On Friday, November 25, 2016 at 4:12:54 PM UTC+8, Gaurav Halwasia wrote: > > I have a scenario where i have a libuv event loop and at some point of > time in my application (C application), i start the timer > > uv_timer_init(&link->loop, timer); > uv_timer_start(timer, modbus_ctl_periodic_monitor, 0, 1000); > > But i see that there are times when this timer goes off periodically > correctly from the beginning and repeats thereafter. But i see that some > times, it takes few seconds (20 to 40 seconds in my case) for the timer to > get fired first time and then it repeats correctly thereafter. > > I am not able to understand/debug why this initial delay is there > (sometimes) > > During the time when this initial delay is there i see that uv_run is > stuck as can be seen below. > #0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38 > #1 0x000000000041a78a in uv.epoll_wait () > #2 0x0000000000418ddc in uv.io_poll () > #3 0x0000000000410030 in uv_run () > #4 0x00007ffff70b6802 in dslink_handshake_handle_ws () from > /home/ghalwasi/work/iox-services/c-mlib/deps/libs/libsdk_dslink_c.so > #5 0x00007ffff70b25db in dslink_init () from > /home/ghalwasi/work/iox-services/c-mlib/deps/libs/libsdk_dslink_c.so > > > When starts working, i see that uv_run has called uv_run_timers. > (gdb) bt > #0 0x00007ffff6ba3c53 in select () at > ../sysdeps/unix/syscall-template.S:81 > #1 0x00007ffff6e7daf5 in _connect (sockfd=29, > addr=addr@entry=0x7ffff3754bd0, addrlen=addrlen@entry=16, > ro_tv=ro_tv@entry=0x7fffdc0079e0) at modbus-tcp.c:284 > #2 0x00007ffff6e7dbcc in _modbus_tcp_connect (ctx=0x7fffdc0079d0) at > modbus-tcp.c:344 > #3 0x000000000040ca63 in mb_master_connect (mb_ctl=0x7fffc800d190) at > modbus_master.c:67 > #4 0x000000000040b868 in modbus_read_snapshot (mb_ctl=0x7fffc800d190) at > modbus_ctrl.c:523 > #5 0x000000000040bac4 in modbus_ctl_periodic_monitor > (timer=0x7fffc8010690) at modbus_ctrl.c:569 > #6 0x00000000004170ae in uv.run_timers () > #7 0x000000000040ff9a in uv_run () > #8 0x00007ffff70b6802 in dslink_handshake_handle_ws () from > /home/ghalwasi/work/iox-services/c-mlib/deps/libs/libsdk_dslink_c.so > > > Can someone shed more light on this and help me resolve this issue.. >
Did you do some slow work in the uv thread ? does function `modbus_ctl_periodic_monitor` execute for a long time ? -- You received this message because you are subscribed to the Google Groups "libuv" group. To unsubscribe from this group and stop receiving emails from it, send an email to libuv+unsubscr...@googlegroups.com. To post to this group, send email to libuv@googlegroups.com. Visit this group at https://groups.google.com/group/libuv. For more options, visit https://groups.google.com/d/optout.
