The Bounded Queue

Implement the bounded queue. The boilerplate declares: ``c #define QCAP 4 typedef struct { long items[QCAP]; size_t head, count; mtx_t m; cnd_t not_full, not_empty; } BQ; void bq_init(BQ *q); /* inits mutex + cnds */ void bq_destroy(BQ *q); /* push: blocks while full; 0 ok */ int bq_push(BQ *q, long v); /* pop: blocks while empty; 0 ok */ int bq_pop(BQ *q, long *out); size_t bq_count(BQ *q); /* call only when no workers run */ `` Producers/consumers will run against it in tests — the predicate re-check MUST be a while loop.

Difficulty: intermediate