From 3cbb76ef86a769cfe3dac5976a14e1bc43c42ca6 Mon Sep 17 00:00:00 2001
From: Morgan Deters <mdeters@gmail.com>
Date: Thu, 13 Oct 2011 04:14:38 +0000
Subject: Interruption, time-out, and deterministic time-out ("resource-out")
 features. Details here:
 http://goedel.cims.nyu.edu/wiki/Meeting_Minutes_-_October_14,_2011#Resource.2Ftime_limiting_API
 This will need more work, but it's a start.

Also implemented TheoryEngine::properPropagation().

Other minor things.
---
 src/prop/prop_engine.cpp | 55 +++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 8 deletions(-)

(limited to 'src/prop/prop_engine.cpp')

diff --git a/src/prop/prop_engine.cpp b/src/prop/prop_engine.cpp
index e123db0ed..3d5a27d00 100644
--- a/src/prop/prop_engine.cpp
+++ b/src/prop/prop_engine.cpp
@@ -62,7 +62,12 @@ public:
 PropEngine::PropEngine(TheoryEngine* te, Context* context) :
   d_inCheckSat(false),
   d_theoryEngine(te),
-  d_context(context) {
+  d_context(context),
+  d_satSolver(NULL),
+  d_cnfStream(NULL),
+  d_satTimer(*this),
+  d_interrupted(false) {
+
   Debug("prop") << "Constructing the PropEngine" << endl;
 
   d_satSolver = new SatSolver(this, d_theoryEngine, d_context);
@@ -121,7 +126,7 @@ void PropEngine::printSatisfyingAssignment(){
   }
 }
 
-Result PropEngine::checkSat() {
+Result PropEngine::checkSat(unsigned long& millis, unsigned long& resource) {
   Assert(!d_inCheckSat, "Sat solver in solve()!");
   Debug("prop") << "PropEngine::checkSat()" << endl;
 
@@ -133,22 +138,37 @@ Result PropEngine::checkSat() {
   d_theoryEngine->presolve();
 
   if(Options::current()->preprocessOnly) {
+    millis = resource = 0;
     return Result(Result::SAT_UNKNOWN, Result::REQUIRES_FULL_CHECK);
   }
 
+  // Set the timer
+  d_satTimer.set(millis);
+
+  // Reset the interrupted flag
+  d_interrupted = false;
+
   // Check the problem
-  bool result = d_satSolver->solve();
+  SatLiteralValue result = d_satSolver->solve(resource);
+
+  millis = d_satTimer.elapsed();
 
-  if( result && Debug.isOn("prop") ) {
+  if( result == l_Undef ) {
+    Result::UnknownExplanation why =
+      d_satTimer.expired() ? Result::TIMEOUT :
+        (d_interrupted ? Result::INTERRUPTED : Result::RESOURCEOUT);
+    return Result(Result::SAT_UNKNOWN, why);
+  }
+
+  if( result == l_True && Debug.isOn("prop") ) {
     printSatisfyingAssignment();
   }
 
-  Debug("prop") << "PropEngine::checkSat() => "
-                << (result ? "true" : "false") << endl;
-  if(result && d_theoryEngine->isIncomplete()) {
+  Debug("prop") << "PropEngine::checkSat() => " << result << endl;
+  if(result == l_True && d_theoryEngine->isIncomplete()) {
     return Result(Result::SAT_UNKNOWN, Result::INCOMPLETE);
   }
-  return Result(result ? Result::SAT : Result::UNSAT);
+  return Result(result == l_True ? Result::SAT : Result::UNSAT);
 }
 
 Node PropEngine::getValue(TNode node) {
@@ -170,6 +190,10 @@ bool PropEngine::isSatLiteral(TNode node) {
   return d_cnfStream->hasLiteral(node);
 }
 
+bool PropEngine::isTranslatedSatLiteral(TNode node) {
+  return d_cnfStream->isTranslated(node);
+}
+
 bool PropEngine::hasValue(TNode node, bool& value) {
   Assert(node.getType().isBoolean());
   SatLiteral lit = d_cnfStream->getLiteral(node);
@@ -203,5 +227,20 @@ void PropEngine::pop() {
   Debug("prop") << "pop()" << endl;
 }
 
+void PropEngine::interrupt() throw(ModalException) {
+  if(! d_inCheckSat) {
+    throw ModalException("SAT solver is not currently solving anything; "
+                         "cannot interrupt it");
+  }
+
+  d_interrupted = true;
+  d_satSolver->interrupt();
+  Debug("prop") << "interrupt()" << endl;
+}
+
+void PropEngine::spendResource() throw() {
+  // TODO implement me
+}
+
 }/* CVC4::prop namespace */
 }/* CVC4 namespace */
-- 
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