Function sem_init 

pub unsafe extern "C" fn sem_init(
    sem: *mut sem_t,
    pshared: i32,
    value: u32,
) -> i32

sem_init() initializes the unnamed semaphore at the address pointed to by sem. The value argument specifies the initial value for the semaphore. If pshared is nonzero, then the semaphore is shared between processes (currently not supported).