Merge

agent/src/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebuggerLocal.java

@@ -572,9 +572,14 @@ public class WindbgDebuggerLocal extends DebuggerBase implements WindbgDebugger
       DTFWHome = sysRoot + File.separator + ".." + File.separator +
           "Program Files" + File.separator + "Debugging Tools For Windows";
       searchList.add(DTFWHome);
+
+      // Only add the search path for the current CPU architecture:
+      String cpu = PlatformInfo.getCPU();
+      if (cpu.equals("x86")) {
           searchList.add(DTFWHome + " (x86)");
+      } else if (cpu.equals("amd64")) {
           searchList.add(DTFWHome + " (x64)");
-
+      }
       // The last place to search is the system directory:
       searchList.add(sysRoot + File.separator + "system32");
     }

src/share/vm/classfile/symbolTable.cpp

@@ -677,9 +677,14 @@ oop StringTable::lookup(Symbol* symbol) {
   ResourceMark rm;
   int length;
   jchar* chars = symbol->as_unicode(length);
-  unsigned int hashValue = hash_string(chars, length);
-  int index = the_table()->hash_to_index(hashValue);
-  return the_table()->lookup(index, chars, length, hashValue);
+  return lookup(chars, length);
+}
+
+
+oop StringTable::lookup(jchar* name, int len) {
+  unsigned int hash = hash_string(name, len);
+  int index = the_table()->hash_to_index(hash);
+  return the_table()->lookup(index, name, len, hash);
 }
 
 

src/share/vm/classfile/symbolTable.hpp

@@ -287,6 +287,7 @@ public:
 
   // Probing
   static oop lookup(Symbol* symbol);
+  static oop lookup(jchar* chars, int length);
 
   // Interning
   static oop intern(Symbol* symbol, TRAPS);

src/share/vm/classfile/systemDictionary.cpp

@@ -816,13 +816,28 @@ Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name, Handle cla
             // We didn't go as far as Klass::restore_unshareable_info(),
             // so nothing to clean up.
           } else {
+            Klass *kk;
+            {
               MutexLocker mu(SystemDictionary_lock, THREAD);
-            Klass* kk = find_class(name, ik->class_loader_data());
+              kk = find_class(name, ik->class_loader_data());
+            }
             if (kk != NULL) {
               // No clean up is needed if the shared class has been entered
               // into system dictionary, as load_shared_class() won't be called
               // again.
             } else {
+              // This must be done outside of the SystemDictionary_lock to
+              // avoid deadlock.
+              //
+              // Note that Klass::restore_unshareable_info (called via
+              // load_instance_class above) is also called outside
+              // of SystemDictionary_lock. Other threads are blocked from
+              // loading this class because they are waiting on the
+              // SystemDictionary_lock until this thread removes
+              // the placeholder below.
+              //
+              // This need to be re-thought when parallel-capable non-boot
+              // classloaders are supported by CDS (today they're not).
               clean_up_shared_class(ik, class_loader, THREAD);
             }
           }
@@ -2185,10 +2200,9 @@ Symbol* SystemDictionary::find_resolution_error(constantPoolHandle pool, int whi
 // Make sure all class components (including arrays) in the given
 // signature will be resolved to the same class in both loaders.
 // Returns the name of the type that failed a loader constraint check, or
-// NULL if no constraint failed. The returned C string needs cleaning up
-// with a ResourceMark in the caller.  No exception except OOME is thrown.
+// NULL if no constraint failed.  No exception except OOME is thrown.
 // Arrays are not added to the loader constraint table, their elements are.
-char* SystemDictionary::check_signature_loaders(Symbol* signature,
+Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
                                                Handle loader1, Handle loader2,
                                                bool is_method, TRAPS)  {
   // Nothing to do if loaders are the same.
@@ -2196,14 +2210,12 @@ char* SystemDictionary::check_signature_loaders(Symbol* signature,
     return NULL;
   }
 
-  ResourceMark rm(THREAD);
   SignatureStream sig_strm(signature, is_method);
   while (!sig_strm.is_done()) {
     if (sig_strm.is_object()) {
-      Symbol* s = sig_strm.as_symbol(CHECK_NULL);
-      Symbol*  sig  = s;
+      Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
       if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
-        return sig->as_C_string();
+        return sig;
       }
     }
     sig_strm.next();

src/share/vm/classfile/systemDictionary.hpp

@@ -483,7 +483,7 @@ public:
   // Check class loader constraints
   static bool add_loader_constraint(Symbol* name, Handle loader1,
                                     Handle loader2, TRAPS);
-  static char* check_signature_loaders(Symbol* signature, Handle loader1,
+  static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
                                          Handle loader2, bool is_method, TRAPS);
 
   // JSR 292

src/share/vm/interpreter/linkResolver.cpp

@@ -458,25 +458,27 @@ void LinkResolver::resolve_method(methodHandle& resolved_method, KlassHandle res
     Handle class_loader (THREAD, resolved_method->method_holder()->class_loader());
     {
       ResourceMark rm(THREAD);
-      char* failed_type_name =
+      Symbol* failed_type_symbol =
         SystemDictionary::check_signature_loaders(method_signature, loader,
                                                   class_loader, true, CHECK);
-      if (failed_type_name != NULL) {
+      if (failed_type_symbol != NULL) {
         const char* msg = "loader constraint violation: when resolving method"
           " \"%s\" the class loader (instance of %s) of the current class, %s,"
-          " and the class loader (instance of %s) for resolved class, %s, have"
+          " and the class loader (instance of %s) for the method's defining class, %s, have"
           " different Class objects for the type %s used in the signature";
         char* sig = Method::name_and_sig_as_C_string(resolved_klass(),method_name,method_signature);
         const char* loader1 = SystemDictionary::loader_name(loader());
         char* current = InstanceKlass::cast(current_klass())->name()->as_C_string();
         const char* loader2 = SystemDictionary::loader_name(class_loader());
-        char* resolved = InstanceKlass::cast(resolved_klass())->name()->as_C_string();
+        char* target = InstanceKlass::cast(resolved_method->method_holder())
+                       ->name()->as_C_string();
+        char* failed_type_name = failed_type_symbol->as_C_string();
         size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
-          strlen(current) + strlen(loader2) + strlen(resolved) +
-          strlen(failed_type_name);
+          strlen(current) + strlen(loader2) + strlen(target) +
+          strlen(failed_type_name) + 1;
         char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
         jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
-                     resolved, failed_type_name);
+                     target, failed_type_name);
         THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
       }
     }
@@ -520,26 +522,28 @@ void LinkResolver::resolve_interface_method(methodHandle& resolved_method,
     Handle class_loader (THREAD, resolved_method->method_holder()->class_loader());
     {
       ResourceMark rm(THREAD);
-      char* failed_type_name =
+      Symbol* failed_type_symbol =
         SystemDictionary::check_signature_loaders(method_signature, loader,
                                                   class_loader, true, CHECK);
-      if (failed_type_name != NULL) {
+      if (failed_type_symbol != NULL) {
         const char* msg = "loader constraint violation: when resolving "
           "interface method \"%s\" the class loader (instance of %s) of the "
           "current class, %s, and the class loader (instance of %s) for "
-          "resolved class, %s, have different Class objects for the type %s "
+          "the method's defining class, %s, have different Class objects for the type %s "
           "used in the signature";
         char* sig = Method::name_and_sig_as_C_string(resolved_klass(),method_name,method_signature);
         const char* loader1 = SystemDictionary::loader_name(loader());
         char* current = InstanceKlass::cast(current_klass())->name()->as_C_string();
         const char* loader2 = SystemDictionary::loader_name(class_loader());
-        char* resolved = InstanceKlass::cast(resolved_klass())->name()->as_C_string();
+        char* target = InstanceKlass::cast(resolved_method->method_holder())
+                       ->name()->as_C_string();
+        char* failed_type_name = failed_type_symbol->as_C_string();
         size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
-          strlen(current) + strlen(loader2) + strlen(resolved) +
-          strlen(failed_type_name);
+          strlen(current) + strlen(loader2) + strlen(target) +
+          strlen(failed_type_name) + 1;
         char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
         jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
-                     resolved, failed_type_name);
+                     target, failed_type_name);
         THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
       }
     }
@@ -642,12 +646,12 @@ void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle poo
     Symbol*  signature_ref  = pool->signature_ref_at(index);
     {
       ResourceMark rm(THREAD);
-      char* failed_type_name =
+      Symbol* failed_type_symbol =
         SystemDictionary::check_signature_loaders(signature_ref,
                                                   ref_loader, sel_loader,
                                                   false,
                                                   CHECK);
-      if (failed_type_name != NULL) {
+      if (failed_type_symbol != NULL) {
         const char* msg = "loader constraint violation: when resolving field"
           " \"%s\" the class loader (instance of %s) of the referring class, "
           "%s, and the class loader (instance of %s) for the field's resolved "
@@ -656,8 +660,9 @@ void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle poo
         const char* loader1 = SystemDictionary::loader_name(ref_loader());
         char* sel = InstanceKlass::cast(sel_klass())->name()->as_C_string();
         const char* loader2 = SystemDictionary::loader_name(sel_loader());
+        char* failed_type_name = failed_type_symbol->as_C_string();
         size_t buflen = strlen(msg) + strlen(field_name) + strlen(loader1) +
-          strlen(sel) + strlen(loader2) + strlen(failed_type_name);
+          strlen(sel) + strlen(loader2) + strlen(failed_type_name) + 1;
         char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
         jio_snprintf(buf, buflen, msg, field_name, loader1, sel, loader2,
                      failed_type_name);

src/share/vm/oops/constMethod.cpp

@@ -363,6 +363,26 @@ AnnotationArray** ConstMethod::default_annotations_addr() const {
   return (AnnotationArray**)constMethod_end() - offset;
 }
 
+// copy annotations from 'cm' to 'this'
+void ConstMethod::copy_annotations_from(ConstMethod* cm) {
+  if (cm->has_method_annotations()) {
+    assert(has_method_annotations(), "should be allocated already");
+    set_method_annotations(cm->method_annotations());
+  }
+  if (cm->has_parameter_annotations()) {
+    assert(has_parameter_annotations(), "should be allocated already");
+    set_parameter_annotations(cm->parameter_annotations());
+  }
+  if (cm->has_type_annotations()) {
+    assert(has_type_annotations(), "should be allocated already");
+    set_type_annotations(cm->type_annotations());
+  }
+  if (cm->has_default_annotations()) {
+    assert(has_default_annotations(), "should be allocated already");
+    set_default_annotations(cm->default_annotations());
+  }
+}
+
 // Printing
 
 void ConstMethod::print_on(outputStream* st) const {

src/share/vm/oops/constMethod.hpp

@@ -441,6 +441,9 @@ public:
     return has_default_annotations() ? default_annotations()->length() : 0;
   }
 
+  // Copy annotations from other ConstMethod
+  void copy_annotations_from(ConstMethod* cm);
+
   // byte codes
   void    set_code(address code) {
     if (code_size() > 0) {

src/share/vm/oops/klassVtable.cpp

@@ -327,11 +327,11 @@ bool klassVtable::update_inherited_vtable(InstanceKlass* klass, methodHandle tar
 
           if (target_loader() != super_loader()) {
             ResourceMark rm(THREAD);
-            char* failed_type_name =
+            Symbol* failed_type_symbol =
               SystemDictionary::check_signature_loaders(signature, target_loader,
                                                         super_loader, true,
                                                         CHECK_(false));
-            if (failed_type_name != NULL) {
+            if (failed_type_symbol != NULL) {
               const char* msg = "loader constraint violation: when resolving "
                 "overridden method \"%s\" the class loader (instance"
                 " of %s) of the current class, %s, and its superclass loader "
@@ -341,6 +341,7 @@ bool klassVtable::update_inherited_vtable(InstanceKlass* klass, methodHandle tar
               const char* loader1 = SystemDictionary::loader_name(target_loader());
               char* current = _klass->name()->as_C_string();
               const char* loader2 = SystemDictionary::loader_name(super_loader());
+              char* failed_type_name = failed_type_symbol->as_C_string();
               size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
                 strlen(current) + strlen(loader2) + strlen(failed_type_name);
               char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
@@ -787,12 +788,12 @@ void klassItable::initialize_itable_for_interface(int method_table_offset, Klass
         Handle method_holder_loader (THREAD, target->method_holder()->class_loader());
         if (method_holder_loader() != interface_loader()) {
           ResourceMark rm(THREAD);
-          char* failed_type_name =
+          Symbol* failed_type_symbol =
             SystemDictionary::check_signature_loaders(method_signature,
                                                       method_holder_loader,
                                                       interface_loader,
                                                       true, CHECK);
-          if (failed_type_name != NULL) {
+          if (failed_type_symbol != NULL) {
             const char* msg = "loader constraint violation in interface "
               "itable initialization: when resolving method \"%s\" the class"
               " loader (instance of %s) of the current class, %s, "
@@ -804,6 +805,7 @@ void klassItable::initialize_itable_for_interface(int method_table_offset, Klass
             char* current = klass->name()->as_C_string();
             const char* loader2 = SystemDictionary::loader_name(interface_loader());
             char* iface = InstanceKlass::cast(interf_h())->name()->as_C_string();
+            char* failed_type_name = failed_type_symbol->as_C_string();
             size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
               strlen(current) + strlen(loader2) + strlen(iface) +
               strlen(failed_type_name);

src/share/vm/oops/method.cpp

@@ -1170,6 +1170,8 @@ methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int n
     newm->set_stackmap_data(stackmap_data);
   }
 
+  // copy annotations over to new method
+  newcm->copy_annotations_from(cm);
   return newm;
 }
 

src/share/vm/oops/symbol.cpp

@@ -162,7 +162,7 @@ char* Symbol::as_quoted_ascii() const {
   const char *ptr = (const char *)&_body[0];
   int quoted_length = UTF8::quoted_ascii_length(ptr, utf8_length());
   char* result = NEW_RESOURCE_ARRAY(char, quoted_length + 1);
-  UTF8::as_quoted_ascii(ptr, result, quoted_length + 1);
+  UTF8::as_quoted_ascii(ptr, utf8_length(), result, quoted_length + 1);
   return result;
 }
 

src/share/vm/prims/whitebox.cpp

@@ -254,6 +254,24 @@ WB_ENTRY(jint, WB_GetCompileQueuesSize(JNIEnv* env, jobject o))
          CompileBroker::queue_size(CompLevel_full_profile) /* C1 */;
 WB_END
 
+WB_ENTRY(jboolean, WB_IsInStringTable(JNIEnv* env, jobject o, jstring javaString))
+  ResourceMark rm(THREAD);
+  int len;
+  jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len);
+  oop found_string = StringTable::the_table()->lookup(name, len);
+  if (found_string == NULL) {
+        return false;
+  }
+  return true;
+WB_END
+
+
+WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o))
+  Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(true);
+  Universe::heap()->collect(GCCause::_last_ditch_collection);
+WB_END
+
+
 //Some convenience methods to deal with objects from java
 int WhiteBox::offset_for_field(const char* field_name, oop object,
     Symbol* signature_symbol) {
@@ -343,6 +361,8 @@ static JNINativeMethod methods[] = {
       CC"(Ljava/lang/reflect/Method;)I",              (void*)&WB_GetMethodCompilationLevel},
   {CC"getCompileQueuesSize",
       CC"()I",                                        (void*)&WB_GetCompileQueuesSize},
+  {CC"isInStringTable",   CC"(Ljava/lang/String;)Z",  (void*)&WB_IsInStringTable  },
+  {CC"fullGC",   CC"()V",                             (void*)&WB_FullGC },
 };
 
 #undef CC

src/share/vm/runtime/arguments.cpp

@@ -3327,6 +3327,13 @@ jint Arguments::parse(const JavaVMInitArgs* args) {
   }
   check_deprecated_gcs();
   check_deprecated_gc_flags();
+  if (AssumeMP && !UseSerialGC) {
+    if (FLAG_IS_DEFAULT(ParallelGCThreads) && ParallelGCThreads == 1) {
+      warning("If the number of processors is expected to increase from one, then"
+              " you should configure the number of parallel GC threads appropriately"
+              " using -XX:ParallelGCThreads=N");
+    }
+  }
 #else // INCLUDE_ALL_GCS
   assert(verify_serial_gc_flags(), "SerialGC unset");
 #endif // INCLUDE_ALL_GCS

src/share/vm/runtime/globals.hpp

@@ -457,6 +457,9 @@ class CommandLineFlags {
   lp64_product(intx, ObjectAlignmentInBytes, 8,                             \
           "Default object alignment in bytes, 8 is minimum")                \
                                                                             \
+  product(bool, AssumeMP, false,                                            \
+          "Instruct the VM to assume multiple processors are available")    \
+                                                                            \
   /* UseMembar is theoretically a temp flag used for memory barrier         \
    * removal testing.  It was supposed to be removed before FCS but has     \
    * been re-added (see 6401008) */                                         \

src/share/vm/runtime/os.hpp

@@ -180,7 +180,7 @@ class os: AllStatic {
   // Interface for detecting multiprocessor system
   static inline bool is_MP() {
     assert(_processor_count > 0, "invalid processor count");
-    return _processor_count > 1;
+    return _processor_count > 1 || AssumeMP;
   }
   static julong available_memory();
   static julong physical_memory();

src/share/vm/services/memTracker.hpp

@@ -86,13 +86,13 @@ class MemTracker : AllStatic {
 
    static inline void set_autoShutdown(bool value) { }
    static void shutdown(ShutdownReason reason) { }
-   static inline bool shutdown_in_progress() {  }
+   static inline bool shutdown_in_progress() { return false; }
    static bool print_memory_usage(BaselineOutputer& out, size_t unit,
-            bool summary_only = true) { }
+            bool summary_only = true) { return false; }
    static bool compare_memory_usage(BaselineOutputer& out, size_t unit,
-            bool summary_only = true) { }
+            bool summary_only = true) { return false; }
 
-   static bool wbtest_wait_for_data_merge() { }
+   static bool wbtest_wait_for_data_merge() { return false; }
 
    static inline void sync() { }
    static inline void thread_exiting(JavaThread* thread) { }

src/share/vm/utilities/utf8.cpp

 /*
- * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -180,11 +180,12 @@ int UTF8::quoted_ascii_length(const char* utf8_str, int utf8_length) {
 }
 
 // converts a utf8 string to quoted ascii
-void UTF8::as_quoted_ascii(const char* utf8_str, char* buf, int buflen) {
+void UTF8::as_quoted_ascii(const char* utf8_str, int utf8_length, char* buf, int buflen) {
   const char *ptr = utf8_str;
+  const char *utf8_end = ptr + utf8_length;
   char* p = buf;
   char* end = buf + buflen;
-  while (*ptr != '\0') {
+  while (ptr < utf8_end) {
     jchar c;
     ptr = UTF8::next(ptr, &c);
     if (c >= 32 && c < 127) {
@@ -196,6 +197,7 @@ void UTF8::as_quoted_ascii(const char* utf8_str, char* buf, int buflen) {
       p += 6;
     }
   }
+  assert(p < end, "sanity");
   *p = '\0';
 }
 

src/share/vm/utilities/utf8.hpp

 /*
- * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,7 @@ class UTF8 : AllStatic {
   static int quoted_ascii_length(const char* utf8_str, int utf8_length);
 
   // converts a utf8 string to quoted ascii
-  static void as_quoted_ascii(const char* utf8_str, char* buf, int buflen);
+  static void as_quoted_ascii(const char* utf8_str, int utf8_length, char* buf, int buflen);
 
   // converts a quoted ascii string to utf8 string.  returns the original
   // string unchanged if nothing needs to be done.

test/runtime/7116786/Test7116786.java

 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -338,9 +338,12 @@ class VerifyErrorCases {
                  "invalid constant pool index in ldc",
                  "Invalid index in ldc"),
 
-        new Case("case58", "verifier.cpp", true, "verify_switch",
+        /* No longer a valid test case for bytecode version >= 51. Nonzero
+         * padding bytes are permitted with lookupswitch and tableswitch
+         * bytecodes as of JVMS 3d edition */
+        new Case("case58", "verifier.cpp", false, "verify_switch",
                  "bad switch padding",
-                 "Nonzero padding byte in lookswitch or tableswitch"),
+                 "Nonzero padding byte in lookupswitch or tableswitch"),
 
         new Case("case59", "verifier.cpp", true, "verify_switch",
                  "tableswitch low is greater than high",

test/runtime/interned/SanityTest.java

+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test SanityTest
+ * @summary Sanity check of String.intern() & GC
+ * @library /testlibrary /testlibrary/whitebox
+ * @build SanityTest
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI SanityTest
+ */
+
+import java.util.*;
+import sun.hotspot.WhiteBox;
+
+
+public class SanityTest {
+    public static Object tmp;
+    public static void main(String... args) {
+
+        WhiteBox wb = WhiteBox.getWhiteBox();
+        StringBuilder sb = new StringBuilder();
+        sb.append("1234x"); sb.append("x56789");
+        String str = sb.toString();
+
+        if (wb.isInStringTable(str)) {
+            throw new RuntimeException("String " + str + " is already interned");
+        }
+        str.intern();
+        if (!wb.isInStringTable(str)) {
+            throw new RuntimeException("String " + str + " is not interned");
+        }
+        str = sb.toString();
+        wb.fullGC();
+        if (wb.isInStringTable(str)) {
+            throw new RuntimeException("String " + str + " is in StringTable even after GC");
+        }
+    }
+}

test/testlibrary/whitebox/sun/hotspot/WhiteBox.java

@@ -94,4 +94,10 @@ public class WhiteBox {
   public native int     getMethodCompilationLevel(Method method);
   public native boolean setDontInlineMethod(Method method, boolean value);
   public native int     getCompileQueuesSize();
+
+  //Intered strings
+  public native boolean isInStringTable(String str);
+
+  // force Full GC
+  public native void fullGC();
 }