vxWorks

[Eric Norum]

Joel Sherrill wrote:
> 
> Just to let everyone know.  Eric Norum and I have worked on the binary
> semaphore code over the past few months as part of his porting EPICS
> to RTEMS.  We added a simple binary semaphore that is supposed to
> match the semantics of one of the VxWorks mutex types.  I have no
> documentation but Eric N can comment.

In the OS-dependent semaphore creation portion of EPICS there is the
following code for vxWorks:

binary semaphore creation:
  return((semBinaryId)semBCreate(
    SEM_Q_FIFO,((initialState==semEmpty) ? SEM_EMPTY : SEM_FULL)));

mutex semaphore creation:
    return((semMutexId)
        semMCreate(SEM_DELETE_SAFE|SEM_INVERSION_SAFE|SEM_Q_PRIORITY));


The corresponding sections for RTEMS are:

binary semaphore creation:
    sc = rtems_semaphore_create (rtems_build_name ('B', c3, c2, c1),
        initialState,
        RTEMS_FIFO | RTEMS_SIMPLE_BINARY_SEMAPHORE |
        RTEMS_NO_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING |
RTEMS_LOCAL,
        0,
        &sid);

mutex semaphore creation:
    sc = rtems_semaphore_create (rtems_build_name ('M', c3, c2, c1),
        1,           
RTEMS_PRIORITY|RTEMS_BINARY_SEMAPHORE|RTEMS_INHERIT_PRIORITY|RTEMS_NO_PRIORITY_CEILING|RTEMS_LOCAL,
        0,
        &sid);


Joel is also working on some lighter-weight routines (macros?) to
obtain/release the above style of mutex semaphore.

-- 
Eric Norum                                 eric at cls.usask.ca
Canadian Light Source                      Phone: (306) 966-6308
University of Saskatchewan                 FAX:   (306) 966-6058
Saskatoon, Canada.