise(i);
}
}
}
diff --git a/nodestack.cc b/nodestack.cc
index 66869ab..131b06c 100644
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -40,6 +40,8 @@ Node::Node(ModelAction *act, Node *par, int nthreads, Node *prevfairness) :
read_from_promise_idx(-1),
future_values(),
future_index(-1),
+ resolve_promise(),
+ resolve_promise_idx(-1),
relseq_break_writes(),
relseq_break_index(0),
misc_index(0),
@@ -122,61 +124,44 @@ void Node::print() const
model_print(" rel seq break: %s\n", relseq_break_empty() ? "empty" : "non-empty");
}
+/*********************************** promise **********************************/
+
/**
* Sets a promise to explore meeting with the given node.
* @param i is the promise index.
*/
-void Node::set_promise(unsigned int i, bool is_rmw)
-{
- if (i >= promises.size())
- promises.resize(i + 1, PROMISE_IGNORE);
- if (promises[i] == PROMISE_IGNORE) {
- promises[i] = PROMISE_UNFULFILLED;
- if (is_rmw)
- promises[i] |= PROMISE_RMW;
- }
+void Node::set_promise(unsigned int i)
+{
+ if (i >= resolve_promise.size())
+ resolve_promise.resize(i + 1, false);
+ resolve_promise[i] = true;
}
/**
* Looks up whether a given promise should be satisfied by this node.
* @param i The promise index.
- * @return true if the promise should be satisfied by the given model action.
+ * @return true if the promise should be satisfied by the given ModelAction.
*/
bool Node::get_promise(unsigned int i) const
{
- return (i < promises.size()) && ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED);
+ return (i < resolve_promise.size()) && (int)i == resolve_promise_idx;
}
/**
- * Increments to the next combination of promises.
+ * Increments to the next promise to resolve.
* @return true if we have a valid combination.
*/
bool Node::increment_promise()
{
DBG();
- unsigned int rmw_count = 0;
- for (unsigned int i = 0; i < promises.size(); i++) {
- if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED))
- rmw_count++;
- }
-
- for (unsigned int i = 0; i < promises.size(); i++) {
- if ((promises[i] & PROMISE_MASK) == PROMISE_UNFULFILLED) {
- if ((rmw_count > 0) && (promises[i] & PROMISE_RMW)) {
- //sending our value to two rmws... not going to work..try next combination
- continue;
- }
- promises[i] = (promises[i] & PROMISE_RMW) | PROMISE_FULFILLED;
- while (i > 0) {
- i--;
- if ((promises[i] & PROMISE_MASK) == PROMISE_FULFILLED)
- promises[i] = (promises[i] & PROMISE_RMW) | PROMISE_UNFULFILLED;
- }
+ if (resolve_promise.empty())
+ return false;
+ int prev_idx = resolve_promise_idx;
+ resolve_promise_idx++;
+ for ( ; resolve_promise_idx < (int)resolve_promise.size(); resolve_promise_idx++)
+ if (resolve_promise[resolve_promise_idx])
return true;
- } else if (promises[i] == (PROMISE_RMW|PROMISE_FULFILLED)) {
- rmw_count--;
- }
- }
+ resolve_promise_idx = prev_idx;
return false;
}
@@ -186,18 +171,21 @@ bool Node::increment_promise()
*/
bool Node::promise_empty() const
{
- bool fulfilledrmw = false;
- for (int i = promises.size() - 1; i >= 0; i--) {
- if (promises[i] == PROMISE_UNFULFILLED)
+ for (int i = resolve_promise_idx + 1; i < (int)resolve_promise.size(); i++)
+ if (i >= 0 && resolve_promise[i])
return false;
- if (!fulfilledrmw && ((promises[i] & PROMISE_MASK) == PROMISE_UNFULFILLED))
- return false;
- if (promises[i] == (PROMISE_FULFILLED | PROMISE_RMW))
- fulfilledrmw = true;
- }
return true;
}
+/** @brief Clear any promise-resolution information for this Node */
+void Node::clear_promise_resolutions()
+{
+ resolve_promise.clear();
+ resolve_promise_idx = -1;
+}
+
+/******************************* end promise **********************************/
+
void Node::set_misc_max(int i)
{
misc_max = i;
@@ -345,7 +333,7 @@ read_from_type_t Node::get_read_from_status()
*/
bool Node::increment_read_from()
{
- promises.clear();
+ clear_promise_resolutions();
if (increment_read_from_past()) {
read_from_status = READ_FROM_PAST;
return true;
@@ -614,7 +602,6 @@ const ModelAction * Node::get_relseq_break() const
bool Node::increment_relseq_break()
{
DBG();
- promises.clear();
if (relseq_break_index < ((int)relseq_break_writes.size())) {
relseq_break_index++;
return (relseq_break_index < ((int)relseq_break_writes.size()));
diff --git a/nodestack.h b/nodestack.h
index 8a20c45..fc566d6 100644
--- a/nodestack.h
+++ b/nodestack.h
@@ -16,22 +16,6 @@
class ModelAction;
class Thread;
-/**
- * A flag used for the promise counting/combination problem within a node,
- * denoting whether a particular Promise is
- * <ol><li>@b applicable: can be satisfied by this Node's ModelAction and</li>
- * <li>@b fulfilled: satisfied by this Node's ModelAction under the current
- * configuration.</li></ol>
- */
-
-#define PROMISE_IGNORE 0 /**< This promise is inapplicable; ignore it */
-#define PROMISE_UNFULFILLED 1 /**< This promise is applicable but unfulfilled */
-#define PROMISE_FULFILLED 2 /**< This promise is applicable and fulfilled */
-#define PROMISE_MASK 0xf
-#define PROMISE_RMW 0x10
-
-typedef int promise_t;
-
struct fairness_info {
unsigned int enabled_count;
unsigned int turns;
@@ -96,10 +80,12 @@ public:
bool add_future_value(struct future_value fv);
struct future_value get_future_value() const;
- void set_promise(unsigned int i, bool is_rmw);
+ void set_promise(unsigned int i);
bool get_promise(unsigned int i) const;
bool increment_promise();
bool promise_empty() const;
+ void clear_promise_resolutions();
+
enabled_type_t *get_enabled_array() {return enabled_array;}
void set_misc_max(int i);
@@ -146,9 +132,11 @@ private:
int read_from_promise_idx;
std::vector< struct future_value, ModelAlloc<struct future_value> > future_values;
- std::vector< promise_t, ModelAlloc<promise_t> > promises;
int future_index;
+ std::vector< bool, ModelAlloc<bool> > resolve_promise;
+ int resolve_promise_idx;
+
std::vector< const ModelAction *, ModelAlloc<const ModelAction *> > relseq_break_writes;
int relseq_break_index;