We went over a crude app that allocated and touched memory in a previous post. Allocations were done using int arrays, and touching the memory was done efficiently, only writing every 1024th element in each int array, which in turn would write each time to a subsequuent memory page (4KB in size, equivalent to 1024 x 4 bytes per int element) and force it into the working set. Yet the memory block size was fixed, the delay between allocations was hardcoded and all the allocated memory was eventually touched. It lacked control.

So what we’ll set out to do is write a new app that allocates (leaks) memory, that allows:

• Custom delay between subsequent allocations
• Adjustable size of the memory block allocated at once
• Memory block size specified in MB
• Variable touch “fill” ratio, specifying how much of the committed memory gets touched per each memory block allocated
• A threshold above which no more allocations will be performed, specified in MB (or 0 to allocate indefinitely)
• Command arguments to specify values for all the parameters described above

What we’ll get is a tool that can leak memory in a controlled fashion, with multiple “knobs” that can alter its behavior.

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