[jbpm-commits] JBoss JBPM SVN: r4147 - jbpm3/branches/jbpm-3.2.6.GA/modules/core/src/main/java/org/jbpm/graph/exe.

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Author: alex.guizar at jboss.com
Date: 2009-03-05 01:21:49 -0500 (Thu, 05 Mar 2009)
New Revision: 4147

Modified:
   jbpm3/branches/jbpm-3.2.6.GA/modules/core/src/main/java/org/jbpm/graph/exe/ExecutionContext.java
Log:
replace Stack in ExecutionContext with List to eliminate the undue synchronization overhead

Modified: jbpm3/branches/jbpm-3.2.6.GA/modules/core/src/main/java/org/jbpm/graph/exe/ExecutionContext.java
===================================================================
--- jbpm3/branches/jbpm-3.2.6.GA/modules/core/src/main/java/org/jbpm/graph/exe/ExecutionContext.java	2009-03-05 06:12:12 UTC (rev 4146)
+++ jbpm3/branches/jbpm-3.2.6.GA/modules/core/src/main/java/org/jbpm/graph/exe/ExecutionContext.java	2009-03-05 06:21:49 UTC (rev 4147)
@@ -21,7 +21,8 @@
  */
 package org.jbpm.graph.exe;
 
-import java.util.Stack;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.jbpm.JbpmContext;
 import org.jbpm.JbpmException;
@@ -286,27 +287,29 @@
 
   // thread local execution context
 
-  static ThreadLocal<Stack<ExecutionContext>> threadLocalContextStack = new ThreadLocal<Stack<ExecutionContext>>();
-
-  static Stack<ExecutionContext> getContextStack()
+  static final ThreadLocal<List<ExecutionContext>> threadLocalContextStack = new ThreadLocal<List<ExecutionContext>>()
   {
-    Stack<ExecutionContext> stack = threadLocalContextStack.get();
-    if (stack == null)
+    @Override
+    protected List<ExecutionContext> initialValue()
     {
-      stack = new Stack<ExecutionContext>();
-      threadLocalContextStack.set(stack);
+      return new ArrayList<ExecutionContext>();
     }
-    return stack;
+  };
+
+  static List<ExecutionContext> getContextStack()
+  {
+    return threadLocalContextStack.get();
   }
 
   public static void pushCurrentContext(ExecutionContext executionContext)
   {
-    getContextStack().push(executionContext);
+    getContextStack().add(executionContext);
   }
 
   public static void popCurrentContext(ExecutionContext executionContext)
   {
-    if (getContextStack().pop() != executionContext)
+    List<ExecutionContext> contextStack = getContextStack();
+    if (contextStack.remove(contextStack.size() - 1) != executionContext)
     {
       throw new JbpmException("current execution context mismatch.  make sure that every pushed context gets popped");
     }
@@ -315,10 +318,10 @@
   public static ExecutionContext currentExecutionContext()
   {
     ExecutionContext executionContext = null;
-    Stack<ExecutionContext> stack = getContextStack();
+    List<ExecutionContext> stack = getContextStack();
     if (!stack.isEmpty())
     {
-      executionContext = stack.peek();
+      executionContext = stack.get(stack.size() - 1);
     }
     return executionContext;
   }