Sorry for the long delay in replying -- this mail got lost in my usual INBOX 
overflow, etc.


On Jan 12, 2012, at 11:05 AM, devendra rai wrote:

> Hello Community:
> 
> I am running into a strange problem. I get a SIGSEGV when I try to execute 
> MPI_Test:
> 
> ==21076== Process terminating with default action of signal 11 (SIGSEGV)
> ==21076==  Bad permissions for mapped region at address 0x43AEE1
> ==21076==    at 0x509B957: ompi_request_default_test (req_test.c:68)
> ==21076==    by 0x50EDEBB: PMPI_Test (ptest.c:59)
> ==21076==    by 0x44210D: InterProcessorTransmit::StartTransmission() 
> (InterProcessorTransmit.cpp:111)

The problem is in your code; see below.

> Here is the relevant piece of code:
> 
>        for ( this->dbIterator = localdb.begin( ) ; this->dbIterator != 
> localdb.end( ); this->dbIterator++)
>         {
>             this->TransmissionDetails = (this->dbIterator)->second;
>             SendComplete = 0;
>             UniqueIDtoSendto = std::get<0>(this->TransmissionDetails);
>             RecepientNode = (this->dbIterator)->first;
>               Isend_request = MPI::COMM_WORLD.Issend(this->transmitbuffer, 
> this->transmissionsize, MPI_BYTE, (this->dbIterator)->first, 
> std::get<0>(this->TransmissionDetails));
> /*This is line 111 */MPI_Test(&(this->Isend_request), &(this->SendComplete), 
> &(this->ISend_status));

You assigned the request to Isend_request, but then tested this->Isend_request.

Those are two different variables.  Your debugger screenshot shows that 
this->Isend_request was NULL (i.e., had a value of 0), so when OMPI tried to 
dereference through it, it segv'ed.

-- 
Jeff Squyres
jsquy...@cisco.com
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/


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