Class fixed_slist
Synopsis
#include <include/EASTL/fixed_slist.h>
template <typename T, size_t nodeCount, bool bEnableOverflow = true, typename OverflowAllocator = EASTLAllocatorType>
class fixed_slist : public slist<T, fixed_node_allocator<sizeof(typename slist<T>::node_type),
nodeCount, EASTL_ALIGN_OF(T), 0, bEnableOverflow, OverflowAllocator> >
Description
fixed_slist is an slist which uses a single block of contiguous memory for its nodes. The purpose of this is to reduce memory usage relative to a conventional memory allocation system (with block headers), to increase allocation speed (often due to avoidance of mutex locks), to increase performance (due to better memory locality), and to decrease memory fragmentation due to the way that fixed block allocators work.
The primary downside to a fixed_slist is that the number of nodes it can contain is fixed upon its declaration. If you want a fixed_slist that doesn't have this limitation, then you probably don't want a fixed_slist. You can always create your own memory allocator that works the way you want.
Template parameters: T The type of object the slist holds. nodeCount The max number of objects to contain. bEnableOverflow Whether or not we should use the overflow heap if our object pool is exhausted. OverflowAllocator Overflow allocator, which is only used if bEnableOverflow == true. Defaults to the global heap.
Mentioned in
- Best Practices / Consider fixed-size containers.
- FAQ / EASTL coverage of std STL
- FAQ / Debug.2 How do I view containers if the visualizer/tooltip support is not present?
- Modules / Module List
Inheritance
Ancestors: slist
Methods
| fixed_slist overload | slist | |
| assign overload | ||
| can_overflow | ||
| full | ||
| get_overflow_allocator overload | OverflowAllocator. | |
| has_overflowed | ||
| max_size | ||
| operator= overload | ||
| reset_lose_memory | ||
| resize overload | ||
| set_overflow_allocator | ||
| size | ||
| swap |
Source
Lines 65-118 in include/EASTL/fixed_slist.h.
template <typename T, size_t nodeCount, bool bEnableOverflow = true, typename OverflowAllocator = EASTLAllocatorType>
class fixed_slist : public slist<T, fixed_node_allocator<sizeof(typename slist<T>::node_type),
nodeCount, EASTL_ALIGN_OF(T), 0, bEnableOverflow, OverflowAllocator> >
{
public:
typedef fixed_node_allocator<sizeof(typename slist<T>::node_type), nodeCount,
EASTL_ALIGN_OF(T), 0, bEnableOverflow, OverflowAllocator> fixed_allocator_type;
typedef OverflowAllocator overflow_allocator_type;
typedef slist<T, fixed_allocator_type> base_type;
typedef fixed_slist<T, nodeCount, bEnableOverflow, OverflowAllocator> this_type;
typedef typename base_type::size_type size_type;
typedef typename base_type::value_type value_type;
typedef typename base_type::node_type node_type;
enum { kMaxSize = nodeCount };
using base_type::assign;
using base_type::resize;
using base_type::size;
protected:
char mBuffer[fixed_allocator_type::kBufferSize]; // kBufferSize will take into account alignment requirements.
using base_type::internalAllocator;
public:
fixed_slist();
explicit fixed_slist(const overflow_allocator_type& overflowAllocator); // Only applicable if bEnableOverflow is true.
explicit fixed_slist(size_type n); // Currently we don't support overflowAllocator specification for other constructors, for simplicity.
fixed_slist(size_type n, const value_type& value);
fixed_slist(const this_type& x);
fixed_slist(this_type&& x);
fixed_slist(this_type&&, const overflow_allocator_type&);
fixed_slist(std::initializer_list<value_type> ilist, const overflow_allocator_type& overflowAllocator = EASTL_FIXED_SLIST_DEFAULT_ALLOCATOR);
template <typename InputIterator>
fixed_slist(InputIterator first, InputIterator last);
this_type& operator=(const this_type& x);
this_type& operator=(std::initializer_list<value_type> ilist);
this_type& operator=(this_type&& x);
void swap(this_type& x);
void reset_lose_memory(); // This is a unilateral reset to an initially empty state. No destructors are called, no deallocation occurs.
size_type max_size() const; // Returns the max fixed size, which is the user-supplied nodeCount parameter.
bool full() const; // Returns true if the fixed space has been fully allocated. Note that if overflow is enabled, the container size can be greater than nodeCount but full() could return true because the fixed space may have a recently freed slot.
bool has_overflowed() const; // Returns true if the allocations spilled over into the overflow allocator. Meaningful only if overflow is enabled.
bool can_overflow() const; // Returns the value of the bEnableOverflow template parameter.
// OverflowAllocator
const overflow_allocator_type& get_overflow_allocator() const EA_NOEXCEPT;
overflow_allocator_type& get_overflow_allocator() EA_NOEXCEPT;
void set_overflow_allocator(const overflow_allocator_type& allocator);
}; // fixed_slist