sem_destroy man page
sem_destroy — destroy an unnamed semaphore
#include <semaphore.h> int sem_destroy(sem_t *sem);
Link with -pthread.
sem_destroy() destroys the unnamed semaphore at the address pointed to by sem.
Only a semaphore that has been initialized by sem_init(3) should be destroyed using sem_destroy().
Destroying a semaphore that other processes or threads are currently blocked on (in sem_wait(3)) produces undefined behavior.
Using a semaphore that has been destroyed produces undefined results, until the semaphore has been reinitialized using sem_init(3).
sem_destroy() returns 0 on success; on error, -1 is returned, and errno is set to indicate the error.
sem is not a valid semaphore.
For an explanation of the terms used in this section, see attributes(7).
An unnamed semaphore should be destroyed with sem_destroy() before the memory in which it is located is deallocated. Failure to do this can result in resource leaks on some implementations.
sem_init(3), sem_post(3), sem_wait(3), sem_overview(7)
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