CODEWITHSUNDEEP
delphidelphi-10-seattle
Kanitatlan
Kanitatlan

Reputation: 395

Large memory aware testing in the IDE

Historically we have had problems with RAD studio running out of memory which no longer happens with XE10 Seattle. We have a lot of our own components which have never been tested for large memory awareness and do not need it when built into our applications BUT we have recently had an IDE fault due to the design time instance of a component being instantiated at an address above 2Gb (which we have fixed).

I have a feeling I read somewhere that Embarcadero have a method for testing RAD Studio (command line option ??) for higher memory compatibility but cannot find the reference anywhere. Does anyone know either how to force higher memory position allocation in the IDE to verify our component set's design time behavior or alternative a way of testing in an application other that writing something that just steals all the lower memory.

I've tried the "allocate from the top" option in FastMM but this just starts allocating from 2Gb downwards even when the executable is set for higher memory use.

Upvotes: 3

Views: 841

Answers (1)

David Heffernan
David Heffernan

Reputation: 613013

The most effective way to test this is to force the system to allocate memory top down. How this is done is described here: https://msdn.microsoft.com/en-us/library/bb613473.aspx

To force allocations to allocate from higher addresses before lower addresses for testing purposes, specify MEM_TOP_DOWN when calling VirtualAlloc or set the following registry value to 0x100000:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management\AllocationPreference

Once you change the registry setting you will need to restart your machine.

Do not be surprised if your machine becomes unstable when you do this. A great many anti-malware products are incapable of operating under system-wide top down memory allocation. You might find it necessary to temporarily disable your anti-malware while performing top down allocation testing.

Upvotes: 3

Related Questions