The IUnityMemoryManager
memory manager API is a C++ interface that allows you to use Unity’s memory management and memory profiling in native plug-insA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
See in Glossary.
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, refer to IUnityMemoryManager API reference.
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.
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.
When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.
More information
These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising. Some 3rd party video providers do not allow video views without targeting cookies. If you are experiencing difficulty viewing a video, you will need to set your cookie preferences for targeting to yes if you wish to view videos from these providers. Unity does not control this.
These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.