An application using the
Performance Metrics Application Programming Interface (PMAPI)
may manipulate several concurrent contexts,
each associated with a source of performance metrics, e.g. pmcd(1)
on some host, or an archive log of performance metrics as created by
pmlogger(1).
Calling
pmUseContext
causes the
current PMAPI context to be set to
the context identified by
handle.
The value of
handle
must be one returned from an earlier call to
pmNewContext(3)
or
pmDupContext(3).
Below the PMAPI, all contexts used by an application are saved in their most
recently modified state, so
pmUseContext
restores the context to the state it was in the last time the context was
used, not the state of the context when it was established.