User mode mutex APIs

Macros
#define	SYS_MUTEX_DEFINE(name)    struct sys_mutex name
	Statically define and initialize a sys_mutex. More...

Functions
static void	sys_mutex_init (struct sys_mutex *mutex)
	Initialize a mutex. More...
static int	sys_mutex_lock (struct sys_mutex *mutex, k_timeout_t timeout)
	Lock a mutex. More...
static int	sys_mutex_unlock (struct sys_mutex *mutex)
	Unlock a mutex. More...

Detailed Description

Macro Definition Documentation

SYS_MUTEX_DEFINE

#define SYS_MUTEX_DEFINE

(

name

)

struct sys_mutex name

#include <include/sys/mutex.h>

Statically define and initialize a sys_mutex.

The mutex can be accessed outside the module where it is defined using:

extern struct sys_mutex <name>; 

Route this to memory domains using K_APP_DMEM().

Parameters

name	Name of the mutex.

Function Documentation

sys_mutex_init()

static void sys_mutex_init ( struct sys_mutex *  mutex )

inlinestatic

#include <include/sys/mutex.h>

Initialize a mutex.

This routine initializes a mutex object, prior to its first use.

Upon completion, the mutex is available and does not have an owner.

This routine is only necessary to call when userspace is disabled and the mutex was not created with SYS_MUTEX_DEFINE().

Parameters

mutex

Address of the mutex.

Returns

N/A

sys_mutex_lock()

static int sys_mutex_lock ( struct sys_mutex *  mutex, k_timeout_t  timeout  )

inlinestatic

#include <include/sys/mutex.h>

Lock a mutex.

This routine locks mutex. If the mutex is locked by another thread, the calling thread waits until the mutex becomes available or until a timeout occurs.

A thread is permitted to lock a mutex it has already locked. The operation completes immediately and the lock count is increased by 1.

Parameters

mutex	Address of the mutex, which may reside in user memory
timeout	Waiting period to lock the mutex, or one of the special values K_NO_WAIT and K_FOREVER.

Return values

0	Mutex locked.
-EBUSY	Returned without waiting.
-EAGAIN	Waiting period timed out.
-EACCES	Caller has no access to provided mutex address
-EINVAL	Provided mutex not recognized by the kernel

sys_mutex_unlock()

static int sys_mutex_unlock ( struct sys_mutex *  mutex )

inlinestatic

#include <include/sys/mutex.h>

Unlock a mutex.

This routine unlocks mutex. The mutex must already be locked by the calling thread.

The mutex cannot be claimed by another thread until it has been unlocked by the calling thread as many times as it was previously locked by that thread.

Parameters

mutex

Address of the mutex, which may reside in user memory

Return values

0	Mutex unlocked
-EACCES	Caller has no access to provided mutex address
-EINVAL	Provided mutex not recognized by the kernel or mutex wasn't locked
-EPERM	Caller does not own the mutex