[libfabric-users] trouble by FI_SOURCE use

[Biddiscombe, John A.]

I think I have the concept of source/dest the wrong way around and I should be using the dest field, since I want to receive on that port number.

Am I correct in thinking that when creating the endpoint, the source field is me if I'm sending, but the dest field if I'm receiving on a particular port?

thanks

JB
________________________________
From: Libfabric-users [libfabric-users-bounces at lists.openfabrics.org] on behalf of Biddiscombe, John A. [biddisco at cscs.ch]
Sent: 10 March 2019 10:21
To: libfabric-users at lists.openfabrics.org
Subject: [libfabric-users] trouble by FI_SOURCE use

Hello list

I need to use a particular port number when setting up a connection, so I have

fabric_hints_->src_addr    = socket_data;
fabric_hints_->addr_format = FI_SOCKADDR_IN;
fabric_hints_->src_addrlen = sizeof(struct sockaddr_in);
//
fabric_hints_->caps        = FI_MSG | FI_RMA | FI_SOURCE |
  FI_WRITE | FI_READ | FI_REMOTE_READ | FI_REMOTE_WRITE | FI_RMA_EVENT;

and all is well, but when a message comes in -
if (src_addr == FI_ADDR_NOTAVAIL)
{
    LOG_DEBUG_MSG("Source address not available...\n");
    std::terminate();
}

my check for the source fails. This is documented - however the documentation/examples appear ambiguous

"src_addr - source address
If specified, indicates the source address. This field will be ignored in hints if FI_SOURCE flag is set."

But the examples/tutorials use src_addr and still set FI_SOURCE, so I tried it too and the endpoint is created on the correct port number. I'm happy.
however,
"FI_SOURCE

Requests that the endpoint return source addressing data as part of its completion data."
So if I need the endpoint on a certain port number and I set src_addr, but now the FI_SOURCE flag is dropped, but I also want to know where messages are coming from - how do I get the source information with the message?

Apologies if this question appears trivial, I've not looked at the code for a long time and forgotten much of what I knew about libfabric.

yours

JB


--
Dr. John Biddiscombe,                    email:biddisco @.at.@ cscs.ch
http://www.cscs.ch/
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
Via Trevano 131, 6900 Lugano, Switzerland   | Fax:  +41 (91) 610.82.82
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