Candy for programmers

This is my second weekend when both my little daughter and I are home all weekend sick. I’m so gracious to only be sick on weekends, which I’m sure my employer appreciates a lot :p

Either way, I got an itch when I checked out Herb’s Effective Concurrency Columns and “Know when to use an active object instead of a mutex” and I just had to upgrade my Active Object C++0x. I moved it to Qt code instead from C++0x since that’s what I’ve available at my current assignment. It turned out very nice. With some unit gtesting and with QWaitCondition I get my Active Object to wait/sleep until it has anything to process and not the silly yield/sleep x-time, then check if anything is in the queue, then if not sleep x-time again (iterative)” (that I used for my C++0x Active Object — but with a comment that it could easily be improved)

< edit: 2011-11-29 you can see the C++11, and Qt active objects here they are efficienly using waitcondition. You can also find a straight C++03 version but that uses currently the inefficient yield/sleep then poll message retrieval

Apart from the coding I’m looking forward to check out the Microsoft PFC2010 seminars. Especially Herb’s talk about lambdas 🙂 Yeah. That’s what the “Candy” in the subject referred to!

I’m also thinking about doing my own logger. We need one at my client but it’s pretty low priority but since it seems lika fun job I will do it open-source at home instead. I checked out a few nice loggers like Glog, Ezlogger and Log4C++ and felt them all lacking…

  • GLOG, nice API but horrible documentation. Almost all of the forum’s question is because it is not well documented, unless you want to read through all the source code — which is not so nice with all the macros in place.
  • EzLogger, previously unknown to me but seems to have nice functionalites when looking in forums.
  • Log4C++ (not so nice public API but just like GLOG it has in essence the functionality we want, I just don’t like the ugly calls)

All of them suffers however from one important criterion that makes them a no-go choice. None of them are asynchronous. It is unacceptable for my assignment to have the thread that puts out a log entry to also pay for the CPU time it takes to write that entry to file.
Most of them has lots-and-lots of features that we don’t need and with a horrible documentation of these features. All this, plus the lack of asynchronous calling makes me want to carve out my own.

Nice and easy syntax like GLOG
LOG(INFO) << "This is just a test of putting a value in the log entry: " << 100;

and with SWERR/Assert/Design-By-Contract mimimalistic functionality like
CHECK(some_expression) << "If this failed, we will "crash" with this message and our watchdog will make us rise again like the Phoenix";

So with a mimimalistic approach, using the nice and easy usage API above but with my Active-Qt-Object as backbone we get a very easy to use logger with asynchronous calling and easy to modify for others since it’s not cluttered with may-be-good functionality.


About kjellkod

Software Engineer by trade, (former?) Martial Artist and Champion by strong will and small skill... and a Swede by nationality :)
This entry was posted in C++, Software Engineering. Bookmark the permalink.

1 Response to Candy for programmers

  1. Pingback: G3log: Asynchronous logging the easy way | Kjellkod's Blog

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