Initial 10.4.4 Release

Changes between FreeRTOS V10.4.3 and FreeRTOS V10.4.4 released May 28 2021

• Minor performance improvements to xTaskIncrementTick() achieved by providing macro versions of uxListRemove() and vListInsertEnd().
• Minor refactor of timers.c that obsoletes the need for the tmrCOMMAND_START_DONT_TRACE macro and removes the need for timers.c to post to its own event queue. A consequence of this change is that auto-reload timers that miss their intended next execution time will execute again immediately rather than executing again the next time the command queue is processed. (thanks Jeff Tenney).
• Fix a race condition in the message buffer implementation. The underlying cause was that length and data bytes are written and read as two distinct operations, which both modify the size of the buffer. If a context switch occurs after adding or removing the length bytes, but before adding or removing the data bytes, then another task may observe the message buffer in an invalid state.
• The xTaskCreate() and xTaskCreateStatic() functions accept a task priority as an input parameter. The priority has always been silently capped to (configMAX_PRIORITIES - 1) should it be set to a value above that priority. Now values above that priority will also trigger a configASSERT() failure.
• Replace configASSERT( pcQueueName ) in vQueueAddToRegistry with a NULL pointer check.
• Introduce the configSTACK_ALLOCATION_FROM_SEPARATE_HEAP configuration constant that enables the stack allocated to tasks to come from a heap other than the heap used by other memory allocations. This enables stacks to be placed within special regions, such as fast tightly coupled memory.
• If there is an attempt to add the same queue or semaphore handle to the queue registry more than once then prior versions would create two separate entries. Now if this is done the first entry is overwritten rather than duplicated.
• Other minor updates include adding additional configASSERT() checks and correcting and improving code comments.