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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='margin-left:.5in'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>One last question on this, as I'm in the middle of reorganizing the code.</span><o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:.5in'><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Shouldn't it be safe to create the rtspClient object in another thread?</span></b><o:p></o:p></p></div></div></blockquote><div><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p></div><p class=MsoNormal style='margin-left:.5in'>Once again, NO! "RTSPClient" objects - like all subclasses of class "Medium" - update shared data structures (stored within the "UsageEnvironment" object) when they are constructed. A single "UsageEnvironment" object MUST NOT be accessed from multiple threads (except that the "triggerEvent()" member function may be called from a non-LIVE555-event-loop thread).<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><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'>Got it. I'm happy that I asked...<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'>For a class that's created outside of liveMedia, it still seem safe to store temporary variables even though they can be accessed via the rtspClient object. I'm thinking of StreamClientState (as used in the testRTSPClient example). It is only part of OurRTSPClient, not RTSPClient. If I add a variable there that I know is only accessed in two places, it appears perfectly safe even if it will be written to from one thread and read from another.<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'>I can't think of any problems passing arguments that way. If anyone see any possible issue, please enlighten me what could potentially go wrong.<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:black'>In the example below, SeekAbsolute() will execute on a second thread, assigning scs.seekToAbsolutePosition, while SeekAbsoluteEvent() will be executed on the liveMedia thread reading the value.<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 style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>void</span><span style='font-size:11.0pt;font-family:"Courier New"'> SeekAbsolute(OurRTSPClient *rtspClient, <span style='color:blue'>char</span> *seekTo)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span> (rtspClient)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> <span style='color:green'>// Pass on the argument.<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> StreamClientState& scs = ((OurRTSPClient*)rtspClient)->scs;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> strcpy_s(scs.seekToAbsolutePosition, <span style='color:blue'>sizeof</span>(scs.seekToAbsolutePosition), seekTo);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> UsageEnvironment& env = rtspClient->envir();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> env.taskScheduler().triggerEvent(mySeekAbsoluteEvent, rtspClient);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New"'>}</span><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'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>void</span><span style='font-size:11.0pt;font-family:"Courier New"'> SeekAbsoluteEvent(OurRTSPClient *rtspClient)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> StreamClientState& scs = ((OurRTSPClient*)rtspClient)->scs;<span style='color:green'><o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Courier New"'> rtspClient->sendPlayCommand(*scs.session, continueAfterPLAY, *scs.seekToAbsolutePosition);<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New"'>}</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='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'>/Claes<o:p></o:p></span></p></div></div></body></html>