How to increase heap size of an android application?

I am writing an Android application which uses several 3D models. Such a model with textures can take up a lot of memory. I found out the manufacturer sets a limit on the heap size an application can use. For example my tablet Samsung Galaxy Tab 8.9 P7310 can take up 64MB of memory.

Is there a way to increase this size of memory an application can use?

Solution 1:

You can use android:largeHeap="true" to request a larger heap size, but this will not work on any pre Honeycomb devices. On pre 2.3 devices, you can use the VMRuntime class, but this will not work on Gingerbread and above.

The only way to have as large a limit as possible is to do memory intensive tasks via the NDK, as the NDK does not impose memory limits like the SDK.

Alternatively, you could only load the part of the model that is currently in view, and load the rest as you need it, while removing the unused parts from memory. However, this may not be possible, depending on your app.

Solution 2:

Is there a way to increase this size of memory an application can use?

Applications running on API Level 11+ can have android:largeHeap="true" on the <application> element in the manifest to request a larger-than-normal heap size, and getLargeMemoryClass() on ActivityManager will tell you how big that heap is. However:

1. This only works on API Level 11+ (i.e., Honeycomb and beyond)

2. There is no guarantee how large the large heap will be

3. The user will perceive your large-heap request, because it will force their other apps out of RAM terminate other apps' processes to free up system RAM for use by your large heap

4. Because of #3, and the fact that I expect that android:largeHeap will be abused, support for this may be abandoned in the future, or the user may be warned about this at install time (e.g., you will need to request a special permission for it)

5. Presently, this feature is lightly documented