DtaWin server exceptions

[robert]

Wolfgang

What I'm interested in: how the code recover block in the begin/end sequence block is translated by the compiler.

We use a similar approach as Vulcan:

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BEGIN SEQUENCE ... RECOVER [USING varname]... END SEQUENCE

is translated to 2 try blocks

The outer block is a

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try .. catch

inside the catch we check to see if the exception ex was a 'WrappedException' which happens when you call BREAK in your code with a value.
If it is a normal Exception (from the framework) then we create a new WrappedException.
We then extract the value from this WrappedException and assign it to the variable in the RECOVER statement
the try block in this try catch contains the inner try statement

The inner try statement is a Try .. FInally where we call

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CompilerServices.EnterBeginSequence()

in the try and

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CompilerServices.ExitBeginSequence()

in the finally.
The rest of this try block is the original code inside the BEGIN SEQUENCE
These 2 helper methods are called so the runtime function _CanBreak() knows that we are in a BEGIN SEQUENCE.. END. Inside the compilerServices class we keep track of the "BreakLevel" for the current thread.

The BREAK <value> statement is translated to a call to

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throw WrappedException{<value>}

We have used similar names as in Vulcan. Why invent the wheel again ?

Robert

[wriedmann]

Hi Robert,

thank you very much for this clarification!

I will add that to the wiki, together with other informations, and then ask you if I have written it correctly.

Wolfgang

[Karl-Heinz]

Guys,

who takes care of the German.resx ?

i suggest to change the "ERROR_STACK" value from "Gerufen von" to "Aufrufreihenfolge". ?

Any better suggestion ?


regards
Karl-Heinz