1 curl https request strace

[ddosoff]

Hello Alex,

I tried to do 1 curl requst to SSLApp from examples/HelloWorlds.js:

$ curl -k https://localhost:9001/

It seems something wrong in the event loop request handling logic:

1549719277.970468 accept4(20, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK) = 21
1549719277.970569 epoll_ctl(3, EPOLL_CTL_ADD, 21, {EPOLLIN, {u32=4294967295, u64=1791001362431}}) = 0
1549719277.970664 epoll_ctl(3, EPOLL_CTL_DEL, 21, 0x7fffac471a20) = 0
1549719277.970690 ioctl(21, FIONBIO, [1]) = 0
1549719277.970713 epoll_ctl(3, EPOLL_CTL_DEL, 21, 0x7fffac471a40) = -1 ENOENT (No such file or directory)
1549719277.970737 setsockopt(21, SOL_TCP, TCP_NODELAY, [1], 4) = 0
1549719277.970776 accept4(20, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
1549719277.970813 epoll_ctl(3, EPOLL_CTL_ADD, 21, {EPOLLIN, {u32=21, u64=563242011197461}}) = 0
1549719277.970837 epoll_pwait(3, [{EPOLLIN, {u32=21, u64=563242011197461}}], 1024, 950, NULL, 8) = 1
1549719277.975440 recvfrom(21, "\26\3\1\0\317\1\0\0\313\3\3X\2776\256\234\356\22d\377t)\t9\\\352\216\3E\353Q\16"..., 524288, 0, NULL, NULL) = 212
...

After accept4 file descriptor 21 we do EPOLL_CTL_ADD then EPOLL_CTL_DEL twice, then accept4 again.

Please correct this behavior, this is not only waste of time. Some bigger problem inside.

[ddosoff]

In the end double DEL too:

1549719277.977965 recvfrom(21, "\25\3\3\0\32\370\207{\"\320\34\225u\340\3622\2672\2105v\310\5\317\250\355%2;\325\277", 524288, 0, NULL, NULL) = 31
1549719277.978002 epoll_ctl(3, EPOLL_CTL_DEL, 21, 0x7fffac471a50) = 0
1549719277.978024 epoll_ctl(3, EPOLL_CTL_DEL, 21, 0x7fffac471a50) = -1 ENOENT (No such file or directory)
1549719277.978046 close(21)             = 0

[ghost]

Maybe you shouldn't be so assertive about low level behavior when you're basically just guessing. This behavior is polling based, isolated to one single small file - and only affects libuv. So, let's debug and see if this is libuv behavior? Hmmmm... yes! It is. Closing this report as invalid. Two strikes now, do more research before yelling at everything you see.

[ddosoff]

Why uWebSockets.js use libuv?

[rnbrady]

@ddosoff may I ask which command you used to obtain such logs?

[ghost]

Strace