PIXRecordMemoryAllocationEvent

Article
2025-04-28

Records a memory allocation event.

Syntax

void PIXRecordMemoryAllocationEvent(  
         USHORT allocatorId,  
         void* baseAddress,  
         size_t size,  
         UINT64 metadata  
)

Parameters

allocatorId
Type: USHORT

An ID you can use to identify groups of memory allocations in the memory profiler. For example, if you have different heaps for things such as graphics, audio, and physics, you can assign each of these categories a different allocatorID so they are easy to identify when viewing a memory capture in PIX.

baseAddress
Type: void*

The starting address of the memory that has been allocated.

size
Type: size_t

The size of the memory that has been allocated in bytes.

metadata
Type: UINT64

A 64-bit unsigned integer you can use to tag an allocation with additional data. This extra data is displayed in PIX in a UserData column. You can use this extra data to identify the type of object within your title that is stored at a given memory location, for example.

Return value

Type: void

Remarks

A PIX memory tracking event provides the data that PIX needs to display information about all memory allocations and releases made from within the title's custom memory allocators in memory profiling captures. By providing this data, PIX will show all the same data for your custom allocators that it does for calls to VirtualAlloc/VirtualFree and HeapAlloc/HeapFree.

If there are many events occurring at the same time or the system is under a heavy load, memory events can be lost by Event Tracing for Windows (ETW). Event loss will result in an incomplete analysis of data. PIX Memory Capture UI will display a warning indicating event loss.

Multiple PIXRecordMemoryFreeEvent calls can be used to track memory that is progressively freed from a single allocation.

See PIX custom memory allocators (NDA topic)Authorization required for information about how data from custom allocations and frees is shown in memory captures.

Requirements

Header: pixmemory.h

Library: pixevt.lib

Supported platforms: Xbox One family consoles and Xbox Series consoles

Share via