I agree that it is difficult to come up with a good scenario, outside of resilience, in which MPI_Probe would return an error (other than a bad argument type of error - which does currently work). I agree with your assessment of the value of the return code, and that it should trigger the error handler. I just wanted to confirm that there was not something I was missing.
I will commit a patch to fix this (it is just a couple lines in pml/ob1) for the trunk. I don't know if we need to push it to the release branches just yet.
On Mar 21, 2011, at 10:17 PM, George Bosilca wrote:
> If we don't take in account resilience I would not expect MPI_Probe to have that many opportunities to return errors. However, in order to keep the implementation consistent (with the other MPI functions) I would abide to the following.
> MPI_ERROR_IN_STATUS is only for calls taking multiple requests as input, so I don't think this should be applied to the MPI_Probe. I would expect the return to be equal to status.MPI_ERROR (similar to only other function working on a single request, such as MPI_Test).
> It better trigger the error-handler attached to the communicator, as explicitly requested by the MPI standard (section 8.3).
>> A user can associate error handlers to three types of objects: communicators, windows, and files. The specified error handling routine will be used for any MPI exception that occurs during a call to MPI for the respective object.
> On Mar 21, 2011, at 16:50 , Joshua Hursey wrote:
>> If MPI_Probe() encounters an error causing it to exit with the 'status.MPI_ERROR' set, say:
>> ret = MPI_Probe(MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
>> Should it return an error? So should it return:
>> - ret = status.MPI_ERROR
>> - ret = MPI_ERROR_IN_STATUS
>> - ret = MPI_SUCCESS
>> Additionally, should it trigger the error handler on the communicator?
>> In Open MPI, it will always return MPI_SUCCESS (pml_ob1_iprobe.c:74), but it feels like this is wrong. I looked to the MPI standard for some insight, but could not find where it addresses the return code of MPI_Probe.
>> Can anyone shed some light on this topic for me?
>> Joshua Hursey
>> Postdoctoral Research Associate
>> Oak Ridge National Laboratory
>> devel mailing list
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Postdoctoral Research Associate
Oak Ridge National Laboratory