✅ A race hazard (or race condition) is an issue in concurrent programming where the outcome of a program depends on the sequence or timing of uncontrollable events like thread execution. This usually occurs when two or more threads or processes try to access and modify shared resources without proper synchronization, leading to unpredictable results and potential bugs.

Imagine two threads, Thread A and Thread B, both trying to increment a shared counter variable. Without safeguards (like locks or other synchronization mechanisms), both threads could read the same initial value, increment it, and then write the same final value, which means one of the increments would effectively be lost. This type of hazard can lead to data corruption, incorrect results, or unexpected behavior.

🔥 To avoid race hazards in C#, the lock keyword and Semaphore are two powerful tools that help control access to shared resources, ensuring only one thread accesses critical code sections at a time.

𝐓𝐡𝐞 𝐥𝐨𝐜𝐤 𝐊𝐞𝐲𝐰𝐨𝐫𝐝
💡The lock keyword is used to create a mutual exclusion region, ensuring that only one thread enters a specific code section, preventing other threads from entering until the first has exited. It's simple to use and often the preferred option when handling thread synchronization in basic cases.

𝐒𝐞𝐦𝐚𝐩𝐡𝐨𝐫𝐞 𝐚𝐧𝐝 𝐒𝐞𝐦𝐚𝐩𝐡𝐨𝐫𝐞𝐒𝐥𝐢𝐦
💡Semaphore (and its more efficient sibling SemaphoreSlim) is more flexible than lock. While lock restricts access to a single thread, a Semaphore allows you to set a count, defining how many threads can access the resource simultaneously. This is especially useful for resource pools or when handling multiple tasks concurrently, but it can increase complexity.

🔗 If you'd like a deeper dive, check out this link:
How to avoid Race Hazards