A format string used in this fix got currupted due to SCCS mis-interpretation and caused the following bug.
6615248: SCCS tag interpetation makes code invalid
And due to this regression, HeapDumpOnCtrlBreak does not work correctly in 5.0u14. This problem has been fixed in 1.4.2_18 and 5.0u17.
There are many ways to trigger a heap dump on demand in jdk6. For example, jconsole or any JMX tool can trigger a heap dump, the jmap -dump option (new in jdk6), and more. This feature request is to provide a way to trigger a heap dump on demand in older releases. In older releases the only way to generate a heap dump is using the HPROF agent or using the jmap -heap:format=b option to recover a heap dump from a core file or process image. As the latter is for post mortem diagnosis it may not be suitable for all environments. Some customers have discovered the HeapDumpOnCtrlBreak option that was added in a test binary for a specific customer. It would be good to make this an offical option and add it to 1.4.2 and 5.0 updates. If this happens then we should come up with a scheme to name the heap dumps (the prototype HeapDumpOnCtrlBreak encoded a timestamp which isn't very useful).