Use case: FastTake/ReleaseAll all semaphores at once with correct Key

This use case shows how the application sets a clear key, takes multiple semaphores using the fast-take mechanism, then releases all semaphores associated with the current core in a single operation.

Sequence diagram

HAL1

HAL2

FastTake/ReleaseAll

@startuml participant "User Application" as App participant "HSEM Driver" as HSEM group Set the clear key App -> HSEM: HAL_HSEM_SetClearKey(clear_key) note right of HSEM The semaphore clear key is configured end note end group Fast take the hardware semaphore 0 App -> HSEM: HAL_HSEM_FastTake(HSEM_ID_0) note right of HSEM Hardware semaphore 0 is taken end note end group Fast take the hardware semaphore 1 App -> HSEM: HAL_HSEM_FastTake(HSEM_ID_1) note right of HSEM Hardware semaphore 1 is taken end note end group get the clear key App -> HSEM: clear_key = HAL_HSEM_GetClearKey() HSEM --> App: <color:green>Return semaphore clear key App</color> end group Release all semaphores App -> HSEM: HAL_HSEM_ReleaseAll(clear_key, 1U) note right of HSEM All semaphores owned by the selected core are released in a single operation end note end group Check semaphore state after release all semaphores App -> HSEM: HAL_HSEM_IsSemTaken(HSEM_ID_0) HSEM --> App: 0U App -> HSEM: HAL_HSEM_IsSemTaken(HSEM_ID_1) HSEM --> App: 0U note right of HSEM The hardware semaphores are released end note end @enduml

FastTake/ReleaseAll

@startuml participant "User Application" as App participant "HSEM Driver" as HSEM group Set the clear key App -> HSEM: HAL_HSEM_SetClearKey(clear_key) note right of HSEM The semaphore clear key is configured end note end group Fast take the hardware semaphore 0 App -> HSEM: HAL_HSEM_FastTake(HAL_HSEM_0) note right of HSEM Hardware semaphore 0 is taken end note end group Fast take the hardware semaphore 1 App -> HSEM: HAL_HSEM_FastTake(HAL_HSEM_1) note right of HSEM Hardware semaphore 1 is taken end note end group get the clear key App -> HSEM: clear_key = HAL_HSEM_GetClearKey() HSEM --> App: <color:green>Return semaphore clear key App</color> end group Release all semaphores App -> HSEM: HAL_HSEM_ReleaseAll(clear_key, HAL_HSEM_LOCKID_CURRENT_CPU) note right of HSEM All semaphores owned by the current CPU are released in a single operation end note end group Check semaphore state after release App -> HSEM: HAL_HSEM_IsTaken(HAL_HSEM_0) HSEM --> App: HAL_HSEM_RELEASED App -> HSEM: HAL_HSEM_IsTaken(HAL_HSEM_1) HSEM --> App: HAL_HSEM_RELEASED note right of HSEM The hardware semaphores are released end note end @enduml

Code snippet

HAL1

HAL2 

uint32_t clear_key;
uint32_t sem_state0, sem_state1;
#define HSEM_ID_0 (0U) /* HW semaphore 0*/
#define HSEM_ID_1 (1U) /* HW semaphore 1*/

/* HW semaphore Clock enable */
__HAL_RCC_HSEM_CLK_ENABLE() ;

HAL_HSEM_SetClearKey(clear_key);

HAL_HSEM_FastTake(HSEM_ID_0);

HAL_HSEM_FastTake(HSEM_ID_1);

clear_key = HAL_HSEM_GetClearKey();

HAL_HSEM_ReleaseAll(clear_key, 1U);

sem_state0 = HAL_HSEM_IsSemTaken(HSEM_SEM_0);

sem_state1 = HAL_HSEM_IsSemTaken(HSEM_SEM_1);

if ((sem_state0 == 0U) && (sem_state1 == 0U))
{
   /* Both hardware semaphores are released */
}

uint32_t clear_key;
hal_hsem_status_t sem_state0, sem_state1;



/* HW semaphore Clock enable */
HAL_RCC_HSEM_EnableClock();

HAL_HSEM_SetClearKey(clear_key);

HAL_HSEM_FastTake(HAL_HSEM_0);

HAL_HSEM_FastTake(HAL_HSEM_1);

clear_key = HAL_HSEM_GetClearKey();

HAL_HSEM_ReleaseAll(clear_key, HAL_HSEM_LOCKID_CURRENT_CPU);

sem_state0 = HAL_HSEM_IsTaken(HAL_HSEM_0);

sem_state1 = HAL_HSEM_IsTaken(HAL_HSEM_1);

if ((sem_state0 == HAL_HSEM_RELEASED) && (sem_state1 == HAL_HSEM_RELEASED))
{
    /* Both hardware semaphores are released */
}