Re: A C++ API for the pcas

[oothoudt@lanl.gov (Michael A. Oothoudt)]

I would like to raise the question of PERFORMANCE if core code is written
in C++.  While I have no direct experience with C++ performance, I had a
couple of recent conversations with experienced people that make me worry.

At ICALEPCS Mike (?) from Triumpf said they had converted a couple of
applications from Fortran to C++.  It cost them a factor of 2-5 in
performance. They had spent considerable time improving the C++ code
performance to get to this level.

At an object oriented programming class, I talked to a couple of high level
engineers from Talegent (they [soon] will be selling a C++ "environment").
They said C++ is inappropriate for realtime uses--among other things
garbage collection is still not solved.  They noted it has been used in
realtime, but the examples they gave had rather slow response bounds (~1
sec).  They said it would be a good choice for user interface work.

Can anyone make estimates on performance hit in EPICS environment?

---------------------------------------------------------------
Michael A. Oothoudt
Accelerator Operations and Technology Division (AOT-6), MS H820
Los Alamos National Laboratory, Los Alamos, NM 87545
oothoudt@lanl.gov