?? pthread_alloc
字號:
} 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 >> 4);
// Try to make use of the left-over piece.
if (__bytes_left > 0) {
_Pthread_alloc_per_thread_state<_Max_size>* __a =
(_Pthread_alloc_per_thread_state<_Max_size>*)
pthread_getspecific(_S_key);
__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<0>::allocate(__bytes_to_get);
}
}
# else /* !SGI_SOURCE */
_S_start_free = (char *)__malloc_alloc<0>::allocate(__bytes_to_get);
# endif
_S_heap_size += __bytes_to_get;
_S_end_free = _S_start_free + __bytes_to_get;
}
}
// lock is released here
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. */
template <size_t _Max_size>
void *_Pthread_alloc_per_thread_state<_Max_size>
::_M_refill(size_t __n)
{
int __nobjs = 128;
char * __chunk =
_Pthread_alloc_template<_Max_size>::_S_chunk_alloc(__n, __nobjs);
__obj * volatile * __my_free_list;
__obj * __result;
__obj * __current_obj, * __next_obj;
int __i;
if (1 == __nobjs) {
return(__chunk);
}
__my_free_list = __free_list
+ _Pthread_alloc_template<_Max_size>::_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);
}
template <size_t _Max_size>
void *_Pthread_alloc_template<_Max_size>
::reallocate(void *__p, size_t __old_sz, size_t __new_sz)
{
void * __result;
size_t __copy_sz;
if (__old_sz > _Max_size
&& __new_sz > _Max_size) {
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);
}
#if __STL_STATIC_TEMPLATE_DATA > 0
template <size_t _Max_size>
_Pthread_alloc_per_thread_state<_Max_size> *
_Pthread_alloc_template<_Max_size>::_S_free_per_thread_states = 0;
template <size_t _Max_size>
pthread_key_t _Pthread_alloc_template<_Max_size>::_S_key;
template <size_t _Max_size>
bool _Pthread_alloc_template<_Max_size>::_S_key_initialized = false;
template <size_t _Max_size>
pthread_mutex_t _Pthread_alloc_template<_Max_size>::_S_chunk_allocator_lock
= PTHREAD_MUTEX_INITIALIZER;
template <size_t _Max_size>
char *_Pthread_alloc_template<_Max_size>
::_S_start_free = 0;
template <size_t _Max_size>
char *_Pthread_alloc_template<_Max_size>
::_S_end_free = 0;
template <size_t _Max_size>
size_t _Pthread_alloc_template<_Max_size>
::_S_heap_size = 0;
# endif
template <class _Tp>
class pthread_allocator {
typedef pthread_alloc _S_Alloc; // The underlying allocator.
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Tp* pointer;
typedef const _Tp* const_pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
typedef _Tp value_type;
#ifdef __STL_MEMBER_TEMPLATE_CLASSES
template <class _NewType> struct rebind {
typedef pthread_allocator<_NewType> other;
};
#endif
pthread_allocator() __STL_NOTHROW {}
pthread_allocator(const pthread_allocator<_Tp>& a) __STL_NOTHROW {}
#if defined (__STL_MEMBER_TEMPLATES) && defined (__STL_FUNCTION_PARTIAL_ORDER)
template <class _OtherType> pthread_allocator(const pthread_allocator<_OtherType>&)
__STL_NOTHROW {}
#endif
~pthread_allocator() __STL_NOTHROW {}
pointer address(reference __x) const { return &__x; }
const_pointer address(const_reference __x) const { return &__x; }
// __n is permitted to be 0. The C++ standard says nothing about what
// the return value is when __n == 0.
_Tp* allocate(size_type __n, const void* = 0) {
return __n != 0 ? __STATIC_CAST(_Tp*,_S_Alloc::allocate(__n * sizeof(_Tp)))
: 0;
}
// p is not permitted to be a null pointer.
void deallocate(pointer __p, size_type __n)
{ _S_Alloc::deallocate(__p, __n * sizeof(_Tp)); }
size_type max_size() const __STL_NOTHROW
{ return size_t(-1) / sizeof(_Tp); }
void construct(pointer __p, const _Tp& __val) { __STL_PLACEMENT_NEW (__p) _Tp(__val); }
void destroy(pointer _p) { _p->~_Tp(); }
};
__STL_TEMPLATE_NULL
class pthread_allocator<void> {
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;
typedef const void* const_pointer;
typedef void value_type;
#ifdef __STL_MEMBER_TEMPLATE_CLASSES
template <class _NewType> struct rebind {
typedef pthread_allocator<_NewType> other;
};
#endif
};
/*
template <size_t _Max_size>
inline bool operator==(const _Pthread_alloc_template<_Max_size>&,
const _Pthread_alloc_template<_Max_size>&)
{
return true;
}
*/
template <class _T1, class _T2>
inline bool operator==(const pthread_allocator<_T1>&,
const pthread_allocator<_T2>& a2)
{
return true;
}
#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER
template <class _T1, class _T2>
inline bool operator!=(const pthread_allocator<_T1>&,
const pthread_allocator<_T2>&)
{
return false;
}
#endif
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
template <class _Tp, size_t _Max_size>
struct _Alloc_traits<_Tp, _Pthread_alloc_template<_Max_size> >
{
typedef __allocator<_Tp, _Pthread_alloc_template<_Max_size> >
allocator_type;
};
/*
template <class _Tp, class _Atype, size_t _Max>
struct _Alloc_traits<_Tp, __allocator<_Atype, _Pthread_alloc_template<_Max> > >
{
typedef __allocator<_Tp, _Pthread_alloc_template<_Max> > allocator_type;
};
*/
template <class _Tp, class _Atype>
struct _Alloc_traits<_Tp, pthread_allocator<_Atype> >
{
typedef pthread_allocator<_Tp> allocator_type;
};
#endif
#if !defined (__STL_MEMBER_TEMPLATE_CLASSES)
template <class _Tp1, class _Tp2>
inline allocator<_Tp2>
__stl_alloc_rebind(pthread_allocator<_Tp1>&, const _Tp2*, __false_type) {
return allocator<_Tp2>();
}
#endif /* __STL_MEMBER_TEMPLATE_CLASSES */
__STL_END_NAMESPACE
#endif /* __SGI_STL_PTHREAD_ALLOC */
// Local Variables:
// mode:C++
// End:
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