semaphore.h File Reference

#include <stdint.h>
#include <common/list.h>

Include dependency graph for semaphore.h:

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Data Structures
struct	semaphore

Functions
void	sema_init (struct semaphore *sem, int val)
	Initialize the semaphore. More...
int	down (struct semaphore *sem)
	Decrease the number of the semaphore. More...
int	down_trylock (struct semaphore *sem)
	The same as down(), except that if the decrement cannot be immediately performed, then call returns an error instead of blocking. More...
int	up (struct semaphore *sem)
	Increase the number of the semaphore. More...

Function Documentation

down()

int down

(

struct semaphore *

sem

)

Decrease the number of the semaphore.

Parameters

sem	Pointer to the semaphore.

Return values

int	0 on success and nonzero error number on error.

down_trylock()

int down_trylock

(

struct semaphore *

sem

)

The same as down(), except that if the decrement cannot be immediately performed, then call returns an error instead of blocking.

Parameters

sem	Pointer to the semaphore.

Return values

int	0 on success and nonzero error number on error.

sema_init()

void sema_init	(	struct semaphore *	sem,
		int	val
	)

Initialize the semaphore.

Parameters

sem	Pointer to the semaphore.
val	Initial value of the semaphore.

Return values

None

up()

int up

(

struct semaphore *

sem

)

Increase the number of the semaphore.

Parameters

sem	Pointer to the semaphore.

Return values

int	0 on success and nonzero error number on error.