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| layout: default |
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| :source-highlighter: coderay |
| :icons: font |
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| include::_banner.adoc[] |
| |
| == Request/Reply (I ask, you answer) |
| |
| image::reqrep.png[I ask, you answer] |
| |
| Request/Reply is used for synchronous communications where each question |
| is responded with a single answer, for example remote procedure calls (RPCs). |
| Like <<pipeline#,Pipeline>>, it also can perform load-balancing. This |
| is the only reliaable messaging pattern in the suite, as it automatically |
| will retry if a request is not matched with a response. |
| |
| .reqprep.c |
| [source,c] |
| ---- |
| include::src/reqrep.c[] |
| ---- |
| <1> Blithely assumes message is ASCIIZ string. Real code should check it. |
| |
| .Compilation |
| [source,bash] |
| ---- |
| gcc reqrep.c -lnanomsg -o reqrep |
| ---- |
| |
| .Execution |
| [source,bash] |
| ---- |
| ./reqrep node0 ipc:///tmp/reqrep.ipc & node0=$! && sleep 1 |
| ./reqrep node1 ipc:///tmp/reqrep.ipc |
| kill $node0 |
| ---- |
| |
| .Output |
| ---- |
| NODE1: SENDING DATE REQUEST DATE |
| NODE0: RECEIVED DATE REQUEST |
| NODE0: SENDING DATE Sat Sep 7 17:39:01 2013 |
| NODE1: RECEIVED DATE Sat Sep 7 17:39:01 2013 |
| ---- |
