AK's weblog

Entries tagged as problem

Monday, February 5. 2007

Kennt wer dreckige Details zur pthread-Implementierung von OSX?

Folgendes Problem: newsbeuter, mein RSS-Feedreader, benützt zum Reloaden aller Feeds einen Thread, der im Hintergrund läuft, und dabei den Fortschritt im mit STFL gezeichneten UI updated. Unter Linux funktioniert das alles perfekt, lediglich unter OSX beobachte ich das absolut schräge Verhalten, dass der Thread nur weiterarbeitet, wenn ich im Vordergrund irgendwelche Sachen mache, wie z.B. mit dem Cursor in der Liste rauf- und runterscrollen, oder zufällige Tasten drücken. Das lässt ja schlimmes vermuten, deswegen die Frage, ob da wer Details kennt. Anyone?

Posted by Andreas Krennmair at 17:26 | Comments (0) | Trackbacks (0)

Defined tags for this entry: obscure, osx, problem, programming, pthread

Wednesday, June 7. 2006

Callbacks and derived classes in C++

I just created a pretty neat callback mechanism for C++:

template<typename T>
class callback {
public:
callback(T* obj, unsigned int (T::*func)(string, ostream&, header_container&, cgiparam_container& ))
: callee(obj), cb(func) { }
~callback();
unsigned int run(string actionstr, ostream& os, header_container& hdrs, cgiparam_container& params) {
return (callee->*cb)(actionstr,os,hdrs,params);
}
private:
T* callee;
unsigned int (T::*cb) (string,ostream&, header_container&, cgiparam_container& );
};
class context {
public:
context();
~context();
unsigned int dispatch_action(string actionstr, ostream& os, header_container& hdrs, cgiparam_container& cgiparams);
protected:
void register_action(string,callback<context>*);
private:
map<string,callback<context>*> actions;
};

The implementation of register_action() looks like this:

void context::register_action(string action, callback<context>* cb) {
actions[action] = cb;
}

And this is used in the following way (called from within the context class):

register_action("foobar",new callback<context>(this,&context::some_method));

Now, the problem that I have is that that adding callbacks that are not actually within the context class but within a derived class is only possible with lots of ugly casting (but it seems to work afterwards):

#define REGISTER_ACTION(name,action) do { register_action((name),new callback<context>((context*)this, (unsigned int (context::*)(std::string, std::ostream&, net::header_container&, net::cgiparam_container&))&action)); } while(0)

Do I see correctly that C++ seems to have certain problems with derived classes and templates, especially when it comes to using pointers to methods? Any input is welcome on how to remove this ugly casting while keeping the same functionality.

Posted by Andreas Krennmair at 21:06 | Comments (5) | Trackback (1)

Defined tags for this entry: c++, problem, programming

Saturday, October 8. 2005

Finding an embeddable OO scripting language

Currently, I'm searching for the right scripting language for which I would like to write my servlet container. The original idea was to use my beloved Ruby scripting language, as it contains all the features I need and like. For using it in my servlet container, I also need the possibility to embed more than just one VM instance, to keep the applications strictly separated. And as far as I was able to research, this isn't possible with Ruby.

And now I'm searching for some other object-oriented, embeddable scripting language that bears no arbitrary limit on the number of VM instances within a single process. AFAICS, Python isn't an option, either (nor are all the other hardly known scripting languages that I found), so I'm open for hints or recommendations. I'm willing to use any language that bears the above-mentioned attributes (as I was unable to find a language that matches all requirements).

Posted by Andreas Krennmair at 12:36 | Comments (2) | Trackbacks (0)

Defined tags for this entry: embeddable, object-oriented, problem, programming, python, ruby, scripting language

Sunday, September 25. 2005

Ich bin echt verzweifelt

Ich bin verzweifelt. Wegen meinem Abfluss in der Dusche. Seit ein paar Tagen ist der verstopft, das Wasser rinnt nur sehr langsam ab. 10 cm stehendes Wasser brauchen locker 15 Minuten, um abzufließen.

Zuerst hab ich probiert, das eventuell händisch freizukriegen, und ich konnte einiges an Haaren herausputzen, jedoch hat das nicht den erhofften Erfolg gebracht.

Als zweiten Schritt habe ich auf Empfehlung einen Abflussreiniger ("auf Enzymbasis") gekauft und angewandt, sogar zweimal, jedoch keine Veränderung. Um einen "harten", chemischen Abflussreiniger habe ich mich ebenfalls umgeschaut, jedoch nirgendwo einen zu kaufen gefunden.

Kann mir irgendjemand eine andere Moeglichkeit empfehlen, den Abfluss wieder freizukriegen? Wenn sich die Wanne schon innerhalb kuerzester Zeit duschen anfuellt, macht Duschen einfach keinen Spass mehr.

Posted by Andreas Krennmair at 17:35 | Comments (11) | Trackbacks (0)

Defined tags for this entry: problem, shower

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