[DUG] Sending data between process on same computer on windows

[Leigh Wanstead]

Hi Conor,

Thanks

Regards
Leigh
  -----Original Message-----
  From: delphi-bounces at delphi.org.nz [mailto:delphi-bounces at delphi.org.nz]On
Behalf Of Conor Boyd
  Sent: Tuesday, 8 May 2007 11:04 a.m.
  To: NZ Borland Developers Group - Delphi List
  Subject: RE: [DUG] Sending data between process on same computer on
windows


  I've already given you one scenario (although I admit it's not one that's
going to bother most people), and couldn't find any doco anywhere to
describe why Send/PostMessage failed in that instance.

  Another scenario was described on the page I linked to: "The easiest way
to do such IPC (inter process communication) is to use the message APIs like
FindWindow + PostMessage. Unfortunately messages may not work inside of non
interactive service/system processes in the NT family."

  C.



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  From: delphi-bounces at delphi.org.nz [mailto:delphi-bounces at delphi.org.nz]
On Behalf Of Leigh Wanstead

  May I ask why sendmessage is not reliable? In what situation will cause
sendmessage fail to break the communication?
    -----Original Message-----
    From: delphi-bounces at delphi.org.nz
[mailto:delphi-bounces at delphi.org.nz]On Behalf Of Myles Penlington



    The devil is in the detail in this kind of stuff, and your actual
implementation can have a great effect.

    As implied, the best method will be to develop 2 or 3 different methods,
test and compare the results.





    From: delphi-bounces at delphi.org.nz [mailto:delphi-bounces at delphi.org.nz]
On Behalf Of Conor Boyd




    Sorry Leigh, I haven't done enough testing with big volume messages to
be able to answer that for you.



    I was more interested in something that worked and was reliable.



    Cheers,



    Conor




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    From: delphi-bounces at delphi.org.nz [mailto:delphi-bounces at delphi.org.nz]
On Behalf Of Leigh Wanstead


    May I ask which is faster, ipc or sendmessage?

      -----Original Message-----
      From: delphi-bounces at delphi.org.nz
[mailto:delphi-bounces at delphi.org.nz]On Behalf Of Conor Boyd


      I found the IPC functionality from madshi.net
(http://help.madshi.net/IPC.htm) to work very nicely.



      I needed a way to send messages from a screensaver I was writing to
another process on the same box, and SendMessage didn't seem to work when a
screensaver was active (which I found strange, but anyway...), and the IPC
stuff from madshi works flawlessly.




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      From: delphi-bounces at delphi.org.nz
[mailto:delphi-bounces at delphi.org.nz] On Behalf Of Leigh Wanstead


      May I ask what is the fastest way to send data between process on same
computer on windows? I assume sendmessage api faster than semaphore waiting,
of course faster than TCP/IP which will go through huge amounts of tcp/ip
stack. I just want lowest overhead on per call. Anyone have any experiences
on that?
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