re: [Sandiaportals-devel] RFC

[Eric H. <ho...@cr...>]

    >2/ I _do_ believe there is a need to allow PtlMDUnlink() to apply to the
    >   MDs passed to PltMDGet() and PtlMDPut(PTL_ACK_REQ).  We can't bound the
    >   time that memory is "exposed" to the network otherwise.  This has been
    >   implemented in sandiaportals, but not documented in the spec.

  I'm not sure about this one.  Unless the target is down, a PtlPut() or 
  PtlGet() should complete pretty quickly.  If the target is down, the END 
  event (in Portals 3.2/3.3) will eventually happen and indicate an 
  error.  When the END event happens is implementation specific but will 
  probably be after a longish timeout when the message's retry limit is 
  reached. 

there is a substantial window in the remote case allowing (for
example) the target MD handle to be freed and reallocated causing
unexpected results. without an instance-unique identifier (your
suggested generation number or a random cookie), there doesn't seem
any way to prevent this without placing additional restrictions on the
use of the API.