SEM_DESTROY(3) | Library Functions Manual | SEM_DESTROY(3)

# NAME

`sem_destroy` — destroy an unnamed semaphore

# SYNOPSIS

POSIX Threads Library (libpthread, -lpthread)
`#include <semaphore.h>`

int
`sem_destroy`(sem_t *sem);

# DESCRIPTION

The `sem_destroy`() function destroys the unnamed semaphore pointed to by sem. After a successful call to `sem_destroy`(), sem is unusable until re-initialized by another call to sem_init(3).

# RETURN VALUES

The `sem_destroy`() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

# ERRORS

`sem_destroy`() will fail if:

[`EINVAL`]
  sem points to an invalid semaphore.
[`EBUSY`]
  There are currently threads blocked on the semaphore that sem points to.

# SEE ALSO

sem_getvalue(3), sem_init(3), sem_open(3), sem_post(3), sem_wait(3)

# STANDARDS

`sem_destroy`() conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).

POSIX does not define the behavior of `sem_destroy`() if called while there are threads blocked on sem, but this implementation is guaranteed to return -1 and set errno to `EBUSY` if there are threads blocked on sem.

June 7, 2025 | Debian