<div dir="ltr">Hi Levente, Hi All,<div><br></div><div> I'm trying to investigate the socket issues in aio.c but have found a much moire basic issue. With my recent changes to Network that more carefully checked for errors the SocketTest>>testSocketReuse test appears to lock up. In fact, the VM is fine, happily doing what it's being told by Socket>>#sendData:count:</div><div><br></div><div>Socket>>sendData: buffer count: n<div><span class="" style="white-space:pre"> </span>"Send the amount of data from the given buffer"</div><div><span class="" style="white-space:pre"> </span>| sent |</div><div><span class="" style="white-space:pre"> </span>sent := 0.</div><div><span class="" style="white-space:pre"> </span>[sent < n] whileTrue:[</div><div><span class="" style="white-space:pre"> </span>sent := sent + (self sendSomeData: buffer startIndex: sent+1 count: (n-sent))].</div><div><br></div><div>The VM keeps trying to send data on a socket that is being reused and gets an error from sendto, answers 0 as the number of bytes sent, as required, but Socket>>#sendData:count: pays no heed and spins hard. Here's the traces:</div><div><br></div><div>The test is SocketTest>>testSocketReuse which spawns two processes, one to send and one to receive data. Here are the processes:</div><div><br></div><div><div>Process 0x48641f8 priority 40</div><div>0xbfec0498 M Socket>sendSomeData:startIndex:count:for: 0x4864d18: a(n) Socket</div><div>0xbfec04c0 M Socket>sendSomeData:startIndex:count: 0x4864d18: a(n) Socket</div><div>0xbfec04ec M Socket>sendData:count: 0x4864d18: a(n) Socket</div><div>0xbfec0520 I [] in SocketTest>testSocketReuse 0x4864dd0: a(n) SocketTest</div><div>0xbfec0540 I [] in BlockClosure>newProcess 0x4864df0: a(n) BlockClosure</div></div><div><br></div><div><div>Process 0x6543178 priority 40</div><div>0xbfec22c8 I [] in Delay>wait 0x4864ea0: a(n) Delay</div><div>0xbfec22f0 I BlockClosure>ifCurtailed: 0x4864eb8: a(n) BlockClosure</div><div>0xbfec2314 I Delay>wait 0x4864ea0: a(n) Delay</div><div>0xbfec2340 I [] in SocketTest>testSocketReuse 0x4864dd0: a(n) SocketTest</div><div>0xbfec2360 M BlockClosure>ensure: 0x4864fa8: a(n) BlockClosure</div><div>0xbfec2390 I SocketTest>testSocketReuse 0x4864dd0: a(n) SocketTest</div></div><div><br></div><div><div>Process 0x4864168 priority 40</div><div>0xbfec3438 I [] in DelayWaitTimeout>wait 0x48652f8: a(n) DelayWaitTimeout</div><div>0xbfec3458 M BlockClosure>ensure: 0x4865378: a(n) BlockClosure</div><div>0xbfec347c I DelayWaitTimeout>wait 0x48652f8: a(n) DelayWaitTimeout</div><div>0xbfec34a0 I Semaphore>waitTimeoutMSecs: 0x48652e0: a(n) Semaphore</div><div>0xbfec34c4 I Socket>waitForDataIfClosed: 0x4865408: a(n) Socket</div><div>0xbfec34f0 I Socket>receiveDataInto:startingAt: 0x4865408: a(n) Socket</div><div>0xbfec3520 I [] in SocketTest>testSocketReuse 0x4864dd0: a(n) SocketTest</div><div>0xbfec3540 I [] in BlockClosure>newProcess 0x48654c0: a(n) BlockClosure</div></div><div><br></div><div>And here's the VM spinning:</div><div><div> 15726 0 sqUnixSocket.c:1128 UDP sendData(11, 16)</div><div> 15726 0 sqUnixSocket.c:1134 UDP send failed 56 Socket is already connected</div><div> 15726 0 sqUnixSocket.c:1128 UDP sendData(11, 16)</div><div> 15726 0 sqUnixSocket.c:1134 UDP send failed 56 Socket is already connected</div><div> 15726 0 sqUnixSocket.c:1128 UDP sendData(11, 16)</div><div> 15726 0 sqUnixSocket.c:1134 UDP send failed 56 Socket is already connected</div></div><div> ...etc...</div><div><br></div><div>Ah!! Of course. Because I have changed the default scheduling semantics in Squeak 5 to make preemption not a yield point, Socket>>#sendData:count: never yields to the other processes. Previously when the Delay process woke up this would implicitly yield the process spinning in Socket>>#sendData:count:.</div><div><br></div><div>So Socket>>#sendData:count: needs to do a yield if no data is sent. However, shouldn't but also check for errors if no data is sent and do something like return an error if it discovers, via Socket>>primSocketError:, that the socket is not happy?</div><div><br></div><div class="gmail_signature"><div dir="ltr"><div><span style="font-size:small;border-collapse:separate"><div>_,,,^..^,,,_<br></div><div>best, Eliot</div></span></div></div></div>
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