Ben,
On 18 Feb 2018, at 15:29, Ben Coman <btc@openinworld.com> wrote:
The websockets guide here.... https://ci.inria.fr/pharo-contribution/job/EnterprisePharoBook/lastSuccessfu...
says "Reading and sending are completely separate and independent" and the class comment says its "full-duplex". From these I presume sending and receiving are okay to occur in separate threads, but this is not explicitly stated, so can someone confirm this?
The reading and the writing over a web socket connection are independent, so yes that would be OK. Of course, they would both share the same network stream (just use each half independently) - that normally works fine.
So for the given example.... | webSocket | webSocket := ZnWebSocket to: 'ws://echo.websocket.org'. [ webSocket sendMessage: 'Pharo Smalltalk using Zinc WebSockets !'; readMessage ] ensure: [ webSocket close ].
re-implementing as follows seems to work... webSocket := ZnWebSocket to: 'ws://echo.websocket.org'. [ webSocket runWith: [ :msg | Transcript crShow: msg ] ] forkAt: 35. webSocket sendMessage: 'Pharo Smalltalk using Zinc WebSockets !'. webSocket sendMessage: 'Another multi-thread echo'. webSocket close
but that could just be by luck, so I ask.
No, that should work.
btw, if I don't send the #close in the last line, after ~30 seconds I get an error ConnectionClosed: Cannot write data which seems reasonable that the other end timed out and closed the connection,
but when I send the #close, after ~30 seconds I get an error... PrimitiveFailed: primitive #primSocketReceiveDataAvailable: in Socket failed which is unfriendly. What is the best way to neatly stop trying to receive data when we explicitly close the websocket?
Of course that fails, you fork a reading loop containing #runWith: which has to end/stop somehow, the lazy way is by allowing an error to bubble up.
cheers -ben
P.S. I wonder if when a ZnWebSocket is closed, it might be worthwhile to do "role:=#closed" to provide some visibility of its state in its GTInspector [Raw] tab..
Maybe, but there is #isConnected and the Socket inspector 'Socket Info' shows lots of details, you can rely on that. Sven