A reference to a variable (most of the time a global variable), used as a lock.
[Expression]
A MASM-like expression to evaluate which is the maximum waiting check for the spinlock to re-check the lock.
By default in spinlock_lock, the maximum waiting check is 65536.
Description
Locks the spinlock referred to by lock and also uses the maximum waiting check to re-check the lock. The lock can be unlocked by spinlock_unlock.
Return value
None
Examples
First of all, you should define a global variable and assign zero to it (unlocked state).
? .my_lock = 0;
Then, you can use it like this:
spinlock_lock_custom_wait(&.my_lock, 500);
The above example locks the spinlock of a global variable (lock) which is called .my_lock. It uses 500 as the maximum waiting check. Note that you should use the unary operator & to pass a reference of the global variable to this function.
Remarks
If your lock needs to be checked more frequently, you should specify a lower value as the second argument. However, it's not a power-efficient approach, but it gives you a more real-time spinlock. If you give a number higher than 65536, it takes longer to re-check the lock by the processor.
It's actually the number of times which the PAUSE instruction is executed.
