Prosilica cameras and bug in EPICS signal handlers

["Mark Rivers" <rivers@cars.uchicago.edu>]

Dear John,

I know it's too late for your new camera purchase, but I want to let you
know that I did get the Prosilica cameras working fine with Linux today.


It turns out that it was really a bug in EPICS, not in their driver.
EPICS was installing signal handlers in an obsolete manner that is
incompatible with the new Posix 1.b interval timer library.

With a minor change to the EPICS signal handler functions I can control
Prosilica cameras from Linux with no problem.

EPICS needs additional work to be compatible with the Posix 1.b timer
routines.  These can cause many system calls to terminate prematurely
with the errno=EINTR.  I had to modify the epicsThreadSleep function to
work properly when Posix timers were running, and there will almost
certainly be other places where system calls need to be checked error
returns for this reason.  It's a lot of work, but other developers are
beginning to use these timer functions in their code, and we need to be
able to use code in EPICS.

Cheers,
Mark