Merge pull request #226 from theresa-m/fix_7332_invoke

Fix LUDCL optimization

Author: DanHeidinga

src/java.base/share/classes/java/io/ObjectInputStream.java

@@ -326,26 +326,30 @@ private static class Logging {
      * read* requests
      */
 
-      /* ClassCache Entry for caching class.forName results upon enableClassCaching */
-     private static final ClassCache classCache;
-     private static final boolean isClassCachingEnabled;
-     static {
-          isClassCachingEnabled =
-             AccessController.doPrivileged(new GetClassCachingSettingAction());
-         classCache = (isClassCachingEnabled ? new ClassCache() : null);
-     }
+    /* ClassCache Entry for caching class.forName results upon enableClassCaching */
+    private static final ClassCache classCache;
+    private static final boolean isClassCachingEnabled;
+    static {
+        isClassCachingEnabled =
+            AccessController.doPrivileged(new GetClassCachingSettingAction());
+        classCache = (isClassCachingEnabled ? new ClassCache() : null);
+    }
 
 
-      /** if true LUDCL/forName results would be cached, false by default starting Java8 */
-     private static final class GetClassCachingSettingAction
-     implements PrivilegedAction<Boolean> {
- public Boolean run() {
-     String property =
-         System.getProperty("com.ibm.enableClassCaching", "false");
-     return property.equalsIgnoreCase("true");
- }
- }
+    /** if true LUDCL/forName results would be cached, true by default starting Java8 */
+    private static final class GetClassCachingSettingAction
+    implements PrivilegedAction<Boolean> {
+        public Boolean run() {
+            String property =
+                System.getProperty("com.ibm.enableClassCaching", "true");
+            return property.equalsIgnoreCase("true");
+        }
+    }
     private ClassLoader cachedLudcl;
+    /* If user code is invoked in the middle of a call to readObject the cachedLudcl
+     * must be refreshed as the ludcl could have been changed while in user code.
+     */
+    private boolean refreshLudcl = false;
 
     /**
      * Creates an ObjectInputStream that reads from the specified InputStream.
@@ -496,7 +500,7 @@ private Object readObjectImpl(Class caller)
         ClassLoader oldCachedLudcl = null;
 	boolean setCached = false;
 
-	if ((curContext == null) && (isClassCachingEnabled)) {
+	if (((null == curContext) || refreshLudcl) && (isClassCachingEnabled)) {
             oldCachedLudcl = cachedLudcl;
 
             // If caller is not provided, follow the standard path to get the cachedLudcl.
@@ -509,6 +513,7 @@ private Object readObjectImpl(Class caller)
             }
 
             setCached = true;
+            refreshLudcl = false;
         }
 
         // if nested read, passHandle contains handle of enclosing object
@@ -613,10 +618,11 @@ public Object readUnshared() throws IOException, ClassNotFoundException {
         ClassLoader oldCachedLudcl = null;
         boolean setCached = false; 
 
-        if ((curContext == null) && (isClassCachingEnabled)) {
+        if (((null == curContext) || refreshLudcl) && (isClassCachingEnabled)) {
             oldCachedLudcl = cachedLudcl;
             cachedLudcl = latestUserDefinedLoader();
             setCached = true;
+            refreshLudcl = false;
         }
 
         // if nested read, passHandle contains handle of enclosing object
@@ -793,10 +799,15 @@ protected Class<?> resolveClass(ObjectStreamClass desc)
     {
         String name = desc.getName();
         try {
-        	return ((classCache == null) ?
-        	        Class.forName(name, false, latestUserDefinedLoader()) :
-        	        classCache.get(name, cachedLudcl));
-           	
+            if (null == classCache) {
+                return Class.forName(name, false, latestUserDefinedLoader());
+            } else {
+                if (refreshLudcl) {
+                    cachedLudcl = latestUserDefinedLoader();
+                    refreshLudcl = false;
+                }
+                return classCache.get(name, cachedLudcl);
+            }
         } catch (ClassNotFoundException ex) {
             Class<?> cl = primClasses.get(name);
             if (cl != null) {
@@ -2199,6 +2210,8 @@ private Object readOrdinaryObject(boolean unshared)
             handles.lookupException(passHandle) == null &&
             desc.hasReadResolveMethod())
         {
+            /* user code is invoked */
+            refreshLudcl = true;
             Object rep = desc.invokeReadResolve(obj);
             if (unshared && rep.getClass().isArray()) {
                 rep = cloneArray(rep);
@@ -2319,6 +2332,9 @@ private void readSerialData(Object obj, ObjectStreamClass desc)
                         curContext = new SerialCallbackContext(obj, slotDesc);
 
                         bin.setBlockDataMode(true);
+
+                        /* user code is invoked */
+                        refreshLudcl = true;
                         slotDesc.invokeReadObject(obj, this);
                     } catch (ClassNotFoundException ex) {
                         /*
@@ -2371,6 +2387,8 @@ private void readSerialData(Object obj, ObjectStreamClass desc)
                     slotDesc.hasReadObjectNoDataMethod() &&
                     handles.lookupException(passHandle) == null)
                 {
+                    /* user code is invoked */
+                    refreshLudcl = true;
                     slotDesc.invokeReadObjectNoData(obj);
                 }
             }