[Ace-users] Connection closing before the answer arrives to the client

[salvatore.gallo at gmail.com]

ACE VERSION: 5.6.2

CLIENT MACHINE and OPERATING SYSTEM: Windows 2003 Server + Java socket
SERVER MACHINE and OPERATING SYSTEM: Linux RedHat + ACE 5.6.2

AREA/CLASS/EXAMPLE AFFECTED: Multi-thread application with TCP/IP
Socket; Affected: ReadHander class

SYNOPSIS: The handle_close method closes the connection before the
client ( Java Socket ) receiving the answer from the server.

DESCRIPTION:
The client (Java socket) returns the message "connection refused". It
happens because, sometimes, the handle_close method closes the
connection before the client receives the message. N.B. These
applications send only one message, i.e.the client (Java) sends only a
query and the server (C++) sends only an answer; after the connection
is closed.
Is there a way to be sure that the client receives the message without
being necessary that the server receives an ack from the client?
Or is there a better way to delay the closing?

SAMPLE FIX/WORKAROUND:
A workaround is:
put an ACE_OS::sleep(0.3) in handle_close() method. So the client can
receive the message before the connection is closed.


   CODE:

ReadHandler::ReadHandler():ACE_Event_Handler(),mStream()
{
  ACE_TRACE(ACE_TEXT("ReadHandler::ReadHandlerHandler()"));
}

ReadHandler::~ReadHandler()
{
  ACE_TRACE(ACE_TEXT("ReadHandler::~ReadHandler()"));
  if(mStream.close()==-1)
    ACE_ERROR((LM_ERROR,ACE_TEXT("%N:%1 Failed to close socket. ")
                ACE_TEXT("(errno = %i: %m)\n"),errno));
}

ACE_SOCK_Stream& ReadHandler::getStream(void)
{
  ACE_TRACE(ACE_TEXT("ReadHandler::getStream(void)"));
  return mStream;
}

ACE_HANDLE ReadHandler::get_handle(void) const
{
  ACE_TRACE(ACE_TEXT("ReadHandler::get_handle(void)"));
  return mStream.get_handle();
}

int ReadHandler::handle_input(ACE_HANDLE)
{
  ACE_TRACE(ACE_TEXT("ReadHandler::get_handle(void)"));

  TPProtocolManager protocol;
  protocol.readQuery(mStream);

  protocol.sendReply(mStream);

  return -1;

}

int ReadHandler::handle_close(ACE_HANDLE,ACE_Reactor_Mask)
{
  ACE_OS::sleep(0.3); //WORKAROUND
  ACE_TRACE(ACE_TEXT("ReadHandler::handle_close"));
  delete this;
  return 0;
}