[ofiwg] Question about endpoints and passive endpoints
sean.hefty at intel.com
Mon Sep 19 15:24:01 PDT 2016
> From what I can tell from fi_endpoint.h and fi_cm.h, fid_pep and fid_ep
> share the method groups fi_ops_ep and fi_ops_cm. It appears that in
> those methods, if fid_t is used, any endpoint can be used and if
> fid_pep is used, a passive endpoint must be used.
If fid_t is specified, then there may be other fabric identifiers which can be used. For example, fi_ep_bind allows binding an active endpoint to either a CQ or counter object. Type protection is provided where possible (e.g. fi_pep_bind only allows binding a passive endpoint.)
> If fid_ep is used, could a passive endpoint use it, or does it have to
> be a normal endpoint?
A normal endpoint must be used.
A good rule is to make sure that you never attempt to cast one fabric id to another. That is, don't do this:
struct fid_pep *pep;
.... (struct fid_ep *) pep; /* bad casting */
However, something like this is okay:
... &pep.fid; /* get at the base fid object */
> Ive also noticed in methods like rx_ctx there are variables such as:
> fid_ep *sep. Does this indicate only a scalable endpoint should be
Yes. Scalable endpoints use the same data structure as normal endpoints (fid_ep).
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