The problem is that all this reasoning is based on logic, and logic does not apply, as we are dealing with computers...
This morning I could again provoke hangs. I have modified the lowest-level I/O callback in XBoard to print something when it returns, to make sure I can exclude the possibility that it hangs in some high-level processing routine for the input:
Code: Select all
void
DoInputCallback(closure, source, xid)
caddr_t closure;
int *source;
XtInputId *xid;
{
InputSource *is = (InputSource *) closure;
int count;
int error;
char *p, *q;
if (is->lineByLine) {
count = read(is->fd, is->unused,
INPUT_SOURCE_BUF_SIZE - (is->unused - is->buf));
if (count <= 0) {
(is->func)(is, is->closure, is->buf, count, count ? errno : 0);
fprintf(debugFP, "bad read\n");
return;
}
is->unused += count;
p = is->buf;
while (p < is->unused) {
q = memchr(p, '\n', is->unused - p);
if (q == NULL) break;
q++;
(is->func)(is, is->closure, p, q - p, 0);
p = q;
}
q = is->buf;
while (p < is->unused) {
*q++ = *p++;
}
is->unused = q;
} else {
count = read(is->fd, is->buf, INPUT_SOURCE_BUF_SIZE);
if (count == -1)
error = errno;
else
error = 0;
(is->func)(is, is->closure, is->buf, count, error);
}
fprintf(debugFP, "successful read from %x\n", is); // ********** Added this *********
}
When the hang occurs, it seems communication to FICS is one way: I can type tell commands, they arrive at the opponent but are not echoed. Tells by the opponent do not arrive, neither am I informed if he resigns the hanging game, or quits FICS altogether,
The last part of the debug file is:
xboard.debug wrote:>ICS: e5h8\015\012
>ICS: kibitz !!! +0.79/9 (0.23 sec, 60637 nodes, 262 knps) PV=e5h8 g4h6 h8e5 h6f7 e5f6 e4e5 d6e5 a2a3 e7e6\015\012
nodes = 60637, 60637
move: e5h8
, parse: Bh8 (
)
AnimateMove: piece 24 slides from 4,4 to 7,7
successful read from 8344e90 // ***** This terminates read from the engine, responsible for move and kibitz to be sent to ICS
<ICS: \007\012\015<12> -------b ----p--- ---p---- --k---p- ---nPpN- p-BP-P-- K-----P- -------- W -1 0 0 0 0 4 19 FairyMax WBtester -1 1 0 10 11 6683 13762 49 B/e5-h8 (0:00.432) Bh8 1 1 0\012\015fics%
ics input 96, castling = -1 -1 -1 -1 -1 -1
wrap(count:1,width:80,line:8,len:1,*lp:7,src: \007
dest: \007
Parsing board: -------b ----p--- ---p---- --k---p- ---nPpN- p-BP-P-- K-----P- -------- W -1 0 0 0 0 4 19 FairyMax WBtester -1 1 0 10 11 6683 13762 49 B/e5-h8 (0:00.432) Bh8 1 1 0
load 8x8 board
parseboard 96, castling = -1 -1 -1 -1 -1 -1
accepted move Bh8 from ICS, parse it.
moveNum = 96
board = 0-8 x 8
move to parse: Bh8
Parser Qa1: yyleng=3, 24(-1,-1)-(7,7) = 0 ( )
Move parsed to 'Bh8 (0:00.432)'
nps: w=-1, b=-1
Display title 'FairyMax (10) vs. WBtester (11) {1 0}, gameInfo.variant = 0'
successful read from 8366ca8 // ***** This terminates read of board from ICS
<ICS: \012\015WBtester(U)(----)[19] kibitzes: !!! +0.74/7 (0.29 sec, 72146 nodes, 248 knps) \012\015\ PV=b3d4 d1c1 c8d7 e1d2 h1c1 d2c1 b7b5 c1d2\012\015(kibitzed to 1 player)\012\015fics%
ics input 96, castling = -1 -1 -1 -1 -1 -1
wrap(count:2,width:80,line:10,len:2,*lp:8,src: 1
dest: 1
successful read from 8366ca8 // ***** This terminates read of kibitz
>ICS: who\015\012
successful read from 8368cc8 // ***** This terminates read from console (where I typed who)
GameEnds(40, xboard exit, 2)
Interrupting first
502077 >first : force
502077 >first : ping 6
502077 >first : quit
As you can see, all processing of input from the various sources terminates succesfully. (I have written the comments behind it afterwards.) The ICS 'input source' has the address ending on ca8. Last activity there is when XBoard gets the kibitz line. XBoard processes it, and the call returns. At that point XBoard is ready and waiting for new input. That new input would be printed to the debug file before anything else is done. The opponent moved, but no new input appears in the log. There also is no response to the 'who' command I type on the console.
I think this is pretty strong evidence that the problem is not in XBoard.
This was without using timeseal, btw. The only way to get ironclad proof that the problem is not in XBoard or in any of the X-libraries it links to would be to use an -icshelper like timeseal and let that make the log. I don't know how to do that, however.
), preventing me to start new test games.
