On 11/27/2010 05:32 AM, Patricia Shanahan wrote:
Scheme 1: Modify each class that calls Runtime.getRuntime.exec to register a shutdownHook to destroy the Process that exec returned.
Scheme 2: Require each public static void main(String[]) method in River to log the pid of its process in a log message with a specific format. Write a program that scans the log file for those messages, and kills each process.
What about having the VM kill itself when a keepalive condition does not occur anymore. A watchdog. The best way for such a condition is a condition managed by the OS. A socket whould be a good candidate. In fact there is already such a mechanism. Just look for KEEPALIVE_PORT in the QA harness, It is in MasterHarness and SlaveHarness.
The strategy would be as follows (not verified with the actual keepaliveport implementation).
The coordinating process opens a ServerSocket. The subordinate processes try to open this socket. If they fail or if the socket is closed at a later stage, they selfdestruct.
I just coded the HeartOfTheMachine because i needed to be sure, and it was much simpler than verifing the keepalive port mechanism. But i prefer the keepaliveport. If we agree on this mechanism beeing theoretically foolproof, we can have a look if this mechanism is implemented for every test scenario, and fix it where its not.
Gr. Sim
