--- a/src/share/vm/oops/constantPool.cpp	Tue Jun 18 14:23:29 2013 -0700
+++ b/src/share/vm/oops/constantPool.cpp	Wed Jun 19 10:45:56 2013 +0200
@@ -40,6 +40,7 @@
 #include "runtime/init.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/signature.hpp"
+#include "runtime/synchronizer.hpp"
 #include "runtime/vframe.hpp"
 
 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
@@ -54,7 +55,7 @@
   // the resolved_references array, which is recreated at startup time.
   // But that could be moved to InstanceKlass (although a pain to access from
   // assembly code).  Maybe it could be moved to the cpCache which is RW.
-  return new (loader_data, size, false, THREAD) ConstantPool(tags);
+  return new (loader_data, size, false, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
 }
 
 ConstantPool::ConstantPool(Array<u1>* tags) {
@@ -69,7 +70,6 @@
 
   // only set to non-zero if constant pool is merged by RedefineClasses
   set_version(0);
-  set_lock(new Monitor(Monitor::nonleaf + 2, "A constant pool lock"));
 
   // initialize tag array
   int length = tags->length();
@@ -95,9 +95,6 @@
 void ConstantPool::release_C_heap_structures() {
   // walk constant pool and decrement symbol reference counts
   unreference_symbols();
-
-  delete _lock;
-  set_lock(NULL);
 }
 
 objArrayOop ConstantPool::resolved_references() const {
@@ -154,9 +151,6 @@
       ClassLoaderData* loader_data = pool_holder()->class_loader_data();
       set_resolved_references(loader_data->add_handle(refs_handle));
     }
-
-    // Also need to recreate the mutex.  Make sure this matches the constructor
-    set_lock(new Monitor(Monitor::nonleaf + 2, "A constant pool lock"));
   }
 }
 
@@ -167,7 +161,23 @@
   set_resolved_reference_length(
     resolved_references() != NULL ? resolved_references()->length() : 0);
   set_resolved_references(NULL);
-  set_lock(NULL);
+}
+
+oop ConstantPool::lock() {
+  if (_pool_holder) {
+    // We re-use the _pool_holder's init_lock to reduce footprint.
+    // Notes on deadlocks:
+    // [1] This lock is a Java oop, so it can be recursively locked by
+    //     the same thread without self-deadlocks.
+    // [2] Deadlock will happen if there is circular dependency between
+    //     the <clinit> of two Java classes. However, in this case,
+    //     the deadlock would have happened long before we reach
+    //     ConstantPool::lock(), so reusing init_lock does not
+    //     increase the possibility of deadlock.
+    return _pool_holder->init_lock();
+  } else {
+    return NULL;
+  }
 }
 
 int ConstantPool::cp_to_object_index(int cp_index) {
@@ -208,7 +218,9 @@
 
   Symbol* name = NULL;
   Handle       loader;
-  {  MonitorLockerEx ml(this_oop->lock());
+  {
+    oop cplock = this_oop->lock();
+    ObjectLocker ol(cplock , THREAD, cplock != NULL);
 
     if (this_oop->tag_at(which).is_unresolved_klass()) {
       if (this_oop->tag_at(which).is_unresolved_klass_in_error()) {
@@ -255,7 +267,8 @@
 
       bool throw_orig_error = false;
       {
-        MonitorLockerEx ml(this_oop->lock());
+        oop cplock = this_oop->lock();
+        ObjectLocker ol(cplock, THREAD, cplock != NULL);
 
         // some other thread has beaten us and has resolved the class.
         if (this_oop->tag_at(which).is_klass()) {
@@ -323,7 +336,8 @@
       }
       return k();
     } else {
-      MonitorLockerEx ml(this_oop->lock());
+      oop cplock = this_oop->lock();
+      ObjectLocker ol(cplock, THREAD, cplock != NULL);
       // Only updated constant pool - if it is resolved.
       do_resolve = this_oop->tag_at(which).is_unresolved_klass();
       if (do_resolve) {
@@ -619,7 +633,8 @@
                                      int tag, TRAPS) {
   ResourceMark rm;
   Symbol* error = PENDING_EXCEPTION->klass()->name();
-  MonitorLockerEx ml(this_oop->lock());  // lock cpool to change tag.
+  oop cplock = this_oop->lock();
+  ObjectLocker ol(cplock, THREAD, cplock != NULL);  // lock cpool to change tag.
 
   int error_tag = (tag == JVM_CONSTANT_MethodHandle) ?
            JVM_CONSTANT_MethodHandleInError : JVM_CONSTANT_MethodTypeInError;
@@ -780,7 +795,8 @@
   if (cache_index >= 0) {
     // Cache the oop here also.
     Handle result_handle(THREAD, result_oop);
-    MonitorLockerEx ml(this_oop->lock());  // don't know if we really need this
+    oop cplock = this_oop->lock();
+    ObjectLocker ol(cplock, THREAD, cplock != NULL);  // don't know if we really need this
     oop result = this_oop->resolved_references()->obj_at(cache_index);
     // Benign race condition:  resolved_references may already be filled in while we were trying to lock.
     // The important thing here is that all threads pick up the same result.
@@ -1043,24 +1059,14 @@
 
   case JVM_CONSTANT_InvokeDynamic:
   {
-    int k1 = invoke_dynamic_bootstrap_method_ref_index_at(index1);
-    int k2 = cp2->invoke_dynamic_bootstrap_method_ref_index_at(index2);
-    bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
-    if (!match)  return false;
-    k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
-    k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
-    match = compare_entry_to(k1, cp2, k2, CHECK_false);
-    if (!match)  return false;
-    int argc = invoke_dynamic_argument_count_at(index1);
-    if (argc == cp2->invoke_dynamic_argument_count_at(index2)) {
-      for (int j = 0; j < argc; j++) {
-        k1 = invoke_dynamic_argument_index_at(index1, j);
-        k2 = cp2->invoke_dynamic_argument_index_at(index2, j);
-        match = compare_entry_to(k1, cp2, k2, CHECK_false);
-        if (!match)  return false;
-      }
-      return true;           // got through loop; all elements equal
-    }
+    int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
+    int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
+    int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
+    int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
+    // separate statements and variables because CHECK_false is used
+    bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
+    bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
+    return (match_entry && match_operand);
   } break;
 
   case JVM_CONSTANT_String:
@@ -1095,6 +1101,80 @@
 } // end compare_entry_to()
 
 
+// Resize the operands array with delta_len and delta_size.
+// Used in RedefineClasses for CP merge.
+void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
+  int old_len  = operand_array_length(operands());
+  int new_len  = old_len + delta_len;
+  int min_len  = (delta_len > 0) ? old_len : new_len;
+
+  int old_size = operands()->length();
+  int new_size = old_size + delta_size;
+  int min_size = (delta_size > 0) ? old_size : new_size;
+
+  ClassLoaderData* loader_data = pool_holder()->class_loader_data();
+  Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
+
+  // Set index in the resized array for existing elements only
+  for (int idx = 0; idx < min_len; idx++) {
+    int offset = operand_offset_at(idx);                       // offset in original array
+    operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
+  }
+  // Copy the bootstrap specifiers only
+  Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
+                               new_ops->adr_at(2*new_len),
+                               (min_size - 2*min_len) * sizeof(u2));
+  // Explicitly deallocate old operands array.
+  // Note, it is not needed for 7u backport.
+  if ( operands() != NULL) { // the safety check
+    MetadataFactory::free_array<u2>(loader_data, operands());
+  }
+  set_operands(new_ops);
+} // end resize_operands()
+
+
+// Extend the operands array with the length and size of the ext_cp operands.
+// Used in RedefineClasses for CP merge.
+void ConstantPool::extend_operands(constantPoolHandle ext_cp, TRAPS) {
+  int delta_len = operand_array_length(ext_cp->operands());
+  if (delta_len == 0) {
+    return; // nothing to do
+  }
+  int delta_size = ext_cp->operands()->length();
+
+  assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
+
+  if (operand_array_length(operands()) == 0) {
+    ClassLoaderData* loader_data = pool_holder()->class_loader_data();
+    Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
+    // The first element index defines the offset of second part
+    operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
+    set_operands(new_ops);
+  } else {
+    resize_operands(delta_len, delta_size, CHECK);
+  }
+
+} // end extend_operands()
+
+
+// Shrink the operands array to a smaller array with new_len length.
+// Used in RedefineClasses for CP merge.
+void ConstantPool::shrink_operands(int new_len, TRAPS) {
+  int old_len = operand_array_length(operands());
+  if (new_len == old_len) {
+    return; // nothing to do
+  }
+  assert(new_len < old_len, "shrunken operands array must be smaller");
+
+  int free_base  = operand_next_offset_at(new_len - 1);
+  int delta_len  = new_len - old_len;
+  int delta_size = 2*delta_len + free_base - operands()->length();
+
+  resize_operands(delta_len, delta_size, CHECK);
+
+} // end shrink_operands()
+
+
 void ConstantPool::copy_operands(constantPoolHandle from_cp,
                                  constantPoolHandle to_cp,
                                  TRAPS) {
@@ -1357,6 +1437,46 @@
 } // end find_matching_entry()
 
 
+// Compare this constant pool's bootstrap specifier at idx1 to the constant pool
+// cp2's bootstrap specifier at idx2.
+bool ConstantPool::compare_operand_to(int idx1, constantPoolHandle cp2, int idx2, TRAPS) {
+  int k1 = operand_bootstrap_method_ref_index_at(idx1);
+  int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
+  bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
+
+  if (!match) {
+    return false;
+  }
+  int argc = operand_argument_count_at(idx1);
+  if (argc == cp2->operand_argument_count_at(idx2)) {
+    for (int j = 0; j < argc; j++) {
+      k1 = operand_argument_index_at(idx1, j);
+      k2 = cp2->operand_argument_index_at(idx2, j);
+      match = compare_entry_to(k1, cp2, k2, CHECK_false);
+      if (!match) {
+        return false;
+      }
+    }
+    return true;           // got through loop; all elements equal
+  }
+  return false;
+} // end compare_operand_to()
+
+// Search constant pool search_cp for a bootstrap specifier that matches
+// this constant pool's bootstrap specifier at pattern_i index.
+// Return the index of a matching bootstrap specifier or (-1) if there is no match.
+int ConstantPool::find_matching_operand(int pattern_i,
+                    constantPoolHandle search_cp, int search_len, TRAPS) {
+  for (int i = 0; i < search_len; i++) {
+    bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
+    if (found) {
+      return i;
+    }
+  }
+  return -1;  // bootstrap specifier not found; return unused index (-1)
+} // end find_matching_operand()
+
+
 #ifndef PRODUCT
 
 const char* ConstantPool::printable_name_at(int which) {