Race-Conditions

← Bank Account Drama | Series Overview | Login Counter → The Problem: Selling Tickets That Don’t Exist A concert has 1,000 tickets. Multiple goroutines handle sales concurrently. Each seller checks if tickets remain, and if yes, decrements the count and sells one. Sounds simple, right? Two sellers check simultaneously. Both see “1 ticket remaining.” Both sell. You’ve just sold ticket number -1. Congratulations, you’ve discovered the check-then-act race condition, one of the most common concurrency bugs in the wild. ...

← Login Counter | Series Overview | Ticket Seller → The Problem: Money Vanishing Into Thin Air Two people share a bank account with $100. Both check the balance at the same time, see $100, and both withdraw $100. The bank just lost $100. This isn’t a hypothetical-race conditions in financial systems have caused real monetary losses. The bank account drama illustrates the fundamental challenge of concurrent programming: read-modify-write operations are not atomic. What seems like a simple operation actually involves multiple steps, and when multiple goroutines execute these steps concurrently, chaos ensues. ...

Go Concurrency Patterns Series: ← Context Propagation | Series Overview | Graceful Shutdown → What is the Go Memory Model? The Go Memory Model specifies the conditions under which reads of a variable in one goroutine can be guaranteed to observe values produced by writes to the same variable in a different goroutine. Understanding this model is crucial for writing correct concurrent code without data races. Core Concepts: Happens-Before: Ordering guarantees between memory operations Memory Visibility: When writes in one goroutine are visible to reads in another Synchronization: Mechanisms that establish happens-before relationships Data Races: Concurrent memory accesses without proper synchronization Real-World Impact Correctness: Prevent subtle bugs in concurrent code Performance: Understand when synchronization is necessary Debugging: Diagnose race conditions and memory visibility issues Optimization: Make informed decisions about lock-free algorithms Code Review: Identify potential concurrency bugs The Happens-Before Relationship Definition A happens-before relationship guarantees that one event occurs before another in program order, and that effects of the first event are visible to the second. ...