/usr/include/boost/regex/v4
Edit: /usr/include/boost/regex/v4/mem_block_cache.hpp (3132B)
/*
* Copyright (c) 2002
* John Maddock
*
* Use, modification and distribution are subject to the
* Boost Software License, Version 1.0. (See accompanying file
* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
*
*/
/*
* LOCATION: see http://www.boost.org for most recent version.
* FILE mem_block_cache.hpp
* VERSION see
* 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
#ifdef BOOST_HAS_THREADS
#include
#endif
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_PREFIX
#endif
#ifndef BOOST_NO_CXX11_HDR_ATOMIC
#include
#if ATOMIC_POINTER_LOCK_FREE == 2
#define BOOST_REGEX_MEM_BLOCK_CACHE_LOCK_FREE
#define BOOST_REGEX_ATOMIC_POINTER std::atomic
#endif
#endif
namespace boost{
namespace BOOST_REGEX_DETAIL_NS{
#ifdef BOOST_REGEX_MEM_BLOCK_CACHE_LOCK_FREE /* lock free implementation */
struct mem_block_cache
{
std::atomic cache[BOOST_REGEX_MAX_CACHE_BLOCKS];
~mem_block_cache()
{
for (size_t i = 0;i < BOOST_REGEX_MAX_CACHE_BLOCKS; ++i) {
if (cache[i].load()) ::operator delete(cache[i].load());
}
}
void* get()
{
for (size_t i = 0;i < BOOST_REGEX_MAX_CACHE_BLOCKS; ++i) {
void* p = cache[i].load();
if (p != NULL) {
if (cache[i].compare_exchange_strong(p, NULL)) return p;
}
}
return ::operator new(BOOST_REGEX_BLOCKSIZE);
}
void put(void* ptr)
{
for (size_t i = 0;i < BOOST_REGEX_MAX_CACHE_BLOCKS; ++i) {
void* p = cache[i].load();
if (p == NULL) {
if (cache[i].compare_exchange_strong(p, ptr)) return;
}
}
::operator delete(ptr);
}
};
#else /* lock-based implementation */
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;
#ifdef BOOST_HAS_THREADS
boost::static_mutex mut;
#endif
~mem_block_cache()
{
while(next)
{
mem_block_node* old = next;
next = next->next;
::operator delete(old);
}
}
void* get()
{
#ifdef BOOST_HAS_THREADS
boost::static_mutex::scoped_lock g(mut);
#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
boost::static_mutex::scoped_lock g(mut);
#endif
if(cached_blocks >= BOOST_REGEX_MAX_CACHE_BLOCKS)
{
::operator delete(p);
}
else
{
mem_block_node* old = static_cast(p);
old->next = next;
next = old;
++cached_blocks;
}
}
};
#endif
extern mem_block_cache block_cache;
}
} // namespace boost
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_SUFFIX
#endif
#endif