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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link=blue vlink=purple style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi All,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Recently I’m writing an Application with ESL in inbound mode. I have two issues:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo3'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>esl_recv_event()<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:-21.0pt;mso-list:l1 level2 lfo3'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>a)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>Each time I call this interface, handle->last_ievent will be updated to be the oldest event. Just like de-queue the oldest event from FIFO.<o:p></o:p></span></p><p class=MsoNormal style='margin-left:42.0pt'><span lang=EN-US>My assumption is right or not?<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:-21.0pt;mso-list:l1 level2 lfo3'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>b)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>After call this interface, may I access “handle->last_ievent” without any protection( without mutex/lock)?<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US>If there is any risk of handle->last_ievent is updated during my access, for example some other interfaces are called or new events are received from FS side.<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US>Per my experience, seems has such risk.<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US><o:p> </o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo3'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>esl_execute()<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'><span lang=EN-US><o:p> </o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'><span lang=EN-US>When I read the implementation of the code, is there any possibility to dead lock as following?<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US>esl_execute()<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US> +-->esl_send_recv /esl_send_recv_timed(_handle, _cmd, 0)<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US> +--> esl_mutex_lock(handle->mutex); <<<<< lock for 1<sup>st</sup> time<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US> +--> esl_recv_event_timed(handle, ms, 0, &handle ->last_sr_event)<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US> +--> esl_recv_event()<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US> +----> esl_mutex_lock(handle->mutex); <<<<<< lock for 2<sup>nd</sup> time, but preview one is not unlock<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> Can anyone confirm this?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>BR<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Leon<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US><o:p> </o:p></span></p></div></body></html>