How to have your cake and eat it too: Dynamic software updating with just-in-time overhead

Abstract

Abstract-We consider the overhead incurred by programs that can be updated dynamically and argue that, in general, and regardless of the mechanism used, the program must incur an overhead during normal execution. We argue that the overhead during normal execution of the updateable program need not be as high as the overhead for the updated program. In light of the fundamental limitations and the differences in the overhead that must be incurred by the updateable and updated programs, we propose a new mechanism for dynamic software update based on a new shifting gears approach. The mechanism attempts to incur just the required overhead depending on the stage of update the application is in. Before an update the execution incurs low overhead and when an update occurs the execution incurs higher overhead which reverts to low overhead as the execution progresses. We evaluate the mechanism by modifying an application by hand. Preliminary performance numbers show that the mechanism performs better than existing mechanisms for dynamic software update.

Dynamic software updating: a systematic mapping study

“…Also, number of authors have highlighted additional DSU approaches including dynamic replacement [22, 54, 66, 75, 86, 92, 93 ], dynamic instrumentation [52, 59, 60, 74, 84, 94 ], dynamic linking [37, 39, 53, 75, 83, 85 ], lust‐in‐time compilation [30, 44, 55, 58, 76, 95 ], wrapper [4, 40, 42, 44, 52 ], dynamic aspect‐oriented [35, 41, 50, 96, 97 ], extension of features [98, 99 ], dynamic adaptation [43, 59 ], rolling update [84 ], object transformer [49 ], data‐driven programming [92 ], distributed DSU [38 ], dynamic core library update [56 ], using run time to support DSU [92 ], procedure‐oriented [30 ], micro‐language‐based [100 ], and dynamic rebinding [5 ].…”

“…Current techniques to define statesA number of studies have demonstrated 12 techniques to define states in DSU including state transformer [45, 73, 83, 95, 115 ], formalise as state machine [9, 61, 83, 120 ], adaptation [41, 65 ], prepare ready tainted states [101 ], state convergence algorithm [126 ], state‐based specification language [83 ], enforcing restrictions [116 ], model checkers [83 ], using check points [37 ], custom state transfer [116 ], convert states bi‐directionally [42 ], and event‐based [66 ]. C. Existing techniques to transfer states in DSUBefore we list the identified states transformations techniques, it is interesting to mention number of techniques utilised in DSU to assist in states transformations in the selected primary studies, the techniques are including wrappers [16, 22, 43, 46, 52, 77, 94, 95 ], adaptation [4, 38, 41, 43, 59, 100, 129 ], refactoring [47, 50, 55, 74, 86, 99, 123 ], proxies [41, 46, 53, 113, 119, 131 ], class loaders [55, 85, 86, 123 ], in‐Place Proxification [43, 55, 91 ], adjustment [41, …”

“…In this examination, we have identified an existing code segment, data segment, stack segment, heap segment, and multithread dynamic updating techniques as follows: A. Code segmentA number of investigations have presented five types of code segment techniques including indirection [4, 46, 47, 53, 55, 74, 77, 94, 99, 106, 119 ], injection [46, 74, 79, 91, 103, 120 ], rewriting [47, 50, 53, 74, 106 ], bytecode manipulation [41, 43, 55 ], and trampolines [4, 106 ]. B. Data segmentA group of studies have demonstrated eight different types of data segment techniques including migration [56, 57, 105, 111, 119 ], shadow data structure [59, 74, 105 ], copy field values [41 ], swapping [95 ], type wrapping [105 ], screen buffering and data caching [73 ], Struct replacement [22 ], and shared data structure [68 ]. C.…”

“…A number of investigations have presented five types of code segment techniques including indirection [4, 46, 47, 53, 55, 74, 77, 94, 99, 106, 119 ], injection [46, 74, 79, 91, 103, 120 ], rewriting [47, 50, 53, 74, 106 ], bytecode manipulation [41, 43, 55 ], and trampolines [4, 106 ].…”

“…A group of examinations have highlighted four different types of stack segment techniques including stack reconstruction [6, 41, 42, 51, 74, 76, 94, 103, 105, 121 ], stack mapping [6, 42, 51, 76, 88, 94, 105, 121 ], stack inspection [5, 70, 79, 101 ] and on‐stack‐replacement [4, 42, 44, 76 ].…”