Lambda the Ultimate

Samurai - Protecting Critical Heap Data in Unsafe Languages.
Karthik Pattabiraman, Vinod Grover, Benjamin G. Zorn.
September 2006.

Programs written in type-unsafe languages such as C and C++ incur costly memory safety errors that result in corrupted data structures, program crashes, and incorrect results. Previous approaches to eliminating these errors attempt to eliminate all unsafe memory operations in a program. We present Samurai, a runtime system that allows programmers to selectively identify heap objects that are critical to correct execution of their program. Samurai supports operations to consistently read and update critical data and probabilistically guarantees that no other memory updates in the program will corrupt critical data. Samurai uses replication and randomization to provide these consistency guarantees. Because Samurai is oblivious to memory operations on noncritical data, the majority of memory operations in programs run at full speed, and Samurai is compatible with 3rd party libraries. We have annotated five benchmark programs with Samurai and we present measurements of the execution overhead and fault tolerance that Samurai provides. Samurai can be applied selectively to parts of a program’s heap allowing the execution overhead to be tailored for the needs of a particular application.

Essentially, you use a custom memory allocator for critical objects, so that they are stored redundantly (i.e, they are replicated).

Related reading: Failure-oblivious computing.