#include "queue.h"Typedefs | |
| typedef xQueueHandle | xSemaphoreHandle |
| #define semBINARY_SEMAPHORE_QUEUE_LENGTH ( ( unsigned char ) 1U ) |
| #define semGIVE_BLOCK_TIME ( ( portTickType ) 0U ) |
| #define semSEMAPHORE_QUEUE_ITEM_LENGTH ( ( unsigned char ) 0U ) |
| #define vSemaphoreCreateBinary | ( | xSemaphore | ) |
| #define vSemaphoreDelete | ( | xSemaphore | ) | vQueueDelete( ( xQueueHandle ) ( xSemaphore ) ) |
| #define xSemaphoreAltGive | ( | xSemaphore | ) | xQueueAltGenericSend( ( xQueueHandle ) ( xSemaphore ), NULL, semGIVE_BLOCK_TIME, queueSEND_TO_BACK ) |
| #define xSemaphoreAltTake | ( | xSemaphore, | |
| xBlockTime | |||
| ) | xQueueAltGenericReceive( ( xQueueHandle ) ( xSemaphore ), NULL, ( xBlockTime ), pdFALSE ) |
| #define xSemaphoreCreateCounting | ( | uxMaxCount, | |
| uxInitialCount | |||
| ) | xQueueCreateCountingSemaphore( ( uxMaxCount ), ( uxInitialCount ) ) |
| #define xSemaphoreCreateMutex | ( | ) | xQueueCreateMutex( queueQUEUE_TYPE_MUTEX ) |
| #define xSemaphoreCreateRecursiveMutex | ( | ) | xQueueCreateMutex( queueQUEUE_TYPE_RECURSIVE_MUTEX ) |
| #define xSemaphoreGetMutexHolder | ( | xSemaphore | ) | xQueueGetMutexHolder( ( xSemaphore ) ) |
semphr.h
xTaskHandle xSemaphoreGetMutexHolder( xSemaphoreHandle xMutex );
If xMutex is indeed a mutex type semaphore, return the current mutex holder. If xMutex is not a mutex type semaphore, or the mutex is available (not held by a task), return NULL.
Note: This Is is a good way of determining if the calling task is the mutex holder, but not a good way of determining the identity of the mutex holder as the holder may change between the function exiting and the returned value being tested.
| #define xSemaphoreGive | ( | xSemaphore | ) | xQueueGenericSend( ( xQueueHandle ) ( xSemaphore ), NULL, semGIVE_BLOCK_TIME, queueSEND_TO_BACK ) |
| #define xSemaphoreGiveFromISR | ( | xSemaphore, | |
| pxHigherPriorityTaskWoken | |||
| ) | xQueueGenericSendFromISR( ( xQueueHandle ) ( xSemaphore ), NULL, ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK ) |
| #define xSemaphoreGiveRecursive | ( | xMutex | ) | xQueueGiveMutexRecursive( ( xMutex ) ) |
| #define xSemaphoreTake | ( | xSemaphore, | |
| xBlockTime | |||
| ) | xQueueGenericReceive( ( xQueueHandle ) ( xSemaphore ), NULL, ( xBlockTime ), pdFALSE ) |
| #define xSemaphoreTakeFromISR | ( | xSemaphore, | |
| pxHigherPriorityTaskWoken | |||
| ) | xQueueReceiveFromISR( ( xQueueHandle ) ( xSemaphore ), NULL, ( pxHigherPriorityTaskWoken ) ) |
semphr.
h
xSemaphoreTakeFromISR(
xSemaphoreHandle xSemaphore,
signed portBASE_TYPE *pxHigherPriorityTaskWoken
)Macro to take a semaphore from an ISR. The semaphore must have previously been created with a call to vSemaphoreCreateBinary() or xSemaphoreCreateCounting().
Mutex type semaphores (those created using a call to xSemaphoreCreateMutex()) must not be used with this macro.
This macro can be used from an ISR, however taking a semaphore from an ISR is not a common operation. It is likely to only be useful when taking a counting semaphore when an interrupt is obtaining an object from a resource pool (when the semaphore count indicates the number of resources available).
| xSemaphore | A handle to the semaphore being taken. This is the handle returned when the semaphore was created. |
| pxHigherPriorityTaskWoken | xSemaphoreTakeFromISR() will set *pxHigherPriorityTaskWoken to pdTRUE if taking the semaphore caused a task to unblock, and the unblocked task has a priority higher than the currently running task. If xSemaphoreTakeFromISR() sets this value to pdTRUE then a context switch should be requested before the interrupt is exited. |
| #define xSemaphoreTakeRecursive | ( | xMutex, | |
| xBlockTime | |||
| ) | xQueueTakeMutexRecursive( ( xMutex ), ( xBlockTime ) ) |
| typedef xQueueHandle xSemaphoreHandle |
1.8.5