Chris@16:  /*
Chris@16:  * Copyright (c) 2002
Chris@16:  * John Maddock
Chris@16:  *
Chris@16:  * Use, modification and distribution are subject to the 
Chris@16:  * Boost Software License, Version 1.0. (See accompanying file 
Chris@16:  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  *
Chris@16:  */
Chris@16: 
Chris@16:  /*
Chris@16:   *   LOCATION:    see http://www.boost.org for most recent version.
Chris@16:   *   FILE         mem_block_cache.hpp
Chris@16:   *   VERSION      see <boost/version.hpp>
Chris@16:   *   DESCRIPTION: memory block cache used by the non-recursive matcher.
Chris@16:   */
Chris@16: 
Chris@16: #ifndef BOOST_REGEX_V4_MEM_BLOCK_CACHE_HPP
Chris@16: #define BOOST_REGEX_V4_MEM_BLOCK_CACHE_HPP
Chris@16: 
Chris@16: #include <new>
Chris@16: #ifdef BOOST_HAS_THREADS
Chris@16: #include <boost/regex/pending/static_mutex.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost{
Chris@16: namespace re_detail{
Chris@16: 
Chris@16: struct mem_block_node
Chris@16: {
Chris@16:    mem_block_node* next;
Chris@16: };
Chris@16: 
Chris@16: struct mem_block_cache
Chris@16: {
Chris@16:    // this member has to be statically initialsed:
Chris@16:    mem_block_node* next;
Chris@16:    unsigned cached_blocks;
Chris@16: #ifdef BOOST_HAS_THREADS
Chris@16:    boost::static_mutex mut;
Chris@16: #endif
Chris@16: 
Chris@16:    ~mem_block_cache()
Chris@16:    {
Chris@16:       while(next)
Chris@16:       {
Chris@16:          mem_block_node* old = next;
Chris@16:          next = next->next;
Chris@16:          ::operator delete(old);
Chris@16:       }
Chris@16:    }
Chris@16:    void* get()
Chris@16:    {
Chris@16: #ifdef BOOST_HAS_THREADS
Chris@16:       boost::static_mutex::scoped_lock g(mut);
Chris@16: #endif
Chris@16:      if(next)
Chris@16:       {
Chris@16:          mem_block_node* result = next;
Chris@16:          next = next->next;
Chris@16:          --cached_blocks;
Chris@16:          return result;
Chris@16:       }
Chris@16:       return ::operator new(BOOST_REGEX_BLOCKSIZE);
Chris@16:    }
Chris@16:    void put(void* p)
Chris@16:    {
Chris@16: #ifdef BOOST_HAS_THREADS
Chris@16:       boost::static_mutex::scoped_lock g(mut);
Chris@16: #endif
Chris@16:       if(cached_blocks >= BOOST_REGEX_MAX_CACHE_BLOCKS)
Chris@16:       {
Chris@16:          ::operator delete(p);
Chris@16:       }
Chris@16:       else
Chris@16:       {
Chris@16:          mem_block_node* old = static_cast<mem_block_node*>(p);
Chris@16:          old->next = next;
Chris@16:          next = old;
Chris@16:          ++cached_blocks;
Chris@16:       }
Chris@16:    }
Chris@16: };
Chris@16: 
Chris@16: extern mem_block_cache block_cache;
Chris@16: 
Chris@16: }
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: 
Chris@16: #endif
Chris@16: