For an example of how to use a Spin Lock, see How to: Use SpinWait and SpinLock.

Spin locks can be used for leaf-level locks where the object allocation implied by using a System.Threading.Monitor, in size or due to garbage collection pressure, is overly expensive. A spin lock can be useful in to avoid blocking; however, if you expect a significant amount of blocking, you should probably not use spin locks due to excessive spinning. Spinning can be beneficial when locks are fine-grained and large in number (for example, a lock per node in a linked list) and also when lock hold-times are always extremely short. In general, while holding a spin lock, one should avoid any of these actions:

• blocking,

• calling anything that itself may block,

• holding more than one spin lock at once,

• making dynamically dispatched calls (interface and virtuals),

• making statically dispatched calls into any code one doesn't own, or

• allocating memory.

System.Threading.SpinLock should only be used after you have been determined that doing so will improve an application's performance. It is also important to note that System.Threading.SpinLock is a value type, for performance reasons. For this reason, you must be very careful not to accidentally copy a System.Threading.SpinLock instance, as the two instances (the original and the copy) would then be completely independent of one another, which would likely lead to erroneous behavior of the application. If a System.Threading.SpinLock instance must be passed around, it should be passed by reference rather than by value.

Do not store System.Threading.SpinLock instances in readonly fields.