The program code and the program state are updated immediately in a single step.
It is not necessary to wait indefinitely for a quiescent program state. A running algorithm can be updated midstream its execution and resumed from a different point (not necessarily the beginning) of another algorithm.
Here are some key features of "UpStare":
- Updating an application recursively computing Fibonacci numbers, while nested deep in the stack, to report additional information when the recursion unwinds.
- Network Sockets:
- Updating a server application while serving multiple clients without closing the network socket.
- Multi-threaded Applications:
- Updating the main function body executed by multiple threads of an application. Also, updating in a producer/consumer multi-threaded application only the consumer threads while the producer threads remained unmodified.
- Multi-nested Long-Lived Loops:
- Updating in the middle of executing Bubblesort, a multi-nested long-lived loop, to continue executing from the middle of a different multi-nested long-lived loop implementing Selectionsort while reusing the existing program state. Additionally, updating from Bubblesort to Heapsort, which is a drastically different sorting algorithm executing over different loop iterators.
- Updating the multi-process (forked processes do not communicate) vsFTPd 2.0.4 server while serving 50 clients.
- Updating the multi-process (forked processes communicate) PostgreSQL 7.4.16 database server while serving 50 clients.
- This version was compiled with debugging statements disabled for performance.
- Parts of the documentation on preparing dynamic updates were corrected.