PriorityQueue Send mark as unsafe for ISR (#3216)

* Updated comment to indicate functions are not ISR safe since they use a mutex under the hood

* added another needed comment

* Adding warning on priorityqueue usage within an ISR

Author: kevin-f-ortega

Os/Generic/PriorityQueue.hpp

@@ -47,6 +47,8 @@ struct PriorityQueueHandle : public QueueHandle {
 };
 //! \brief generic priority queue implementation
 //!
+//! \warning This Priority Queue is not ISR safe
+//!
 //! A generic implementation of a priority queue to support the Os::QueueInterface. This queue uses OSAL mutexes,
 //! and condition variables to provide for a task-safe blocking queue implementation. Data is stored in heap memory.
 //!
@@ -88,6 +90,7 @@ class PriorityQueue : public Os::QueueInterface {
     //!
     //! \warning It is invalid to send a null buffer
     //! \warning This method will block if the queue is full and blockType is set to BLOCKING
+    //! \warning This method is not ISR safe
     //!
     //! \param buffer: message data
     //! \param size: size of message data
@@ -124,6 +127,8 @@ class PriorityQueue : public Os::QueueInterface {
 
     //! \brief get maximum messages stored at any given time
     //!
+    //! \warning This method is not ISR safe
+    //!
     //! Returns the maximum number of messages in this queue at any given time. This is the high-water mark for this
     //! queue.
     //! \return queue message high-water mark

Os/Generic/docs/sdd.md

@@ -12,6 +12,9 @@ Os::PriorityQueue is an in-memory implementation of Os::Queue. It allows project
 
 For memory protection, Os::PriorityQueue delegates to Os::Mutex and Os::ConditionVariable.
 
+> [!WARNING]
+> This Queue implementation is insufficient to be used for sending messages in ISR context due to the use of Os::Mutex as mentioned in above.
+
 ### Os::PriorityQueue Key Algorithms
 
 Os::PriorityQueue stores messages in a set of dynamically allocated unordered parallel arrays. These arrays store: message data, and message data size respectively. There is also an index-free list that stores the indices that are available for storage in the fixed size arrays.