diff src/share/vm/adlc/arena.hpp @ 0:a61af66fc99e

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children c18cbe5936b8
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/adlc/arena.hpp	Sat Dec 01 00:00:00 2007 +0000
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+/*
+ * Copyright 1998-2002 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// All classes in the virtual machine must be subclassed
+// by one of the following allocation classes:
+//
+//
+// For objects allocated in the C-heap (managed by: free & malloc).
+// - CHeapObj
+//
+//
+// For embedded objects.
+// - ValueObj
+//
+// For classes used as name spaces.
+// - AllStatic
+//
+
+class CHeapObj {
+ public:
+  void* operator new(size_t size);
+  void  operator delete(void* p);
+  void* new_array(size_t size);
+};
+
+
+// Base class for objects used as value objects.
+// Calling new or delete will result in fatal error.
+
+class ValueObj {
+ public:
+  void* operator new(size_t size);
+  void operator delete(void* p);
+};
+
+// Base class for classes that constitute name spaces.
+
+class AllStatic {
+ public:
+  void* operator new(size_t size);
+  void operator delete(void* p);
+};
+
+
+//------------------------------Chunk------------------------------------------
+// Linked list of raw memory chunks
+class Chunk: public CHeapObj {
+ public:
+  void* operator new(size_t size, size_t length);
+  void  operator delete(void* p, size_t length);
+  Chunk(size_t length);
+
+  enum {
+      init_size =  1*1024,      // Size of first chunk
+      size      = 32*1024       // Default size of an Arena chunk (following the first)
+  };
+  Chunk*       _next;           // Next Chunk in list
+  size_t       _len;            // Size of this Chunk
+
+  void chop();                  // Chop this chunk
+  void next_chop();             // Chop next chunk
+
+  // Boundaries of data area (possibly unused)
+  char* bottom() const { return ((char*) this) + sizeof(Chunk);  }
+  char* top()    const { return bottom() + _len; }
+};
+
+
+//------------------------------Arena------------------------------------------
+// Fast allocation of memory
+class Arena: public CHeapObj {
+protected:
+  friend class ResourceMark;
+  friend class HandleMark;
+  friend class NoHandleMark;
+  Chunk *_first;                // First chunk
+  Chunk *_chunk;                // current chunk
+  char *_hwm, *_max;            // High water mark and max in current chunk
+  void* grow(size_t x);         // Get a new Chunk of at least size x
+  size_t _size_in_bytes;          // Size of arena (used for memory usage tracing)
+public:
+  Arena();
+  Arena(size_t init_size);
+  Arena(Arena *old);
+  ~Arena()                      { _first->chop(); }
+  char* hwm() const             { return _hwm; }
+
+  // Fast allocate in the arena.  Common case is: pointer test + increment.
+  void* Amalloc(size_t x) {
+#ifdef _LP64
+    x = (x + (8-1)) & ((unsigned)(-8));
+#else
+    x = (x + (4-1)) & ((unsigned)(-4));
+#endif
+    if (_hwm + x > _max) {
+      return grow(x);
+    } else {
+      char *old = _hwm;
+      _hwm += x;
+      return old;
+    }
+  }
+  // Further assume size is padded out to words
+  // Warning:  in LP64, Amalloc_4 is really Amalloc_8
+  void *Amalloc_4(size_t x) {
+    assert( (x&(sizeof(char*)-1)) == 0, "misaligned size" );
+    if (_hwm + x > _max) {
+      return grow(x);
+    } else {
+      char *old = _hwm;
+      _hwm += x;
+      return old;
+    }
+  }
+
+  // Fast delete in area.  Common case is: NOP (except for storage reclaimed)
+  void Afree(void *ptr, size_t size) {
+    if (((char*)ptr) + size == _hwm) _hwm = (char*)ptr;
+  }
+
+  void *Acalloc( size_t items, size_t x );
+  void *Arealloc( void *old_ptr, size_t old_size, size_t new_size );
+
+  // Reset this Arena to empty, and return this Arenas guts in a new Arena.
+  Arena *reset(void);
+
+  // Determine if pointer belongs to this Arena or not.
+  bool contains( const void *ptr ) const;
+
+  // Total of all chunks in use (not thread-safe)
+  size_t used() const;
+
+  // Total # of bytes used
+  size_t size_in_bytes() const         {  return _size_in_bytes; }
+  void   set_size_in_bytes(size_t size)  { _size_in_bytes = size;   }
+};