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/*******************************************************************************
* $Copyright ST-Ericsson 2011 $
******************************************************************************/
/*
* @addtogroup critical_section
* @{
*/
/*******************************************************************************
* Includes
******************************************************************************/
#include "stdlib.h"
#include "t_basicdefinitions.h"
#include "r_critical_section.h"
#include "r_atomic_functions.h"
/*******************************************************************************
* File scope types, constants and variables
******************************************************************************/
#define CS_LOCKED 1
#define CS_UNLOCKED 0
/*******************************************************************************
* Declaration of internal functions
******************************************************************************/
/*******************************************************************************
* Definition of external functions
******************************************************************************/
/**
* Perform initialization of Critical Section.
*
* Creates a critical section object and returns pointer to it for later usage
* when it is needed to enter and leave the critical part of the code,
* and destroy the critical section object when not used anymore.
*
* @retval Pointer to initialized critical section object if initialization was
* successful, otherwise NULL.
*/
CriticalSection_t Do_CriticalSection_Create(void)
{
uint32 *cs = (uint32 *)malloc(sizeof(uint32));
if (NULL != cs) {
*cs = CS_UNLOCKED;
}
return cs;
}
/**
* Free resources used for Critical Section object.
*
* Free all resources and destroy the critical section object given as parameter
* to the function.
*
* @param [in] CriticalSectionObject Pointer to pointer at the object to be destroyed.
*
* @retval None.
*/
void Do_CriticalSection_Destroy(CriticalSection_t *CriticalSectionObject)
{
uint32 **cs = (uint32 **)CriticalSectionObject;
if (NULL != *cs) {
free(*cs);
*cs = NULL;
}
}
/**
* Enter to the Critical Section code.
*
* Take ownership over critical section object and execute the part of the code
* covered by the Critical Section object passed as parameter to the function.
*
* @param [in] CriticalSectionObject Pointer to the object used to exclusively
* lock some critical part of the code.
*
* @retval TRUE if Critical Section code entered successfully, otherwise FALSE.
*/
boolean Do_CriticalSection_Enter(CriticalSection_t CriticalSectionObject)
{
volatile uint32 *cs = (volatile uint32 *)CriticalSectionObject;
if (NULL != cs) {
uint32 cs_status = CS_LOCKED;
cs_status = Do_Atomic_CompareAndSwap(cs, CS_UNLOCKED, CS_LOCKED);
if (CS_UNLOCKED == cs_status) {
return TRUE;
} else {
return FALSE;
}
}
return TRUE;
}
/**
* Leave the Critical Section code.
*
* Release the Critical Section object when finished execution to allow someone
* else to execute the code covered by the Critical Section object passed as
* parameter to the function.
*
* @param [in] CriticalSectionObject Pointer to the object used to exclusively
* lock some critical part of the code.
*
* @retval None.
*/
void Do_CriticalSection_Leave(CriticalSection_t CriticalSectionObject)
{
volatile uint32 *cs = (volatile uint32 *)CriticalSectionObject;
if (NULL != cs) {
uint32 cs_status = CS_UNLOCKED;
cs_status = Do_Atomic_CompareAndSwap(cs, CS_LOCKED, CS_UNLOCKED);
if (CS_LOCKED == cs_status) {
/* SUCCESS */
} else {
/* FAILED */
}
}
}
/*******************************************************************************
* Definition of internal functions
******************************************************************************/
/* @} */
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