Volatile (computer programming)

Common card · No. 472279

In computer programming, a variable is said to be volatile if its value can be read or modified asynchronously by something other than the current thread of execution. The value of a volatile variable may spontaneously change for reasons such as: sharing values with other threads; sharing values with asynchronous signal handlers; accessing hardware devices via memory-mapped I/O (where messages from peripheral devices can be received and sent by reading from and writing to memory). Support for these use cases varies considerably among the programming languages that have the volatile keyword. Volatility can have implications regarding function calling conventions and how variables are stored, accessed and cached.

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