The IUnityMemoryManager
memory manager API is a C++ interface that allows you to use Unity’s memory management and memory profiling in native plug-ins.
This API enables you to:
These features make it easier to manage and profile your plug-in’s memory allocations when compared to the equivalent C++ memory management methods.
The plug-in API is provided by the IUnityMemoryManager interface, which is declared in the IUnityMemoryManager.h
header. The full reference for the API is available in this file. To find the header file:
<UnityInstallPath>\Editor\Data\PluginAPI
folder of your Unity installation.Contents\PluginAPI
.You should be familiar with the following concepts to use this API effectively:
To track your plug-in’s memory usage, use the Memory Profiler package to take a snapshot, then open the snapshot in the All Of Memory tab. When you use the IUnityMemoryManager
to allocate memory, the Memory Profiler displays the plug-in’s memory allocations under the area and object name you assigned when you created each allocator.
The below screenshot shows the Memory Profiler package window displaying memory used by a native plug-in with memory allocated with the IUnityMemoryManager
API. In this example, the method CreateAllocator was called, with “MyNativePlugin” as the areaName parameter, and “MyPluginAllocator” as the objectName parameter. For more information, see CreateAllocator.
For more information, see Snapshots.
This API enables you to use Unity’s memory management system when you develop native plug-ins. This has major benefits as described above, but there are still limitations. Unity’s memory management system:
Since memory in native C++ isn’t managed, you need to keep track of any memory requirements your application has. This includes choosing the correct amount of memory to allocate and making sure you deallocate it when it’s no longer needed.
The IUnityMemoryManager
API impacts performance because each allocation requires a virtual call. To minimize this performance impact, use the API to allocate larger blocks of memory less frequently. To handle smaller and more frequent allocations, use this API to allocate a single larger block, then write your own code to manage the memory within this block. Don’t use this API for frequent small allocations.
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