Re: flexfax: Re: fix for "Can not open document"

[Matthias.Apitz@SOFTCON.de]

Hong Kong Observatory wrote:
    
    Hi Matthias,
    
    I just download Hylafax V4.0pl1 into my IBM PowerPC running AIX 4.2 with
    gcc 2.7.2 and ghostscript 4.02.
    
    I compiled and installed the package without any problem (without your
    patch). But I cannot reproduce the 'Cannot open document file' problem.
    
    I issued the command : sendfax -n -d 1111 -d 2222 doc.ps
    and made the line 1111 busy. I found that the server did the  conversion
    ps2fax twice (once for each FAX). Therefore there is no "cannot open
    document file" problem. But I think this is another problem because
    the conversion is done once for each destination, this will waste a lot
    of CPU resource ! Do you think that I have made any mistake in my
    installation ?

No. The racing between faxq(1M) and faxsend(1M) (or call it a bug)
will not show up on each system nor in each situation. With the
unpatched code of v4.0pl1 it's just a gamble which part wins.
    
    Also from the 'syslog' file, I found an error from faxgetty every time
    before each dispatch :
    Faxgetty [12345]: ANSWER: Can not lock modem device.
    but the document was dispatched without errors. Does this imply any
    potential porblem ?

No. The faxsend(1M) plays with the modem to send the fax, the modem
answers with something like "OK" and both (faxsend(1M) and faxgetty(1M))
can "see" (with poll(2) or select(3C)) that the modem says something
in response to the AT-cmd (sent down by faxsend(1M)), but because
the faxsend(1M) has the lock for the device, faxgetty(1M) goes out
of the way stumbling about it with "Can not lock modem device"
and waits for the lock to be cleared. That's all.

	matthias