Freertos的队列的具体实现
阅读queue.c可以看到,版本V10.0.1
#define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
#define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
xQueueReceive(): Receive (read) an item from a queue.
xQueueSend(), xQueueSendToFront(), xQueueSendToBack(): Sends (writes) an item to the front or the back of a queue.
Queue有两个状态:
empty - errQUEUE_EMPTY
full - errQUEUE_FULL
在向队列里面写入item的时候,prvCopyDataToQueue,会将uxMessagesWaiting加1.
暂时不懂xQueueGiveFromISR的具体作用