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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hello Nikolai,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thank you for taking the time to reply to my questions.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I am well aware of the resolution of “GetTickCount(),” I even mentioned it in an earlier post. Gicen the times we are trying to confirm it is more than adequate.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Also, Ross has explained very well the way the process operates in a response to me earlier and events are not involved.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I have run performance monitoring, again mentioned in an earlier post and I know pretty well that the “OnDemandRTSPServer” is consuming about 7% of my CPU time when Idle (just ran the tests and the earlier figure I quoted was not accurate). My hope was to reduce this to an absolute minimum by changing to a true event driven server. However I am not sure how practical that is without changing Ross’ basic code and I do not want to do that.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Again, thank you,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sid.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> live-devel-bounces@ns.live555.com [mailto:live-devel-bounces@ns.live555.com] <b>On Behalf Of </b>Nikolai Vorontsov<br><b>Sent:</b> Friday, August 17, 2012 5:18 AM<br><b>To:</b> LIVE555 Streaming Media - development & use<br><b>Subject:</b> Re: [Live-devel] Do the test applications ever sleep?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Hello Sid,</span><o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>GetTickCount() is inaccurate in milliseconds interval. You better use timeGetTime() one (you will need to link a mm library).</span><o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>In any case I suppose that Ross holds the working thread on an event or something and thus efficiently release any time slices. Do a simple test - run idle server and check how much CPU it uses.</span><o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Nikolai.</span><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div class=MsoNormal align=center style='text-align:center'><hr size=2 width="100%" align=center></div><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:live-devel-bounces@ns.live555.com">live-devel-bounces@ns.live555.com</a> <a href="mailto:[mailto:live-devel-bounces@ns.live555.com]">[mailto:live-devel-bounces@ns.live555.com]</a> <b>On Behalf Of </b>Sid Price<br><b>Sent:</b> Thursday, August 16, 2012 11:16 PM<br><b>To:</b> 'LIVE555 Streaming Media - development & use'<br><b>Subject:</b> Re: [Live-devel] Do the test applications ever sleep?</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks Ross.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I used the word “sleeping” to mean that the process gives up any remaining time from its current time-slice for the OS to allocate as required.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Using your information I did some more digging and if I measure the execution time of “SingleStep” when the OnDemandRTSPServer application is running with no client connections I see <1mS execution time. I think my test code is good:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";color:blue'>void</span><span style='font-size:10.0pt;font-family:"Courier New"'> BasicTaskScheduler0::doEventLoop(<span style='color:blue'>char</span>* watchVariable) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> <span style='color:green'>// Repeatedly loop, handling readble sockets and timed events:<o:p></o:p></span></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> <span style='color:blue'>while</span> (1) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span> (watchVariable != NULL && *watchVariable != 0) <span style='color:blue'>break</span>;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> DWORD dwTick_1, dwTick_2 ;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> DWORD dwTickDelta ;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> dwTick_1 = GetTickCount();<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> SingleStep();<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> dwTick_2 = GetTickCount() ;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> dwTickDelta = dwTick_2 - dwTick_1 ;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> dwTick_1 = 0 ; <span style='color:green'>// Place to breakpoint<o:p></o:p></span></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>GetTickCount is a Windows API that retrieves the number of milliseconds that have elapsed since the system was started, up to 49.7 days, then it wraps.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Syntax.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>“dwTickDelta” is always zero, meaning <1mS.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>What led me here was that I used a process monitor to measure the CPU % that the test application was consuming and when I have no client attached and therefore no streaming happening I see higher CPU usage than I expected. In the range 15-25% of CPU. The CPU is a fast ARM that should be more than enough horsepower for this task.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sid.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Since there is nothing else in the “doEventLoop” I terms of calls I have to assume the 10mS you mentioned should be the execution time of the “SingleStep” method.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:live-devel-bounces@ns.live555.com">live-devel-bounces@ns.live555.com</a> <a href="mailto:[mailto:live-devel-bounces@ns.live555.com]">[mailto:live-devel-bounces@ns.live555.com]</a> <b>On Behalf Of </b>Ross Finlayson<br><b>Sent:</b> Thursday, August 16, 2012 2:28 PM<br><b>To:</b> LIVE555 Streaming Media - development & use<br><b>Subject:</b> Re: [Live-devel] Do the test applications ever sleep?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>While investigating another issue I began to dig a little deeper into how the library operates and it appears to me that the process running the servers never sleeps, is this correct?<o:p></o:p></span></p></div></div></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>Not really. I don't know what specifically you mean by 'sleep', but - as you know - LIVE555-based applications are event driven, and execute code only when handling an event. When there are no events to be handled, then the application does not run. You can call this 'sleeping' if you like.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>What you might be referring to, however, is the fact that - in the "BasicTaskScheduler" implementation - there is a periodic delayed task called "schedulerTickTask()" that runs every 10 milliseconds (not 10 microseconds as the comment in the code incorrectly says). This task does no work, and exists only to ensure that the code periodically returns from "select()", to handle any triggered events. But this causes only a brief period of activity (with almost no overhead) every 10 ms; for the rest of the time, the application is effectively 'sleeping' if there are no other events to be handled.<o:p></o:p></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal><span class=apple-style-span><span style='font-size:13.5pt;font-family:"Helvetica","sans-serif";color:black'>Ross Finlayson</span></span><span style='font-size:13.5pt;font-family:"Helvetica","sans-serif";color:black'><br><span class=apple-style-span>Live Networks, Inc.</span><br><span class=apple-style-span><a href="http://www.live555.com/">http://www.live555.com/</a></span></span> <o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>