lwpa_mutex

Overview

A mutual-exclusion (mutex) object.

Sometimes also referred to as a critical section. Only one thread can take the mutex at a time using lwpa_mutex_take(). Where possible on real-time platforms, the mutex provides priority inheritance.

lwpa_mutex implementations use the following constructs under the hood on various platforms:

On: | lwpa_mutex uses:

Windows | Critical Section objects FreeRTOS/lwIP | Mutexes MQX | Lightweight Semaphores

Typedefs
typedef UNDEFINED	lwpa_mutex_t
	The mutex identifier. More...

Functions
bool	lwpa_mutex_create (lwpa_mutex_t *id)
	Create a new mutex. More...
bool	lwpa_mutex_take (lwpa_mutex_t *id, int wait_ms)
	Acquire a mutex. More...
void	lwpa_mutex_give (lwpa_mutex_t *id)
	Release a mutex. More...
void	lwpa_mutex_destroy (lwpa_mutex_t *id)
	Destroy a mutex object. More...

Typedef Documentation

lwpa_mutex_t

typedef UNDEFINED lwpa_mutex_t

The mutex identifier.

Depending on the platform, this could be a scalar type or a struct.

Function Documentation

lwpa_mutex_create()

bool lwpa_mutex_create

(

lwpa_mutex_t *

id

)

Create a new mutex.

Parameters

[in,out]

id

Mutex identifier on which to create a mutex. If this function returns true, id becomes valid for calls to lwpa_mutex_take() and lwpa_mutex_give().

Returns

true (the mutex was created) or false (the mutex was not created).

lwpa_mutex_destroy()

void lwpa_mutex_destroy

(

lwpa_mutex_t *

id

)

Destroy a mutex object.

Parameters

[in]

id

Identifier for the mutex to destroy.

lwpa_mutex_give()

void lwpa_mutex_give

(

lwpa_mutex_t *

id

)

Release a mutex.

Parameters

[in]

id

Identifier for the mutex to release.

lwpa_mutex_take()

bool lwpa_mutex_take	(	lwpa_mutex_t *	id,
		int	wait_ms
	)

Acquire a mutex.

Parameters

[in]	id	Identifier for the mutex to acquire.
[in]	wait_ms	How long to wait to acquire the mutex, in milliseconds (use LWPA_WAIT_FOREVER to wait indefinitely).

Returns

true (the mutex was acquired) or false (timeout or failure while waiting to acquire the mutex).