cache line

[ytgui]

array vs vector

false sharing

https://software.intel.com/en-us/articles/avoiding-and-identifying-false-sharing-among-threads

row major and slide window size

spinlock

https://zhuanlan.zhihu.com/p/133445693

MESI protocol

[ytgui]

Spinlock

struct spinlock {
        int locked;
};

void spin_lock(struct spinlock *lock)
{
    // test_and_set: set flag to `1` and return old value
    // if the func returns 0, flag 0->1, means get the lock
    while (atomic_test_and_set(&lock->locked));
}

void spin_lock(struct spinlock *lock)
{
    // `test_and_set` always write to cache line, which cause performance issue
    // read only op before write, reduce cache line flush
    while (!lock->locked && atomic_test_and_set(&lock->locked));
}

void spin_unlock(struct spinlock *lock)
{
    lock->locked = 0;
}