Volatile Keyword

• the volatile keyword indicates that a field might be modified by multiple threads that are executing at the same time
• the compiler, the runtime system, and even hardware may, by default, rearrange reads and writes to memory locations for performance reasons
  • Fields that are declared volatile are not subject to these optimizations
• Adding the volatile modifier ensures that all threads will observe volatile writes performed by any other thread in the order in which they were performed
  • There is no guarantee of a single total ordering of volatile writes as seen from all threads of execution

The volatile keyword can be applied to fields of these types:

• Reference types
• Pointer types (Note that although the pointer itself can be volatile, the object that it points to cannot. In other words, you cannot declare a "pointer to volatile")
• Simple types such as sbyte, byte, short, ushort, int, uint, char, float, and bool
• An enum type with one of the following base types: byte, sbyte, short, ushort, int, or uint
• Generic type parameters known to be reference types