Various Benchmark Fixes for AzCore (#7611)

Fixed crash in Allocators Benchmark multithreaded test due to the HPHA schema not having proper multithread protection around the `mFreeTree` member in `tree_get_unused_memory` function.
The `mFreeTree intrusive set is able to modified on multiple threads.

Replaced the custom intrusive_list implementation n HPHA schema with AZStd::intrusive_list

Added a `ScopedAllocatorBenchmarkEnvironment` class to provide an RAI mechanism for initializing the SystemAllocator in Benchmark Test

Rermoved the `AzCoreBenchmarkEnvironment` in lieu of the `ScopedAllocatorBenchmarkEnvironment` class

Fixed assert when running Allocator Benchmarks in debug due to mismatch PauseTiming/ResumeTiming in Allocator Benchmark Fixtures

Added `ScopedRegisterBenchmarkEnvironment` RAII class to provide lifetime guarantees on BenchmarkEnvironments registered via the `AZ_UNIT_TEST_HOOK`

Initialized the intrusive_multiset_node members to nullptr in all build configurations instead of only debug as the cost negligible and it is useful for debugging.

fixes LYN-10210

Signed-off-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>

Code/Framework/AzCore/Tests/Main.cpp

@@ -7,29 +7,13 @@
  */
 
 #include <AzCore/UnitTest/UnitTest.h>
+#include <AzCore/UnitTest/TestTypes.h>
 #include <AzTest/AzTest.h>
-#include <AzCore/Memory/SystemAllocator.h>
 
 
 #if defined(HAVE_BENCHMARK)
 
-namespace AzCore
-{
-    class AzCoreBenchmarkEnvironment
-        : public AZ::Test::BenchmarkEnvironmentBase
-    {
-        void SetUpBenchmark() override
-        {
-            AZ::AllocatorInstance<AZ::SystemAllocator>::Create();
-        }
-        void TearDownBenchmark() override
-        {
-            AZ::AllocatorInstance<AZ::SystemAllocator>::Destroy();
-        }
-    };
-}
-
-AZ_UNIT_TEST_HOOK(DEFAULT_UNIT_TEST_ENV, AzCore::AzCoreBenchmarkEnvironment)
+AZ_UNIT_TEST_HOOK(DEFAULT_UNIT_TEST_ENV, UnitTest::ScopedAllocatorBenchmarkEnvironment)
 
 #else
 

Code/Framework/AzCore/Tests/Memory/AllocatorBenchmarks.cpp

@@ -291,7 +291,7 @@ namespace Benchmark
             for (auto _ : state)
             {
                 state.PauseTiming();
-                
+
                 AZStd::vector<void*>& perThreadAllocations = base::GetPerThreadAllocations(state.thread_index);
                 const size_t numberOfAllocations = perThreadAllocations.size();
                 size_t totalAllocationSize = 0;
@@ -300,7 +300,7 @@ namespace Benchmark
                     const AllocationSizeArray& allocationArray = s_allocationSizes[TAllocationSize];
                     const size_t allocationSize = allocationArray[allocationIndex % allocationArray.size()];
                     totalAllocationSize += allocationSize;
-                    
+
                     state.ResumeTiming();
                     perThreadAllocations[allocationIndex] = TestAllocatorType::Allocate(allocationSize, 0);
                     state.PauseTiming();
@@ -319,6 +319,8 @@ namespace Benchmark
                 TestAllocatorType::GarbageCollect();
 
                 state.SetItemsProcessed(numberOfAllocations);
+
+                state.ResumeTiming();
             }
         }
     };
@@ -364,6 +366,8 @@ namespace Benchmark
                 state.SetItemsProcessed(numberOfAllocations);
 
                 TestAllocatorType::GarbageCollect();
+
+                state.ResumeTiming();
             }
         }
     };
@@ -519,6 +523,8 @@ namespace Benchmark
                 state.SetItemsProcessed(itemsProcessed);
 
                 TestAllocatorType::GarbageCollect();
+
+                state.ResumeTiming();
             }
         }
     };