Container Framework
The Java VM is executed by a work process. If an ABAP program calls a function module implemented in Java, a VM from the VM pool is assigned to the work process ( attach; see Resource Management in the VM Container).
If there is no VM in the pool, a VM is copied (cloned).
Cloning works on all SAP platforms except on HP-UX. On this platform a VM has to be started normally.
The VM remains assigned to the work process for as long as the user context is rolled in (this means mapped to the work process). (At the end of the dialog step the user context is rolled out and the VM is detached from the work process). Furthermore, with synchronous updates the ABAP context (and therefore the VM also) is rolled out.
In the statistic record the number of attachments ( count attach) and detachments ( count detach) of a VM is stored along with the time needed for the attachments and detachments ( time attach, time detach). The time taken for the cloning ( time clone) and the maximum runtime of a thread ( Time max thread run) (before a thread is switched) is also recorded. The number of thread switches is also recorded ( Count thread switch).
