Kernel API

Kernel API interface is intended to be used in trusted code (drivers, filesystem implementation, etc.) whereas user interface is for user application which will be load at runtime.

Scheduler

• void schedule_yield(void)

Thread

User interface:

• int pthread_create(pthread_t *thread, void (*start_routine)(void *), void *arg, unsigned int priority)
• int pthread_join(pthread_t *thread, void **retval)

Kernel interface:

• struct thread *thread_create(void (*func)(void), void *arg, unsigned int priority)
• struct thread *add_thread(void (*func)(void), void *arg, unsigned int priority, int privileged)
• int thread_join(struct thread *t)

Mutex

Kernel interface:

Mutex should NOT be used from interrupt handler

• int kmutex_init(struct mutex *mutex)
• int kmutex_lock(struct mutex *mutex)
• int kmutex_unlock(struct mutex *mutex)

User interface:

• int pthread_mutex_init(pthread_mutex_t *mutex)
• int pthread_mutex_lock(pthread_mutex_t *mutex)
• int pthread_mutex_unlock(pthread_mutex_t *mutex)

Semaphore

Kernel interface:

• int ksem_init(struct semaphore *sem, int value)
• int ksem_wait(struct semaphore *sem)
• int ksem_post(struct semaphore *sem)
• int ksem_post_isr(struct semaphore *sem)

User interface:

• void sem_init(sem_t *sem, unsigned int value)
• void sem_wait(sem_t *sem)
• void sem_post(sem_t *sem)

Queue

Kernel interface:

• int kqueue_init(struct queue *queue, unsigned int size, unsigned int item_size)
• int kqueue_clear(struct queue *queue)
• int kqueue_destroy(struct queue *queue)
• int kqueue_update(struct queue *queue, unsigned int size, unsigned int item_size)
• int kqueue_post(struct queue *queue, void *item, unsigned int timeout)
• int kqueue_receive(struct queue *queue, void *item, unsigned int timeout)

User interface:

• mqd_t mq_open(const char *name, int flags, ...)
• int mq_close(mqd_t fd)
• int mq_getattr(mqd_t fd, struct mq_attr *attr)
• int mq_setattr(mqd_t fd, const struct mq_attr *attr, struct mq_attr *oldattr)
• int mq_receive(mqd_t fd, char *msg, size_t msg_len, unsigned int msg_prio)
• int mq_send(mqd_t fd, const char *msg, size_t msg_len, unsigned int msg_prio)

Wait queue

Wait queue are generic objects used by mutex and semaphore to implement waiting mechanism

Kernel interface:

• int wait_queue_block_irqstate(struct wait_queue *wait, unsigned long *irqstate)
• int wait_queue_block(struct wait_queue *wait)
• int wait_queue_wake_irqstate(struct wait_queue *wait, unsigned long *irqstate)
• int wait_queue_wake(struct wait_queue *wait)