Small steps towards a pipestream...
The current implementation of the LyXServer doesn't work well under Tru64
unix. The pipes are opened and closed continually because
LyXComm::read_ready() is called from the GUI callback routine on every cycle
until the pipe first receives some input.
Ie, with the patch below I get console output:
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
[snip...]
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: Receiving from fd 6
LyXComm: status:19, lsbuf:, cmd:LYXSRV:angus:hello
LyXServer: Received: 'LYXSRV:angus:hello'
LyXServer: Client: 'angus' Command: 'hello' Argument: ''
LyXServer: Greeting angus
LyXComm: Sending 'LYXSRV:angus:hello'
Thereafter, all behaves "normally". Ie, input to LyXComm::read_ready() is
received only when something is passed to the pipe.
Clearly, therefore, the real "problem" lies in the xforms routine
fl_add_io_callback(), or rather in fl_watch_io() that does the actual
polling. Jean-Marc has noted that pipes under Tru64 unix have slightly
different semantics to those under Linux. I guess that this is the net result.
Nonetheless, the following patch to LyXComm::read_ready() fixes the symptoms
(pipes opened and closed continually), makes the code clearer and certainly
does no harm. It does no more than move closeConnection(); openConnection();
inside the if-error block where it really belongs.
Ok to apply?
Angus
Index: lyxserver.C
===================================================================
RCS file: /usr/local/lyx/cvsroot/lyx-devel/src/lyxserver.C,v
retrieving revision 1.45
diff -u -p -r1.45 lyxserver.C
--- lyxserver.C 14 Aug 2002 21:22:29 -0000 1.45
+++ lyxserver.C 2 Sep 2002 13:55:23 -0000
@@ -290,23 +286,26 @@ void LyXComm::read_ready()
//\n or not \n?
}
}
+
if (rerrno == EAGAIN) {
- errno = 0;
- return;
- }
- if (rerrno != 0) {
+ break;
+
+ } else if (rerrno != 0) {
lyxerr << "LyXComm: " << strerror(rerrno) << endl;
if (!lsbuf.empty()) {
lyxerr << "LyXComm: truncated command: "
<< lsbuf << endl;
lsbuf.erase();
}
- break; // reset connection
+
+ // reset connection
+ closeConnection();
+ openConnection();
+ break;
}
}
- closeConnection();
- openConnection();
- errno= 0;
+
+ errno = 0;
}
