Re: A simple unit test framework

James Kanze <>
8 May 2007 03:26:03 -0700
On May 7, 10:54 pm, Gianni Mariani <> wrote:

James Kanze wrote:

Gianni Mariani wrote:


Example ?

Bug #21334 in the std::string implementation in g++.

Not a bug in my opinion. See my other post for a unit test case that
finds the supposed bug in less than 25 milliseconds.

I'll try it. (I'm not 100% sure that there isn't a bug in your
code, however.)

Most of the problems in DCL.

They are surprisingly easy to find too.

Really. Consider the following implementation of DCL:

    pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER ;
    pthread_mutex_t mutex2 = PTHREAD_MUTEX_INITIALIZER ;
    Singleton* theOneAndOnly = NULL ;

    static Singleton*
        if ( theOneAndOnly == NULL ) {
            Locker lock( mutex1 ) ;
            if ( theOneAndOnly == NULL ) {
                Singleton* tmp ;
                    Locker lock2( mutex2 ) ;
                    tmp = new Singleton ;
                theOneAndOnly = tmp ;
        return theOneAndOnly ;

It doesn't work, but can you write a test which will reveal the
error? (For starters, you certainly cannot on most Intel 32
bits processors, because they do guarantee that it works, even
if it violates Posix, and fails in practice on some other

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