Initial revision

src/new.cc

@@ -0,0 +1,87 @@
+/* Defines a buffered memory allocation abstraction that reduces calls to
+   malloc.
+   Copyright (C) 1989-1998 Free Software Foundation, Inc.
+   written by Douglas C. Schmidt (schmidt@ics.uci.edu)
+
+This file is part of GNU GPERF.
+
+GNU GPERF 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 1, or (at your option)
+any later version.
+
+GNU GPERF 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 GNU GPERF; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA.  */
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h> /* declares malloc(), exit() */
+#include "trace.h"
+
+/* Determine default alignment.  If your C++ compiler does not
+   like this then try something like #define DEFAULT_ALIGNMENT 8. */
+struct fooalign {char x; double d;};
+const int ALIGNMENT = ((char *)&((struct fooalign *) 0)->d - (char *)0);
+
+/* Provide an abstraction that cuts down on the number of
+   calls to NEW by buffering the memory pool from which
+   strings are allocated. */
+
+void *
+operator new (size_t size)
+{
+  T (Trace t ("operator new");)
+  static char *buf_start = 0;          /* Large array used to reduce calls to NEW. */
+  static char *buf_end = 0;            /* Indicates end of BUF_START. */
+  static size_t buf_size = 4096;       /* Size of buffer pointed to by BUF_START. */
+         char *temp;
+
+  /* Align this on correct boundaries, just to be safe... */
+  size = ((size + ALIGNMENT - 1) / ALIGNMENT) * ALIGNMENT;
+
+  /* If we are about to overflow our buffer we'll just grab another
+     chunk of memory.  Since we never free the original memory it
+     doesn't matter that no one points to the beginning of that
+     chunk. Note we use a heuristic that grows the buffer either by
+     size of the request or by twice the previous size, whichever is
+     larger. */
+
+  if (buf_start + size >= buf_end)
+    {
+      buf_size *= 2;
+      if (buf_size < size)
+        buf_size = size;
+      if ((buf_start = (char *)malloc (buf_size)) != (char *)0)
+        buf_end = buf_start + buf_size;
+      else
+        {
+          fprintf (stderr, "Virtual memory exhausted in `operator new'\n");
+          exit (1);
+        }
+    }
+
+  temp = buf_start;
+  buf_start += size;
+  return temp;
+}
+
+/* We need this deletion operator in order to make the linker happy.
+   Because `operator new' and `operator delete' always come together.  */
+
+void
+operator delete (void *ptr)
+#ifdef HAVE_THROW_DECL
+  throw()
+#endif
+{
+  T (Trace t ("operator delete");)
+  // We cannot call free here, as it doesn't match the mallocs.
+  // free ((char *) ptr);
+  (void) ptr;
+}