[Bug]: Jaeger agent gets stuck when closing with SocketBufferSize set

[ChenX1993]

What happened?

Problem

With SocketBufferSize set in config, the jaeger-agent gets stuck when closing.

jaeger/cmd/agent/app/builder.go

Line 90 in 5c3c20d

SocketBufferSize int `yaml:"socketBufferSize"`

Root cause

This is because Close()of net.UDPConn will be blocked if Fd() is used to get the file descriptor.

The place to set the SocketBufferSize in jaeger-agent is below :

jaeger/cmd/agent/app/servers/thriftudp/socket_buffer.go

Lines 25 to 32 in 5c3c20d

	func setSocketBuffer(conn *net.UDPConn, bufferSize int) error {
	file, err := conn.File()
	if err != nil {
	return err
	}
	return syscall.SetsockoptInt(int(file.Fd()), syscall.SOL_SOCKET, syscall.SO_RCVBUF, bufferSize)
	}

And the implementation of Fd():

func (f *File) Fd() uintptr {
	if f == nil {
		return ^(uintptr(0))
	}

	// If we put the file descriptor into nonblocking mode,
	// then set it to blocking mode before we return it,
	// because historically we have always returned a descriptor
	// opened in blocking mode. The File will continue to work,
	// but any blocking operation will tie up a thread.
	if f.nonblock {
		f.pfd.SetBlocking()
	}

	return uintptr(f.pfd.Sysfd)
}

The exact same problem has been discussed here: golang/go#29277

Will create PR for fix.

Steps to reproduce

1. Set SocketBufferSize with any valid number
2. Run agent
3. Stop agent

This issue can also reproduce in unit test:
e25216c

Expected behavior

Jaeger agent can stop successfully.

Relevant log output

No response

Screenshot

No response

Additional context

No response

Jaeger backend version

latest

SDK

without sdk

Pipeline

No response

Stogage backend

No response

Operating system

Linux, Mac

Deployment model

No response

Deployment configs

No response