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Understand C11 Memory Ordering: relaxed, acquire, release, seq_cst

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2.0s Limit 256MB

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Implementation

Demonstrate understanding of C11 memory ordering with acquire-release synchronization.

Requirements:

Implement producer-consumer pattern using atomics
Use memory_order_release in producer
Use memory_order_acquire in consumer
Show correct synchronization (data ready before flag set)
Compare with memory_order_relaxed (buggy version)
Use C11 atomic.h or C++ std::atomic
Demonstrate happens-before relationship
Print synchronization states
Include proper thread creation with pthread
Show understanding of ordering guarantees

Why This Matters

The C11/C++11 memory model formalized what Linux's own memory-barrier documentation (Documentation/memory-barriers.txt) had been explaining informally for years, and Linux's RCU and seqlock primitives depend on precisely this acquire/release reasoning to publish data safely across CPUs without a lock. Getting it wrong is invisible on x86 in testing but produces real, hard-to-reproduce corruption on ARM's weaker memory model, which is why ThreadSanitizer exists.

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