Announcement

Edwin Knoppert · 6 May 2008, 03:31 PM

ASP seems obsolete to me, unless you meant ASP.NET?

If you don't do both ISAPI can be great since you will be able to manage all content as desired.
And of course with PowerBASIC

ISAPI this way will be light-weight, ASP.NET is also a learning curve but you won't need to invent the basic functionality.

If there wasn't ASP.NET and i was forced to write html stuff, ISAPI would be my choice i guess.
Forget CGI..

Shawn Anderson · 9 May 2008, 11:44 PM

I heard ASP (not .net) will no longer be supported in an upcoming version of IIS.

I use CGI a lot (I wouldn't use anything else) and I'm wondering if it's some other issue causing your slowdown, like the database itself or perhaps a permissions problem in IIS. There is no shortage of work with CGI and AJAX.

Mike Doty · 10 May 2008, 01:46 AM

I'm using fastcgi. Cgi is fine, but was looking for some more speed.

jeroen brouwers · 20 May 2008, 05:20 AM

I've learned ISAPI many years ago and it's great: go get rid of an extra layer (an asp or asp.net page) which handles the incoming requests of users and puts it throught to your application. Thus, all libraries which are loaded to support asp(.net) are not activate. Hence, you gain tremendous speed!

imo, CGI is fine but loads an exe upon each request which can overload your server when it gets busy. Eg, it's not multithreaded.

Which bring me to the downside: ISAPI is multithreaded and you have yo manage the threads and be carefull with global memory. It's a bit more work this way but for me, the amount of control you get and the speed improvements are well worth it.

Check out the ISAPI template. that'll get you started.

Regards
Jeroen

Mike Doty · 20 May 2008, 09:00 AM

I'll search again for ISAPI and see if I can find that template.
Found postings where people gave up after many years.
Fastcgi is easy, but I'll look again.
Any link would be appreciated.

jeroen brouwers · 31 May 2008, 06:23 AM

Hi Mike, just checked the forum... bit late. You will get a lot of problems on the forum but of course, that's what it's for, no?

To get you started (I couldn't find nice links right away) as Don, Eric and others have done for me: http://www.powerbasic.com/support/pb...ad.php?t=22882

Search for Don, since he contributed quite some good internet stuff.

I made my own variation on details which might help:

Code:

 
' get incoming
    RequestMethode = LCASE$(TRIM$([email protected]))
    SELECT CASE RequestMethode
        CASE "get"
            QueryString = TRIM$([email protected])
        CASE "post"
            QueryString = TRIM$(isapiPostData(ECB))
        CASE ELSE
            txtOutput = $ERROR_QUERYSTRING_ANSWER
            GOTO SendOutput
    END SELECT

Remember though, you're in multithreaded mode, so be carefull with global, files IO and the like. You need to use CriticalSection (or another serialization mechanisme; CS is the simple light weight variant) for all things that are shared between threads in the same process. A simple set-up I use for all kinds of stuff that needs to be serialized, is in the code below:

Code:

    CSEntered& = 0
    TGP& = 0
    
    DO WHILE NOT %TRUE = %FAlse

        IF TryEnterCriticalSection( GSC1 ) > 0 THEN
            CSEntered& = 1

            ' do serialized stuff here
            LeaveCriticalSection GSC1
            CSEntered& = 0
            EXIT DO
        ELSE
            ' prevent endless loop
            INCR TGP&
            IF TGP& = 500 THEN FUNCTION = -1: EXIT FUNCTION
        END IF
    LOOP

    EXIT FUNCTION
ErrHandle:
    IF CSEntered& = 1 THEN LeaveCriticalSection GSC1

<hr>
Logging: debugging is a bit harder since it's a dll in memory if iis (or another webservice). Good tip I got: use the event log! Stress testing in IIS and logging to harddisk do not go well together (or at least it takes time to create a decent multithreaded-proof logging function.

search for parts of this:

Code:

    lLogAPIRetVal = RegisterEventSource(BYVAL %NULL, BYCOPY $EVENTLOG_APP_NAME)

    IF lLogAPIRetVal <> %NULL THEN
        lPointer = STRPTR(sMessage)

        lReturnX = ReportEvent(lLogAPIRetVal, hErrSeverity, 0, 255, BYVAL 0&, 1, 0&, BYCOPY lPointer, BYVAL %NULL)
            ' all is mapped to 255: custom message!! (use hEventID for predefined messages)

        IF lReturnX = %NULL THEN
            lReturn = GetLastError()
        END IF

        DeregisterEventSource lLogAPIRetVal
    END IF

Since the ISAPI is in IIS, even the ProcessID is the same.

IIS
For IIS, keep in mind that there are application pools (from v5?) which can be tricky: each app pool is isolated, eg has it's own memory and handles. This means that your isapi is loaded once for each pool and there's no way to share memory or handles or what soever (I've tried).
So start with 1 Apppool, stress test that first, then upgrade to multiple and work your way through.

<hr>
One more: if you are going to use the isapi as an internet wrapper to your 'real' dll and you're going to use SQL Tools in this dll, remember this (it took me a while):

1) create a thread from the isapi to your dll (so, pass a ptr to a UDT to your underlying dll to pass the info). THe thread (of course) is created in your isapi on a function in the isapi, which in turn just calls your real dll entry function.

2) use the Libmain\process attach to handle all global / init stuff (like SQL_Init)
3) use SQL_THREAD %THREAD_Start at the entry function as one of the first things you do (or at least don't do sql stuff yet)
4) get your thread unique statement number(s) by keeping a global array (protected access from the thread can be archieved by the basic function above).
5) do you functions and try to keep variables local as much as possible.
6) use SQL_THREAD %THREAD_Stop at the entry function as the last thing you do.

Good thing: since the thread are all in the same process, you can keep your databases connections opened (which saves a considerable amount of time).

Happy programming. I hope this helps a bit.

Regards
Jeroen

Mike Doty · 12 Jun 2008, 03:42 PM

The dd_isapi,inc file at
http://www.greatwebdivide.com/code_tcpip.htm
is not the same as the one on the PowerBASIC site.
The one on PowerBASIC compiles fine and has the GetCookies function.
Compiled to a DLL and called over the internet using the htm code below.
Get error 405 Method not allowed.
Using Abyss Web Server and DLL is the default extension.

Code:

<HTML>
<HEAD><title>ISAPI Test Page</title></HEAD>
<BODY>
<CENTER><H2>ISAPI Test Page</H2></CENTER><BR><HR>
<P>
This tests the POST method of the isapi interface. It tries to
call the function in istest32.dll. Currently, this dll must be
in the /docs directory if you're running the <A href="[URL]http://www.sambar.com[/URL]">
Sambar Server</A>. I can't seem to make it work if it's anywhere
else. I don't use IIS, so I don't know where the dll needs to bin
with that system. If you're using omnihttpd, the DLL goes in the httpd\ISAPI
directory. There is a configuration option to specify directories where ISAPI
dlls may be. I have tested this on Sambar and OmniHTTPd.
The dll was written in pb-dll6 and based on a sample from
Dave Navarro of Power Basic. 
<P>
<FORM method="POST" action="istest32.dll">
<PRE>
Company Name <INPUT type=text name=company>
Your Name    <INPUT type=text name=contact>
             <INPUT type=submit>
</PRE>
</FORM>
</BODY></HTML>

Knuth Konrad · 13 Jun 2008, 07:15 AM

Try a forum search for Lothar Pink. He has done a lot with ISAPI and has developed an ISAPI SDK for PB: http://www.powerbasic.com/support/fo...ML/001190.html

The download link doesn't work anymore. I've still got the download package on disk, send me a PM, if you'd like me to send you a copy.

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ISAPI instead of ASP?

ISAPI instead of ASP?

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