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 /*

  *

  * Copyright (c) 1996,1997

  * Silicon Graphics Computer Systems, Inc.

  *

  * Copyright (c) 1997

  * Moscow Center for SPARC Technology

  *

  * Copyright (c) 1999

  * Boris Fomitchev

  *

  * This material is provided "as is", with absolutely no warranty expressed

  * or implied. Any use is at your own risk.

  *

  * Permission to use or copy this software for any purpose is hereby granted

  * without fee, provided the above notices are retained on all copies.

  * Permission to modify the code and to distribute modified code is granted,

  * provided the above notices are retained, and a notice that the code was

  * modified is included with the above copyright notice.

  *

  */

 #include "stlport_prefix.h"

 #include <memory>

 #if defined (__GNUC__) && (defined (__CYGWIN__) || defined (__MINGW32__))

 #  include <malloc.h>

 #endif

 #if defined (_STLP_PTHREADS) && !defined (_STLP_NO_THREADS)

 #  include <pthread_alloc>

 #  include <cerrno>

 #endif

 #include <stl/_threads.h>

 #include "lock_free_slist.h"

 #if defined (__WATCOMC__)

 #  pragma warning 13 9

 #  pragma warning 367 9

 #  pragma warning 368 9

 #endif

 #if defined (_STLP_SGI_THREADS)

   // We test whether threads are in use before locking.

   // Perhaps this should be moved into stl_threads.h, but that

   // probably makes it harder to avoid the procedure call when

   // it isn't needed.

 extern "C" {

   extern int __us_rsthread_malloc;

 }

 #endif

 // Specialised debug form of new operator which does not provide "false"

 // memory leaks when run with debug CRT libraries.

 #if defined (_STLP_MSVC) && (_STLP_MSVC >= 1020 && defined (_STLP_DEBUG_ALLOC)) && !defined (_STLP_WCE)

 #  include <crtdbg.h>

 inline char* __stlp_new_chunk(size_t __bytes) {

   void *__chunk = _STLP_CHECK_NULL_ALLOC(::operator new(__bytes, __FILE__, __LINE__));

   return __STATIC_CAST(char*, __chunk);

 }

 inline void __stlp_delete_chunck(void* __p) { ::operator delete(__p, __FILE__, __LINE__); }

 #else

 #  ifdef _STLP_NODE_ALLOC_USE_MALLOC

 #    include <cstdlib>

 inline char* __stlp_new_chunk(size_t __bytes) {

   // do not use _STLP_CHECK_NULL_ALLOC, this macro is dedicated to new operator.

   void *__chunk = _STLP_VENDOR_CSTD::malloc(__bytes);

   if (__chunk == 0) {

     _STLP_THROW_BAD_ALLOC;

   }

   return __STATIC_CAST(char*, __chunk);

 }

 inline void __stlp_delete_chunck(void* __p) { _STLP_VENDOR_CSTD::free(__p); }

 #  else

 inline char* __stlp_new_chunk(size_t __bytes)

 { return __STATIC_CAST(char*, _STLP_STD::__stl_new(__bytes)); }

 inline void __stlp_delete_chunck(void* __p) { _STLP_STD::__stl_delete(__p); }

 #  endif

 #endif

 /* This is an additional atomic operations to the ones already defined in

  * stl/_threads.h, platform should try to support it to improve performance.

  * __add_atomic_t _STLP_ATOMIC_ADD(volatile __add_atomic_t* __target, __add_atomic_t __val) :

  * does *__target = *__target + __val and returns the old *__target value */

 typedef long __add_atomic_t;

 typedef unsigned long __uadd_atomic_t;

 #if defined (__GNUC__) && defined (__i386__)

 inline long _STLP_atomic_add_gcc_x86(long volatile* p, long addend) {

   long result;

   __asm__ __volatile__

     ("lock; xaddl %1, %0;"

     :"=m" (*p), "=r" (result)

     :"m"  (*p), "1"  (addend)

     :"cc");

  return result + addend;

 }

 #  define _STLP_ATOMIC_ADD(__dst, __val)  _STLP_atomic_add_gcc_x86(__dst, __val)

 #elif defined (_STLP_WIN32THREADS)

 // The Win32 API function InterlockedExchangeAdd is not available on Windows 95.

 #  if !defined (_STLP_WIN95_LIKE)

 #    if defined (_STLP_NEW_PLATFORM_SDK)

 #      define _STLP_ATOMIC_ADD(__dst, __val) InterlockedExchangeAdd(__dst, __val)

 #    else

 #      define _STLP_ATOMIC_ADD(__dst, __val) InterlockedExchangeAdd(__CONST_CAST(__add_atomic_t*, __dst), __val)

 #    endif

 #  endif

 #endif

 #if defined (__OS400__)

 // dums 02/05/2007: is it really necessary ?

 enum { _ALIGN = 16, _ALIGN_SHIFT = 4 };

 #else

 enum { _ALIGN = 2 * sizeof(void*), _ALIGN_SHIFT = 2 + sizeof(void*) / 4 };

 #endif

 #define _S_FREELIST_INDEX(__bytes) ((__bytes - size_t(1)) >> (int)_ALIGN_SHIFT)

 _STLP_BEGIN_NAMESPACE

 // malloc_alloc out-of-memory handling

 static __oom_handler_type __oom_handler = __STATIC_CAST(__oom_handler_type, 0);

 #ifdef _STLP_THREADS

 _STLP_mutex __oom_handler_lock;

 #endif

 void* _STLP_CALL __malloc_alloc::allocate(size_t __n)

 {

   void *__result = malloc(__n);

   if ( 0 == __result ) {

     __oom_handler_type __my_malloc_handler;

     for (;;) {

       {

 #ifdef _STLP_THREADS

         _STLP_auto_lock _l( __oom_handler_lock );

 #endif

         __my_malloc_handler = __oom_handler;

       }

       if ( 0 == __my_malloc_handler) {

         _STLP_THROW_BAD_ALLOC;

       }

       (*__my_malloc_handler)();

       __result = malloc(__n);

       if ( __result )

         return __result;

     }

   }

   return __result;

 }

 __oom_handler_type _STLP_CALL __malloc_alloc::set_malloc_handler(__oom_handler_type __f)

 {

 #ifdef _STLP_THREADS

   _STLP_auto_lock _l( __oom_handler_lock );

 #endif

   __oom_handler_type __old = __oom_handler;

   __oom_handler = __f;

   return __old;

 }

 // *******************************************************

 // Default node allocator.

 // With a reasonable compiler, this should be roughly as fast as the

 // original STL class-specific allocators, but with less fragmentation.

 //

 // Important implementation properties:

 // 1. If the client request an object of size > _MAX_BYTES, the resulting

 //    object will be obtained directly from malloc.

 // 2. In all other cases, we allocate an object of size exactly

 //    _S_round_up(requested_size).  Thus the client has enough size

 //    information that we can return the object to the proper free list

 //    without permanently losing part of the object.

 //

 #define _STLP_NFREELISTS 16

 #if defined (_STLP_LEAKS_PEDANTIC) && defined (_STLP_USE_DYNAMIC_LIB)

 /*

  * We can only do cleanup of the node allocator memory pool if we are

  * sure that the STLport library is used as a shared one as it guaranties

  * the unicity of the node allocator instance. Without that guaranty node

  * allocator instances might exchange memory blocks making the implementation

  * of a cleaning process much more complicated.

  */

 #  define _STLP_DO_CLEAN_NODE_ALLOC

 #endif

 /* When STLport is used without multi threaded safety we use the node allocator

  * implementation with locks as locks becomes no-op. The lock free implementation

  * always use system specific atomic operations which are slower than 'normal'

  * ones.

  */

 #if defined (_STLP_THREADS) && \

     defined (_STLP_HAS_ATOMIC_FREELIST) && defined (_STLP_ATOMIC_ADD)

 /*

  * We have an implementation of the atomic freelist (_STLP_atomic_freelist)

  * for this architecture and compiler.  That means we can use the non-blocking

  * implementation of the node-allocation engine.*/

 #  define _STLP_USE_LOCK_FREE_IMPLEMENTATION

 #endif

 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 #  if defined (_STLP_THREADS)

 class _Node_Alloc_Lock {

   static _STLP_STATIC_MUTEX& _S_Mutex() {

     static _STLP_STATIC_MUTEX mutex _STLP_MUTEX_INITIALIZER;

     return mutex;

   }

 public:

   _Node_Alloc_Lock() {

 #    if defined (_STLP_SGI_THREADS)

     if (__us_rsthread_malloc)

 #    endif

       _S_Mutex()._M_acquire_lock();

   }

   ~_Node_Alloc_Lock() {

 #    if defined (_STLP_SGI_THREADS)

     if (__us_rsthread_malloc)

 #    endif

       _S_Mutex()._M_release_lock();

   }

 };

 #  else

 class _Node_Alloc_Lock {

 public:

   _Node_Alloc_Lock() { }

   ~_Node_Alloc_Lock() { }

 };

 #  endif

 struct _Node_alloc_obj {

   _Node_alloc_obj * _M_next;

 };

 #endif

 class __node_alloc_impl {

   static inline size_t _STLP_CALL _S_round_up(size_t __bytes)

   { return (((__bytes) + (size_t)_ALIGN-1) & ~((size_t)_ALIGN - 1)); }

 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

   typedef _STLP_atomic_freelist::item   _Obj;

   typedef _STLP_atomic_freelist         _Freelist;

   typedef _STLP_atomic_freelist         _ChunkList;

   // Header of blocks of memory that have been allocated as part of

   // a larger chunk but have not yet been chopped up into nodes.

   struct _FreeBlockHeader : public _STLP_atomic_freelist::item {

     char* _M_end;     // pointer to end of free memory

   };

 #else

   typedef _Node_alloc_obj       _Obj;

   typedef _Obj* _STLP_VOLATILE  _Freelist;

   typedef _Obj*                 _ChunkList;

 #endif

 private:

   // Returns an object of size __n, and optionally adds to size __n free list.

   static _Obj* _S_refill(size_t __n);

   // Allocates a chunk for nobjs of size __p_size.  nobjs may be reduced

   // if it is inconvenient to allocate the requested number.

   static char* _S_chunk_alloc(size_t __p_size, int& __nobjs);

   // Chunk allocation state.

   static _Freelist _S_free_list[_STLP_NFREELISTS];

   // Amount of total allocated memory

 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

   static _STLP_VOLATILE __add_atomic_t _S_heap_size;

 #else

   static size_t _S_heap_size;

 #endif

 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

   // List of blocks of free memory

   static _STLP_atomic_freelist  _S_free_mem_blocks;

 #else

   // Start of the current free memory buffer

   static char* _S_start_free;

   // End of the current free memory buffer

   static char* _S_end_free;

 #endif

 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 public:

   // Methods to report alloc/dealloc calls to the counter system.

 #  if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

   typedef _STLP_VOLATILE __stl_atomic_t _AllocCounter;

 #  else

   typedef __stl_atomic_t _AllocCounter;

 #  endif

   static _AllocCounter& _STLP_CALL _S_alloc_counter();

   static void _S_alloc_call();

   static void _S_dealloc_call();

 private:

   // Free all the allocated chuncks of memory

   static void _S_chunk_dealloc();

   // Beginning of the linked list of allocated chunks of memory

   static _ChunkList _S_chunks;

 #endif /* _STLP_DO_CLEAN_NODE_ALLOC */

 public:

   /* __n must be > 0      */

   static void* _M_allocate(size_t& __n);

   /* __p may not be 0 */

   static void _M_deallocate(void *__p, size_t __n);

 };

 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 void* __node_alloc_impl::_M_allocate(size_t& __n) {

   __n = _S_round_up(__n);

   _Obj * _STLP_VOLATILE * __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);

   _Obj *__r;

   // Acquire the lock here with a constructor call.

   // This ensures that it is released in exit or during stack

   // unwinding.

   _Node_Alloc_Lock __lock_instance;

   if ( (__r  = *__my_free_list) != 0 ) {

     *__my_free_list = __r->_M_next;

   } else {

     __r = _S_refill(__n);

   }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   _S_alloc_call();

 #  endif

   // lock is released here

   return __r;

 }

 void __node_alloc_impl::_M_deallocate(void *__p, size_t __n) {

   _Obj * _STLP_VOLATILE * __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);

   _Obj * __pobj = __STATIC_CAST(_Obj*, __p);

   // acquire lock

   _Node_Alloc_Lock __lock_instance;

   __pobj->_M_next = *__my_free_list;

   *__my_free_list = __pobj;

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   _S_dealloc_call();

 #  endif

   // lock is released here

 }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 #    define _STLP_OFFSET sizeof(_Obj)

 #  else

 #    define _STLP_OFFSET 0

 #  endif

 /* We allocate memory in large chunks in order to avoid fragmenting     */

 /* the malloc heap too much.                                            */

 /* We assume that size is properly aligned.                             */

 /* We hold the allocation lock.                                         */

 char* __node_alloc_impl::_S_chunk_alloc(size_t _p_size, int& __nobjs) {

   char* __result;

   size_t __total_bytes = _p_size * __nobjs;

   size_t __bytes_left = _S_end_free - _S_start_free;

   if (__bytes_left > 0) {

     if (__bytes_left >= __total_bytes) {

       __result = _S_start_free;

       _S_start_free += __total_bytes;

       return __result;

     }

     if (__bytes_left >= _p_size) {

       __nobjs = (int)(__bytes_left / _p_size);

       __total_bytes = _p_size * __nobjs;

       __result = _S_start_free;

       _S_start_free += __total_bytes;

       return __result;

     }

     // Try to make use of the left-over piece.

     _Obj* _STLP_VOLATILE* __my_free_list = _S_free_list + _S_FREELIST_INDEX(__bytes_left);

     __REINTERPRET_CAST(_Obj*, _S_start_free)->_M_next = *__my_free_list;

     *__my_free_list = __REINTERPRET_CAST(_Obj*, _S_start_free);

     _S_start_free = _S_end_free = 0;

   }

   size_t __bytes_to_get = 2 * __total_bytes + _S_round_up(_S_heap_size) + _STLP_OFFSET;

   _STLP_TRY {

     _S_start_free = __stlp_new_chunk(__bytes_to_get);

   }

 #if defined (_STLP_USE_EXCEPTIONS)

   catch (const _STLP_STD::bad_alloc&) {

     _Obj* _STLP_VOLATILE* __my_free_list;

     _Obj* __p;

     // Try to do with what we have.  That can't hurt.

     // We do not try smaller requests, since that tends

     // to result in disaster on multi-process machines.

     for (size_t __i = _p_size; __i <= (size_t)_MAX_BYTES; __i += (size_t)_ALIGN) {

       __my_free_list = _S_free_list + _S_FREELIST_INDEX(__i);

       __p = *__my_free_list;

       if (0 != __p) {

         *__my_free_list = __p -> _M_next;

         _S_start_free = __REINTERPRET_CAST(char*, __p);

         _S_end_free = _S_start_free + __i;

         return _S_chunk_alloc(_p_size, __nobjs);

         // Any leftover piece will eventually make it to the

         // right free list.

       }

     }

     __bytes_to_get = __total_bytes + _STLP_OFFSET;

     _S_start_free = __stlp_new_chunk(__bytes_to_get);

   }

 #endif

   _S_heap_size += __bytes_to_get >> 4;

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   __REINTERPRET_CAST(_Obj*, _S_start_free)->_M_next = _S_chunks;

   _S_chunks = __REINTERPRET_CAST(_Obj*, _S_start_free);

 #  endif

   _S_end_free = _S_start_free + __bytes_to_get;

   _S_start_free += _STLP_OFFSET;

   return _S_chunk_alloc(_p_size, __nobjs);

 }

 /* Returns an object of size __n, and optionally adds to size __n free list.*/

 /* We assume that __n is properly aligned.                                  */

 /* We hold the allocation lock.                                             */

 _Node_alloc_obj* __node_alloc_impl::_S_refill(size_t __n) {

   int __nobjs = 20;

   char* __chunk = _S_chunk_alloc(__n, __nobjs);

   if (1 == __nobjs) return __REINTERPRET_CAST(_Obj*, __chunk);

   _Obj* _STLP_VOLATILE* __my_free_list = _S_free_list + _S_FREELIST_INDEX(__n);

   _Obj* __result;

   _Obj* __current_obj;

   _Obj* __next_obj;

   /* Build free list in chunk */

   __result = __REINTERPRET_CAST(_Obj*, __chunk);

   *__my_free_list = __next_obj = __REINTERPRET_CAST(_Obj*, __chunk + __n);

   for (--__nobjs; --__nobjs; ) {

     __current_obj = __next_obj;

     __next_obj = __REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __next_obj) + __n);

     __current_obj->_M_next = __next_obj;

   }

   __next_obj->_M_next = 0;

   return __result;

 }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 void __node_alloc_impl::_S_alloc_call()

 { ++_S_alloc_counter(); }

 void __node_alloc_impl::_S_dealloc_call() {

   __stl_atomic_t &counter = _S_alloc_counter();

   if (--counter == 0)

   { _S_chunk_dealloc(); }

 }

 /* We deallocate all the memory chunks      */

 void __node_alloc_impl::_S_chunk_dealloc() {

   _Obj *__pcur = _S_chunks, *__pnext;

   while (__pcur != 0) {

     __pnext = __pcur->_M_next;

     __stlp_delete_chunck(__pcur);

     __pcur = __pnext;

   }

   _S_chunks = 0;

   _S_start_free = _S_end_free = 0;

   _S_heap_size = 0;

   memset(__REINTERPRET_CAST(char*, __CONST_CAST(_Obj**, &_S_free_list[0])), 0, _STLP_NFREELISTS * sizeof(_Obj*));

 }

 #  endif

 #else

 void* __node_alloc_impl::_M_allocate(size_t& __n) {

   __n = _S_round_up(__n);

   _Obj* __r = _S_free_list[_S_FREELIST_INDEX(__n)].pop();

   if (__r  == 0)

   { __r = _S_refill(__n); }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   _S_alloc_call();

 #  endif

   return __r;

 }

 void __node_alloc_impl::_M_deallocate(void *__p, size_t __n) {

   _S_free_list[_S_FREELIST_INDEX(__n)].push(__STATIC_CAST(_Obj*, __p));

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   _S_dealloc_call();

 #  endif

 }

 /* Returns an object of size __n, and optionally adds additional ones to    */

 /* freelist of objects of size __n.                                         */

 /* We assume that __n is properly aligned.                                  */

 __node_alloc_impl::_Obj* __node_alloc_impl::_S_refill(size_t __n) {

   int __nobjs = 20;

   char* __chunk = _S_chunk_alloc(__n, __nobjs);

   if (__nobjs <= 1)

     return __REINTERPRET_CAST(_Obj*, __chunk);

   // Push all new nodes (minus first one) onto freelist

   _Obj* __result   = __REINTERPRET_CAST(_Obj*, __chunk);

   _Obj* __cur_item = __result;

   _Freelist* __my_freelist = _S_free_list + _S_FREELIST_INDEX(__n);

   for (--__nobjs; __nobjs != 0; --__nobjs) {

     __cur_item  = __REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __cur_item) + __n);

     __my_freelist->push(__cur_item);

   }

   return __result;

 }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 #    define _STLP_OFFSET _ALIGN

 #  else

 #    define _STLP_OFFSET 0

 #  endif

 /* We allocate memory in large chunks in order to avoid fragmenting     */

 /* the malloc heap too much.                                            */

 /* We assume that size is properly aligned.                             */

 char* __node_alloc_impl::_S_chunk_alloc(size_t _p_size, int& __nobjs) {

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   //We are going to add a small memory block to keep all the allocated blocks

   //address, we need to do so respecting the memory alignment. The following

   //static assert checks that the reserved block is big enough to store a pointer.

   _STLP_STATIC_ASSERT(sizeof(_Obj) <= _ALIGN)

 #  endif

   char*  __result       = 0;

   __add_atomic_t __total_bytes  = __STATIC_CAST(__add_atomic_t, _p_size) * __nobjs;

   _FreeBlockHeader* __block = __STATIC_CAST(_FreeBlockHeader*, _S_free_mem_blocks.pop());

   if (__block != 0) {

     // We checked a block out and can now mess with it with impugnity.

     // We'll put the remainder back into the list if we're done with it below.

     char*  __buf_start  = __REINTERPRET_CAST(char*, __block);

     __add_atomic_t __bytes_left = __block->_M_end - __buf_start;

     if ((__bytes_left < __total_bytes) && (__bytes_left >= __STATIC_CAST(__add_atomic_t, _p_size))) {

       // There's enough left for at least one object, but not as much as we wanted

       __result      = __buf_start;

       __nobjs       = (int)(__bytes_left/_p_size);

       __total_bytes = __STATIC_CAST(__add_atomic_t, _p_size) * __nobjs;

       __bytes_left -= __total_bytes;

       __buf_start  += __total_bytes;

     }

     else if (__bytes_left >= __total_bytes) {

       // The block has enough left to satisfy all that was asked for

       __result      = __buf_start;

       __bytes_left -= __total_bytes;

       __buf_start  += __total_bytes;

     }

     if (__bytes_left != 0) {

       // There is still some memory left over in block after we satisfied our request.

       if ((__result != 0) && (__bytes_left >= (__add_atomic_t)sizeof(_FreeBlockHeader))) {

         // We were able to allocate at least one object and there is still enough

         // left to put remainder back into list.

         _FreeBlockHeader* __newblock = __REINTERPRET_CAST(_FreeBlockHeader*, __buf_start);

         __newblock->_M_end  = __block->_M_end;

         _S_free_mem_blocks.push(__newblock);

       }

       else {

         // We were not able to allocate enough for at least one object.

         // Shove into freelist of nearest (rounded-down!) size.

         size_t __rounded_down = _S_round_up(__bytes_left + 1) - (size_t)_ALIGN;

         if (__rounded_down > 0)

           _S_free_list[_S_FREELIST_INDEX(__rounded_down)].push((_Obj*)__buf_start);

       }

     }

     if (__result != 0)

       return __result;

   }

   // We couldn't satisfy it from the list of free blocks, get new memory.

   __add_atomic_t __bytes_to_get = 2 * __total_bytes +

                                   __STATIC_CAST(__add_atomic_t,

                                                 _S_round_up(__STATIC_CAST(__uadd_atomic_t, _STLP_ATOMIC_ADD(&_S_heap_size, 0)))) +

                                   _STLP_OFFSET;

   _STLP_TRY {

     __result = __stlp_new_chunk(__bytes_to_get);

   }

 #if defined (_STLP_USE_EXCEPTIONS)

   catch (const bad_alloc&) {

     // Allocation failed; try to canibalize from freelist of a larger object size.

     for (size_t __i = _p_size; __i <= (size_t)_MAX_BYTES; __i += (size_t)_ALIGN) {

       _Obj* __p  = _S_free_list[_S_FREELIST_INDEX(__i)].pop();

       if (0 != __p) {

         if (__i < sizeof(_FreeBlockHeader)) {

           // Not enough to put into list of free blocks, divvy it up here.

           // Use as much as possible for this request and shove remainder into freelist.

           __nobjs = (int)(__i/_p_size);

           __total_bytes = __nobjs * __STATIC_CAST(__add_atomic_t, _p_size);

           size_t __bytes_left = __i - __total_bytes;

           size_t __rounded_down = _S_round_up(__bytes_left+1) - (size_t)_ALIGN;

           if (__rounded_down > 0) {

             _S_free_list[_S_FREELIST_INDEX(__rounded_down)].push(__REINTERPRET_CAST(_Obj*, __REINTERPRET_CAST(char*, __p) + __total_bytes));

           }

           return __REINTERPRET_CAST(char*, __p);

         }

         else {

           // Add node to list of available blocks and recursively allocate from it.

           _FreeBlockHeader* __newblock = (_FreeBlockHeader*)__p;

           __newblock->_M_end  = __REINTERPRET_CAST(char*, __p) + __i;

           _S_free_mem_blocks.push(__newblock);

           return _S_chunk_alloc(_p_size, __nobjs);

         }

       }

     }

     // We were not able to find something in a freelist, try to allocate a smaller amount.

     __bytes_to_get  = __total_bytes + _STLP_OFFSET;

     __result = __stlp_new_chunk(__bytes_to_get);

     // This should either throw an exception or remedy the situation.

     // Thus we assume it succeeded.

   }

 #endif

   // Alignment check

   _STLP_VERBOSE_ASSERT(((__REINTERPRET_CAST(size_t, __result) & __STATIC_CAST(size_t, _ALIGN - 1)) == 0),

                        _StlMsg_DBA_DELETED_TWICE)

   _STLP_ATOMIC_ADD(&_S_heap_size, __bytes_to_get >> 4);

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

   // We have to track the allocated memory chunks for release on exit.

   _S_chunks.push(__REINTERPRET_CAST(_Obj*, __result));

   __result       += _ALIGN;

   __bytes_to_get -= _ALIGN;

 #  endif

   if (__bytes_to_get > __total_bytes) {

     // Push excess memory allocated in this chunk into list of free memory blocks

     _FreeBlockHeader* __freeblock = __REINTERPRET_CAST(_FreeBlockHeader*, __result + __total_bytes);

     __freeblock->_M_end  = __result + __bytes_to_get;

     _S_free_mem_blocks.push(__freeblock);

   }

   return __result;

 }

 #  if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 void __node_alloc_impl::_S_alloc_call()

 { _STLP_ATOMIC_INCREMENT(&_S_alloc_counter()); }

 void __node_alloc_impl::_S_dealloc_call() {

   _STLP_VOLATILE __stl_atomic_t *pcounter = &_S_alloc_counter();

   if (_STLP_ATOMIC_DECREMENT(pcounter) == 0)

     _S_chunk_dealloc();

 }

 /* We deallocate all the memory chunks      */

 void __node_alloc_impl::_S_chunk_dealloc() {

   // Note: The _Node_alloc_helper class ensures that this function

   // will only be called when the (shared) library is unloaded or the

   // process is shutdown.  It's thus not possible that another thread

   // is currently trying to allocate a node (we're not thread-safe here).

   //

   // Clear the free blocks and all freelistst.  This makes sure that if

   // for some reason more memory is allocated again during shutdown

   // (it'd also be really nasty to leave references to deallocated memory).

   _S_free_mem_blocks.clear();

   _S_heap_size      = 0;

   for (size_t __i = 0; __i < _STLP_NFREELISTS; ++__i) {

     _S_free_list[__i].clear();

   }

   // Detach list of chunks and free them all

   _Obj* __chunk = _S_chunks.clear();

   while (__chunk != 0) {

     _Obj* __next = __chunk->_M_next;

     __stlp_delete_chunck(__chunk);

     __chunk  = __next;

   }

 }

 #  endif

 #endif

 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 struct __node_alloc_cleaner {

   ~__node_alloc_cleaner()

   { __node_alloc_impl::_S_dealloc_call(); }

 };

 #  if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 _STLP_VOLATILE __stl_atomic_t& _STLP_CALL

 #  else

 __stl_atomic_t& _STLP_CALL

 #  endif

 __node_alloc_impl::_S_alloc_counter() {

   static _AllocCounter _S_counter = 1;

   static __node_alloc_cleaner _S_node_alloc_cleaner;

   return _S_counter;

 }

 #endif

 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 _Node_alloc_obj * _STLP_VOLATILE

 __node_alloc_impl::_S_free_list[_STLP_NFREELISTS]

 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

 // The 16 zeros are necessary to make version 4.1 of the SunPro

 // compiler happy.  Otherwise it appears to allocate too little

 // space for the array.

 #else

 _STLP_atomic_freelist __node_alloc_impl::_S_free_list[_STLP_NFREELISTS];

 _STLP_atomic_freelist __node_alloc_impl::_S_free_mem_blocks;

 #endif

 #if !defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 char *__node_alloc_impl::_S_start_free = 0;

 char *__node_alloc_impl::_S_end_free = 0;

 #endif

 #if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 _STLP_VOLATILE __add_atomic_t

 #else

 size_t

 #endif

 __node_alloc_impl::_S_heap_size = 0;

 #if defined (_STLP_DO_CLEAN_NODE_ALLOC)

 #  if defined (_STLP_USE_LOCK_FREE_IMPLEMENTATION)

 _STLP_atomic_freelist __node_alloc_impl::_S_chunks;

 #  else

 _Node_alloc_obj* __node_alloc_impl::_S_chunks  = 0;

 #  endif

 #endif

 void * _STLP_CALL __node_alloc::_M_allocate(size_t& __n)

 { return __node_alloc_impl::_M_allocate(__n); }

 void _STLP_CALL __node_alloc::_M_deallocate(void *__p, size_t __n)

 { __node_alloc_impl::_M_deallocate(__p, __n); }

 #if defined (_STLP_PTHREADS) && !defined (_STLP_NO_THREADS)

 #  define _STLP_DATA_ALIGNMENT 8

 _STLP_MOVE_TO_PRIV_NAMESPACE

 // *******************************************************

 // __perthread_alloc implementation

 union _Pthread_alloc_obj {

   union _Pthread_alloc_obj * __free_list_link;

   char __client_data[_STLP_DATA_ALIGNMENT];    /* The client sees this.    */

 };

 // Pthread allocators don't appear to the client to have meaningful

 // instances.  We do in fact need to associate some state with each

 // thread.  That state is represented by _Pthread_alloc_per_thread_state.

 struct _Pthread_alloc_per_thread_state {

   typedef _Pthread_alloc_obj __obj;

   enum { _S_NFREELISTS = _MAX_BYTES / _STLP_DATA_ALIGNMENT };

   // Free list link for list of available per thread structures.

   // When one of these becomes available for reuse due to thread

   // termination, any objects in its free list remain associated

   // with it.  The whole structure may then be used by a newly

   // created thread.

   _Pthread_alloc_per_thread_state() : __next(0)

   { memset((void *)__CONST_CAST(_Pthread_alloc_obj**, __free_list), 0, (size_t)_S_NFREELISTS * sizeof(__obj *)); }

   // Returns an object of size __n, and possibly adds to size n free list.

   void *_M_refill(size_t __n);

   _Pthread_alloc_obj* volatile __free_list[_S_NFREELISTS];

   _Pthread_alloc_per_thread_state *__next;

   // this data member is only to be used by per_thread_allocator, which returns memory to the originating thread.

   _STLP_mutex _M_lock;

 };

 // Pthread-specific allocator.

 class _Pthread_alloc_impl {

 public: // but only for internal use:

   typedef _Pthread_alloc_per_thread_state __state_type;

   typedef char value_type;

   // Allocates a chunk for nobjs of size size.  nobjs may be reduced

   // if it is inconvenient to allocate the requested number.

   static char *_S_chunk_alloc(size_t __size, size_t &__nobjs, __state_type*);

   enum {_S_ALIGN = _STLP_DATA_ALIGNMENT};

   static size_t _S_round_up(size_t __bytes)

   { return (((__bytes) + (int)_S_ALIGN - 1) & ~((int)_S_ALIGN - 1)); }

   static size_t _S_freelist_index(size_t __bytes)

   { return (((__bytes) + (int)_S_ALIGN - 1) / (int)_S_ALIGN - 1); }

 private:

   // Chunk allocation state. And other shared state.

   // Protected by _S_chunk_allocator_lock.

   static _STLP_STATIC_MUTEX _S_chunk_allocator_lock;

   static char *_S_start_free;

   static char *_S_end_free;

   static size_t _S_heap_size;

   static __state_type *_S_free_per_thread_states;

   static pthread_key_t _S_key;

   static bool _S_key_initialized;

   // Pthread key under which per thread state is stored.

   // Allocator instances that are currently unclaimed by any thread.

   static void _S_destructor(void *instance);

   // Function to be called on thread exit to reclaim per thread

   // state.

   static __state_type *_S_new_per_thread_state();

 public:

   // Return a recycled or new per thread state.

   static __state_type *_S_get_per_thread_state();

 private:

         // ensure that the current thread has an associated

         // per thread state.

   class _M_lock;

   friend class _M_lock;

   class _M_lock {

   public:

     _M_lock () { _S_chunk_allocator_lock._M_acquire_lock(); }

     ~_M_lock () { _S_chunk_allocator_lock._M_release_lock(); }

   };

 public:

   /* n must be > 0      */

   static void * allocate(size_t& __n);

   /* p may not be 0 */

   static void deallocate(void *__p, size_t __n);

   // boris : versions for per_thread_allocator

   /* n must be > 0      */

   static void * allocate(size_t& __n, __state_type* __a);

   /* p may not be 0 */

   static void deallocate(void *__p, size_t __n, __state_type* __a);

   static void * reallocate(void *__p, size_t __old_sz, size_t& __new_sz);

 };

 /* Returns an object of size n, and optionally adds to size n free list.*/

 /* We assume that n is properly aligned.                                */

 /* We hold the allocation lock.                                         */

 void *_Pthread_alloc_per_thread_state::_M_refill(size_t __n) {

   typedef _Pthread_alloc_obj __obj;

   size_t __nobjs = 128;

   char * __chunk = _Pthread_alloc_impl::_S_chunk_alloc(__n, __nobjs, this);

   __obj * volatile * __my_free_list;

   __obj * __result;

   __obj * __current_obj, * __next_obj;

   size_t __i;

   if (1 == __nobjs)  {

     return __chunk;

   }

   __my_free_list = __free_list + _Pthread_alloc_impl::_S_freelist_index(__n);

   /* Build free list in chunk */

   __result = (__obj *)__chunk;

   *__my_free_list = __next_obj = (__obj *)(__chunk + __n);

   for (__i = 1; ; ++__i) {

     __current_obj = __next_obj;

     __next_obj = (__obj *)((char *)__next_obj + __n);

     if (__nobjs - 1 == __i) {

       __current_obj -> __free_list_link = 0;

       break;

     } else {

       __current_obj -> __free_list_link = __next_obj;

     }

   }

   return __result;

 }

 void _Pthread_alloc_impl::_S_destructor(void *__instance) {

   _M_lock __lock_instance;  // Need to acquire lock here.

   _Pthread_alloc_per_thread_state* __s = (_Pthread_alloc_per_thread_state*)__instance;

   __s -> __next = _S_free_per_thread_states;

   _S_free_per_thread_states = __s;

 }

 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_new_per_thread_state() {

   /* lock already held here.  */

   if (0 != _S_free_per_thread_states) {

     _Pthread_alloc_per_thread_state *__result = _S_free_per_thread_states;

     _S_free_per_thread_states = _S_free_per_thread_states -> __next;

     return __result;

   }

   else {

     return new _Pthread_alloc_per_thread_state;

   }

 }

 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_get_per_thread_state() {

   int __ret_code;

   __state_type* __result;

   if (_S_key_initialized && (__result = (__state_type*) pthread_getspecific(_S_key)))

     return __result;

   /*REFERENCED*/

   _M_lock __lock_instance;  // Need to acquire lock here.

   if (!_S_key_initialized) {

     if (pthread_key_create(&_S_key, _S_destructor)) {

       _STLP_THROW_BAD_ALLOC;  // failed

     }

     _S_key_initialized = true;

   }

   __result = _S_new_per_thread_state();

   __ret_code = pthread_setspecific(_S_key, __result);

   if (__ret_code) {

     if (__ret_code == ENOMEM) {

       _STLP_THROW_BAD_ALLOC;

     } else {

   // EINVAL

       _STLP_ABORT();

     }

   }

   return __result;

 }

 /* We allocate memory in large chunks in order to avoid fragmenting     */

 /* the malloc heap too much.                                            */

 /* We assume that size is properly aligned.                             */

 char *_Pthread_alloc_impl::_S_chunk_alloc(size_t __p_size, size_t &__nobjs, _Pthread_alloc_per_thread_state *__a) {

   typedef _Pthread_alloc_obj __obj;

   {

     char * __result;

     size_t __total_bytes;

     size_t __bytes_left;

     /*REFERENCED*/

     _M_lock __lock_instance;         // Acquire lock for this routine

     __total_bytes = __p_size * __nobjs;

     __bytes_left = _S_end_free - _S_start_free;

     if (__bytes_left >= __total_bytes) {

       __result = _S_start_free;

       _S_start_free += __total_bytes;

       return __result;

     } else if (__bytes_left >= __p_size) {

       __nobjs = __bytes_left/__p_size;

       __total_bytes = __p_size * __nobjs;

       __result = _S_start_free;

       _S_start_free += __total_bytes;

       return __result;

     } else {

       size_t __bytes_to_get = 2 * __total_bytes + _S_round_up(_S_heap_size);

       // Try to make use of the left-over piece.

       if (__bytes_left > 0) {

         __obj * volatile * __my_free_list = __a->__free_list + _S_freelist_index(__bytes_left);

         ((__obj *)_S_start_free) -> __free_list_link = *__my_free_list;

         *__my_free_list = (__obj *)_S_start_free;

       }

 #  ifdef _SGI_SOURCE

       // Try to get memory that's aligned on something like a

       // cache line boundary, so as to avoid parceling out

       // parts of the same line to different threads and thus

       // possibly different processors.

       {

         const int __cache_line_size = 128;  // probable upper bound

         __bytes_to_get &= ~(__cache_line_size-1);

         _S_start_free = (char *)memalign(__cache_line_size, __bytes_to_get);

         if (0 == _S_start_free) {

           _S_start_free = (char *)__malloc_alloc::allocate(__bytes_to_get);

         }

       }

 #  else  /* !SGI_SOURCE */

       _S_start_free = (char *)__malloc_alloc::allocate(__bytes_to_get);

 #  endif

       _S_heap_size += __bytes_to_get >> 4;

       _S_end_free = _S_start_free + __bytes_to_get;

     }

   }

   // lock is released here

   return _S_chunk_alloc(__p_size, __nobjs, __a);

 }

 /* n must be > 0      */

 void *_Pthread_alloc_impl::allocate(size_t& __n) {

   typedef _Pthread_alloc_obj __obj;

   __obj * volatile * __my_free_list;

   __obj * __result;

   __state_type* __a;

   if (__n > _MAX_BYTES) {

     return __malloc_alloc::allocate(__n);

   }

   __n = _S_round_up(__n);

   __a = _S_get_per_thread_state();

   __my_free_list = __a->__free_list + _S_freelist_index(__n);

   __result = *__my_free_list;

   if (__result == 0) {

     void *__r = __a->_M_refill(__n);

     return __r;

   }

   *__my_free_list = __result->__free_list_link;

   return __result;

 };

 /* p may not be 0 */

 void _Pthread_alloc_impl::deallocate(void *__p, size_t __n) {

   typedef _Pthread_alloc_obj __obj;

   __obj *__q = (__obj *)__p;

   __obj * volatile * __my_free_list;

   __state_type* __a;

   if (__n > _MAX_BYTES) {

       __malloc_alloc::deallocate(__p, __n);

       return;

   }

   __a = _S_get_per_thread_state();

   __my_free_list = __a->__free_list + _S_freelist_index(__n);

   __q -> __free_list_link = *__my_free_list;

   *__my_free_list = __q;

 }

 // boris : versions for per_thread_allocator

 /* n must be > 0      */

 void *_Pthread_alloc_impl::allocate(size_t& __n, __state_type* __a) {

   typedef _Pthread_alloc_obj __obj;

   __obj * volatile * __my_free_list;

   __obj * __result;

   if (__n > _MAX_BYTES) {

     return __malloc_alloc::allocate(__n);

   }

   __n = _S_round_up(__n);

   // boris : here, we have to lock per thread state, as we may be getting memory from

   // different thread pool.

   _STLP_auto_lock __lock(__a->_M_lock);

   __my_free_list = __a->__free_list + _S_freelist_index(__n);

   __result = *__my_free_list;

   if (__result == 0) {

     void *__r = __a->_M_refill(__n);

     return __r;

   }

   *__my_free_list = __result->__free_list_link;

   return __result;

 };

 /* p may not be 0 */

 void _Pthread_alloc_impl::deallocate(void *__p, size_t __n, __state_type* __a) {

   typedef _Pthread_alloc_obj __obj;

   __obj *__q = (__obj *)__p;

   __obj * volatile * __my_free_list;

   if (__n > _MAX_BYTES) {

     __malloc_alloc::deallocate(__p, __n);

     return;

   }

   // boris : here, we have to lock per thread state, as we may be returning memory from

   // different thread.

   _STLP_auto_lock __lock(__a->_M_lock);

   __my_free_list = __a->__free_list + _S_freelist_index(__n);

   __q -> __free_list_link = *__my_free_list;

   *__my_free_list = __q;

 }

 void *_Pthread_alloc_impl::reallocate(void *__p, size_t __old_sz, size_t& __new_sz) {

   void * __result;

   size_t __copy_sz;

   if (__old_sz > _MAX_BYTES && __new_sz > _MAX_BYTES) {

     return realloc(__p, __new_sz);

   }

   if (_S_round_up(__old_sz) == _S_round_up(__new_sz)) return __p;

   __result = allocate(__new_sz);

   __copy_sz = __new_sz > __old_sz? __old_sz : __new_sz;

   memcpy(__result, __p, __copy_sz);

   deallocate(__p, __old_sz);

   return __result;

 }

 _Pthread_alloc_per_thread_state* _Pthread_alloc_impl::_S_free_per_thread_states = 0;

 pthread_key_t _Pthread_alloc_impl::_S_key = 0;

 _STLP_STATIC_MUTEX _Pthread_alloc_impl::_S_chunk_allocator_lock _STLP_MUTEX_INITIALIZER;

 bool _Pthread_alloc_impl::_S_key_initialized = false;

 char *_Pthread_alloc_impl::_S_start_free = 0;

 char *_Pthread_alloc_impl::_S_end_free = 0;

 size_t _Pthread_alloc_impl::_S_heap_size = 0;

 void * _STLP_CALL _Pthread_alloc::allocate(size_t& __n)

 { return _Pthread_alloc_impl::allocate(__n); }

 void _STLP_CALL _Pthread_alloc::deallocate(void *__p, size_t __n)

 { _Pthread_alloc_impl::deallocate(__p, __n); }

 void * _STLP_CALL _Pthread_alloc::allocate(size_t& __n, __state_type* __a)

 { return _Pthread_alloc_impl::allocate(__n, __a); }

 void _STLP_CALL _Pthread_alloc::deallocate(void *__p, size_t __n, __state_type* __a)

 { _Pthread_alloc_impl::deallocate(__p, __n, __a); }

 void * _STLP_CALL _Pthread_alloc::reallocate(void *__p, size_t __old_sz, size_t& __new_sz)

 { return _Pthread_alloc_impl::reallocate(__p, __old_sz, __new_sz); }

 _Pthread_alloc_per_thread_state* _STLP_CALL _Pthread_alloc::_S_get_per_thread_state()

 { return _Pthread_alloc_impl::_S_get_per_thread_state(); }

 _STLP_MOVE_TO_STD_NAMESPACE

 #endif

 _STLP_END_NAMESPACE

 #undef _S_FREELIST_INDEX