Merged regex-4 branch.

[SVN r18430]

include/boost/regex/v4/mem_block_cache.hpp

@@ -0,0 +1,97 @@
+ /*
+ * Copyright (c) 2002
+ * Dr John Maddock
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.  Dr John Maddock makes no representations
+ * about the suitability of this software for any purpose.
+ * It is provided "as is" without express or implied warranty.
+ *
+ */
+
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         mem_block_cache.hpp
+  *   VERSION      see <boost/version.hpp>
+  *   DESCRIPTION: memory block cache used by the non-recursive matcher.
+  */
+
+#ifndef BOOST_REGEX_V4_MEM_BLOCK_CACHE_HPP
+#define BOOST_REGEX_V4_MEM_BLOCK_CACHE_HPP
+
+#include <new>
+#include <boost/regex/v4/regex_synch.hpp>
+
+#ifdef __BORLANDC__
+#  pragma option push -a8 -b -Vx -Ve -pc -w-8027
+#endif
+
+namespace boost{
+namespace re_detail{
+
+struct mem_block_node
+{
+   mem_block_node* next;
+};
+
+struct mem_block_cache
+{
+   // this member has to be statically initialsed:
+   mem_block_node* next;
+   unsigned cached_blocks;
+
+   ~mem_block_cache()
+   {
+      while(next)
+      {
+         mem_block_node* old = next;
+         next = next->next;
+         ::operator delete(old);
+      }
+   }
+   void* get()
+   {
+#ifdef BOOST_HAS_THREADS
+      re_detail::cs_guard g(*re_detail::p_re_lock);
+#endif
+     if(next)
+      {
+         mem_block_node* result = next;
+         next = next->next;
+         --cached_blocks;
+         return result;
+      }
+      return ::operator new(BOOST_REGEX_BLOCKSIZE);
+   }
+   void put(void* p)
+   {
+#ifdef BOOST_HAS_THREADS
+      re_detail::cs_guard g(*re_detail::p_re_lock);
+#endif
+      if(cached_blocks >= BOOST_REGEX_MAX_CACHE_BLOCKS)
+      {
+         ::operator delete(p);
+      }
+      else
+      {
+         mem_block_node* old = static_cast<mem_block_node*>(p);
+         old->next = next;
+         next = old;
+         ++cached_blocks;
+      }
+   }
+};
+
+extern mem_block_cache block_cache;
+
+}
+} // namespace boost
+
+#ifdef __BORLANDC__
+#  pragma option pop
+#endif
+
+#endif