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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The reason behind the second one is security – which is
even tighter on Vista. You can no longer do a SendMessage to a process running
at a higher security level, and for that matter from a interactive program to a
service – all due to security restrictions that have been added in recent
years by M$ to stop viruses etc. E.g In Vista you can no longer allow a service
to interact with the desktop.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Things need to be running on the same window station (which is
the root of all security in windows). If you have processes running on
different window stations (which applies to services etc), then you will have
security issues.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Myles.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> delphi-bounces@delphi.org.nz
[mailto:delphi-bounces@delphi.org.nz] <b>On Behalf Of </b>Leigh Wanstead<br>
<b>Sent:</b> Tuesday, 8 May 2007 11:18<br>
<b>To:</b> NZ Borland Developers Group - Delphi List<br>
<b>Subject:</b> RE: [DUG] Sending data between process on same computer on
windows<o:p></o:p></span></p>
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</div>
<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Hi Conor,</span><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
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<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Thanks</span><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Regards</span><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Leigh</span><o:p></o:p></p>
</div>
<blockquote style='margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'>-----Original Message-----<br>
<b>From:</b> delphi-bounces@delphi.org.nz [mailto:delphi-bounces@delphi.org.nz]<b>On
Behalf Of </b>Conor Boyd<br>
<b>Sent:</b> Tuesday, 8 May 2007 11:04 a.m.<br>
<b>To:</b> NZ Borland Developers Group - Delphi List<br>
<b>Subject:</b> RE: [DUG] Sending data between process on same computer on
windows</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>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.</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>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."</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>C.</span><o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<div class=MsoNormal align=center style='text-align:center'><span lang=EN-US>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> delphi-bounces@delphi.org.nz
[mailto:delphi-bounces@delphi.org.nz] <b>On Behalf Of </b>Leigh Wanstead<br>
</span><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>May I ask why sendmessage is not reliable? In what situation will
cause sendmessage fail to break the communication?</span><span lang=EN-US><o:p></o:p></span></p>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>-----Original
Message-----<br>
<b>From:</b> delphi-bounces@delphi.org.nz [mailto:delphi-bounces@delphi.org.nz]<b>On
Behalf Of </b>Myles Penlington</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The devil is in the detail in this kind of stuff, and your
actual implementation can have a great effect.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>As implied, the best method will be to develop 2 or 3 different
methods, test and compare the results.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> delphi-bounces@delphi.org.nz
[mailto:delphi-bounces@delphi.org.nz] <b>On Behalf Of </b>Conor Boyd</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Sorry Leigh, I haven't done enough testing with big volume messages
to be able to answer that for you.</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>I was more interested in something that worked and was reliable.</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Cheers,</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Conor</span><o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<div class=MsoNormal align=center style='text-align:center'><span lang=EN-US>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> delphi-bounces@delphi.org.nz
[mailto:delphi-bounces@delphi.org.nz] <b>On Behalf Of </b>Leigh Wanstead<br>
</span><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>May I ask which is faster, ipc or sendmessage?</span><span
lang=EN-US><o:p></o:p></span></p>
<blockquote style='margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>-----Original
Message-----<br>
<b>From:</b> delphi-bounces@delphi.org.nz [mailto:delphi-bounces@delphi.org.nz]<b>On
Behalf Of </b>Conor Boyd<br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>I found the IPC functionality from madshi.net (</span><span
style='font-size:10.0pt'><a href="http://help.madshi.net/IPC.htm"><span
style='font-family:"Arial","sans-serif"'>http://help.madshi.net/IPC.htm</span></a></span><span
style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>) to work
very nicely.</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>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.</span><o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<div class=MsoNormal align=center style='text-align:center'><span lang=EN-US>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> delphi-bounces@delphi.org.nz
[mailto:delphi-bounces@delphi.org.nz] <b>On Behalf Of </b>Leigh Wanstead<br>
</span><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Arial","sans-serif"'>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?</span><span
style='font-size:7.5pt;font-family:"Verdana","sans-serif"'><o:p></o:p></span></p>
</blockquote>
</blockquote>
</blockquote>
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