Add MSF plugins

examples/msf/SolverFoundation.Plugin.Z3/AbortWorker.cs

@@ -0,0 +1,92 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using Microsoft.Z3;
+
+namespace Microsoft.SolverFoundation.Plugin.Z3
+{
+    /// <summary>
+    /// Thread that will wait until the query abort function returns true or 
+    /// the stop method is called. If the abort function returns true at some
+    /// point it will issue a softCancel() call to Z3.
+    /// </summary>
+    internal class AbortWorker
+    {
+        #region Private Members
+
+        /// <summary>The Z3 solver</summary>
+        private Microsoft.Z3.Context _context;
+        /// <summary>The abort function to use to check if we are aborted</summary>
+        private Func<bool> _QueryAbortFunction;
+        /// <summary>Flag indicating that worker should stop</summary>
+        private bool _stop = false;
+        /// <summary>Flag indicating that we have been sent an abort signal</summary>
+        private bool _aborted = false;
+
+        #endregion Private Members
+
+        #region Construction
+
+        /// <summary>
+        /// Worker constructor taking a Z3 instance and a function to periodically
+        /// check for aborts.
+        /// </summary>
+        /// <param name="z3">Z3 instance</param>
+        /// <param name="queryAbortFunction">method to call to check for aborts</param>
+        public AbortWorker(Context context, Func<bool> queryAbortFunction)
+        {
+            _context = context;
+            _QueryAbortFunction = queryAbortFunction;
+        }
+
+        #endregion Construction
+
+        #region Public Methods
+
+        /// <summary>
+        /// Stop the abort worker.
+        /// </summary>
+        public void Stop()
+        {
+            _stop = true;
+        }
+
+        /// <summary>
+        /// Is true if we have been aborted.
+        /// </summary>
+        public bool Aborted
+        {
+            get
+            {
+                return _aborted;
+            }
+        }
+
+        /// <summary>
+        /// Starts the abort worker. The worker checks the abort method
+        /// periodically until either it is stopped by a call to the Stop()
+        /// method or it gets an abort signal. In the latter case it will
+        /// issue a soft abort signal to Z3.
+        /// </summary>
+        public void Start()
+        {
+            // We go until someone stops us
+            _stop = false;
+            while (!_stop && !_QueryAbortFunction())
+            {
+                // Wait for a while
+                Thread.Sleep(10);
+            }
+            // If we were stopped on abort, cancel z3
+            if (!_stop)
+            {
+                _context.Interrupt();
+                _aborted = true;
+            }
+        }
+
+        #endregion Public Methods
+    }
+}