[ofw] programming custom appliaction

[Hefty, Sean]

>I have a customer that wants to programm an application for image data
>transfer in Windows XP 64.
>Currently I want to recommend using verbs. Is this the right choice?

There's a plethora of interfaces to choose from:

libibverbs - OFA interface available on windows and linux
This is the only linux verbs interface, which was ported to windows to support portability.  This sits over winverbs.  It provides low abstraction to the hardware, but does not expose windows specific features, like overlapped operations for asynchronous control.  This is a good choice for low-level access, with portability between windows and linux.

winverbs - OFA windows interface
Lowest level windows verbs interface for applications.  Most of the other interfaces sit over this interface.  This provides the lowest abstraction to the hardware, while also exposing windows specific features.  This is a good choice for low-level access on windows.

dapl - industry standard RDMA interface for multiple OS's
Hardware providers may support this interface, even if not part of OFA.  This sits over libibverbs.  This provides a higher level of abstraction, but provides the most portability.

network direct - MS defined interface for windows
Hardware providers may support this interface, even if not part of OFA.  This sits over winverbs.  This provides a higher level of abstraction, but may provide access to the most hardware on Windows platforms.

ibal - OFA windows interface
Older windows interface.  This is currently a peer to winverbs, with a longer term goal of moving it over winverbs.  The interface will be supported going forward.  This provides low level abstraction, but does not expose windows specific features.

>As an coding example I was thinking of
>svn://openib.tc.cornell.edu/gen1/trunk/tests/perftest/rdma_bw/rdma_bw.c
>
>Are there better examples to look at?

There are examples that use all of the interfaces above.  There are more applications that use the libibverbs interface, but most run on linux or are ports of the linux applications.

- Sean