EmptyCrate Software. Travel. Stuff.

I often mention books that I use as resources, but rarely websites. It seems, on average, that online C++ resources are lacking. However, there are a few that I have found that provide quite valuable insight.

colorgcc is an awesome little tool for colorizing the output of gcc and g++, making compiler errors and warnings much easier to spot.

It hasn't been updated since 1999, but it hardly seems to matter. It's written in perl and available on most (if not all) Linux distributions. In gentoo colorgcc is installed as a compiler front-end. This makes it trivially easy to use.

By default, all views and stored routines in MySQL run with the privileges of the definer, not the invoker. This is equivalent to the setuid bit in Unix.

In the case where you need to provide execute permissions to stored routines (via EXECUTE) to a read-only user, it is possible to inadvertantly give your read-only user the ability to modify data. If the user has access to a stored routine that modifies data, then the user will be able to modify data.

If you have dozens or hundreds of threads doing work they are probably producing some sort of output. I'm not referring to logger output, but to permanent storage, perhaps in a database. If you cannot store the data as quickly as you produce it, you will eventually run into problems. If you are just barely able to keep up with data storage then your scalability will be limited.

While debugging my massively multithreaded C++ application I would notice times where the application would seem to pause for a few moments. During one of these pauses I halted the application and attached to it with the debugger (GDB). From within GDB I listed (info threads), switched to (thread <num>) and looked at the stack (bt) of each thread running.

I saw something surprising and very telling. Nearly every single thread that was supposed to be performing work was actually blocked on a mutex inside of either malloc or free.

If your application does not scale as your threads increase, you should check the code to make sure there are no hidden mutexes limiting your concurrency.

Logging System