Dynamic software updating hicks validating xml editor mac
We have used Kitsune to update five popular, open-source, single- and multi-threaded programs, and find that few program changes are required to use Kitsune, and that it incurs essentially no performance overhead. Hicks is an associate professor in the Computer Science department and UMIACS at the University of Maryland, College Park, and is the Director of the Maryland Cybersecurity Center (MC2).
His research focuses on using programming languages and analyses to improve the security, reliability, and availability of software.
This article presents Proteus, a core calculus that models dynamic software updating, a service for fixing bugs and adding features to a running program.
Proteus permits a program's type structure to change dynamically but guarantees the updated program remains type-correct by ensuring a property we call con-freeness.
KGraft enforces version consistency on a per-process basis, so it is possible for one process to execute the new code while another process executes the old code.Or, if the new code uses two threads to perform some functionality which in the old version requires only one thread, then we need to map the existing thread’s stack to an equivalent one for the new code, and start a new thread to handle the extracted functionality.Changes to in-memory data, like the first example, we call These two descend from earlier research, by Jeff Arnold and Frans Kaashoek, on a solution called Ksplice, which was bought by Oracle in 2011. The basic approach to dynamically updating a function f is to overwrite the first few instructions of the current f to jump to its new version.This approach has the benefit that any references to f elsewhere in the code or data (i.e., as function pointers) will still work.Function f cannot be running when this change takes place, for obvious reasons.Or, imagine upgrades to systems hosting in-memory databases: Right now, you have to checkpoint the DB to stable storage, stop the system, upgrade it, restart it, read the data from stable storage, and restart service.Just the checkpointing and re-reading from disk could take tens of minutes.Hackerman B-17 Dynamic software updating (DSU) systems allow programs to be updated while running, thereby permitting developers to add features and fix bugs without downtime.This paper introduces Kitsune, a new DSU system for C whose design has three notable features.I’m particularly excited by this announcement because I’ve been working on the general problem of updating running software, which I call (DSU), for nearly 15 years.In this post, co-authored with my Ph D student Luís Pina, I take a closer look at the challenge that DSU presents, showing that what Linux will support is still quite far from what we might hope for, but that ideas from the research community promise to get us closer to the ideal, both for operating systems and hopefully for many other applications as well. If in the updated program the entries of a hash table are extended with a timeout field, then a dynamic update needs to convert in-memory hashtable entries to now contain a timeout field; otherwise, when the updated code goes to access that field, it will behave unpredictably.