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Re: [Patch] bitmap_allocator.
On Wed, 2004-10-13 at 20:35, Paolo Carlini wrote:
> Dhruv Matani wrote:
>
> >While I'm not entirely happy with this, I'll try converting it back to
> >the inline functions and see what happens.
> >
> I see, please do that and resend the result: actually, in the library we
> strive to
> minimize macro usage.
Ok, I have removed those pesky macros and replaced them by inline
functions.
>
> By the way, this is my final report:
> 1- pthread7-rope fails everywhere: history tells us that poor rope
> failing probably
> means there is something wrong at destruction time.
You mean that when the allocator is being destroyed, something is going
wrong?
> 2- Still *lots* of warning about insufficient alignment on ia64: it
> seems you are
> still using casts to <unsigned int> and this is definitely not ok:
Ok, I have added a macro _BALLOC_ALIGN_BYTES by which you can set the
alignment in bytes at compile time itself. However, I don't think that I
can do away entirely with those reinterpret_casts to unsigned int. What
I have done is that whenever I do perform those casts, I make sure that
the memory is aligned to _BALLOC_ALIGN_BYTES.
> the
> other allocators
> guarantee 8 by default (and this can be easily tuned), your allocator
> only 4.
Fixed that!
> Do you
> know that malloc returns memory allocated 16 on 64-bit machines?
Ok, I did not know this! I though that 8 was the norm everywhere. If 8
was in fact the norm, then also currently there were problems with those
casts.
> Please
> try to
> achieve at least 8.
>
> That being said, since, for the first time in *months* the build
> succeeds and the
> testsuites are good overall, IMO we should commit the changes very soon,
> as soon
> as there are no more (very annoying for *everyone* not only to users of
> bitmap)
> warnings at build time.
Fixed that too. Now, after having converted to the inline functions,
these warnings have gone.
>
> Paolo.
--
-Dhruv Matani.
http://www.geocities.com/dhruvbird/
The price of freedom is responsibility, but it's a bargain, because
freedom is priceless. ~ Hugh Downs
diff -Nrup -x '.cvs*' cvs_libstdc++-v3/config/linker-map.gnu modified_libv3/config/linker-map.gnu
--- cvs_libstdc++-v3/config/linker-map.gnu 2004-10-08 21:27:03.000000000 +0530
+++ modified_libv3/config/linker-map.gnu 2004-10-13 14:08:40.000000000 +0530
@@ -270,6 +270,12 @@ GLIBCXX_3.4.3 {
_ZN9__gnu_cxx6__poolILb[01]EE16_M_reserve_blockE[jm][jm];
_ZN9__gnu_cxx6__poolILb[01]EE16_M_reclaim_blockEPc[jm];
_ZN9__gnu_cxx6__poolILb[01]EED[12]Ev;
+
+ _ZN9__gnu_cxx9free_list12_S_free_listE;
+ _ZN9__gnu_cxx9free_list12_S_bfl_mutexE;
+ _ZN9__gnu_cxx9free_list6_M_getEj;
+ _ZN9__gnu_cxx9free_list8_M_clearEv;
+
# stub functions from libmath
acosf;
diff -Nrup -x '.cvs*' cvs_libstdc++-v3/include/ext/bitmap_allocator.h modified_libv3/include/ext/bitmap_allocator.h
--- cvs_libstdc++-v3/include/ext/bitmap_allocator.h 2004-03-24 23:57:43.000000000 +0530
+++ modified_libv3/include/ext/bitmap_allocator.h 2004-10-13 22:38:25.000000000 +0530
@@ -1,4 +1,4 @@
-// Bitmapped Allocator. -*- C++ -*-
+// Bitmap Allocator. -*- C++ -*-
// Copyright (C) 2004 Free Software Foundation, Inc.
//
@@ -27,53 +27,72 @@
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
+/** @file ext/bitmap_allocator.h
+ * This file is a GNU extension to the Standard C++ Library.
+ * You should only include this header if you are using GCC 3 or later.
+ */
-
-#if !defined _BITMAP_ALLOCATOR_H
+#ifndef _BITMAP_ALLOCATOR_H
#define _BITMAP_ALLOCATOR_H 1
+// For std::size_t, and ptrdiff_t.
#include <cstddef>
-//For std::size_t, and ptrdiff_t.
+
+// For std::pair.
#include <utility>
-//For std::pair.
-#include <algorithm>
-//std::find_if, and std::lower_bound.
-#include <vector>
-//For the free list of exponentially growing memory blocks. At max,
-//size of the vector should be not more than the number of bits in an
-//integer or an unsigned integer.
+
+// For greater_equal, and less_equal.
#include <functional>
-//For greater_equal, and less_equal.
+
+// For operator new.
#include <new>
-//For operator new.
+
+// For __gthread_mutex_t, __gthread_mutex_lock and __gthread_mutex_unlock.
#include <bits/gthr.h>
-//For __gthread_mutex_t, __gthread_mutex_lock and __gthread_mutex_unlock.
-#include <ext/new_allocator.h>
-//For __gnu_cxx::new_allocator for std::vector.
+// Define this to enable error checking withing the allocator
+// itself(to debug the allocator itself).
+//#define _BALLOC_SANITY_CHECK
+
+// The constant in the expression below is the alignment required in
+// bytes.
+#define _BALLOC_ALIGN_BYTES \
+(sizeof(unsigned int) > 8 ? sizeof(unsigned int) : 8)
+
+#if defined _BALLOC_SANITY_CHECK
#include <cassert>
-#define NDEBUG
+#define _BALLOC_ASSERT(_EXPR) assert(_EXPR)
+#else
+#define _BALLOC_ASSERT(_EXPR)
+#endif
-//#define CHECK_FOR_ERRORS
-//#define __CPU_HAS_BACKWARD_BRANCH_PREDICTION
namespace __gnu_cxx
{
- namespace {
#if defined __GTHREADS
+ namespace
+ {
+ // If true, then the application being compiled will be using
+ // threads, so use mutexes as a synchronization primitive, else do
+ // no use any synchronization primitives.
bool const __threads_enabled = __gthread_active_p();
-#endif
-
}
+#endif
#if defined __GTHREADS
- class _Mutex {
+ // _Mutex is an OO-Wrapper for __gthread_mutex_t. It does not allow
+ // you to copy or assign an already initialized mutex. This is used
+ // merely as a convenience for the locking classes.
+ class _Mutex
+ {
__gthread_mutex_t _M_mut;
- //Prevent Copying and assignment.
- _Mutex (_Mutex const&);
- _Mutex& operator= (_Mutex const&);
+
+ // Prevent Copying and assignment.
+ _Mutex(_Mutex const&);
+ _Mutex& operator=(_Mutex const&);
+
public:
- _Mutex ()
+ _Mutex()
{
if (__threads_enabled)
{
@@ -85,24 +104,38 @@ namespace __gnu_cxx
#endif
}
}
- ~_Mutex ()
+
+ ~_Mutex()
{
- //Gthreads does not define a Mutex Destruction Function.
+ // Gthreads does not define a Mutex Destruction Function.
}
- __gthread_mutex_t *_M_get() { return &_M_mut; }
+
+ __gthread_mutex_t*
+ _M_get() { return &_M_mut; }
};
- class _Lock {
+ // _Lock is a simple manual lokcing class which allows you to
+ // manually lock and unlock a mutex associated with the lock. There
+ // is not automatic locking or unlocking happening without the
+ // programmer's explicit instructions. This class unlocks the mutex
+ // ONLY if it has not been locked. However, this check does not
+ // apply for lokcing, and wayward use may cause dead-locks.
+ class _Lock
+ {
_Mutex* _M_pmt;
bool _M_locked;
- //Prevent Copying and assignment.
- _Lock (_Lock const&);
- _Lock& operator= (_Lock const&);
+
+ // Prevent Copying and assignment.
+ _Lock(_Lock const&);
+ _Lock& operator=(_Lock const&);
+
public:
_Lock(_Mutex* __mptr)
- : _M_pmt(__mptr), _M_locked(false)
- { this->_M_lock(); }
- void _M_lock()
+ : _M_pmt(__mptr), _M_locked(false)
+ { }
+
+ void
+ _M_lock()
{
if (__threads_enabled)
{
@@ -110,7 +143,9 @@ namespace __gnu_cxx
__gthread_mutex_lock(_M_pmt->_M_get());
}
}
- void _M_unlock()
+
+ void
+ _M_unlock()
{
if (__threads_enabled)
{
@@ -121,739 +156,1018 @@ namespace __gnu_cxx
}
}
}
- ~_Lock() { this->_M_unlock(); }
+
+ ~_Lock() { }
};
-#endif
-
-
- namespace __aux_balloc {
- static const unsigned int _Bits_Per_Byte = 8;
- static const unsigned int _Bits_Per_Block = sizeof(unsigned int) * _Bits_Per_Byte;
+ // _Auto_Lock locks the associated mutex on construction, and
+ // unlocks on it's destruction. There are no checks performed, and
+ // this calss follows the RAII principle.
+ class _Auto_Lock
+ {
+ _Mutex* _M_pmt;
+ // Prevent Copying and assignment.
+ _Auto_Lock(_Auto_Lock const&);
+ _Auto_Lock& operator=(_Auto_Lock const&);
- template <typename _Addr_Pair_t>
- inline size_t __balloc_num_blocks (_Addr_Pair_t __ap)
+ void
+ _M_lock()
{
- return (__ap.second - __ap.first) + 1;
+ if (__threads_enabled)
+ __gthread_mutex_lock(_M_pmt->_M_get());
}
- template <typename _Addr_Pair_t>
- inline size_t __balloc_num_bit_maps (_Addr_Pair_t __ap)
+ void
+ _M_unlock()
{
- return __balloc_num_blocks(__ap) / _Bits_Per_Block;
+ if (__threads_enabled)
+ __gthread_mutex_unlock(_M_pmt->_M_get());
}
- //T should be a pointer type.
- template <typename _Tp>
- class _Inclusive_between : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> {
- typedef _Tp pointer;
- pointer _M_ptr_value;
- typedef typename std::pair<_Tp, _Tp> _Block_pair;
+ public:
+ _Auto_Lock(_Mutex* __mptr) : _M_pmt(__mptr)
+ { this->_M_lock(); }
- public:
- _Inclusive_between (pointer __ptr) : _M_ptr_value(__ptr) { }
- bool operator () (_Block_pair __bp) const throw ()
+ ~_Auto_Lock() { this->_M_unlock(); }
+ };
+#endif
+
+ namespace balloc
+ {
+ // __mini_vector<> is to be used only for built-in types or
+ // PODs. It is a stripped down version of the full-fledged
+ // std::vector<>. Noteable differences are:
+ //
+ // 1. Not all accessor functions are present.
+ // 2. Used ONLY for PODs.
+ // 3. No Allocator template argument. Uses ::operator new() to get
+ // memory, and ::operator delete() to free it.
+ template<typename _Tp>
+ class __mini_vector
{
- if (std::less_equal<pointer> ()(_M_ptr_value, __bp.second) &&
- std::greater_equal<pointer> ()(_M_ptr_value, __bp.first))
- return true;
- else
- return false;
- }
- };
-
- //Used to pass a Functor to functions by reference.
- template <typename _Functor>
- class _Functor_Ref :
- public std::unary_function<typename _Functor::argument_type, typename _Functor::result_type> {
- _Functor& _M_fref;
-
- public:
- typedef typename _Functor::argument_type argument_type;
- typedef typename _Functor::result_type result_type;
+ __mini_vector(const __mini_vector&);
+ __mini_vector& operator=(const __mini_vector&);
- _Functor_Ref (_Functor& __fref) : _M_fref(__fref) { }
- result_type operator() (argument_type __arg) { return _M_fref (__arg); }
- };
+ public:
+ typedef _Tp value_type;
+ typedef _Tp* pointer;
+ typedef _Tp& reference;
+ typedef const _Tp& const_reference;
+ typedef std::size_t size_type;
+ typedef std::ptrdiff_t difference_type;
+ typedef pointer iterator;
+
+ private:
+ pointer _M_start;
+ pointer _M_finish;
+ pointer _M_end_of_storage;
+
+ size_type
+ _M_space_left() const throw()
+ { return _M_end_of_storage - _M_finish; }
+
+ pointer
+ allocate(size_type __n)
+ { return static_cast<pointer>(::operator new(__n * sizeof(_Tp))); }
+
+ void
+ deallocate(pointer __p, size_type)
+ { ::operator delete(__p); }
+
+ public:
+ // Members used: size(), push_back(), pop_back(),
+ // insert(iterator, const_reference), erase(iterator),
+ // begin(), end(), back(), operator[].
+
+ __mini_vector() : _M_start(0), _M_finish(0),
+ _M_end_of_storage(0)
+ { }
+ ~__mini_vector()
+ {
+ if (this->_M_start)
+ {
+ this->deallocate(this->_M_start, this->_M_end_of_storage
+ - this->_M_start);
+ }
+ }
- //T should be a pointer type, and A is the Allocator for the vector.
- template <typename _Tp, typename _Alloc>
- class _Ffit_finder
- : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> {
- typedef typename std::vector<std::pair<_Tp, _Tp>, _Alloc> _BPVector;
- typedef typename _BPVector::difference_type _Counter_type;
- typedef typename std::pair<_Tp, _Tp> _Block_pair;
+ size_type
+ size() const throw()
+ { return _M_finish - _M_start; }
+
+ iterator
+ begin() const throw()
+ { return this->_M_start; }
+
+ iterator
+ end() const throw()
+ { return this->_M_finish; }
+
+ reference
+ back() const throw()
+ { return *(this->end() - 1); }
+
+ reference
+ operator[](const size_type __pos) const throw()
+ { return this->_M_start[__pos]; }
- unsigned int *_M_pbitmap;
- unsigned int _M_data_offset;
+ void
+ insert(iterator __pos, const_reference __x);
- public:
- _Ffit_finder ()
- : _M_pbitmap (0), _M_data_offset (0)
- { }
+ void
+ push_back(const_reference __x)
+ {
+ if (this->_M_space_left())
+ {
+ *this->end() = __x;
+ ++this->_M_finish;
+ }
+ else
+ this->insert(this->end(), __x);
+ }
- bool operator() (_Block_pair __bp) throw()
+ void
+ pop_back() throw()
+ { --this->_M_finish; }
+
+ void
+ erase(iterator __pos) throw();
+
+ void
+ clear() throw()
+ { this->_M_finish = this->_M_start; }
+ };
+
+ // Out of line function definitions.
+ template<typename _Tp>
+ void __mini_vector<_Tp>::
+ insert(iterator __pos, const_reference __x)
{
- //Set the _rover to the last unsigned integer, which is the
- //bitmap to the first free block. Thus, the bitmaps are in exact
- //reverse order of the actual memory layout. So, we count down
- //the bimaps, which is the same as moving up the memory.
-
- //If the used count stored at the start of the Bit Map headers
- //is equal to the number of Objects that the current Block can
- //store, then there is definitely no space for another single
- //object, so just return false.
- _Counter_type __diff = __gnu_cxx::__aux_balloc::__balloc_num_bit_maps (__bp);
-
- assert (*(reinterpret_cast<unsigned int*>(__bp.first) - (__diff + 1)) <=
- __gnu_cxx::__aux_balloc::__balloc_num_blocks (__bp));
-
- if (*(reinterpret_cast<unsigned int*>(__bp.first) - (__diff + 1)) ==
- __gnu_cxx::__aux_balloc::__balloc_num_blocks (__bp))
- return false;
+ if (this->_M_space_left())
+ {
+ size_type __to_move = this->_M_finish - __pos;
+ iterator __dest = this->end();
+ iterator __src = this->end() - 1;
- unsigned int *__rover = reinterpret_cast<unsigned int*>(__bp.first) - 1;
- for (_Counter_type __i = 0; __i < __diff; ++__i)
+ ++this->_M_finish;
+ while (__to_move)
+ {
+ *__dest = *__src;
+ --__dest; --__src; --__to_move;
+ }
+ *__pos = __x;
+ }
+ else
{
- _M_data_offset = __i;
- if (*__rover)
+ size_type __new_size = this->size() ? this->size() * 2 : 1;
+ iterator __new_start = this->allocate(__new_size);
+ iterator __first = this->begin();
+ iterator __start = __new_start;
+ while (__first != __pos)
{
- _M_pbitmap = __rover;
- return true;
+ *__start = *__first;
+ ++__start; ++__first;
}
- --__rover;
+ *__start = __x;
+ ++__start;
+ while (__first != this->end())
+ {
+ *__start = *__first;
+ ++__start; ++__first;
+ }
+ if (this->_M_start)
+ this->deallocate(this->_M_start, this->size());
+
+ this->_M_start = __new_start;
+ this->_M_finish = __start;
+ this->_M_end_of_storage = this->_M_start + __new_size;
}
- return false;
- }
-
- unsigned int *_M_get () { return _M_pbitmap; }
- unsigned int _M_offset () { return _M_data_offset * _Bits_Per_Block; }
- };
-
- //T should be a pointer type.
- template <typename _Tp, typename _Alloc>
- class _Bit_map_counter {
-
- typedef typename std::vector<std::pair<_Tp, _Tp>, _Alloc> _BPVector;
- typedef typename _BPVector::size_type _Index_type;
- typedef _Tp pointer;
-
- _BPVector& _M_vbp;
- unsigned int *_M_curr_bmap;
- unsigned int *_M_last_bmap_in_block;
- _Index_type _M_curr_index;
-
- public:
- //Use the 2nd parameter with care. Make sure that such an entry
- //exists in the vector before passing that particular index to
- //this ctor.
- _Bit_map_counter (_BPVector& Rvbp, int __index = -1)
- : _M_vbp(Rvbp)
- {
- this->_M_reset(__index);
}
-
- void _M_reset (int __index = -1) throw()
+
+ template<typename _Tp>
+ void __mini_vector<_Tp>::
+ erase(iterator __pos) throw()
{
- if (__index == -1)
+ while (__pos + 1 != this->end())
{
- _M_curr_bmap = 0;
- _M_curr_index = (_Index_type)-1;
- return;
+ *__pos = __pos[1];
+ ++__pos;
}
+ --this->_M_finish;
+ }
- _M_curr_index = __index;
- _M_curr_bmap = reinterpret_cast<unsigned int*>(_M_vbp[_M_curr_index].first) - 1;
- assert (__index <= (int)_M_vbp.size() - 1);
-
- _M_last_bmap_in_block = _M_curr_bmap -
- ((_M_vbp[_M_curr_index].second - _M_vbp[_M_curr_index].first + 1) / _Bits_Per_Block - 1);
- }
-
- //Dangerous Function! Use with extreme care. Pass to this
- //function ONLY those values that are known to be correct,
- //otherwise this will mess up big time.
- void _M_set_internal_bit_map (unsigned int *__new_internal_marker) throw()
+ template<typename _Tp>
+ struct __mv_iter_traits
{
- _M_curr_bmap = __new_internal_marker;
- }
-
- bool _M_finished () const throw()
+ typedef typename _Tp::value_type value_type;
+ typedef typename _Tp::difference_type difference_type;
+ };
+
+ template<typename _Tp>
+ struct __mv_iter_traits<_Tp*>
{
- return (_M_curr_bmap == 0);
- }
-
- _Bit_map_counter& operator++ () throw()
+ typedef _Tp value_type;
+ typedef std::ptrdiff_t difference_type;
+ };
+
+ enum
+ {
+ bits_per_byte = 8,
+ bits_per_block = sizeof(unsigned int) * bits_per_byte
+ };
+
+ template<typename _ForwardIterator, typename _Tp, typename _Compare>
+ _ForwardIterator
+ __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
+ const _Tp& __val, _Compare __comp)
{
- if (_M_curr_bmap == _M_last_bmap_in_block)
+ typedef typename __mv_iter_traits<_ForwardIterator>::value_type
+ _ValueType;
+ typedef typename __mv_iter_traits<_ForwardIterator>::difference_type
+ _DistanceType;
+
+ _DistanceType __len = __last - __first;
+ _DistanceType __half;
+ _ForwardIterator __middle;
+
+ while (__len > 0)
{
- if (++_M_curr_index == _M_vbp.size())
+ __half = __len >> 1;
+ __middle = __first;
+ __middle += __half;
+ if (__comp(*__middle, __val))
{
- _M_curr_bmap = 0;
+ __first = __middle;
+ ++__first;
+ __len = __len - __half - 1;
}
else
- {
- this->_M_reset (_M_curr_index);
- }
- }
- else
- {
- --_M_curr_bmap;
+ __len = __half;
}
- return *this;
+ return __first;
}
-
- unsigned int *_M_get ()
+
+ template<typename _InputIterator, typename _Predicate>
+ inline _InputIterator
+ __find_if(_InputIterator __first, _InputIterator __last, _Predicate __p)
{
- return _M_curr_bmap;
+ while (__first != __last && !__p(*__first))
+ ++__first;
+ return __first;
}
+
+ template<typename _AddrPair>
+ inline size_t
+ __num_blocks(_AddrPair __ap)
+ { return (__ap.second - __ap.first) + 1; }
+
+ template<typename _AddrPair>
+ inline size_t
+ __num_bitmaps(_AddrPair __ap)
+ { return __num_blocks(__ap) / bits_per_block; }
+
+ // _Tp should be a pointer type.
+ template<typename _Tp>
+ class _Inclusive_between
+ : public std::unary_function<typename std::pair<_Tp, _Tp>, bool>
+ {
+ typedef _Tp pointer;
+ pointer _M_ptr_value;
+ typedef typename std::pair<_Tp, _Tp> _Block_pair;
+
+ public:
+ _Inclusive_between(pointer __ptr) : _M_ptr_value(__ptr)
+ { }
+
+ bool
+ operator()(_Block_pair __bp) const throw()
+ {
+ if (std::less_equal<pointer>()(_M_ptr_value, __bp.second)
+ && std::greater_equal<pointer>()(_M_ptr_value, __bp.first))
+ return true;
+ else
+ return false;
+ }
+ };
+
+ // Used to pass a Functor to functions by reference.
+ template<typename _Functor>
+ class _Functor_Ref
+ : public std::unary_function<typename _Functor::argument_type,
+ typename _Functor::result_type>
+ {
+ _Functor& _M_fref;
+
+ public:
+ typedef typename _Functor::argument_type argument_type;
+ typedef typename _Functor::result_type result_type;
+
+ _Functor_Ref(_Functor& __fref) : _M_fref(__fref)
+ { }
+
+ result_type
+ operator()(argument_type __arg)
+ { return _M_fref(__arg); }
+ };
+
+ // _Tp should be a pointer type, and _Alloc is the Allocator for
+ // the vector.
+ template<typename _Tp>
+ class _Ffit_finder
+ : public std::unary_function<typename std::pair<_Tp, _Tp>, bool>
+ {
+ typedef typename std::pair<_Tp, _Tp> _Block_pair;
+ typedef typename balloc::__mini_vector<_Block_pair> _BPVector;
+ typedef typename _BPVector::difference_type _Counter_type;
+
+ unsigned int* _M_pbitmap;
+ unsigned int _M_data_offset;
+
+ public:
+ _Ffit_finder() : _M_pbitmap(0), _M_data_offset(0)
+ { }
+
+ bool
+ operator()(_Block_pair __bp) throw()
+ {
+ // Set the _rover to the last unsigned integer, which is the
+ // bitmap to the first free block. Thus, the bitmaps are in exact
+ // reverse order of the actual memory layout. So, we count down
+ // the bimaps, which is the same as moving up the memory.
+
+ // If the used count stored at the start of the Bit Map headers
+ // is equal to the number of Objects that the current Block can
+ // store, then there is definitely no space for another single
+ // object, so just return false.
+ _Counter_type __diff =
+ __gnu_cxx::balloc::__num_bitmaps(__bp);
+
+ if (*reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>
+ (reinterpret_cast<unsigned int*>(__bp.first) - (__diff))
+ - _BALLOC_ALIGN_BYTES)
+ == __gnu_cxx::balloc::__num_blocks(__bp))
+ return false;
+
+ unsigned int* __rover = reinterpret_cast<unsigned int*>(__bp.first) - 1;
+
+ for (_Counter_type __i = 0; __i < __diff; ++__i)
+ {
+ _M_data_offset = __i;
+ if (*__rover)
+ {
+ _M_pbitmap = __rover;
+ return true;
+ }
+ --__rover;
+ }
+ return false;
+ }
+
- pointer _M_base () { return _M_vbp[_M_curr_index].first; }
- unsigned int _M_offset ()
+ unsigned int*
+ _M_get() const throw()
+ { return _M_pbitmap; }
+
+ unsigned int
+ _M_offset() const throw()
+ { return _M_data_offset * bits_per_block; }
+ };
+
+
+
+ // _Tp should be a pointer type.
+ template<typename _Tp>
+ class _Bitmap_counter
{
- return _Bits_Per_Block * ((reinterpret_cast<unsigned int*>(this->_M_base()) - _M_curr_bmap) - 1);
- }
+ typedef typename balloc::__mini_vector<typename std::pair<_Tp, _Tp> >
+ _BPVector;
+ typedef typename _BPVector::size_type _Index_type;
+ typedef _Tp pointer;
- unsigned int _M_where () { return _M_curr_index; }
- };
- }
+ _BPVector& _M_vbp;
+ unsigned int* _M_curr_bmap;
+ unsigned int* _M_last_bmap_in_block;
+ _Index_type _M_curr_index;
+
+ public:
+ // Use the 2nd parameter with care. Make sure that such an
+ // entry exists in the vector before passing that particular
+ // index to this ctor.
+ _Bitmap_counter(_BPVector& Rvbp, int __index = -1) : _M_vbp(Rvbp)
+ { this->_M_reset(__index); }
+
+ void
+ _M_reset(int __index = -1) throw()
+ {
+ if (__index == -1)
+ {
+ _M_curr_bmap = 0;
+ _M_curr_index = static_cast<_Index_type>(-1);
+ return;
+ }
- //Generic Version of the bsf instruction.
- typedef unsigned int _Bit_map_type;
- static inline unsigned int _Bit_scan_forward (register _Bit_map_type __num)
- {
- return static_cast<unsigned int>(__builtin_ctz(__num));
- }
+ _M_curr_index = __index;
+ _M_curr_bmap = reinterpret_cast<unsigned int*>
+ (_M_vbp[_M_curr_index].first) - 1;
- struct _OOM_handler {
- static std::new_handler _S_old_handler;
- static bool _S_handled_oom;
- typedef void (*_FL_clear_proc)(void);
- static _FL_clear_proc _S_oom_fcp;
+ _BALLOC_ASSERT(__index <= (int)_M_vbp.size() - 1);
+
+ _M_last_bmap_in_block = _M_curr_bmap
+ - ((_M_vbp[_M_curr_index].second
+ - _M_vbp[_M_curr_index].first + 1)
+ / bits_per_block - 1);
+ }
- _OOM_handler (_FL_clear_proc __fcp)
- {
- _S_oom_fcp = __fcp;
- _S_old_handler = std::set_new_handler (_S_handle_oom_proc);
- _S_handled_oom = false;
- }
+ // Dangerous Function! Use with extreme care. Pass to this
+ // function ONLY those values that are known to be correct,
+ // otherwise this will mess up big time.
+ void
+ _M_set_internal_bitmap(unsigned int* __new_internal_marker) throw()
+ { _M_curr_bmap = __new_internal_marker; }
+
+ bool
+ _M_finished() const throw()
+ { return(_M_curr_bmap == 0); }
+
+ _Bitmap_counter&
+ operator++() throw()
+ {
+ if (_M_curr_bmap == _M_last_bmap_in_block)
+ {
+ if (++_M_curr_index == _M_vbp.size())
+ _M_curr_bmap = 0;
+ else
+ this->_M_reset(_M_curr_index);
+ }
+ else
+ --_M_curr_bmap;
+ return *this;
+ }
+
+ unsigned int*
+ _M_get() const throw()
+ { return _M_curr_bmap; }
+
+ pointer
+ _M_base() const throw()
+ { return _M_vbp[_M_curr_index].first; }
- static void _S_handle_oom_proc()
- {
- _S_oom_fcp();
- std::set_new_handler (_S_old_handler);
- _S_handled_oom = true;
- }
+ unsigned int
+ _M_offset() const throw()
+ {
+ return bits_per_block
+ * ((reinterpret_cast<unsigned int*>(this->_M_base())
+ - _M_curr_bmap) - 1);
+ }
+
+ unsigned int
+ _M_where() const throw()
+ { return _M_curr_index; }
+ };
- ~_OOM_handler ()
+ inline void
+ __bit_allocate(unsigned int* __pbmap, unsigned int __pos) throw()
{
- if (!_S_handled_oom)
- std::set_new_handler (_S_old_handler);
+ unsigned int __mask = 1 << __pos;
+ __mask = ~__mask;
+ *__pbmap &= __mask;
}
- };
-
- std::new_handler _OOM_handler::_S_old_handler;
- bool _OOM_handler::_S_handled_oom = false;
- _OOM_handler::_FL_clear_proc _OOM_handler::_S_oom_fcp = 0;
+ inline void
+ __bit_free(unsigned int* __pbmap, unsigned int __pos) throw()
+ {
+ unsigned int __mask = 1 << __pos;
+ *__pbmap |= __mask;
+ }
+ } // namespace balloc
- class _BA_free_list_store {
- struct _LT_pointer_compare {
- template <typename _Tp>
- bool operator() (_Tp* __pt, _Tp const& __crt) const throw()
- {
- return *__pt < __crt;
- }
+ // Generic Version of the bsf instruction.
+ inline unsigned int
+ _Bit_scan_forward(register unsigned int __num)
+ { return static_cast<unsigned int>(__builtin_ctz(__num)); }
+
+ class free_list
+ {
+ typedef unsigned int* value_type;
+ typedef balloc::__mini_vector<value_type> vector_type;
+ typedef vector_type::iterator iterator;
+
+ struct _LT_pointer_compare
+ {
+ bool
+ operator()(const unsigned int* __pui, const unsigned int __cui) const throw()
+ { return *__pui < __cui; }
};
-#if defined __GTHREADS
+#if defined __GTHREADS
static _Mutex _S_bfl_mutex;
#endif
- static std::vector<unsigned int*> _S_free_list;
- typedef std::vector<unsigned int*>::iterator _FLIter;
-
- static void _S_validate_free_list(unsigned int *__addr) throw()
+ static vector_type _S_free_list;
+
+ void
+ _M_validate(unsigned int* __addr) throw()
{
const unsigned int __max_size = 64;
if (_S_free_list.size() >= __max_size)
{
- //Ok, the threshold value has been reached.
- //We determine which block to remove from the list of free
- //blocks.
+ // Ok, the threshold value has been reached. We determine
+ // which block to remove from the list of free blocks.
if (*__addr >= *_S_free_list.back())
{
- //Ok, the new block is greater than or equal to the last
- //block in the list of free blocks. We just free the new
- //block.
- operator delete((void*)__addr);
+ // Ok, the new block is greater than or equal to the
+ // last block in the list of free blocks. We just free
+ // the new block.
+ operator delete(static_cast<void*>(__addr));
return;
}
else
{
- //Deallocate the last block in the list of free lists, and
- //insert the new one in it's correct position.
- operator delete((void*)_S_free_list.back());
+ // Deallocate the last block in the list of free lists,
+ // and insert the new one in it's correct position.
+ operator delete(static_cast<void*>(_S_free_list.back()));
_S_free_list.pop_back();
}
}
- //Just add the block to the list of free lists
- //unconditionally.
- _FLIter __temp = std::lower_bound(_S_free_list.begin(), _S_free_list.end(),
- *__addr, _LT_pointer_compare ());
- //We may insert the new free list before _temp;
+ // Just add the block to the list of free lists unconditionally.
+ iterator __temp = __gnu_cxx::balloc::__lower_bound
+ (_S_free_list.begin(), _S_free_list.end(),
+ *__addr, _LT_pointer_compare());
+
+ // We may insert the new free list before _temp;
_S_free_list.insert(__temp, __addr);
}
- static bool _S_should_i_give(unsigned int __block_size, unsigned int __required_size) throw()
+ bool
+ _M_should_i_give(unsigned int __block_size,
+ unsigned int __required_size) throw()
{
const unsigned int __max_wastage_percentage = 36;
if (__block_size >= __required_size &&
- (((__block_size - __required_size) * 100 / __block_size) < __max_wastage_percentage))
+ (((__block_size - __required_size) * 100 / __block_size)
+ < __max_wastage_percentage))
return true;
else
return false;
}
public:
- typedef _BA_free_list_store _BFL_type;
-
- static inline void _S_insert_free_list(unsigned int *__addr) throw()
+ inline void
+ _M_insert(unsigned int* __addr) throw()
{
#if defined __GTHREADS
- _Lock __bfl_lock(&_S_bfl_mutex);
+ _Auto_Lock __bfl_lock(&_S_bfl_mutex);
#endif
- //Call _S_validate_free_list to decide what should be done with this
- //particular free list.
- _S_validate_free_list(--__addr);
+ // Call _M_validate to decide what should be done with
+ // this particular free list.
+ this->_M_validate(reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>(__addr)
+ - _BALLOC_ALIGN_BYTES));
}
- static unsigned int *_S_get_free_list(unsigned int __sz) throw (std::bad_alloc)
- {
-#if defined __GTHREADS
- _Lock __bfl_lock(&_S_bfl_mutex);
-#endif
- _FLIter __temp = std::lower_bound(_S_free_list.begin(), _S_free_list.end(),
- __sz, _LT_pointer_compare());
- if (__temp == _S_free_list.end() || !_S_should_i_give (**__temp, __sz))
- {
- //We hold the lock because the OOM_Handler is a stateless
- //entity.
- _OOM_handler __set_handler(_BFL_type::_S_clear);
- unsigned int *__ret_val = reinterpret_cast<unsigned int*>
- (operator new (__sz + sizeof(unsigned int)));
- *__ret_val = __sz;
- return ++__ret_val;
- }
- else
- {
- unsigned int* __ret_val = *__temp;
- _S_free_list.erase (__temp);
- return ++__ret_val;
- }
- }
-
- //This function just clears the internal Free List, and gives back
- //all the memory to the OS.
- static void _S_clear()
- {
-#if defined __GTHREADS
- _Lock __bfl_lock(&_S_bfl_mutex);
-#endif
- _FLIter __iter = _S_free_list.begin();
- while (__iter != _S_free_list.end())
- {
- operator delete((void*)*__iter);
- ++__iter;
- }
- _S_free_list.clear();
- }
-
- };
-
-#if defined __GTHREADS
- _Mutex _BA_free_list_store::_S_bfl_mutex;
-#endif
- std::vector<unsigned int*> _BA_free_list_store::_S_free_list;
+ unsigned int*
+ _M_get(unsigned int __sz) throw(std::bad_alloc);
- template <typename _Tp> class bitmap_allocator;
- // specialize for void:
- template <> class bitmap_allocator<void> {
- public:
- typedef void* pointer;
- typedef const void* const_pointer;
- // reference-to-void members are impossible.
- typedef void value_type;
- template <typename _Tp1> struct rebind { typedef bitmap_allocator<_Tp1> other; };
+ // This function just clears the internal Free List, and gives back
+ // all the memory to the OS.
+ void
+ _M_clear();
};
- template <typename _Tp> class bitmap_allocator : private _BA_free_list_store {
- 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;
- template <typename _Tp1> struct rebind { typedef bitmap_allocator<_Tp1> other; };
-
- private:
- static const unsigned int _Bits_Per_Byte = 8;
- static const unsigned int _Bits_Per_Block = sizeof(unsigned int) * _Bits_Per_Byte;
- static inline void _S_bit_allocate(unsigned int *__pbmap, unsigned int __pos) throw()
- {
- unsigned int __mask = 1 << __pos;
- __mask = ~__mask;
- *__pbmap &= __mask;
- }
-
- static inline void _S_bit_free(unsigned int *__pbmap, unsigned int __pos) throw()
+ // Forward declare the class.
+ template<typename _Tp>
+ class bitmap_allocator;
+
+ // Specialize for void:
+ template<>
+ class bitmap_allocator<void>
{
- unsigned int __mask = 1 << __pos;
- *__pbmap |= __mask;
- }
+ public:
+ typedef void* pointer;
+ typedef const void* const_pointer;
- static inline void *_S_memory_get(size_t __sz) throw (std::bad_alloc)
- {
- return operator new(__sz);
- }
+ // Reference-to-void members are impossible.
+ typedef void value_type;
+ template<typename _Tp1>
+ struct rebind
+ {
+ typedef bitmap_allocator<_Tp1> other;
+ };
+ };
- static inline void _S_memory_put(void *__vptr) throw ()
+ template<typename _Tp>
+ class bitmap_allocator : private free_list
{
- operator delete(__vptr);
- }
+ public:
+ typedef std::size_t size_type;
+ typedef std::ptrdiff_t difference_type;
+ typedef _Tp* pointer;
+ typedef const _Tp* const_pointer;
+ typedef _Tp& reference;
+ typedef const _Tp& const_reference;
+ typedef _Tp value_type;
+ template<typename _Tp1>
+ struct rebind
+ {
+ typedef bitmap_allocator<_Tp1> other;
+ };
- typedef typename std::pair<pointer, pointer> _Block_pair;
- typedef typename __gnu_cxx::new_allocator<_Block_pair> _BPVec_allocator_type;
- typedef typename std::vector<_Block_pair, _BPVec_allocator_type> _BPVector;
+ private:
+ template<unsigned int _BSize, unsigned int _AlignSize>
+ struct aligned_size
+ {
+ enum
+ {
+ modulus = _BSize % _AlignSize,
+ value = _BSize + (modulus ? _AlignSize - (modulus) : 0)
+ };
+ };
+ struct _Alloc_block
+ {
+ char __unused[aligned_size<sizeof(value_type), _BALLOC_ALIGN_BYTES>::value];
+ };
-#if defined CHECK_FOR_ERRORS
- //Complexity: O(lg(N)). Where, N is the number of block of size
- //sizeof(value_type).
- static void _S_check_for_free_blocks() throw()
- {
- typedef typename __gnu_cxx::__aux_balloc::_Ffit_finder<pointer, _BPVec_allocator_type> _FFF;
- _FFF __fff;
- typedef typename _BPVector::iterator _BPiter;
- _BPiter __bpi = std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
- __gnu_cxx::__aux_balloc::_Functor_Ref<_FFF>(__fff));
- assert(__bpi == _S_mem_blocks.end());
- }
-#endif
+ typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair;
- //Complexity: O(1), but internally depends upon the complexity of
- //the function _BA_free_list_store::_S_get_free_list. The part
- //where the bitmap headers are written is of worst case complexity:
- //O(X),where X is the number of blocks of size sizeof(value_type)
- //within the newly acquired block. Having a tight bound.
- static void _S_refill_pool() throw (std::bad_alloc)
- {
-#if defined CHECK_FOR_ERRORS
- _S_check_for_free_blocks();
-#endif
+ typedef typename
+ balloc::__mini_vector<_Block_pair> _BPVector;
- const unsigned int __num_bit_maps = _S_block_size / _Bits_Per_Block;
- const unsigned int __size_to_allocate = sizeof(unsigned int) +
- _S_block_size * sizeof(value_type) + __num_bit_maps*sizeof(unsigned int);
+#if defined _BALLOC_SANITY_CHECK
+ // Complexity: O(lg(N)). Where, N is the number of block of size
+ // sizeof(value_type).
+ void
+ _S_check_for_free_blocks() throw()
+ {
+ typedef typename
+ __gnu_cxx::balloc::_Ffit_finder<_Alloc_block*> _FFF;
+ _FFF __fff;
+ typedef typename _BPVector::iterator _BPiter;
+ _BPiter __bpi =
+ __gnu_cxx::balloc::__find_if
+ (_S_mem_blocks.begin(), _S_mem_blocks.end(),
+ __gnu_cxx::balloc::_Functor_Ref<_FFF>(__fff));
- unsigned int *__temp =
- reinterpret_cast<unsigned int*>(_BA_free_list_store::_S_get_free_list(__size_to_allocate));
- *__temp = 0;
- ++__temp;
+ _BALLOC_ASSERT(__bpi == _S_mem_blocks.end());
+ }
+#endif
- //The Header information goes at the Beginning of the Block.
- _Block_pair __bp = std::make_pair(reinterpret_cast<pointer>(__temp + __num_bit_maps),
- reinterpret_cast<pointer>(__temp + __num_bit_maps)
- + _S_block_size - 1);
+ // Complexity: O(1), but internally depends upon the complexity
+ // of the function free_list::_M_get. The
+ // part where the bitmap headers are written is of worst case
+ // complexity: O(X),where X is the number of blocks of size
+ // sizeof(value_type) within the newly acquired block. Having a
+ // tight bound.
+ void
+ _S_refill_pool() throw(std::bad_alloc)
+ {
+#if defined _BALLOC_SANITY_CHECK
+ _S_check_for_free_blocks();
+#endif
- //Fill the Vector with this information.
- _S_mem_blocks.push_back(__bp);
+ const unsigned int __num_bitmaps = _S_block_size / balloc::bits_per_block;
+ const unsigned int __size_to_allocate = _BALLOC_ALIGN_BYTES //sizeof(unsigned int)
+ + _S_block_size * sizeof(_Alloc_block)
+ + __num_bitmaps*sizeof(unsigned int);
+
+ unsigned int* __temp =
+ reinterpret_cast<unsigned int*>(this->_M_get(__size_to_allocate));
+ *__temp = 0;
+ // ++__temp;
+ __temp = reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>(__temp) + _BALLOC_ALIGN_BYTES);
+
+ // The Header information goes at the Beginning of the Block.
+ _Block_pair __bp =
+ std::make_pair(reinterpret_cast<_Alloc_block*>
+ (__temp + __num_bitmaps),
+ reinterpret_cast<_Alloc_block*>
+ (__temp + __num_bitmaps)
+ + _S_block_size - 1);
+
+ // Fill the Vector with this information.
+ _S_mem_blocks.push_back(__bp);
- unsigned int __bit_mask = 0; //0 Indicates all Allocated.
- __bit_mask = ~__bit_mask; //1 Indicates all Free.
+ unsigned int __bit_mask = 0; // 0 Indicates all Allocated.
+ __bit_mask = ~__bit_mask; // 1 Indicates all Free.
- for (unsigned int __i = 0; __i < __num_bit_maps; ++__i)
- __temp[__i] = __bit_mask;
+ for (unsigned int __i = 0; __i < __num_bitmaps; ++__i)
+ __temp[__i] = __bit_mask;
- //On some implementations, operator new might throw bad_alloc, or
- //malloc might fail if the size passed is too large, therefore, we
- //limit the size passed to malloc or operator new.
- _S_block_size *= 2;
- }
+ _S_block_size *= 2;
+ }
- static _BPVector _S_mem_blocks;
- static unsigned int _S_block_size;
- static __gnu_cxx::__aux_balloc::_Bit_map_counter<pointer, _BPVec_allocator_type> _S_last_request;
- static typename _BPVector::size_type _S_last_dealloc_index;
-#if defined __GTHREADS
- static _Mutex _S_mut;
-#endif
- //Complexity: Worst case complexity is O(N), but that is hardly ever
- //hit. if and when this particular case is encountered, the next few
- //cases are guaranteed to have a worst case complexity of O(1)!
- //That's why this function performs very well on the average. you
- //can consider this function to be having a complexity refrred to
- //commonly as: Amortized Constant time.
- static pointer _S_allocate_single_object()
- {
+ static _BPVector _S_mem_blocks;
+ static unsigned int _S_block_size;
+ static __gnu_cxx::balloc::
+ _Bitmap_counter<_Alloc_block*> _S_last_request;
+ static typename _BPVector::size_type _S_last_dealloc_index;
#if defined __GTHREADS
- _Lock __bit_lock(&_S_mut);
+ static _Mutex _S_mut;
#endif
- //The algorithm is something like this: The last_requst variable
- //points to the last accessed Bit Map. When such a condition
- //occurs, we try to find a free block in the current bitmap, or
- //succeeding bitmaps until the last bitmap is reached. If no free
- //block turns up, we resort to First Fit method.
-
- //WARNING: Do not re-order the condition in the while statement
- //below, because it relies on C++'s short-circuit
- //evaluation. The return from _S_last_request->_M_get() will NOT
- //be dereferenceable if _S_last_request->_M_finished() returns
- //true. This would inevitibly lead to a NULL pointer dereference
- //if tinkered with.
- while (_S_last_request._M_finished() == false && (*(_S_last_request._M_get()) == 0))
- {
- _S_last_request.operator++();
- }
-
- if (__builtin_expect(_S_last_request._M_finished() == true, false))
- {
- //Fall Back to First Fit algorithm.
- typedef typename __gnu_cxx::__aux_balloc::_Ffit_finder<pointer, _BPVec_allocator_type> _FFF;
- _FFF __fff;
- typedef typename _BPVector::iterator _BPiter;
- _BPiter __bpi = std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
- __gnu_cxx::__aux_balloc::_Functor_Ref<_FFF>(__fff));
-
- if (__bpi != _S_mem_blocks.end())
- {
- //Search was successful. Ok, now mark the first bit from
- //the right as 0, meaning Allocated. This bit is obtained
- //by calling _M_get() on __fff.
- unsigned int __nz_bit = _Bit_scan_forward(*__fff._M_get());
- _S_bit_allocate(__fff._M_get(), __nz_bit);
-
- _S_last_request._M_reset(__bpi - _S_mem_blocks.begin());
-
- //Now, get the address of the bit we marked as allocated.
- pointer __ret_val = __bpi->first + __fff._M_offset() + __nz_bit;
- unsigned int *__puse_count = reinterpret_cast<unsigned int*>(__bpi->first) -
- (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(*__bpi) + 1);
- ++(*__puse_count);
- return __ret_val;
- }
- else
- {
- //Search was unsuccessful. We Add more memory to the pool
- //by calling _S_refill_pool().
- _S_refill_pool();
-
- //_M_Reset the _S_last_request structure to the first free
- //block's bit map.
- _S_last_request._M_reset(_S_mem_blocks.size() - 1);
+ public:
- //Now, mark that bit as allocated.
- }
- }
- //_S_last_request holds a pointer to a valid bit map, that points
- //to a free block in memory.
- unsigned int __nz_bit = _Bit_scan_forward(*_S_last_request._M_get());
- _S_bit_allocate(_S_last_request._M_get(), __nz_bit);
-
- pointer __ret_val = _S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit;
-
- unsigned int *__puse_count = reinterpret_cast<unsigned int*>
- (_S_mem_blocks[_S_last_request._M_where()].first) -
- (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(_S_mem_blocks[_S_last_request._M_where()]) + 1);
- ++(*__puse_count);
- return __ret_val;
- }
-
- //Complexity: O(lg(N)), but the worst case is hit quite often! I
- //need to do something about this. I'll be able to work on it, only
- //when I have some solid figures from a few real apps.
- static void _S_deallocate_single_object(pointer __p) throw()
- {
+ // Complexity: Worst case complexity is O(N), but that is hardly
+ // ever hit. if and when this particular case is encountered,
+ // the next few cases are guaranteed to have a worst case
+ // complexity of O(1)! That's why this function performs very
+ // well on the average. you can consider this function to be
+ // having a complexity referred to commonly as: Amortized
+ // Constant time.
+ pointer
+ _M_allocate_single_object() throw(std::bad_alloc)
+ {
#if defined __GTHREADS
- _Lock __bit_lock(&_S_mut);
+ _Auto_Lock __bit_lock(&_S_mut);
#endif
- typedef typename _BPVector::iterator _Iterator;
- typedef typename _BPVector::difference_type _Difference_type;
+ // The algorithm is something like this: The last_request
+ // variable points to the last accessed Bit Map. When such a
+ // condition occurs, we try to find a free block in the
+ // current bitmap, or succeeding bitmaps until the last bitmap
+ // is reached. If no free block turns up, we resort to First
+ // Fit method.
+
+ // WARNING: Do not re-order the condition in the while
+ // statement below, because it relies on C++'s short-circuit
+ // evaluation. The return from _S_last_request->_M_get() will
+ // NOT be dereference able if _S_last_request->_M_finished()
+ // returns true. This would inevitably lead to a NULL pointer
+ // dereference if tinkered with.
+ while (_S_last_request._M_finished() == false
+ && (*(_S_last_request._M_get()) == 0))
+ {
+ _S_last_request.operator++();
+ }
- _Difference_type __diff;
- int __displacement;
+ if (__builtin_expect(_S_last_request._M_finished() == true, false))
+ {
+ // Fall Back to First Fit algorithm.
+ typedef typename
+ __gnu_cxx::balloc::_Ffit_finder<_Alloc_block*> _FFF;
+ _FFF __fff;
+ typedef typename _BPVector::iterator _BPiter;
+ _BPiter __bpi =
+ __gnu_cxx::balloc::__find_if
+ (_S_mem_blocks.begin(), _S_mem_blocks.end(),
+ __gnu_cxx::balloc::_Functor_Ref<_FFF>(__fff));
- assert(_S_last_dealloc_index >= 0);
+ if (__bpi != _S_mem_blocks.end())
+ {
+ // Search was successful. Ok, now mark the first bit from
+ // the right as 0, meaning Allocated. This bit is obtained
+ // by calling _M_get() on __fff.
+ unsigned int __nz_bit = _Bit_scan_forward(*__fff._M_get());
+ balloc::__bit_allocate(__fff._M_get(), __nz_bit);
+
+ _S_last_request._M_reset(__bpi - _S_mem_blocks.begin());
+
+ // Now, get the address of the bit we marked as allocated.
+ pointer __ret = reinterpret_cast<pointer>
+ (__bpi->first + __fff._M_offset() + __nz_bit);
+ unsigned int* __puse_count = reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>
+ (reinterpret_cast<unsigned int*>(__bpi->first)
+ - (__gnu_cxx::balloc::__num_bitmaps(*__bpi))) - _BALLOC_ALIGN_BYTES);
- if (__gnu_cxx::__aux_balloc::_Inclusive_between<pointer>(__p)(_S_mem_blocks[_S_last_dealloc_index]))
- {
- assert(_S_last_dealloc_index <= _S_mem_blocks.size() - 1);
+ ++(*__puse_count);
+ return __ret;
+ }
+ else
+ {
+ // Search was unsuccessful. We Add more memory to the
+ // pool by calling _S_refill_pool().
+ _S_refill_pool();
+
+ // _M_Reset the _S_last_request structure to the first
+ // free block's bit map.
+ _S_last_request._M_reset(_S_mem_blocks.size() - 1);
- //Initial Assumption was correct!
- __diff = _S_last_dealloc_index;
- __displacement = __p - _S_mem_blocks[__diff].first;
- }
- else
- {
- _Iterator _iter = (std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
- __gnu_cxx::__aux_balloc::_Inclusive_between<pointer>(__p)));
- assert(_iter != _S_mem_blocks.end());
-
- __diff = _iter - _S_mem_blocks.begin();
- __displacement = __p - _S_mem_blocks[__diff].first;
- _S_last_dealloc_index = __diff;
- }
+ // Now, mark that bit as allocated.
+ }
+ }
- //Get the position of the iterator that has been found.
- const unsigned int __rotate = __displacement % _Bits_Per_Block;
- unsigned int *__bit_mapC = reinterpret_cast<unsigned int*>(_S_mem_blocks[__diff].first) - 1;
- __bit_mapC -= (__displacement / _Bits_Per_Block);
-
- _S_bit_free(__bit_mapC, __rotate);
- unsigned int *__puse_count = reinterpret_cast<unsigned int*>
- (_S_mem_blocks[__diff].first) -
- (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(_S_mem_blocks[__diff]) + 1);
+ // _S_last_request holds a pointer to a valid bit map, that
+ // points to a free block in memory.
+ unsigned int __nz_bit = _Bit_scan_forward(*_S_last_request._M_get());
+ balloc::__bit_allocate(_S_last_request._M_get(), __nz_bit);
+
+ pointer __ret = reinterpret_cast<pointer>
+ (_S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit);
+
+ unsigned int* __puse_count = reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>
+ (reinterpret_cast<unsigned int*>
+ (_S_mem_blocks[_S_last_request._M_where()].first)
+ - (__gnu_cxx::balloc::
+ __num_bitmaps(_S_mem_blocks[_S_last_request._M_where()])))
+ - _BALLOC_ALIGN_BYTES);
- assert(*__puse_count != 0);
+ ++(*__puse_count);
+ return __ret;
+ }
- --(*__puse_count);
+ // Complexity: O(lg(N)), but the worst case is hit quite often!
+ // I need to do something about this. I'll be able to work on
+ // it, only when I have some solid figures from a few real apps.
+ void
+ _M_deallocate_single_object(pointer __p) throw()
+ {
+#if defined __GTHREADS
+ _Auto_Lock __bit_lock(&_S_mut);
+#endif
+ _Alloc_block* __real_p = reinterpret_cast<_Alloc_block*>(__p);
- if (__builtin_expect(*__puse_count == 0, false))
- {
- _S_block_size /= 2;
-
- //We may safely remove this block.
- _Block_pair __bp = _S_mem_blocks[__diff];
- _S_insert_free_list(__puse_count);
- _S_mem_blocks.erase(_S_mem_blocks.begin() + __diff);
-
- //We reset the _S_last_request variable to reflect the erased
- //block. We do this to protect future requests after the last
- //block has been removed from a particular memory Chunk,
- //which in turn has been returned to the free list, and
- //hence had been erased from the vector, so the size of the
- //vector gets reduced by 1.
- if ((_Difference_type)_S_last_request._M_where() >= __diff--)
- {
- _S_last_request._M_reset(__diff);
- // assert(__diff >= 0);
- }
+ typedef typename _BPVector::iterator _Iterator;
+ typedef typename _BPVector::difference_type _Difference_type;
- //If the Index into the vector of the region of memory that
- //might hold the next address that will be passed to
- //deallocated may have been invalidated due to the above
- //erase procedure being called on the vector, hence we try
- //to restore this invariant too.
- if (_S_last_dealloc_index >= _S_mem_blocks.size())
- {
- _S_last_dealloc_index =(__diff != -1 ? __diff : 0);
- assert(_S_last_dealloc_index >= 0);
- }
- }
- }
+ _Difference_type __diff;
+ int __displacement;
- public:
- bitmap_allocator() throw()
- { }
+ _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
- bitmap_allocator(const bitmap_allocator&) { }
+
+ if (__gnu_cxx::balloc::_Inclusive_between<_Alloc_block*>
+ (__real_p)
+ (_S_mem_blocks[_S_last_dealloc_index]))
+ {
+ _BALLOC_ASSERT(_S_last_dealloc_index <= _S_mem_blocks.size() - 1);
- template <typename _Tp1> bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
- { }
+ // Initial Assumption was correct!
+ __diff = _S_last_dealloc_index;
+ __displacement = __real_p - _S_mem_blocks[__diff].first;
+ }
+ else
+ {
+ _Iterator _iter =
+ __gnu_cxx::balloc::__find_if(_S_mem_blocks.begin(),
+ _S_mem_blocks.end(),
+ __gnu_cxx::balloc::
+ _Inclusive_between<_Alloc_block*>(__real_p));
+ _BALLOC_ASSERT(_iter != _S_mem_blocks.end());
+
+ __diff = _iter - _S_mem_blocks.begin();
+ __displacement = __real_p - _S_mem_blocks[__diff].first;
+ _S_last_dealloc_index = __diff;
+ }
- ~bitmap_allocator() throw()
- { }
+ // Get the position of the iterator that has been found.
+ const unsigned int __rotate = __displacement % balloc::bits_per_block;
+ unsigned int* __bitmapC =
+ reinterpret_cast<unsigned int*>(_S_mem_blocks[__diff].first) - 1;
+ __bitmapC -= (__displacement / balloc::bits_per_block);
+
+ balloc::__bit_free(__bitmapC, __rotate);
+ unsigned int* __puse_count = reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>
+ (reinterpret_cast<unsigned int*>
+ (_S_mem_blocks[__diff].first)
+ - (__gnu_cxx::balloc::__num_bitmaps(_S_mem_blocks[__diff])))
+ - _BALLOC_ALIGN_BYTES);
+
+ _BALLOC_ASSERT(*__puse_count != 0);
- //Complexity: O(1), but internally the complexity depends upon the
- //complexity of the function(s) _S_allocate_single_object and
- //_S_memory_get.
- pointer allocate(size_type __n)
- {
- if (__builtin_expect(__n == 1, true))
- return _S_allocate_single_object();
- else
- return reinterpret_cast<pointer>(_S_memory_get(__n * sizeof(value_type)));
- }
+ --(*__puse_count);
- //Complexity: Worst case complexity is O(N) where N is the number of
- //blocks of size sizeof(value_type) within the free lists that the
- //allocator holds. However, this worst case is hit only when the
- //user supplies a bogus argument to hint. If the hint argument is
- //sensible, then the complexity drops to O(lg(N)), and in extreme
- //cases, even drops to as low as O(1). So, if the user supplied
- //argument is good, then this function performs very well.
- pointer allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
- {
- return allocate(__n);
- }
+ if (__builtin_expect(*__puse_count == 0, false))
+ {
+ _S_block_size /= 2;
+
+ // We can safely remove this block.
+ // _Block_pair __bp = _S_mem_blocks[__diff];
+ this->_M_insert(__puse_count);
+ _S_mem_blocks.erase(_S_mem_blocks.begin() + __diff);
+
+ // Reset the _S_last_request variable to reflect the
+ // erased block. We do this to protect future requests
+ // after the last block has been removed from a particular
+ // memory Chunk, which in turn has been returned to the
+ // free list, and hence had been erased from the vector,
+ // so the size of the vector gets reduced by 1.
+ if ((_Difference_type)_S_last_request._M_where() >= __diff--)
+ _S_last_request._M_reset(__diff);
+
+ // If the Index into the vector of the region of memory
+ // that might hold the next address that will be passed to
+ // deallocated may have been invalidated due to the above
+ // erase procedure being called on the vector, hence we
+ // try to restore this invariant too.
+ if (_S_last_dealloc_index >= _S_mem_blocks.size())
+ {
+ _S_last_dealloc_index =(__diff != -1 ? __diff : 0);
+ _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
+ }
+ }
+ }
- void deallocate(pointer __p, size_type __n) throw()
- {
- if (__builtin_expect(__n == 1, true))
- _S_deallocate_single_object(__p);
- else
- _S_memory_put(__p);
- }
+ public:
+ bitmap_allocator() throw()
+ { }
- pointer address(reference r) const { return &r; }
- const_pointer address(const_reference r) const { return &r; }
+ bitmap_allocator(const bitmap_allocator&)
+ { }
- size_type max_size(void) const throw() { return (size_type()-1)/sizeof(value_type); }
+ template<typename _Tp1>
+ bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
+ { }
- void construct (pointer p, const_reference __data)
- {
- ::new(p) value_type(__data);
- }
+ ~bitmap_allocator() throw()
+ { }
- void destroy (pointer p)
- {
- p->~value_type();
- }
+ // Complexity: O(1), but internally the complexity depends upon the
+ // complexity of the function(s) _S_allocate_single_object and
+ // operator new.
+ pointer
+ allocate(size_type __n)
+ {
+ if (__builtin_expect(__n == 1, true))
+ return this->_M_allocate_single_object();
+ else
+ {
+ const size_type __b = __n * sizeof(value_type);
+ return reinterpret_cast<pointer>(::operator new(__b));
+ }
+ }
- };
+ pointer
+ allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
+ { return allocate(__n); }
- template <typename _Tp>
- typename bitmap_allocator<_Tp>::_BPVector bitmap_allocator<_Tp>::_S_mem_blocks;
+ void
+ deallocate(pointer __p, size_type __n) throw()
+ {
+ if (__builtin_expect(__n == 1, true))
+ this->_M_deallocate_single_object(__p);
+ else
+ ::operator delete(__p);
+ }
- template <typename _Tp>
- unsigned int bitmap_allocator<_Tp>::_S_block_size = bitmap_allocator<_Tp>::_Bits_Per_Block;
+ pointer
+ address(reference __r) const
+ { return &__r; }
+
+ const_pointer
+ address(const_reference __r) const
+ { return &__r; }
+
+ size_type
+ max_size() const throw()
+ { return (size_type()-1)/sizeof(value_type); }
+
+ void
+ construct(pointer __p, const_reference __data)
+ { ::new(__p) value_type(__data); }
+
+ void
+ destroy(pointer __p)
+ { __p->~value_type(); }
+ };
- template <typename _Tp>
- typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type
- bitmap_allocator<_Tp>::_S_last_dealloc_index = 0;
-
- template <typename _Tp>
- __gnu_cxx::__aux_balloc::_Bit_map_counter
- <typename bitmap_allocator<_Tp>::pointer, typename bitmap_allocator<_Tp>::_BPVec_allocator_type>
- bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks);
+ template<typename _Tp1, typename _Tp2>
+ bool
+ operator==(const bitmap_allocator<_Tp1>&,
+ const bitmap_allocator<_Tp2>&) throw()
+ { return true; }
+
+ template<typename _Tp1, typename _Tp2>
+ bool
+ operator!=(const bitmap_allocator<_Tp1>&,
+ const bitmap_allocator<_Tp2>&) throw()
+ { return false; }
+
+ // Static member definitions.
+ template<typename _Tp>
+ typename bitmap_allocator<_Tp>::_BPVector
+ bitmap_allocator<_Tp>::_S_mem_blocks;
+
+ template<typename _Tp>
+ unsigned int bitmap_allocator<_Tp>::_S_block_size = balloc::bits_per_block;
+
+ template<typename _Tp>
+ typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type
+ bitmap_allocator<_Tp>::_S_last_dealloc_index = 0;
+
+ template<typename _Tp>
+ __gnu_cxx::balloc::_Bitmap_counter
+ <typename bitmap_allocator<_Tp>::_Alloc_block*>
+ bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks);
#if defined __GTHREADS
- template <typename _Tp>
- __gnu_cxx::_Mutex
- bitmap_allocator<_Tp>::_S_mut;
+ template<typename _Tp>
+ __gnu_cxx::_Mutex
+ bitmap_allocator<_Tp>::_S_mut;
#endif
- template <typename _Tp1, typename _Tp2>
- bool operator== (const bitmap_allocator<_Tp1>&, const bitmap_allocator<_Tp2>&) throw()
- {
- return true;
- }
-
- template <typename _Tp1, typename _Tp2>
- bool operator!= (const bitmap_allocator<_Tp1>&, const bitmap_allocator<_Tp2>&) throw()
- {
- return false;
- }
+
}
+#endif
-#endif //_BITMAP_ALLOCATOR_H
+// LocalWords: namespace GTHREADS bool const gthread endif Mutex mutex
diff -Nrup -x '.cvs*' cvs_libstdc++-v3/src/bitmap_allocator.cc modified_libv3/src/bitmap_allocator.cc
--- cvs_libstdc++-v3/src/bitmap_allocator.cc 1970-01-01 05:30:00.000000000 +0530
+++ modified_libv3/src/bitmap_allocator.cc 2004-10-13 22:38:35.000000000 +0530
@@ -0,0 +1,133 @@
+// Bitmap Allocator. Out of line function definitions. -*- C++ -*-
+
+// Copyright (C) 2004 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING. If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// As a special exception, you may use this file as part of a free software
+// library without restriction. Specifically, if other files instantiate
+// templates or use macros or inline functions from this file, or you compile
+// this file and link it with other files to produce an executable, this
+// file does not by itself cause the resulting executable to be covered by
+// the GNU General Public License. This exception does not however
+// invalidate any other reasons why the executable file might be covered by
+// the GNU General Public License.
+
+#include <ext/bitmap_allocator.h>
+
+namespace __gnu_cxx
+{
+ namespace balloc
+ {
+ template class __mini_vector<std::pair
+ <bitmap_allocator<char>::_Alloc_block*,
+ bitmap_allocator<char>::_Alloc_block*> >;
+
+ template class __mini_vector<std::pair
+ <bitmap_allocator<wchar_t>::_Alloc_block*,
+ bitmap_allocator<wchar_t>::_Alloc_block*> >;
+
+ template class __mini_vector<unsigned int*>;
+
+ template unsigned int** __lower_bound
+ (unsigned int**, unsigned int**,
+ unsigned int const&, free_list::_LT_pointer_compare);
+ }
+
+#if defined __GTHREADS
+ _Mutex free_list::_S_bfl_mutex;
+#endif
+ free_list::vector_type free_list::_S_free_list;
+
+ unsigned int*
+ free_list::
+ _M_get(unsigned int __sz) throw(std::bad_alloc)
+ {
+#if defined __GTHREADS
+ _Lock __bfl_lock(&_S_bfl_mutex);
+ __bfl_lock._M_lock();
+#endif
+ iterator __temp =
+ __gnu_cxx::balloc::__lower_bound
+ (_S_free_list.begin(), _S_free_list.end(),
+ __sz, _LT_pointer_compare());
+
+ if (__temp == _S_free_list.end() || !_M_should_i_give(**__temp, __sz))
+ {
+ // We release the lock here, because operator new is
+ // guaranteed to be thread-safe by the underlying
+ // implementation.
+#if defined __GTHREADS
+ __bfl_lock._M_unlock();
+#endif
+ // Try twice to get the memory: once directly, and the 2nd
+ // time after clearing the free list. If both fail, then
+ // throw std::bad_alloc().
+ unsigned int __ctr = 2;
+ while (__ctr)
+ {
+ unsigned int* __ret = 0;
+ --__ctr;
+ try
+ {
+ __ret = reinterpret_cast<unsigned int*>
+ (::operator new(__sz + _BALLOC_ALIGN_BYTES));
+ }
+ catch(...)
+ {
+ this->_M_clear();
+ }
+ if (!__ret)
+ continue;
+ *__ret = __sz;
+ return reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>(__ret) + _BALLOC_ALIGN_BYTES);
+ }
+ throw std::bad_alloc();
+ }
+ else
+ {
+ unsigned int* __ret = *__temp;
+ _S_free_list.erase(__temp);
+#if defined __GTHREADS
+ __bfl_lock._M_unlock();
+#endif
+ return reinterpret_cast<unsigned int*>
+ (reinterpret_cast<char*>(__ret) + _BALLOC_ALIGN_BYTES);
+ }
+ }
+
+ void
+ free_list::
+ _M_clear()
+ {
+#if defined __GTHREADS
+ _Auto_Lock __bfl_lock(&_S_bfl_mutex);
+#endif
+ iterator __iter = _S_free_list.begin();
+ while (__iter != _S_free_list.end())
+ {
+ operator delete((void*)*__iter);
+ ++__iter;
+ }
+ _S_free_list.clear();
+ }
+
+ // Instantiations.
+ template class bitmap_allocator<char>;
+ template class bitmap_allocator<wchar_t>;
+} // namespace __gnu_cxx
diff -Nrup -x '.cvs*' cvs_libstdc++-v3/src/Makefile.am modified_libv3/src/Makefile.am
--- cvs_libstdc++-v3/src/Makefile.am 2004-09-13 14:58:03.000000000 +0530
+++ modified_libv3/src/Makefile.am 2004-10-13 14:09:12.000000000 +0530
@@ -96,6 +96,7 @@ basic_file.cc: ${glibcxx_srcdir}/$(BASIC
# Sources present in the src directory.
sources = \
+ bitmap_allocator.cc \
pool_allocator.cc \
mt_allocator.cc \
codecvt.cc \
diff -Nrup -x '.cvs*' cvs_libstdc++-v3/src/Makefile.in modified_libv3/src/Makefile.in
--- cvs_libstdc++-v3/src/Makefile.in 2004-10-08 21:27:22.000000000 +0530
+++ modified_libv3/src/Makefile.in 2004-10-13 14:09:16.000000000 +0530
@@ -64,14 +64,14 @@ am__objects_1 = atomicity.lo codecvt_mem
ctype_members.lo messages_members.lo monetary_members.lo \
numeric_members.lo time_members.lo
am__objects_2 = basic_file.lo c++locale.lo
-am__objects_3 = pool_allocator.lo mt_allocator.lo codecvt.lo \
- complex_io.lo ctype.lo debug.lo debug_list.lo functexcept.lo \
- globals_locale.lo globals_io.lo ios.lo ios_failure.lo \
- ios_init.lo ios_locale.lo limits.lo list.lo locale.lo \
- locale_init.lo locale_facets.lo localename.lo stdexcept.lo \
- strstream.lo tree.lo allocator-inst.lo concept-inst.lo \
- fstream-inst.lo ext-inst.lo io-inst.lo istream-inst.lo \
- locale-inst.lo locale-misc-inst.lo misc-inst.lo \
+am__objects_3 = bitmap_allocator.lo pool_allocator.lo mt_allocator.lo \
+ codecvt.lo complex_io.lo ctype.lo debug.lo debug_list.lo \
+ functexcept.lo globals_locale.lo globals_io.lo ios.lo \
+ ios_failure.lo ios_init.lo ios_locale.lo limits.lo list.lo \
+ locale.lo locale_init.lo locale_facets.lo localename.lo \
+ stdexcept.lo strstream.lo tree.lo allocator-inst.lo \
+ concept-inst.lo fstream-inst.lo ext-inst.lo io-inst.lo \
+ istream-inst.lo locale-inst.lo locale-misc-inst.lo misc-inst.lo \
ostream-inst.lo sstream-inst.lo streambuf-inst.lo \
string-inst.lo valarray-inst.lo wlocale-inst.lo \
wstring-inst.lo $(am__objects_1) $(am__objects_2)
@@ -306,6 +306,7 @@ host_sources_extra = \
# Sources present in the src directory.
sources = \
+ bitmap_allocator.cc \
pool_allocator.cc \
mt_allocator.cc \
codecvt.cc \