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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 style='color:#1F497D'>I¡¯ll answer this myself:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>When esl_mutex_t is created in esl_mutex_create(), attribution ¡°PTHREAD_MUTEX_RECERSIVE¡± is set. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>This attribution allows mutex is locked for several times without unlock in the same thread.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>So there is no dead lock issue for esl_execute()<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>But I still meet another dead lock between main thread (sending ESL cmd) and ESL event process thread, is there any constrain for esl interface usages in *INBOUND* mode under multi-thread?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>>>>>>>>>><o:p> </o:p></span></p><p class=MsoNormal style='text-indent:15.75pt'><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=MsoListParagraph style='margin-left:42.0pt;text-indent:0cm'><span lang=EN-US><o:p> </o:p></span></p></div></body></html>