Lost Updates & Their Cure

The boilerplate declares a tiny work harness: ``c /* runs workers threads, each calling inc_n_times(count_target) per_thread times; joins them all; returns 0 if all joined ok. inc_n_times is YOURS to implement. */ int run_workers(int workers, int per_thread); /* the shared counter all workers increment */ extern long g_counter; /* the mutex protecting it — you must USE it in inc_n_times */ extern mtx_t g_counter_mtx; void inc_n_times(int n); /* increments g_counter exactly n times */ `` Round 1 of the test runs your implementation with the mutex and expects the exact total. Round 2 (after you pass) reveals what happens without it — the harness runs the *reference buggy* counter to demonstrate the lost update.

Difficulty: intermediate