Revert "Add LockSupport.park to 004-ThreadStress"

This reverts commit 91587ea543d42e05975f16f9dc7720d47f5cd75d.

Reason for revert: Creates timeouts in automated testing.

Bug: 119017401
Change-Id: I0e0217d30b564d8224d73a381a34ca5394f3128c
diff --git a/test/004-ThreadStress/src-art/Main.java b/test/004-ThreadStress/src-art/Main.java
index b8bfafb..3a89f4f 100644
--- a/test/004-ThreadStress/src-art/Main.java
+++ b/test/004-ThreadStress/src-art/Main.java
@@ -26,7 +26,6 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.Semaphore;
-import java.util.concurrent.locks.LockSupport;
 
 // Run on host with:
 //   javac ThreadTest.java && java ThreadStress && rm *.class
@@ -252,31 +251,6 @@
         }
     }
 
-    private final static class TimedPark extends Operation {
-        private final static int SLEEP_TIME = 100;
-
-        public TimedPark() {}
-
-        @Override
-        public boolean perform() {
-            LockSupport.parkNanos(this, 100*1000000);
-            return true;
-        }
-    }
-
-    private final static class UnparkAllThreads extends Operation {
-        public UnparkAllThreads() {}
-
-        @Override
-        public boolean perform() {
-            Set<Thread> threads = Thread.getAllStackTraces().keySet();
-            for (Thread candidate : threads) {
-                LockSupport.unpark(candidate);
-            }
-            return true;
-        }
-    }
-
     private final static class SyncAndWork extends Operation {
         private final Object lock;
 
@@ -346,9 +320,7 @@
         frequencyMap.put(new NonMovingAlloc(), 0.025);        //   5/200
         frequencyMap.put(new StackTrace(), 0.1);              //  20/200
         frequencyMap.put(new Exit(), 0.225);                  //  45/200
-        frequencyMap.put(new Sleep(), 0.125);                 //  15/200
-        frequencyMap.put(new TimedPark(), 0.025);             //   5/200
-        frequencyMap.put(new UnparkAllThreads(), 0.025);      //   5/200
+        frequencyMap.put(new Sleep(), 0.125);                 //  25/200
         frequencyMap.put(new TimedWait(lock), 0.05);          //  10/200
         frequencyMap.put(new Wait(lock), 0.075);              //  15/200
         frequencyMap.put(new QueuedWait(semaphore), 0.05);    //  10/200
@@ -369,11 +341,9 @@
     private final static Map<Operation, Double> createLockFrequencyMap(Object lock) {
       Map<Operation, Double> frequencyMap = new HashMap<Operation, Double>();
       frequencyMap.put(new Sleep(), 0.2);                     //  40/200
-      frequencyMap.put(new TimedWait(lock), 0.1);             //  20/200
-      frequencyMap.put(new Wait(lock), 0.1);                  //  20/200
+      frequencyMap.put(new TimedWait(lock), 0.2);             //  40/200
+      frequencyMap.put(new Wait(lock), 0.2);                  //  40/200
       frequencyMap.put(new SyncAndWork(lock), 0.4);           //  80/200
-      frequencyMap.put(new TimedPark(), 0.1);                 //  20/200
-      frequencyMap.put(new UnparkAllThreads(), 0.1);          //  20/200
 
       return frequencyMap;
     }