Subj : Serial port query
To   : Vitus Jensen
From : Darin McBride
Date : Sun Aug 06 2000 04:12 pm

Hello Vitus!

Replying to a message of Vitus Jensen to Darin McBride:

 DM>> I've been asked how to do something I'm at a loss as to where to
 DM>> start - if it's possible at all.  To quote the person asking me:

 DM>> Is there a way 1. to check the state of a port, 2. determine the
 DM>> application using it?

 DM>> By #1, I believe he means "determine if a comm port was in use".

 DM>> Any ideas whatsoever would be appreciated.  I believe #1 can be done
 DM>> by an attempt to open the port as a file in "DENY_ALL" mode - if it
 DM>> fails, someone is using it.  I don't believe #2 is possible.  If I
 DM>> could be corrected, that would be great.  :-)

 VJ> Get OS2UNDOC from hobbes and have a look at the DosQuerySysState API. 
 VJ> It will return infos about all open files of a single or all
 VJ> processes.  There are problems when using it at certain fixpak levels
 VJ> (older Warp 3 fixpaks).

Of course!  I forgot all about that.  I already use that call for a number of 
things, so one more is no biggie.  :-)  Unfortunately, I can't figure out how 
to trace back from the file to the process(es).  I've done some slight 
modifications to the sample programs given in the undoc INF file, and I get:

    name: D:\BBS\MAIL\ECHO\FIDONET\BACKBONE\OS2PROG.SQD
 opencnt: 1
 sfn: e0
 refcnt: 1
 flags: 0
 accmode: c2
 filesize: 62315
 volhnd: 264
 attrib: 20 [A-----]

Now, *I* know which process this is:

    PID: 1736
 PPID: 30
 type: 3
 state: 10
 session id: 36
 mod handle: 1be8 (D:\BBS\FLEET\FLTSTRT.EXE)
 # of threads: 4
[...]

I just can't tell how to get from one to the other.

 VJ> And Scott Garfinkle posted in C.O.O.P.Misc that it is now possible
 VJ> getting infos about all open semaphore handles as well.  Starting
 VJ> with FP 13 AFAIR (got the msg stored somewhere).

DQSS doesn't seem to get 32-bit sem handles yet... :-(  16-bit doesn't seem to 
be a problem.  (I recently installed FP14.)

Darin

---
 * Origin: Tanktalus' Tower BBS (1:250/102)

.