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Re: patch: mt_allocator.h


Hi,
	Here is the patch. check & check-performance on x86-linux.



On Wed, 2004-06-09 at 12:56, Paolo Carlini wrote:
> Dhruv Matani wrote:
> 
> >Think about it this way. Suppose it wasn't, and I used:
> >list<int>;
> >list<string>;
> >list<float>;
> >
> >Then, under the current design, all would have their separate free-lists
> >per thread! Which is obviously insane!
> >  
> >
> Ok, ok, let's work on this assumption ;)
> 
> >>In any case, what about not splitting mt_allocator in a __gnu_internal::
> >>part and a std:: part? 
> >>    
> >>
> >You mean a __gnu_internal and a __gnu_cxx part right?
> >  
> >
> Indeed.
> 
> >>Can't we put *all* the implementation details
> >>inside _Mt_alloc_base?
> >>    
> >>
> >Probably? Would you want me to try and do that?
> >
> Yes, please. Always both 'make check' and 'make check-performance', thanks.
> 
> Paolo.
-- 
        -Dhruv Matani.
http://www.geocities.com/dhruvbird/

Proud to be a Vegetarian.
http://www.vegetarianstarterkit.com/
http://www.vegkids.com/vegkids/index.html

*** mt_allocator.h	2004-05-20 07:59:04.000000000 +0530
--- /home/dhruv/projects/new_libstdc++-v3/mt_allocator.h	2004-06-09 17:35:52.000000000 +0530
***************
*** 41,46 ****
--- 41,396 ----
  #include <bits/gthr.h>
  #include <bits/atomicity.h>
  
+ namespace __gnu_internal
+ {
+   // Variables used to configure the behavior of the allocator,
+   // assigned and explained in detail below.
+   struct _Tune
+   {
+     // Allocation requests (after round-up to power of 2) below
+     // this value will be handled by the allocator. A raw new/
+     // call will be used for requests larger than this value.
+     size_t	_M_max_bytes; 
+ 
+     // Size in bytes of the smallest bin (must be a power of 2).
+     size_t  _M_min_bin;
+ 
+     // In order to avoid fragmenting and minimize the number of
+     // new() calls we always request new memory using this
+     // value. Based on previous discussions on the libstdc++
+     // mailing list we have choosen the value below.
+     // See http://gcc.gnu.org/ml/libstdc++/2001-07/msg00077.html
+     size_t 	_M_chunk_size;
+ 
+     // The maximum number of supported threads. Our Linux 2.4.18
+     // reports 4070 in /proc/sys/kernel/threads-max
+     size_t 	_M_max_threads;
+ 
+     // Each time a deallocation occurs in a threaded application
+     // we make sure that there are no more than
+     // _M_freelist_headroom % of used memory on the freelist. If
+     // the number of additional records is more than
+     // _M_freelist_headroom % of the freelist, we move these
+     // records back to the global pool.
+     size_t 	_M_freelist_headroom;
+ 
+     // Set to true forces all allocations to use new().
+     bool 	_M_force_new; 
+      
+     explicit
+     _Tune()
+       : _M_max_bytes(128), _M_min_bin(8),
+ 	_M_chunk_size(4096 - 4 * sizeof(void*)), 
+ 	_M_max_threads(4096), _M_freelist_headroom(10), 
+ 	_M_force_new(getenv("GLIBCXX_FORCE_NEW") ? true : false)
+     { }
+ 
+     explicit
+     _Tune(size_t __maxb, size_t __minbin, size_t __chunk,
+ 	  size_t __maxthreads, size_t __headroom, bool __force) 
+       : _M_max_bytes(__maxb), _M_min_bin(__minbin), _M_chunk_size(__chunk), 
+ 	_M_max_threads(__maxthreads), _M_freelist_headroom(__headroom), 
+ 	_M_force_new(__force)
+     { }
+   };
+ 
+   // Each requesting thread is assigned an id ranging from 1 to
+   // _S_max_threads. Thread id 0 is used as a global memory pool.
+   // In order to get constant performance on the thread assignment
+   // routine, we keep a list of free ids. When a thread first
+   // requests memory we remove the first record in this list and
+   // stores the address in a __gthread_key. When initializing the
+   // __gthread_key we specify a destructor. When this destructor
+   // (i.e. the thread dies) is called, we return the thread id to
+   // the front of this list.
+ #ifdef __GTHREADS
+   struct _Thread_record
+   {
+     // Points to next free thread id record. NULL if last record in list.
+     _Thread_record* volatile        _M_next;
+ 
+     // Thread id ranging from 1 to _S_max_threads.
+     size_t                          _M_id;
+   };
+ #endif
+ 
+   union _Block_record
+   {
+     // Points to the block_record of the next free block.
+     _Block_record* volatile         _M_next;
+ 
+ #ifdef __GTHREADS
+     // The thread id of the thread which has requested this block.
+     size_t                          _M_thread_id;
+ #endif
+   };
+ 
+   struct _Bin_record
+   {
+     // An "array" of pointers to the first free block for each
+     // thread id. Memory to this "array" is allocated in _S_initialize()
+     // for _S_max_threads + global pool 0.
+     _Block_record** volatile        _M_first;
+ 
+ #ifdef __GTHREADS
+     // An "array" of counters used to keep track of the amount of
+     // blocks that are on the freelist/used for each thread id.
+     // Memory to these "arrays" is allocated in _S_initialize() for
+     // _S_max_threads + global pool 0.
+     size_t* volatile                _M_free;
+     size_t* volatile                _M_used;
+ 
+     // Each bin has its own mutex which is used to ensure data
+     // integrity while changing "ownership" on a block.  The mutex
+     // is initialized in _S_initialize().
+     __gthread_mutex_t*              _M_mutex;
+ #endif
+   };
+ 
+   struct _Mt_alloc_base
+   {
+     // We need to create the initial lists and set up some variables
+     // before we can answer to the first request for memory.
+ #ifdef __GTHREADS
+     static __gthread_once_t 		_S_once;
+ #endif
+     static bool 			_S_init;
+ 
+     // Configuration options.
+     static _Tune 	       		_S_options;
+ 
+     static const _Tune
+     _S_get_options()
+     { return _S_options; }
+ 
+     static void
+     _S_set_options(_Tune __t)
+     { 
+       if (!_S_init)
+ 	_S_options = __t;
+     }
+ 
+     // Using short int as type for the binmap implies we are never
+     // caching blocks larger than 65535 with this allocator
+     typedef unsigned short int        _Binmap_type;
+     static _Binmap_type* 		_S_binmap;
+ 
+ #ifdef __GTHREADS
+     static _Thread_record* volatile 	_S_thread_freelist_first;
+     static __gthread_mutex_t 		_S_thread_freelist_mutex;
+     static __gthread_key_t 		_S_thread_key;
+ #endif
+ 
+     // An "array" of bin_records each of which represents a specific
+     // power of 2 size. Memory to this "array" is allocated in
+     // _S_initialize().
+     static _Bin_record* volatile     	_S_bin;
+ 
+     // Actual value calculated in _S_initialize().
+     static size_t 	       	     	_S_bin_size; 
+ 
+   protected:
+     static void
+     _S_initialize();
+ 
+ #ifdef __GTHREADS
+     static void 
+     _S_destroy_thread_key(void* __freelist_pos);
+ #endif
+ 
+     static size_t 
+     _S_get_thread_id();
+   };
+ 
+ #ifdef __GTHREADS
+   void
+   _Mt_alloc_base::
+   _S_destroy_thread_key(void* __freelist_pos)
+   {
+     // Return this thread id record to front of thread_freelist.
+     __gthread_mutex_lock(&_S_thread_freelist_mutex);
+     _Thread_record* __tr = static_cast<_Thread_record*>(__freelist_pos);
+     __tr->_M_next = _S_thread_freelist_first;
+     _S_thread_freelist_first = __tr;
+     __gthread_mutex_unlock(&_S_thread_freelist_mutex);
+   }
+ #endif
+ 
+   size_t
+   _Mt_alloc_base::
+   _S_get_thread_id()
+   {
+ #ifdef __GTHREADS
+     // If we have thread support and it's active we check the thread
+     // key value and return its id or if it's not set we take the
+     // first record from _S_thread_freelist and sets the key and
+     // returns it's id.
+     if (__gthread_active_p())
+       {
+ 	_Thread_record* __freelist_pos =
+ 	  static_cast<_Thread_record*>(__gthread_getspecific(_S_thread_key)); 
+ 	if (__freelist_pos == NULL)
+ 	  {
+ 	    // Since _S_options._M_max_threads must be larger than
+ 	    // the theoretical max number of threads of the OS the
+ 	    // list can never be empty.
+ 	    __gthread_mutex_lock(&_S_thread_freelist_mutex);
+ 	    __freelist_pos = _S_thread_freelist_first;
+ 	    _S_thread_freelist_first = _S_thread_freelist_first->_M_next;
+ 	    __gthread_mutex_unlock(&_S_thread_freelist_mutex);
+ 
+ 	    __gthread_setspecific(_S_thread_key, 
+ 				  static_cast<void*>(__freelist_pos));
+ 	  }
+ 	return __freelist_pos->_M_id;
+       }
+ #endif
+     // Otherwise (no thread support or inactive) all requests are
+     // served from the global pool 0.
+     return 0;
+   }
+ 
+     void
+     _Mt_alloc_base::
+     _S_initialize()
+     {
+       if (_S_options._M_force_new)
+ 	return;
+ 
+       // Calculate the number of bins required based on _M_max_bytes.
+       // _S_bin_size is statically-initialized to one.
+       size_t __bin_size = _S_options._M_min_bin;
+       while (_S_options._M_max_bytes > __bin_size)
+ 	{
+ 	  __bin_size <<= 1;
+ 	  ++_S_bin_size;
+ 	}
+ 
+       // Setup the bin map for quick lookup of the relevant bin.
+       const size_t __j = (_S_options._M_max_bytes + 1) * sizeof(_Binmap_type);
+       _S_binmap = static_cast<_Binmap_type*>(::operator new(__j));
+ 
+       _Binmap_type* __bp = _S_binmap;
+       _Binmap_type __bin_max = _S_options._M_min_bin;
+       _Binmap_type __bint = 0;
+       for (_Binmap_type __ct = 0; __ct <= _S_options._M_max_bytes; ++__ct)
+         {
+           if (__ct > __bin_max)
+             {
+               __bin_max <<= 1;
+               ++__bint;
+             }
+           *__bp++ = __bint;
+         }
+ 
+       // Initialize _S_bin and its members.
+       void* __v = ::operator new(sizeof(_Bin_record) * _S_bin_size);
+       _S_bin = static_cast<_Bin_record*>(__v);
+ 
+       // If __gthread_active_p() create and initialize the list of
+       // free thread ids. Single threaded applications use thread id 0
+       // directly and have no need for this.
+ #ifdef __GTHREADS
+       if (__gthread_active_p())
+         {
+ 	  const size_t __k = sizeof(_Thread_record) * _S_options._M_max_threads;
+ 	  __v = ::operator new(__k);
+           _S_thread_freelist_first = static_cast<_Thread_record*>(__v);
+ 
+ 	  // NOTE! The first assignable thread id is 1 since the
+ 	  // global pool uses id 0
+           size_t __i;
+           for (__i = 1; __i < _S_options._M_max_threads; ++__i)
+             {
+ 	      _Thread_record& __tr = _S_thread_freelist_first[__i - 1];
+               __tr._M_next = &_S_thread_freelist_first[__i];
+               __tr._M_id = __i;
+             }
+ 
+           // Set last record.
+           _S_thread_freelist_first[__i - 1]._M_next = NULL;
+           _S_thread_freelist_first[__i - 1]._M_id = __i;
+ 
+ 	  // Make sure this is initialized.
+ #ifndef __GTHREAD_MUTEX_INIT
+ 	  __GTHREAD_MUTEX_INIT_FUNCTION(&_S_thread_freelist_mutex);
+ #endif
+           // Initialize per thread key to hold pointer to
+           // _S_thread_freelist.
+           __gthread_key_create(&_S_thread_key, _S_destroy_thread_key);
+ 
+ 	  const size_t __max_threads = _S_options._M_max_threads + 1;
+ 	  for (size_t __n = 0; __n < _S_bin_size; ++__n)
+ 	    {
+ 	      _Bin_record& __bin = _S_bin[__n];
+ 	      __v = ::operator new(sizeof(_Block_record*) * __max_threads);
+ 	      __bin._M_first = static_cast<_Block_record**>(__v);
+ 
+ 	      __v = ::operator new(sizeof(size_t) * __max_threads);
+               __bin._M_free = static_cast<size_t*>(__v);
+ 
+ 	      __v = ::operator new(sizeof(size_t) * __max_threads);
+               __bin._M_used = static_cast<size_t*>(__v);
+ 
+ 	      __v = ::operator new(sizeof(__gthread_mutex_t));
+               __bin._M_mutex = static_cast<__gthread_mutex_t*>(__v);
+ 
+ #ifdef __GTHREAD_MUTEX_INIT
+               {
+                 // Do not copy a POSIX/gthr mutex once in use.
+                 __gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
+                 *__bin._M_mutex = __tmp;
+               }
+ #else
+               { __GTHREAD_MUTEX_INIT_FUNCTION(__bin._M_mutex); }
+ #endif
+ 
+ 	      for (size_t __threadn = 0; __threadn < __max_threads;
+ 		   ++__threadn)
+ 		{
+ 		  __bin._M_first[__threadn] = NULL;
+ 		  __bin._M_free[__threadn] = 0;
+ 		  __bin._M_used[__threadn] = 0;
+ 		}
+ 	    }
+ 	}
+       else
+ #endif	
+ 	for (size_t __n = 0; __n < _S_bin_size; ++__n)
+ 	  {
+ 	    _Bin_record& __bin = _S_bin[__n];
+ 	    __v = ::operator new(sizeof(_Block_record*));
+ 	    __bin._M_first = static_cast<_Block_record**>(__v);
+ 	    __bin._M_first[0] = NULL;
+ 	  }
+ 
+       _S_init = true;
+     }
+ 
+   bool _Mt_alloc_base::_S_init = false;
+   _Tune _Mt_alloc_base::_S_options;
+   _Mt_alloc_base::_Binmap_type* _Mt_alloc_base::_S_binmap;
+   _Bin_record* volatile _Mt_alloc_base::_S_bin;
+   size_t _Mt_alloc_base::_S_bin_size = 1;
+ 
+   // Actual initialization in _S_initialize().
+ #ifdef __GTHREADS
+   __gthread_once_t _Mt_alloc_base::_S_once = __GTHREAD_ONCE_INIT;
+ 
+   _Thread_record*
+   volatile _Mt_alloc_base::_S_thread_freelist_first = NULL;
+ 
+   __gthread_key_t _Mt_alloc_base::_S_thread_key;
+ 
+   __gthread_mutex_t
+ #ifdef __GTHREAD_MUTEX_INIT
+   _Mt_alloc_base::_S_thread_freelist_mutex = __GTHREAD_MUTEX_INIT;
+ #else
+   _Mt_alloc_base::_S_thread_freelist_mutex;
+ #endif
+ #endif
+ } //namespace __gnu_internal
+ 
  namespace __gnu_cxx
  {
    /**
*************** namespace __gnu_cxx
*** 54,61 ****
     *  http://gcc.gnu.org/onlinedocs/libstdc++/ext/mt_allocator.html
     */
    template<typename _Tp>
!     class __mt_alloc
      {
      public:
        typedef size_t                    size_type;
        typedef ptrdiff_t                 difference_type;
--- 404,417 ----
     *  http://gcc.gnu.org/onlinedocs/libstdc++/ext/mt_allocator.html
     */
    template<typename _Tp>
!   class __mt_alloc : private __gnu_internal::_Mt_alloc_base
      {
+       typedef ::__gnu_internal::_Tune _Tune;
+       typedef ::__gnu_internal::_Block_record _Block_record;
+       typedef ::__gnu_internal::_Thread_record _Thread_record;
+       typedef ::__gnu_internal::_Bin_record _Bin_record;
+       typedef ::__gnu_internal::_Block_record _Block_record;
+ 
      public:
        typedef size_t                    size_type;
        typedef ptrdiff_t                 difference_type;
*************** namespace __gnu_cxx
*** 114,271 ****
        void
        deallocate(pointer __p, size_type __n);
  
!       // Variables used to configure the behavior of the allocator,
!       // assigned and explained in detail below.
!       struct _Tune
!       {
! 	// Allocation requests (after round-up to power of 2) below
! 	// this value will be handled by the allocator. A raw new/
! 	// call will be used for requests larger than this value.
! 	size_t	_M_max_bytes; 
! 
! 	// Size in bytes of the smallest bin (must be a power of 2).
! 	size_t  _M_min_bin;
! 
! 	// In order to avoid fragmenting and minimize the number of
! 	// new() calls we always request new memory using this
! 	// value. Based on previous discussions on the libstdc++
! 	// mailing list we have choosen the value below.
! 	// See http://gcc.gnu.org/ml/libstdc++/2001-07/msg00077.html
! 	size_t 	_M_chunk_size;
! 
! 	// The maximum number of supported threads. Our Linux 2.4.18
! 	// reports 4070 in /proc/sys/kernel/threads-max
! 	size_t 	_M_max_threads;
! 
! 	// Each time a deallocation occurs in a threaded application
! 	// we make sure that there are no more than
! 	// _M_freelist_headroom % of used memory on the freelist. If
! 	// the number of additional records is more than
! 	// _M_freelist_headroom % of the freelist, we move these
! 	// records back to the global pool.
! 	size_t 	_M_freelist_headroom;
! 
! 	// Set to true forces all allocations to use new().
! 	bool 	_M_force_new; 
!      
! 	explicit
! 	_Tune()
! 	: _M_max_bytes(128), _M_min_bin(8),
! 	  _M_chunk_size(4096 - 4 * sizeof(void*)), 
! 	  _M_max_threads(4096), _M_freelist_headroom(10), 
! 	  _M_force_new(getenv("GLIBCXX_FORCE_NEW") ? true : false)
! 	{ }
! 
! 	explicit
! 	_Tune(size_t __maxb, size_t __minbin, size_t __chunk,
! 	      size_t __maxthreads, size_t __headroom, bool __force) 
! 	: _M_max_bytes(__maxb), _M_min_bin(__minbin), _M_chunk_size(__chunk), 
! 	  _M_max_threads(__maxthreads), _M_freelist_headroom(__headroom), 
! 	  _M_force_new(__force)
! 	{ }
!       };
! 
!     private:
!       // We need to create the initial lists and set up some variables
!       // before we can answer to the first request for memory.
! #ifdef __GTHREADS
!       static __gthread_once_t 		_S_once;
! #endif
!       static bool 			_S_init;
! 
!       static void
!       _S_initialize();
! 
!       // Configuration options.
!       static _Tune 	       		_S_options;
! 
!       static const _Tune
!       _S_get_options()
!       { return _S_options; }
! 
!       static void
!       _S_set_options(_Tune __t)
!       { 
! 	if (!_S_init)
! 	  _S_options = __t;
!       }
! 
!       // Using short int as type for the binmap implies we are never
!       // caching blocks larger than 65535 with this allocator
!       typedef unsigned short int        _Binmap_type;
!       static _Binmap_type* 		_S_binmap;
! 
!       // Each requesting thread is assigned an id ranging from 1 to
!       // _S_max_threads. Thread id 0 is used as a global memory pool.
!       // In order to get constant performance on the thread assignment
!       // routine, we keep a list of free ids. When a thread first
!       // requests memory we remove the first record in this list and
!       // stores the address in a __gthread_key. When initializing the
!       // __gthread_key we specify a destructor. When this destructor
!       // (i.e. the thread dies) is called, we return the thread id to
!       // the front of this list.
! #ifdef __GTHREADS
!       struct _Thread_record
!       {
!         // Points to next free thread id record. NULL if last record in list.
!         _Thread_record* volatile        _M_next;
! 
! 	// Thread id ranging from 1 to _S_max_threads.
!         size_t                          _M_id;
!       };
! 
!       static _Thread_record* volatile 	_S_thread_freelist_first;
!       static __gthread_mutex_t 		_S_thread_freelist_mutex;
!       static __gthread_key_t 		_S_thread_key;
! 
!       static void 
!       _S_destroy_thread_key(void* __freelist_pos);
! #endif
! 
!       static size_t 
!       _S_get_thread_id();
! 
!       union _Block_record
!       {
! 	// Points to the block_record of the next free block.
!         _Block_record* volatile         _M_next;
! 
! #ifdef __GTHREADS
! 	// The thread id of the thread which has requested this block.
!         size_t                          _M_thread_id;
! #endif
!       };
! 
!       struct _Bin_record
!       {
! 	// An "array" of pointers to the first free block for each
! 	// thread id. Memory to this "array" is allocated in _S_initialize()
! 	// for _S_max_threads + global pool 0.
!         _Block_record** volatile        _M_first;
! 
! #ifdef __GTHREADS
! 	// An "array" of counters used to keep track of the amount of
! 	// blocks that are on the freelist/used for each thread id.
! 	// Memory to these "arrays" is allocated in _S_initialize() for
! 	// _S_max_threads + global pool 0.
!         size_t* volatile                _M_free;
!         size_t* volatile                _M_used;
! 
! 	// Each bin has its own mutex which is used to ensure data
! 	// integrity while changing "ownership" on a block.  The mutex
! 	// is initialized in _S_initialize().
!         __gthread_mutex_t*              _M_mutex;
! #endif
!       };
! 
!       // An "array" of bin_records each of which represents a specific
!       // power of 2 size. Memory to this "array" is allocated in
!       // _S_initialize().
!       static _Bin_record* volatile     	_S_bin;
! 
!       // Actual value calculated in _S_initialize().
!       static size_t 	       	     	_S_bin_size; 
!     };
  
    template<typename _Tp>
      typename __mt_alloc<_Tp>::pointer
--- 470,478 ----
        void
        deallocate(pointer __p, size_type __n);
  
!       using _Mt_alloc_base::_S_get_options;
!       using _Mt_alloc_base::_S_set_options;
!   };
  
    template<typename _Tp>
      typename __mt_alloc<_Tp>::pointer
*************** namespace __gnu_cxx
*** 475,648 ****
      }
    
    template<typename _Tp>
-     void
-     __mt_alloc<_Tp>::
-     _S_initialize()
-     {
-       if (_S_options._M_force_new)
- 	return;
- 
-       // Calculate the number of bins required based on _M_max_bytes.
-       // _S_bin_size is statically-initialized to one.
-       size_t __bin_size = _S_options._M_min_bin;
-       while (_S_options._M_max_bytes > __bin_size)
- 	{
- 	  __bin_size <<= 1;
- 	  ++_S_bin_size;
- 	}
- 
-       // Setup the bin map for quick lookup of the relevant bin.
-       const size_t __j = (_S_options._M_max_bytes + 1) * sizeof(_Binmap_type);
-       _S_binmap = static_cast<_Binmap_type*>(::operator new(__j));
- 
-       _Binmap_type* __bp = _S_binmap;
-       _Binmap_type __bin_max = _S_options._M_min_bin;
-       _Binmap_type __bint = 0;
-       for (_Binmap_type __ct = 0; __ct <= _S_options._M_max_bytes; ++__ct)
-         {
-           if (__ct > __bin_max)
-             {
-               __bin_max <<= 1;
-               ++__bint;
-             }
-           *__bp++ = __bint;
-         }
- 
-       // Initialize _S_bin and its members.
-       void* __v = ::operator new(sizeof(_Bin_record) * _S_bin_size);
-       _S_bin = static_cast<_Bin_record*>(__v);
- 
-       // If __gthread_active_p() create and initialize the list of
-       // free thread ids. Single threaded applications use thread id 0
-       // directly and have no need for this.
- #ifdef __GTHREADS
-       if (__gthread_active_p())
-         {
- 	  const size_t __k = sizeof(_Thread_record) * _S_options._M_max_threads;
- 	  __v = ::operator new(__k);
-           _S_thread_freelist_first = static_cast<_Thread_record*>(__v);
- 
- 	  // NOTE! The first assignable thread id is 1 since the
- 	  // global pool uses id 0
-           size_t __i;
-           for (__i = 1; __i < _S_options._M_max_threads; ++__i)
-             {
- 	      _Thread_record& __tr = _S_thread_freelist_first[__i - 1];
-               __tr._M_next = &_S_thread_freelist_first[__i];
-               __tr._M_id = __i;
-             }
- 
-           // Set last record.
-           _S_thread_freelist_first[__i - 1]._M_next = NULL;
-           _S_thread_freelist_first[__i - 1]._M_id = __i;
- 
- 	  // Make sure this is initialized.
- #ifndef __GTHREAD_MUTEX_INIT
- 	  __GTHREAD_MUTEX_INIT_FUNCTION(&_S_thread_freelist_mutex);
- #endif
-           // Initialize per thread key to hold pointer to
-           // _S_thread_freelist.
-           __gthread_key_create(&_S_thread_key, _S_destroy_thread_key);
- 
- 	  const size_t __max_threads = _S_options._M_max_threads + 1;
- 	  for (size_t __n = 0; __n < _S_bin_size; ++__n)
- 	    {
- 	      _Bin_record& __bin = _S_bin[__n];
- 	      __v = ::operator new(sizeof(_Block_record*) * __max_threads);
- 	      __bin._M_first = static_cast<_Block_record**>(__v);
- 
- 	      __v = ::operator new(sizeof(size_t) * __max_threads);
-               __bin._M_free = static_cast<size_t*>(__v);
- 
- 	      __v = ::operator new(sizeof(size_t) * __max_threads);
-               __bin._M_used = static_cast<size_t*>(__v);
- 
- 	      __v = ::operator new(sizeof(__gthread_mutex_t));
-               __bin._M_mutex = static_cast<__gthread_mutex_t*>(__v);
- 
- #ifdef __GTHREAD_MUTEX_INIT
-               {
-                 // Do not copy a POSIX/gthr mutex once in use.
-                 __gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
-                 *__bin._M_mutex = __tmp;
-               }
- #else
-               { __GTHREAD_MUTEX_INIT_FUNCTION(__bin._M_mutex); }
- #endif
- 
- 	      for (size_t __threadn = 0; __threadn < __max_threads;
- 		   ++__threadn)
- 		{
- 		  __bin._M_first[__threadn] = NULL;
- 		  __bin._M_free[__threadn] = 0;
- 		  __bin._M_used[__threadn] = 0;
- 		}
- 	    }
- 	}
-       else
- #endif	
- 	for (size_t __n = 0; __n < _S_bin_size; ++__n)
- 	  {
- 	    _Bin_record& __bin = _S_bin[__n];
- 	    __v = ::operator new(sizeof(_Block_record*));
- 	    __bin._M_first = static_cast<_Block_record**>(__v);
- 	    __bin._M_first[0] = NULL;
- 	  }
- 
-       _S_init = true;
-     }
- 
-   template<typename _Tp>
-     size_t
-     __mt_alloc<_Tp>::
-     _S_get_thread_id()
-     {
- #ifdef __GTHREADS
-       // If we have thread support and it's active we check the thread
-       // key value and return its id or if it's not set we take the
-       // first record from _S_thread_freelist and sets the key and
-       // returns it's id.
-       if (__gthread_active_p())
-         {
-           _Thread_record* __freelist_pos =
- 	    static_cast<_Thread_record*>(__gthread_getspecific(_S_thread_key)); 
- 	  if (__freelist_pos == NULL)
-             {
- 	      // Since _S_options._M_max_threads must be larger than
- 	      // the theoretical max number of threads of the OS the
- 	      // list can never be empty.
-               __gthread_mutex_lock(&_S_thread_freelist_mutex);
-               __freelist_pos = _S_thread_freelist_first;
-               _S_thread_freelist_first = _S_thread_freelist_first->_M_next;
-               __gthread_mutex_unlock(&_S_thread_freelist_mutex);
- 
-               __gthread_setspecific(_S_thread_key, 
- 				    static_cast<void*>(__freelist_pos));
-             }
-           return __freelist_pos->_M_id;
-         }
- #endif
-       // Otherwise (no thread support or inactive) all requests are
-       // served from the global pool 0.
-       return 0;
-     }
- 
- #ifdef __GTHREADS
-   template<typename _Tp>
-     void
-     __mt_alloc<_Tp>::
-     _S_destroy_thread_key(void* __freelist_pos)
-     {
-       // Return this thread id record to front of thread_freelist.
-       __gthread_mutex_lock(&_S_thread_freelist_mutex);
-       _Thread_record* __tr = static_cast<_Thread_record*>(__freelist_pos);
-       __tr->_M_next = _S_thread_freelist_first;
-       _S_thread_freelist_first = __tr;
-       __gthread_mutex_unlock(&_S_thread_freelist_mutex);
-     }
- #endif
- 
-   template<typename _Tp>
      inline bool
      operator==(const __mt_alloc<_Tp>&, const __mt_alloc<_Tp>&)
      { return true; }
--- 682,687 ----
*************** namespace __gnu_cxx
*** 651,692 ****
      inline bool
      operator!=(const __mt_alloc<_Tp>&, const __mt_alloc<_Tp>&)
      { return false; }
- 
-   template<typename _Tp> 
-     bool __mt_alloc<_Tp>::_S_init = false;
- 
-   template<typename _Tp> 
-     typename __mt_alloc<_Tp>::_Tune __mt_alloc<_Tp>::_S_options;
- 
-   template<typename _Tp> 
-     typename __mt_alloc<_Tp>::_Binmap_type* __mt_alloc<_Tp>::_S_binmap;
- 
-   template<typename _Tp> 
-     typename __mt_alloc<_Tp>::_Bin_record* volatile __mt_alloc<_Tp>::_S_bin;
- 
-   template<typename _Tp> 
-     size_t __mt_alloc<_Tp>::_S_bin_size = 1;
- 
-   // Actual initialization in _S_initialize().
- #ifdef __GTHREADS
-   template<typename _Tp> 
-     __gthread_once_t __mt_alloc<_Tp>::_S_once = __GTHREAD_ONCE_INIT;
- 
-   template<typename _Tp> 
-     typename __mt_alloc<_Tp>::_Thread_record*
-     volatile __mt_alloc<_Tp>::_S_thread_freelist_first = NULL;
- 
-   template<typename _Tp> 
-     __gthread_key_t __mt_alloc<_Tp>::_S_thread_key;
- 
-   template<typename _Tp> 
-     __gthread_mutex_t
- #ifdef __GTHREAD_MUTEX_INIT
-     __mt_alloc<_Tp>::_S_thread_freelist_mutex = __GTHREAD_MUTEX_INIT;
- #else
-     __mt_alloc<_Tp>::_S_thread_freelist_mutex;
- #endif
- #endif
  } // namespace __gnu_cxx
  
  #endif
--- 690,695 ----

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