Clarify allocation failure error (#3566)

* Clarify allocation failure error

It's not useful to report an UNKNOWN_ERROR when the cause is known.

* Adding model to CPP enum check

---------

Co-authored-by: M Starch <LeStarch@googlemail.com>

Author: celskeggs

Os/Generic/PriorityQueue.cpp

@@ -53,28 +53,28 @@ QueueInterface::Status PriorityQueue::create(const Fw::StringBase& name, FwSizeT
     // Allocate indices list
     FwSizeType* indices = new (std::nothrow) FwSizeType[depth];
     if (indices == nullptr) {
-        return QueueInterface::Status::UNKNOWN_ERROR;
+        return QueueInterface::Status::ALLOCATION_FAILED;
     }
     // Allocate sizes list or clean-up
     FwSizeType* sizes = new (std::nothrow) FwSizeType[depth];
     if (sizes == nullptr) {
         delete[] indices;
-        return QueueInterface::Status::UNKNOWN_ERROR;
+        return QueueInterface::Status::ALLOCATION_FAILED;
     }
     // Allocate sizes list or clean-up
     U8* data = new (std::nothrow) U8[depth * messageSize];
     if (data == nullptr) {
         delete[] indices;
         delete[] sizes;
-        return QueueInterface::Status::UNKNOWN_ERROR;
+        return QueueInterface::Status::ALLOCATION_FAILED;
     }
     // Allocate max heap or clean-up
     bool created = this->m_handle.m_heap.create(depth);
     if (not created) {
         delete[] indices;
         delete[] sizes;
         delete[] data;
-        return QueueInterface::Status::UNKNOWN_ERROR;
+        return QueueInterface::Status::ALLOCATION_FAILED;
     }
     // Assign initial indices and sizes
     for (FwSizeType i = 0; i < depth; i++) {

Os/Models/Models.cpp

@@ -204,6 +204,8 @@ static_assert(static_cast<Os::QueueStatus::T>(Os::Queue::Status::FULL) == Os::Qu
               "Queue status enums do not match");
 static_assert(static_cast<Os::QueueStatus::T>(Os::Queue::Status::UNKNOWN_ERROR) == Os::QueueStatus::T::UNKNOWN_ERROR,
               "Queue status enums do not match");
+static_assert(static_cast<Os::QueueStatus::T>(Os::Queue::Status::ALLOCATION_FAILED) == Os::QueueStatus::T::ALLOCATION_FAILED,
+              "Queue status enums do not match");
 
 // Check consistency of every constant in the Os::Queue::BlockingType enum
 static_assert(static_cast<Os::QueueBlockingType::T>(Os::Queue::BlockingType::BLOCKING) == Os::QueueBlockingType::T::BLOCKING,

Os/Models/Queue.fpp

@@ -16,6 +16,7 @@ module Os {
         INVALID_PRIORITY,  @<  invalid priority requested
         FULL,              @<  Queue was full when attempting to send a message
         NOT_SUPPORTED,     @<  Queue feature is not supported
+        ALLOCATION_FAILED, @<  required memory could not be allocated
         UNKNOWN_ERROR      @<  Unexpected error; can't match with returns
     }
 

Os/Queue.hpp

@@ -38,6 +38,7 @@ class QueueInterface {
         INVALID_PRIORITY,  //!<  invalid priority requested
         FULL,              //!<  Queue was full when attempting to send a message
         NOT_SUPPORTED,     //!<  Queue feature is not supported
+        ALLOCATION_FAILED, //!<  required memory could not be allocated
         UNKNOWN_ERROR      //!<  Unexpected error; can't match with returns
     };