Semaphore Implementation in TRON, QNX, BeOS and NuttX

sem-compare.txt

Let's Write Scientific Article About Comparison of Semaphore Implementation in different Real-Time OS: TRON, QNX, BeOS, NuttX:

Our Intention is to buils refined API on all thoese API to achieve best real-time performance and idiomatic implementation.
Could you propose your version of Real-Time Semaphore implementation that is far better in terms of provability
of correcntess (simplicity) and performance?

BeOS:

status_t acquire_sem(sem_id sem);
status_t acquire_sem_etc(sem_id sem, uint32 count, uint32 flags, bigtime_t timeout);
sem_id create_sem(uint32 thread_count, const char * name);
status_t delete_sem(sem_id sem);
status_t get_sem_count(sem_id sem, int32* thread_count);
status_t get_sem_info(sem_id sem, sem_info* info);
status_t get_next_sem_info(team_id team, uint32* cookie, sem_info* info);
status_t release_sem(sem_id sem);
status_t release_sem_etc(sem_id sem, int32 count, uint32 flags);
status_t set_sem_owner(sem_id sem, team_id team);

typedef struct sem_info {
    sem_id    sem;
    team_id   team;
    char      name[B_OS_NAME_LENGTH];
    int32     count;
    thread_id latest_holder;
}

NuttX:

int sem_init(sem_t *sem, int pshared, unsigned int value)
int sem_destroy(sem_t *sem)
sem_t *sem_open(const char *name, int oflag, ...)
int sem_close(sem_t *sem)
int sem_unlink(const char *name)
int sem_wait(sem_t *sem)
int sem_timedwait(sem_t *sem, const struct timespec *abstime)
int sem_trywait(sem_t *sem)
int sem_post(sem_t *sem)
int sem_getvalue(sem_t *sem, int *sval)
int sem_getprotocol(FAR const pthread_mutexattr_t *attr, FAR int *protocol)
int sem_setprotocol(FAR pthread_mutexattr_t *attr, int protocol)

TRON:

typedef struct semaphore_control_block {
	QUEUE	wait_queue;	/* Semaphore wait queue */
	ID	semid;		/* Semaphore ID */
	void	*exinf;		/* Extended information */
	ATR	sematr;		/* Semaphore attribute */
	INT	semcnt;		/* Semaphore current count value */
	INT	maxsem;		/* Semaphore maximum count value */
} SEMCB;

EXPORT ER knl_semaphore_initialize( void )
SYSCALL ID tk_cre_sem( CONST T_CSEM *pk_csem )
SYSCALL ER tk_del_sem( ID semid )
SYSCALL ER tk_sig_sem( ID semid, INT cnt )
LOCAL void sem_chg_pri( TCB *tcb, INT oldpri )
LOCAL void sem_rel_wai( TCB *tcb )
SYSCALL ER tk_wai_sem( ID semid, INT cnt, TMO tmout )
SYSCALL ER tk_ref_sem( ID semid, T_RSEM *pk_rsem )
EXPORT ER knl_semaphore_getname(ID id, UB **name)
SYSCALL INT td_lst_sem( ID list[], INT nent )
SYSCALL ER td_ref_sem( ID semid, TD_RSEM *pk_rsem )
SYSCALL INT td_sem_que( ID semid, ID list[], INT nent )