6964458: Reimplement class meta-data storage to use native memory

Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes

Co-authored-by: Stefan Karlsson <stefan.karlsson@oracle.com>
Co-authored-by: Mikael Gerdin <mikael.gerdin@oracle.com>
Co-authored-by: Tom Rodriguez <tom.rodriguez@oracle.com>
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland

hotspot/src/share/vm/utilities/array.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2012, 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
@@ -27,6 +27,7 @@
 
 #include "memory/allocation.hpp"
 #include "memory/allocation.inline.hpp"
+#include "memory/metaspace.hpp"
 
 // correct linkage required to compile w/o warnings
 // (must be on file level - cannot be local)
@@ -97,6 +98,10 @@ template <MEMFLAGS F>class CHeapArray: public CHeapObj<F> {
     _data    = (void*) NEW_C_HEAP_ARRAY(char *, esize * length, F);
   }
 
+  void initialize(size_t esize, int length) {
+    // In debug set array to 0?
+  }
+
 #ifdef ASSERT
   void init_nesting();
 #endif
@@ -123,7 +128,7 @@ template <MEMFLAGS F>class CHeapArray: public CHeapObj<F> {
    public:                                                                               \
     /* creation */                                                                       \
     array_name() : base_class()                       {}                                 \
-    array_name(const int length) : base_class(esize, length) {}                          \
+    explicit array_name(const int length) : base_class(esize, length) {}                          \
     array_name(const int length, const etype fx)      { initialize(length, fx); }        \
     void initialize(const int length)     { base_class::initialize(esize, length); }     \
     void initialize(const int length, const etype fx) {                                  \
@@ -292,4 +297,96 @@ template <MEMFLAGS F>class CHeapArray: public CHeapObj<F> {
 define_array(boolArray, bool)          define_stack(boolStack, boolArray)
 define_array(intArray , int )          define_stack(intStack , intArray )
 
+// Array for metadata allocation
+
+template <typename T>
+class Array: public MetaspaceObj {
+  friend class MetadataFactory;
+  friend class VMStructs;
+  friend class MethodHandleCompiler;           // special case
+protected:
+  int _length;                                 // the number of array elements
+  T   _data[1];                                // the array memory
+
+  void initialize(int length) {
+    _length = length;
+  }
+
+ private:
+  // Turn off copy constructor and assignment operator.
+  Array(const Array<T>&);
+  void operator=(const Array<T>&);
+
+  void* operator new(size_t size, ClassLoaderData* loader_data, int length, bool read_only, TRAPS) {
+    size_t word_size = Array::size(length);
+    return (void*) Metaspace::allocate(loader_data, word_size, read_only,
+                        Metaspace::NonClassType, CHECK_NULL);
+  }
+
+  static size_t byte_sizeof(int length) { return sizeof(Array<T>) + MAX2(length - 1, 0) * sizeof(T); }
+
+  explicit Array(int length) : _length(length) {
+    assert(length >= 0, "illegal length");
+  }
+
+  Array(int length, T init) : _length(length) {
+    assert(length >= 0, "illegal length");
+    for (int i = 0; i < length; i++) {
+      _data[i] = init;
+    }
+  }
+
+ public:
+
+  // standard operations
+  int  length() const                 { return _length; }
+  T* data()                           { return _data; }
+  bool is_empty() const               { return length() == 0; }
+
+  int index_of(const T& x) const {
+    int i = length();
+    while (i-- > 0 && _data[i] != x) ;
+
+    return i;
+  }
+
+  // sort the array.
+  bool contains(const T& x) const      { return index_of(x) >= 0; }
+
+  T    at(int i) const                 { return _data[i]; }
+  void at_put(const int i, const T& x) { _data[i] = x; }
+  T*   adr_at(const int i)             { return &_data[i]; }
+  int  find(const T& x)                { return index_of(x); }
+
+  T at_acquire(const int which)              { return OrderAccess::load_acquire(adr_at(which)); }
+  void release_at_put(int which, T contents) { OrderAccess::release_store(adr_at(which), contents); }
+
+  static int size(int length) {
+    return align_size_up(byte_sizeof(length), BytesPerWord) / BytesPerWord;
+  }
+
+  int size() {
+    return size(_length);
+  }
+
+  static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }
+  // Note, this offset don't have to be wordSize aligned.
+  static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };
+
+  // FIXME: How to handle this?
+  void print_value_on(outputStream* st) const {
+    st->print("Array<T>(" INTPTR_FORMAT ")", this);
+  }
+
+#ifndef PRODUCT
+  void print(outputStream* st) {
+     for (int i = 0; i< _length; i++) {
+       st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));
+     }
+  }
+  void print() { print(tty); }
+#endif // PRODUCT
+};
+
+
 #endif // SHARE_VM_UTILITIES_ARRAY_HPP