How Linux 3.6 Nearly Broke PostgreSQL(lwn.net)

    class Spinlock {
    private:
        bool state;
    public:
        Spinlock() { state = false; }
        void lock() {
            while(!__sync_bool_compare_and_swap(&state, false, true));
        }
        void unlock() {
            state = false;
            __sync_synchronize();
        }
    };
    
    class PthreadMutex {
    private:
        pthread_mutex_t mutex;
    public:
        PthreadMutex() {
            pthread_mutex_init(&mutex, NULL);
        }
        void lock() {
            pthread_mutex_lock(&mutex);
        }
        void unlock() {
            pthread_mutex_unlock(&mutex);
        }
        ~PthreadMutex() {
            pthread_mutex_destroy(&mutex);
        }
    };

    0,5944405
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    6,5727638
    7,5953505
    8,4567648
    9,5106300

    0,154817
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