Pick activity eats messages that it does not consume

Question

Consider the following code fragment:
<while name="while-1" condition="bpws:getVariableData('counter') &lt; 2">
<pick name="pick-1">
<onMessage partnerLink="rcvr1" portType="tns:BasicCallback" operation="onResult" variable="rcvd1">
</onMessage>
<onMessage partnerLink="rcvr2" portType="tns:BasicCallback" operation="onResult" variable="rcvd2">
</onMessage>
<onMessage partnerLink="rcvr3" portType="tns:BasicCallback" operation="onResult" variable="rcvd3">
</onMessage>
</pick>
</while>
In principle, this fragment of process will perform a number of iterations (let's say two iterations) and for each of these iterations it will consume one among three possible types of messages (the messages have the same type but come from different partner links).
I have run this process in a situation where all the three messages (which come from the three different partner links) are sent at the same time and thus (in most executions) they arrive to the BPEL process at the same time. The problem that I'm having is that during the first iteration, the Pick activity consumes one of the message (say the message over "rcvr1") and it then discards the other two messages which are sitting on the message queue (i.e. the messages that arrived through partner links "rcvr2" and "rcvr3"). As a result, these two messages are no longer available during the second iteration of the "while" loop, and the process just waits forever.
Reading Section 12.4 of the BPEL 1.1 spec. there's nothing in there that says that messages that are not consumed by a Pick activity should be discarded.
Specifically, the execution log that I'm getting looks something like the following:
... [first iteration]
rcvr3 (onResult) (cancelled)
[2005/06/09 14:42:28] Waiting for message from "rcvr3", operation is "onResult".
[2005/06/09 14:42:32] Receive activity has been cancelled.
rcvr2 (onResult) (cancelled)
[2005/06/09 14:42:28] Waiting for message from "rcvr2", operation is "onResult".
[2005/06/09 14:42:32] Receive activity has been cancelled.
rcvr1 (onResult)
[2005/06/09 14:42:28] Waiting for message from "rcvr1", operation is "onResult".
[2005/06/09 14:42:32] Received "onResult" callback from partner "rcvr1" More...
<rcvd1>
... [second iteration]
rcvr3 (onResult) - pending
[2005/06/09 14:42:32] Waiting for message from "rcvr3", operation is "onResult".
rcvr2 (onResult) - pending
[2005/06/09 14:42:32] Waiting for message from "rcvr2", operation is "onResult".
rcvr1 (onResult) - pending
[2005/06/09 14:42:32] Waiting for message from "rcvr1", operation is "onResult".
Interestingly, sometimes it happens that one of the 3 messages arrives one second before the other two. In this case, The Pick activity consumes the first message during the first iteration, then the process goes into the second iteration and the "Pick" activity then consumes a second randomly chosen message (but still it "eats" the third message).
This behaviour has been observed in Oracle BPEL 2.1.2
Kind regards
Marlon Dumas (m . dumas @ qut . edu . au)
Queensland University of Technology, Australia

Answer 1

Thanks Marlon. I will communicate the same to dev team.