When and Why Should You Use the `volatile` Keyword?

Why Use the Volatile Keyword?

The volatile keyword in programming signifies that a variable can change unpredictably from outside the scope of the current program. This prompts the compiler to refrain from optimizing the code related to that variable, ensuring that its value is always accurately retrieved.

Imagine the following code:

int some_int = 100;

while(some_int == 100)
{
   // your code
}

Typically, the compiler would optimize this loop by replacing it with "while(true)" since the condition "some_int == 100" always evaluates to true. However, this optimization can cause issues if "some_int" is being modified outside of the program, for instance, by another thread or an external process.

To prevent this optimization and ensure that the loop accurately checks the value of "some_int," you can use the volatile keyword:

volatile int some_int = 100;

This tells the compiler that "some_int" can be modified unexpectedly, preventing it from making incorrect assumptions and ensuring that the loop continues to execute as intended.

In essence, the volatile keyword warns the compiler that the variable in question is susceptible to unforeseen changes. It requests the compiler to avoid optimizations that might lead to incorrect results, ensuring that the program accurately accounts for potential external modifications.

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