MemoryHeap

Scaleform::MemoryHeap

Declaration

class MemoryHeap : public ListNode<MemoryHeap>;

Description

The memory heap from which allocations take place. This interface supports creation of child heaps for dedicated purposes, such that when child heaps are released all of their memory is released as well. The benefit of child heaps is that they grab memory in large chunks of Granularity from the root, such that all of heap-local allocations take place in those chunks. This strategy reduces overall fragmentation, since once child heap is released it will make all of its large chunks available for reuse.

The child memory heap use in GFx relies on ability to determine target heap based on the address within allocation in it, done by AllocAutoHeap function. This function takes an address that must be within some other allocation of the desired heap and allocated new memory within the same heap as that allocation. Note that the passed address does NOT have to point to the head of previous allocation, it can also be in the middle of it. This functionality allows convenient initialization of aggregate structures and arrays located within other objects, and their allocations will automatically take place within the same heap as the containing object.

Internally, heaps rely on SysAlloc/SysAllocPaged interface for allocating large blocks of system memory; this interface is specified in Scaleform::GFx::System/Scaleform::System constructor. Developers can substitute GFx allocator by re-implementing SysAlloc/SysAllocPaged interface.

Enumerations

Enumeration	Description
MemReportType	Lists the different types of memory report that can be generated.
HeapFlags	Flag bits set to indicate if the heap is root heap, thread safe, uses debug mode and so on.
RootHeapParameters	Provides the parameters set for the root memory heap.

Methods

Method	Description
AddRef	Increments the heap reference count.
Alloc	Allocates memory block. If size is 0, Alloc will allocate a tiny block and return a valid pointer.
AllocAutoHeap	Allocates memory block while automatically identifying heap and allocation id based on the specified address.
AllocSysDirect	Allocates memory block directly from the system allocator.
ArenaIsEmpty	Checks if the memory arena is empty.
AssignToCurrentThread	Assigns heap to current thread causing ASSERTs if called for other thread.
CheckRead
CreateArena	Creates a memory arena that can be used by the heap for allocation purposes.
CreateHeap	Creates a nested child heap. The heap should be destroyed by calling Release.
CleanUpMH	Releases the memory block allocated for the root heap in the malloc based memory allocations.
CleanUpPT	Releases the memory block allocated for the root heap in page based memory allocation.
CreateRootHeapMH	Creates the root heap in the malloc based memory allocations.
CreateRootHeapPT	Creates the root heap in the page based memory allocations.
DestroyArena	Destroys the memory arena created for the heap.
DumpMemoryLeaks	Traverses through all child heaps and dumps memory leaks.
Free	Frees the memory allocated for a resource.
FreeSysDirect	Releases the memory block allocated directly from the system allocator by AllocSysDirect.
GetAllocHeap	Determines which heap the allocation belongs to.
GetAllocHeapOrNULL	Determine which heap allocation belongs to
GetFlags	Returns the flags set for the heap.
GetFootprint	Returns the number of bytes allocated from the system for the heap.
GetGranularity	Returns the granularity size of the heap allocations.
GetHeapInfo	Fills in the heap descriptor with information.
GetId	Returns the Id of the memory heap.
GetLimit	Returns the memory limit on the heap.
GetMinAlign	Returns the minimum alignment enforced for all allocations from heap.
GetName	Returns the name of the memory heap.
GetParentHeap	Returns the parent heap used for allocation.
GetRootStats	Obtains the allocation statistics pertaining to the root heap.
GetStats	Obtains the memory statistics for the heap.
GetTotalFootprint	Returns the total amount of memory allocation for the parent and nested child heaps.
GetTotalUsedSpace	Recursively iterates through all child heaps and sums up the total used space.
GetUsableSize	Returns the actual allocation size that can be safely used.
GetUsedSpace	Returns the actual amount of allocated bytes in a heap.
InitMH	Initializes the root memory heap for heaps in malloc based memory allocations.
InitPT	Initializes the root memory heap for heaps in page based memory allocations.
IsThreadSafe	Determines if the heap is thread safe or not.
MemReport	Generates a brief or detailed GFx memory heap report within a string buffer.
Realloc	Reallocates memory set by Alloc.
Release	Releases the heap and deallocates it unless there are other references to the heap.
ReleaseCachedMem	Releases cached memory segments from all heaps.
ReleaseOnFree	Marks allocation for automatic cleanup of heap.
ReleaseRootHeapMH	Releases the root heap and/or de-initializes it.
ReleaseRootHeapPT	Releases the root heap and/or de-initializes it.
SetLimitHandler	Sets the limit handler for handling memory limit exceeds.
SetLimit	Sets a fixed memory limit on the allocation size.
VisitChildHeaps	Enumerates all of the child heaps by calling HeapVisitor::Visit.

Structures

Structure	Description
HeapDesc	Structure providing description of memory heap created.
HeapInfo	Heap descriptor used to indicate the attributes of the heap.
HeapVisitor	Heap visitor for calling child heaps within each parent heap.
LimitHandler	Handler for handling memory limit exceeds.
RootHeapDesc	Root heap descriptor and used for initializing a root heap object.
RootStats	Structure used to indicate the memory allocation statistics of the root heap.

File

SF_MemoryHeap.h