Initial revision

lbtt/src/LbttAlloc.h

+/*
+ *  Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004
+ *  Heikki Tauriainen <Heikki.Tauriainen@hut.fi>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program 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 for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef LBTTALLOC_H
+#define LBTTALLOC_H
+
+#include <config.h>
+
+#ifdef HAVE_SINGLE_CLIENT_ALLOC
+#define ALLOC(typename) single_client_alloc
+#else
+#define ALLOC(typename) allocator<typename>
+#endif /* HAVE_SINGLE_CLIENT_ALLOC */
+
+#ifdef HAVE_OBSTACK_H
+
+/* GNU libc 2.3.2's copy of obstack.h uses a definition of __INT_TO_PTR
+   which does not compile in C++.  Fortunately it will not override
+   an existing definition.  */
+
+#ifdef GLIBC_OBSTACK_WORKAROUND
+#define __INT_TO_PTR(P) ((P) + (char *) 0)
+#endif
+
+#include <obstack.h>
+#include <cstdlib>
+#include <new>
+
+/******************************************************************************
+ *
+ * A wrapper class for allocating memory through an obstack.
+ *
+ *****************************************************************************/
+
+class ObstackAllocator
+{
+public:
+  ObstackAllocator();                               /* Constructor. */
+
+  ~ObstackAllocator();                              /* Destructor. */
+
+  void* alloc(int size);                            /* Allocates memory. */
+
+  void free(void* obj);                             /* Deallocates memory. */
+
+  static void failure();                            /* Callback function for
+						     * reporting a memory
+						     * allocation failure.
+						     */
+private:
+  ObstackAllocator(const ObstackAllocator&);        /* Prevent copying and */
+  ObstackAllocator& operator=                       /* assignment of       */
+    (const ObstackAllocator&);                      /* ObstackAllocator
+						     * objects.
+						     */
+
+  struct obstack store;                             /* The obstack. */
+};
+
+#define obstack_chunk_alloc std::malloc
+#define obstack_chunk_free std::free
+
+
+
+/******************************************************************************
+ *
+ * Inline function definitions for class ObstackAllocator.
+ *
+ *****************************************************************************/
+
+/* ========================================================================= */
+inline ObstackAllocator::ObstackAllocator()
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Constructor for class ObstackAllocator.
+ *
+ * Arguments:     None.
+ *
+ * Returns:       Nothing.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  obstack_init(&store);
+}
+
+/* ========================================================================= */
+inline ObstackAllocator::~ObstackAllocator()
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Destructor for class ObstackAllocator.
+ *
+ * Arguments:     None.
+ *
+ * Returns:       Nothing.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  obstack_free(&store, NULL);
+}
+
+/* ========================================================================= */
+inline void* ObstackAllocator::alloc(int size)
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Interface to the memory allocator.
+ *
+ * Argument:      size  --  Number of bytes to allocate.
+ *
+ * Returns:       A pointer to the beginning of the newly allocated memory.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  return obstack_alloc(&store, size);
+}
+
+/* ========================================================================= */
+inline void ObstackAllocator::free(void* obj)
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Interface to the memory deallocation function.
+ *
+ * Argument:      obj  --  A pointer to the object to deallocate. (Because the
+ *                         underlying memory allocator is an obstack, freeing
+ *                         an object also releases all objects allocated after
+ *                         the given object.)
+ *
+ * Returns:       Nothing.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  obstack_free(&store, obj);
+}
+
+/* ========================================================================= */
+inline void ObstackAllocator::failure()
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Callback function for reporting memory allocation failures.
+ *
+ * Arguments:     None.
+ *
+ * Returns:       Nothing.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  throw std::bad_alloc();
+}
+
+#endif /* HAVE_OBSTACK_H */
+
+#endif /* !LBTTALLOC_H */