Server crash after client calls QtTcpSocket::disconnectFromHost();

SGaist

Hi and welcome to devnet,

What are you using of the server ?

Please provide the stack trace of your crash.

Vadru

I'm new to linux and I dont know how can I get the stack trace?

The server is running on a RaspberryPI.
The RaspberryPI is controlling my boiler and gathering some information like temperature, etc.
And the server is sending that information to the client so I can watch my boiler on my pc even when I'm not home.

SGaist

Use gdb to run your application.

Vadru

This is the stack trace:

Thread 5 "test" received signal SIGPIPE, Broken pipe.
[Switching to Thread 0xb4fff450 (LWP 7463)]
__GI___libc_write (nbytes=52, buf=0xb50008a0, fd=5)
    at ../sysdeps/unix/sysv/linux/write.c:26
26      ../sysdeps/unix/sysv/linux/write.c: No such file or directory.

Vadru

__libc_write (int fd, const void *buf, size_t nbytes)
{
  return SYSCALL_CANCEL (write, fd, buf, nbytes); <- this is that line of code
}

SGaist

Are you using a QTcpServer ?

SGaist

If not, are you handling that signal ? See here for some suggestions related to that.

Vadru

Such a simple mistake I have not used TCP in such a long time that I forgot all about signals.
I was getting so frustrated trying to solve it for several hours.
Now it works, thank you so much!

Vadru

Just of curiosity, why does disconnectFromHost() sends a sigpipe but when I close application it does not send a sigpipe?

SGaist

Sorry, I currently don't know although I am also intrigued.