Feature/memory arena improvements (#633)

* First pass at MemoryArena.

* First pass at RandomGenerator.

* Extract TestContext into external source file.

* Fix warning on printf.

* Use enum classes for Test enums.
OutputMode -> TestOutputMode.

* First pass at FreeList unit test.

* Auto registering tests.
Improvements to RandomGenerator.

* Remove the need for unitTest headers - cos can use registering.

* Added unitTest for MemoryArena.

* Do unit tests.

* Fix typo.

* Fix problem limiting errors from TestContext.

* Refactor of MemoryArena
* Removed the ability to rewind (to improve memory usage/simplify)
* Better memory usage - around oversized blocks
  + Will keep allocating from a normal block if more than 1/3 memory left, or an oversided block is allocated

* Better unitTest coverage for MemoryArena.

* Fixes based on code review

* Remove e prefix from enum class types for TestContext
* Added extra checking for allocations sizes
* Fixed some typos
* Added std::is_pod test to allocateAndCopyArray

* Add include for is_pod needed for linux build.

4 files changed, 171 insertions, 153 deletions

diff --git a/tools/slang-test/main.cpp b/tools/slang-test/main.cpp
index b57dc6d9c..a4b903e25 100644
--- a/tools/slang-test/main.cpp
+++ b/tools/slang-test/main.cpp
@@ -99,7 +99,7 @@ struct Options
     bool dumpOutputOnFailure = false;
 
     // kind of output to generate
-    TestOutputMode outputMode = TestOutputMode::eDefault;
+    TestOutputMode outputMode = TestOutputMode::Default;
 
     // Only run tests that match one of the given categories
     Dictionary<TestCategory*, TestCategory*> includeCategories;
@@ -212,21 +212,21 @@ Result parseOptions(int* argc, char** argv)
         }
         else if( strcmp(arg, "-appveyor") == 0 )
         {
-            g_options.outputMode = TestOutputMode::eAppVeyor;
+            g_options.outputMode = TestOutputMode::AppVeyor;
             g_options.dumpOutputOnFailure = true;
         }
         else if( strcmp(arg, "-travis") == 0 )
         {
-            g_options.outputMode = TestOutputMode::eTravis;
+            g_options.outputMode = TestOutputMode::Travis;
             g_options.dumpOutputOnFailure = true;
         }
         else if (strcmp(arg, "-xunit") == 0)
         {
-            g_options.outputMode = TestOutputMode::eXUnit;
+            g_options.outputMode = TestOutputMode::XUnit;
         }
         else if (strcmp(arg, "-xunit2") == 0)
         {
-            g_options.outputMode = TestOutputMode::eXUnit2;
+            g_options.outputMode = TestOutputMode::XUnit2;
         }
         else if( strcmp(arg, "-category") == 0 )
         {
@@ -484,7 +484,7 @@ TestResult gatherTestOptions(
 
                     if(!category)
                     {
-                        return TestResult::eFail;
+                        return TestResult::Fail;
                     }
 
                     testOptions.categories.Add(category);
@@ -499,7 +499,7 @@ TestResult gatherTestOptions(
                 break;
         
             case 0: case '\r': case '\n':
-                return TestResult::eFail;
+                return TestResult::Fail;
             }
 
             break;
@@ -516,7 +516,7 @@ TestResult gatherTestOptions(
         cursor++;
     else
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     // Next scan for a sub-command name
@@ -533,7 +533,7 @@ TestResult gatherTestOptions(
             break;
         
         case 0: case '\r': case '\n':
-            return TestResult::eFail;
+            return TestResult::Fail;
         }
 
         break;
@@ -546,7 +546,7 @@ TestResult gatherTestOptions(
         cursor++;
     else
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     // Now scan for arguments. For now we just assume that
@@ -562,7 +562,7 @@ TestResult gatherTestOptions(
         case 0: case '\r': case '\n':
             skipToEndOfLine(&cursor);
             testList->tests.Add(testOptions);
-            return TestResult::ePass;
+            return TestResult::Pass;
 
         default:
             break;
@@ -603,7 +603,7 @@ TestResult gatherTestsForFile(
     }
     catch (Slang::IOException)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
 
@@ -619,12 +619,12 @@ TestResult gatherTestsForFile(
         // Look for a pattern that matches what we want
         if(match(&cursor, "//TEST_IGNORE_FILE"))
         {
-            return TestResult::eIgnored;
+            return TestResult::Ignored;
         }
         else if(match(&cursor, "//TEST"))
         {
-            if(gatherTestOptions(&cursor, testList) != TestResult::ePass)
-                return TestResult::eFail;
+            if(gatherTestOptions(&cursor, testList) != TestResult::Pass)
+                return TestResult::Fail;
         }
         else
         {
@@ -632,7 +632,7 @@ TestResult gatherTestsForFile(
         }
     }
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 OSError spawnAndWait(TestContext* context, const String& testPath, OSProcessSpawner& spawner)
@@ -642,14 +642,14 @@ OSError spawnAndWait(TestContext* context, const String& testPath, OSProcessSpaw
     if(context->m_isVerbose)
     {
         String commandLine = spawner.getCommandLine();
-        context->messageFormat(TestMessageType::eInfo, "%s\n", commandLine.begin());
+        context->messageFormat(TestMessageType::Info, "%s\n", commandLine.begin());
     }
     
     OSError err = spawner.spawnAndWaitForCompletion();
     if (err != kOSError_None)
     {
 //        fprintf(stderr, "failed to run test '%S'\n", testPath.ToWString());
-        context->messageFormat(TestMessageType::eRunError, "failed to run test '%S'", testPath.ToWString().begin());
+        context->messageFormat(TestMessageType::RunError, "failed to run test '%S'", testPath.ToWString().begin());
     }
     return err;
 }
@@ -731,7 +731,7 @@ TestResult runSimpleTest(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     String actualOutput = getOutput(spawner);
@@ -753,19 +753,19 @@ TestResult runSimpleTest(TestContext* context, TestInput& input)
         expectedOutput = "result code = 0\nstandard error = {\n}\nstandard output = {\n}\n";
     }
 
-    TestResult result = TestResult::ePass;
+    TestResult result = TestResult::Pass;
 
     // Otherwise we compare to the expected output
     if (actualOutput != expectedOutput)
     {
         context->dumpOutputDifference(expectedOutput, actualOutput);
-        result = TestResult::eFail;
+        result = TestResult::Fail;
     }
 
     // If the test failed, then we write the actual output to a file
     // so that we can easily diff it from the command line and
     // diagnose the problem.
-    if (result == TestResult::eFail)
+    if (result == TestResult::Fail)
     {
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
@@ -793,7 +793,7 @@ TestResult runReflectionTest(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     String actualOutput = getOutput(spawner);
@@ -815,18 +815,18 @@ TestResult runReflectionTest(TestContext* context, TestInput& input)
         expectedOutput = "result code = 0\nstandard error = {\n}\nstandard output = {\n}\n";
     }
 
-    TestResult result = TestResult::ePass;
+    TestResult result = TestResult::Pass;
 
     // Otherwise we compare to the expected output
     if (actualOutput != expectedOutput)
     {
-        result = TestResult::eFail;
+        result = TestResult::Fail;
     }
 
     // If the test failed, then we write the actual output to a file
     // so that we can easily diff it from the command line and
     // diagnose the problem.
-    if (result == TestResult::eFail)
+    if (result == TestResult::Fail)
     {
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
@@ -878,24 +878,24 @@ TestResult runEvalTest(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     String actualOutput = getOutput(spawner);
     String expectedOutput = getExpectedOutput(outputStem);
 
-    TestResult result = TestResult::ePass;
+    TestResult result = TestResult::Pass;
 
     // Otherwise we compare to the expected output
     if (actualOutput != expectedOutput)
     {
-        result = TestResult::eFail;
+        result = TestResult::Fail;
     }
 
     // If the test failed, then we write the actual output to a file
     // so that we can easily diff it from the command line and
     // diagnose the problem.
-    if (result == TestResult::eFail)
+    if (result == TestResult::Fail)
     {
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
@@ -934,7 +934,7 @@ TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, expectedSpawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     String expectedOutput = getOutput(expectedSpawner);
@@ -945,27 +945,27 @@ TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
     }
     catch (Slang::IOException)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     if (spawnAndWait(context, outputStem, actualSpawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
     String actualOutput = getOutput(actualSpawner);
 
-    TestResult result = TestResult::ePass;
+    TestResult result = TestResult::Pass;
 
     // Otherwise we compare to the expected output
     if (actualOutput != expectedOutput)
     {
-        result = TestResult::eFail;
+        result = TestResult::Fail;
     }
 
     // If the test failed, then we write the actual output to a file
     // so that we can easily diff it from the command line and
     // diagnose the problem.
-    if (result == TestResult::eFail)
+    if (result == TestResult::Fail)
     {
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
@@ -999,7 +999,7 @@ TestResult generateHLSLBaseline(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     String expectedOutput = getOutput(spawner);
@@ -1010,9 +1010,9 @@ TestResult generateHLSLBaseline(TestContext* context, TestInput& input)
     }
     catch (Slang::IOException)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 TestResult runHLSLComparisonTest(TestContext* context, TestInput& input)
@@ -1047,7 +1047,7 @@ TestResult runHLSLComparisonTest(TestContext* context, TestInput& input)
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     // We ignore output to stdout, and only worry about what the compiler
@@ -1079,26 +1079,26 @@ TestResult runHLSLComparisonTest(TestContext* context, TestInput& input)
     {
     }
 
-    TestResult result = TestResult::ePass;
+    TestResult result = TestResult::Pass;
 
     // If no expected output file was found, then we
     // expect everything to be empty
     if (expectedOutput.Length() == 0)
     {
-        if (resultCode != 0)				result = TestResult::eFail;
-        if (standardError.Length() != 0)	result = TestResult::eFail;
-        if (standardOutput.Length() != 0)	result = TestResult::eFail;
+        if (resultCode != 0)				result = TestResult::Fail;
+        if (standardError.Length() != 0)	result = TestResult::Fail;
+        if (standardOutput.Length() != 0)	result = TestResult::Fail;
     }
     // Otherwise we compare to the expected output
     else if (actualOutput != expectedOutput)
     {
-        result = TestResult::eFail;
+        result = TestResult::Fail;
     }
 
     // If the test failed, then we write the actual output to a file
     // so that we can easily diff it from the command line and
     // diagnose the problem.
-    if (result == TestResult::eFail)
+    if (result == TestResult::Fail)
     {
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
@@ -1147,7 +1147,7 @@ TestResult doGLSLComparisonTestRun(TestContext* context,
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     OSProcessSpawner::ResultCode resultCode = spawner.getResultCode();
@@ -1170,7 +1170,7 @@ TestResult doGLSLComparisonTestRun(TestContext* context,
 
     *outOutput = output;
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 TestResult runGLSLComparisonTest(TestContext* context, TestInput& input)
@@ -1187,17 +1187,17 @@ TestResult runGLSLComparisonTest(TestContext* context, TestInput& input)
     Slang::File::WriteAllText(outputStem + ".expected", expectedOutput);
     Slang::File::WriteAllText(outputStem + ".actual",   actualOutput);
 
-    if( hlslResult  == TestResult::eFail )   return TestResult::eFail;
-    if( slangResult == TestResult::eFail )   return TestResult::eFail;
+    if( hlslResult  == TestResult::Fail )   return TestResult::Fail;
+    if( slangResult == TestResult::Fail )   return TestResult::Fail;
 
     if (actualOutput != expectedOutput)
     {
         context->dumpOutputDifference(expectedOutput, actualOutput);
 
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 
@@ -1210,7 +1210,7 @@ TestResult runComputeComparisonImpl(TestContext* context, TestInput& input, cons
     const String referenceOutput = findExpectedPath(input, ".expected.txt");
     if (referenceOutput.Length() <= 0)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
 	OSProcessSpawner spawner;
@@ -1234,7 +1234,7 @@ TestResult runComputeComparisonImpl(TestContext* context, TestInput& input, cons
 	if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
 	{
         printf("error spawning render-test\n");
-		return TestResult::eFail;
+		return TestResult::Fail;
 	}
 
     auto actualOutput = getOutput(spawner);
@@ -1246,7 +1246,7 @@ TestResult runComputeComparisonImpl(TestContext* context, TestInput& input, cons
         String actualOutputPath = outputStem + ".actual";
         Slang::File::WriteAllText(actualOutputPath, actualOutput);
 
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
 	// check against reference output
@@ -1254,24 +1254,24 @@ TestResult runComputeComparisonImpl(TestContext* context, TestInput& input, cons
     {
         printf("render-test not producing expected outputs.\n");
         printf("render-test output:\n%s\n", actualOutput.Buffer());
-		return TestResult::eFail;
+		return TestResult::Fail;
     }
     if (!File::Exists(referenceOutput))
     {
         printf("referenceOutput %s not found.\n", referenceOutput.Buffer());
-		return TestResult::eFail;
+		return TestResult::Fail;
     }
     auto actualOutputContent = File::ReadAllText(actualOutputFile);
 	auto actualProgramOutput = Split(actualOutputContent, '\n');
 	auto referenceProgramOutput = Split(File::ReadAllText(referenceOutput), '\n');
     auto printOutput = [&]()
     {
-        context->messageFormat(TestMessageType::eTestFailure, "output mismatch! actual output: {\n%s\n}, \n%s\n", actualOutputContent.Buffer(), actualOutput.Buffer());
+        context->messageFormat(TestMessageType::TestFailure, "output mismatch! actual output: {\n%s\n}, \n%s\n", actualOutputContent.Buffer(), actualOutput.Buffer());
     };
     if (actualProgramOutput.Count() < referenceProgramOutput.Count())
     {
         printOutput();
-		return TestResult::eFail;
+		return TestResult::Fail;
     }
 	for (int i = 0; i < (int)referenceProgramOutput.Count(); i++)
 	{
@@ -1285,13 +1285,13 @@ TestResult runComputeComparisonImpl(TestContext* context, TestInput& input, cons
             if (actual != uval)
             {
                 printOutput();
-			    return TestResult::eFail;
+			    return TestResult::Fail;
             }
             else
-                return TestResult::ePass;
+                return TestResult::Pass;
         }
 	}
-	return TestResult::ePass;
+	return TestResult::Pass;
 }
 
 TestResult runSlangComputeComparisonTest(TestContext* context, TestInput& input)
@@ -1337,7 +1337,7 @@ TestResult doRenderComparisonTestRun(TestContext* context, TestInput& input, cha
 
     if (spawnAndWait(context, outputStem, spawner) != kOSError_None)
     {
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     OSProcessSpawner::ResultCode resultCode = spawner.getResultCode();
@@ -1360,7 +1360,7 @@ TestResult doRenderComparisonTestRun(TestContext* context, TestInput& input, cha
 
     *outOutput = output;
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 TestResult doImageComparison(TestContext* context, String const& filePath)
@@ -1382,19 +1382,19 @@ TestResult doImageComparison(TestContext* context, String const& filePath)
 
     if(!expectedData)   
     {
-        context->messageFormat(TestMessageType::eRunError, "Unable to load image ;%s'", expectedPath.Buffer());
-        return TestResult::eFail;
+        context->messageFormat(TestMessageType::RunError, "Unable to load image ;%s'", expectedPath.Buffer());
+        return TestResult::Fail;
     }
     if(!actualData)
     {
-        context->messageFormat(TestMessageType::eRunError, "Unable to load image '%s'", actualPath.Buffer());
-        return TestResult::eFail;
+        context->messageFormat(TestMessageType::RunError, "Unable to load image '%s'", actualPath.Buffer());
+        return TestResult::Fail;
     }
 
     if(expectedX != actualX || expectedY != actualY || expectedN != actualN)    
     {
-        context->messageFormat(TestMessageType::eTestFailure, "Images are different sizes '%s' '%s'", actualPath.Buffer(), expectedPath.Buffer());
-        return TestResult::eFail;
+        context->messageFormat(TestMessageType::TestFailure, "Images are different sizes '%s' '%s'", actualPath.Buffer(), expectedPath.Buffer());
+        return TestResult::Fail;
     }
 
     unsigned char* expectedCursor = expectedData;
@@ -1434,7 +1434,7 @@ TestResult doImageComparison(TestContext* context, String const& filePath)
 				// cases where vertex shader results lead to rendering that is off
 				// by one pixel...
 
-                context->messageFormat(TestMessageType::eTestFailure, "image compare failure at (%d,%d) channel %d. expected %d got %d (absolute error: %d, relative error: %f)\n",
+                context->messageFormat(TestMessageType::TestFailure, "image compare failure at (%d,%d) channel %d. expected %d got %d (absolute error: %d, relative error: %f)\n",
                     x, y, n,
                     expectedVal,
                     actualVal,
@@ -1442,12 +1442,12 @@ TestResult doImageComparison(TestContext* context, String const& filePath)
                     relativeDiff);
 
 			    // There was a difference we couldn't excuse!
-			    return TestResult::eFail;
+			    return TestResult::Fail;
 		    }
 		}
 	}
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 TestResult runHLSLRenderComparisonTestImpl(
@@ -1468,23 +1468,23 @@ TestResult runHLSLRenderComparisonTestImpl(
     Slang::File::WriteAllText(outputStem + ".expected", expectedOutput);
     Slang::File::WriteAllText(outputStem + ".actual",   actualOutput);
 
-    if( hlslResult  == TestResult::eFail )   return TestResult::eFail;
-    if( slangResult == TestResult::eFail )   return TestResult::eFail;
+    if( hlslResult  == TestResult::Fail )   return TestResult::Fail;
+    if( slangResult == TestResult::Fail )   return TestResult::Fail;
 
     if (actualOutput != expectedOutput)
     {
         context->dumpOutputDifference(expectedOutput, actualOutput);
 
-        return TestResult::eFail;
+        return TestResult::Fail;
     }
 
     // Next do an image comparison on the expected output images!
 
     TestResult imageCompareResult = doImageComparison(context, outputStem);
-    if(imageCompareResult != TestResult::ePass)
+    if(imageCompareResult != TestResult::Pass)
         return imageCompareResult;
 
-    return TestResult::ePass;
+    return TestResult::Pass;
 }
 
 TestResult runHLSLRenderComparisonTest(TestContext* context, TestInput& input)
@@ -1504,7 +1504,7 @@ TestResult runHLSLAndGLSLRenderComparisonTest(TestContext* context, TestInput& i
 
 TestResult skipTest(TestContext* /* context */, TestInput& /*input*/)
 {
-    return TestResult::eIgnored;
+    return TestResult::Ignored;
 }
 
 
@@ -1610,7 +1610,7 @@ TestResult runTest(
     // If this test can be ignored
     if (canIgnoreTestWithDisabledRenderer(testOptions))
     {
-        return TestResult::eIgnored;
+        return TestResult::Ignored;
     }
     
     // based on command name, dispatch to an appropriate callback
@@ -1673,7 +1673,7 @@ TestResult runTest(
 
     // No actual test runner found!
 
-    return TestResult::eFail;
+    return TestResult::Fail;
 }
 
 bool testCategoryMatches(
@@ -1732,7 +1732,7 @@ void runTestsOnFile(
     // Gather a list of tests to run
     FileTestList testList;
 
-    if( gatherTestsForFile(filePath, &testList) == TestResult::eIgnored )
+    if( gatherTestsForFile(filePath, &testList) == TestResult::Ignored )
     {
         // Test was explicitly ignored
         return;
@@ -1741,7 +1741,7 @@ void runTestsOnFile(
     // Note cases where a test file exists, but we found nothing to run
     if( testList.tests.Count() == 0 )
     {
-        context->addTest(filePath, TestResult::eIgnored);
+        context->addTest(filePath, TestResult::Ignored);
         return;
     }
 
@@ -1933,7 +1933,7 @@ int main(
     // Exclude rendering tests when building under AppVeyor.
     //
     // TODO: this is very ad hoc, and we should do something cleaner.
-    if( g_options.outputMode == TestOutputMode::eAppVeyor )
+    if( g_options.outputMode == TestOutputMode::AppVeyor )
     {
         g_options.excludeCategories.Add(renderTestCategory, renderTestCategory);
         g_options.excludeCategories.Add(vulkanTestCategory, vulkanTestCategory);
@@ -1972,7 +1972,6 @@ int main(
         // TODO: add more directories to this list
         // TODO: allow for a command-line argument to select a particular directory
         runTestsInDirectory(&context, "tests/");
-
     }
 
     context.outputSummary();
diff --git a/tools/slang-test/test-context.cpp b/tools/slang-test/test-context.cpp
index f77262001..822a5953c 100644
--- a/tools/slang-test/test-context.cpp
+++ b/tools/slang-test/test-context.cpp
@@ -77,7 +77,7 @@ TestContext::TestContext(TestOutputMode outputMode) :
     m_failedTestCount = 0;
     m_ignoredTestCount = 0;
 
-    m_maxTestResults = 10;
+    m_maxFailTestResults = 10;
 
     m_inTest = false;
     m_dumpOutputOnFailure = false;
@@ -88,8 +88,8 @@ bool TestContext::canWriteStdError() const
 {
     switch (m_outputMode)
     {
-        case TestOutputMode::eXUnit:
-        case TestOutputMode::eXUnit2:
+        case TestOutputMode::XUnit:
+        case TestOutputMode::XUnit2:
         {
             return false;
         }
@@ -103,6 +103,8 @@ void TestContext::startTest(const String& testName)
     m_inTest = true;
 
     m_numCurrentResults = 0;
+    m_numFailResults = 0;
+
     m_currentInfo = TestInfo();
     m_currentInfo.name = testName;
     m_currentMessage.Clear();
@@ -133,19 +135,22 @@ void TestContext::addResultWithLocation(TestResult result, const char* testText,
     m_numCurrentResults++;
 
     m_currentInfo.testResult = combine(m_currentInfo.testResult, result);
-    if (result != TestResult::eFail)
+    if (result != TestResult::Fail)
     {
         // We don't need to output the result if it 
         return;
     }
 
-    if (m_maxTestResults > 0)
+    m_numFailResults++;
+
+    if (m_maxFailTestResults > 0)
     {
-        if (m_numCurrentResults > m_maxTestResults)
+        if (m_numFailResults > m_maxFailTestResults)
         {
-            if (m_numCurrentResults == m_maxTestResults + 1)
+            if (m_numFailResults == m_maxFailTestResults + 1)
             {
-                message(TestMessageType::eInfo, "...");
+                // It's a failure, but to show that there are more than are going to be shown, just show '...'
+                message(TestMessageType::TestFailure, "...");
             }
             return;
         }
@@ -154,17 +159,17 @@ void TestContext::addResultWithLocation(TestResult result, const char* testText,
     StringBuilder buf;
     buf <<  testText << " - " << file << " (" << line << ")";
 
-    message(TestMessageType::eTestFailure, buf);
+    message(TestMessageType::TestFailure, buf);
 }
 
 void TestContext::addResultWithLocation(bool testSucceeded, const char* testText, const char* file, int line)
 {
-    addResultWithLocation(testSucceeded ? TestResult::ePass : TestResult::eFail, testText, file, line);
+    addResultWithLocation(testSucceeded ? TestResult::Pass : TestResult::Fail, testText, file, line);
 }
 
 TestResult TestContext::addTest(const String& testName, bool isPass)
 {
-    const TestResult res = isPass ? TestResult::ePass : TestResult::eFail;
+    const TestResult res = isPass ? TestResult::Pass : TestResult::Fail;
     addTest(testName, res);
     return res;
 }
@@ -188,7 +193,7 @@ void TestContext::dumpOutputDifference(const String& expectedOutput, const Strin
     }
 
     // Add to the m_currentInfo
-    message(TestMessageType::eTestFailure, builder);
+    message(TestMessageType::TestFailure, builder);
 }
 
 void TestContext::_addResult(const TestInfo& info)
@@ -197,15 +202,15 @@ void TestContext::_addResult(const TestInfo& info)
 
     switch (info.testResult)
     {
-        case TestResult::eFail:
+        case TestResult::Fail:
             m_failedTestCount++;
             break;
 
-        case TestResult::ePass:
+        case TestResult::Pass:
             m_passedTestCount++;
             break;
 
-        case TestResult::eIgnored:
+        case TestResult::Ignored:
             m_ignoredTestCount++;
             break;
 
@@ -224,9 +229,9 @@ void TestContext::_addResult(const TestInfo& info)
             char const* resultString = "UNEXPECTED";
             switch (info.testResult)
             {
-                case TestResult::eFail:      resultString = "FAILED";  break;
-                case TestResult::ePass:      resultString = "passed";  break;
-                case TestResult::eIgnored:   resultString = "ignored"; break;
+                case TestResult::Fail:      resultString = "FAILED";  break;
+                case TestResult::Pass:      resultString = "passed";  break;
+                case TestResult::Ignored:   resultString = "ignored"; break;
                 default:
                     assert(!"unexpected");
                     break;
@@ -234,20 +239,20 @@ void TestContext::_addResult(const TestInfo& info)
             printf("%s test: '%S'\n", resultString, info.name.ToWString().begin());
             break;
         }
-        case TestOutputMode::eXUnit2:
-        case TestOutputMode::eXUnit:
+        case TestOutputMode::XUnit2:
+        case TestOutputMode::XUnit:
         {
             // Don't output anything -> we'll output all in one go at the end
             break;
         }
-        case TestOutputMode::eAppVeyor:
+        case TestOutputMode::AppVeyor:
         {
             char const* resultString = "None";
             switch (info.testResult)
             {
-                case TestResult::eFail:      resultString = "Failed";  break;
-                case TestResult::ePass:      resultString = "Passed";  break;
-                case TestResult::eIgnored:   resultString = "Ignored"; break;
+                case TestResult::Fail:      resultString = "Failed";  break;
+                case TestResult::Pass:      resultString = "Passed";  break;
+                case TestResult::Ignored:   resultString = "Ignored"; break;
                 default:
                     assert(!"unexpected");
                     break;
@@ -269,7 +274,7 @@ void TestContext::_addResult(const TestInfo& info)
 
             if (err != kOSError_None)
             {
-                messageFormat(TestMessageType::eInfo, "failed to add appveyor test results for '%S'\n", info.name.ToWString().begin());
+                messageFormat(TestMessageType::Info, "failed to add appveyor test results for '%S'\n", info.name.ToWString().begin());
 
 #if 0
                 fprintf(stderr, "[%d] TEST RESULT: %s {%d} {%s} {%s}\n", err, spawner.commandLine_.Buffer(),
@@ -297,7 +302,7 @@ void TestContext::addTest(const String& testName, TestResult testResult)
 
 void TestContext::message(TestMessageType type, const String& message)
 {
-    if (type == TestMessageType::eInfo)
+    if (type == TestMessageType::Info)
     {
         if (m_isVerbose && canWriteStdError())
         {
@@ -310,7 +315,7 @@ void TestContext::message(TestMessageType type, const String& message)
 
     if (canWriteStdError())
     {
-        if (type == TestMessageType::eRunError || type == TestMessageType::eTestFailure)
+        if (type == TestMessageType::RunError || type == TestMessageType::TestFailure)
         {
             fprintf(stderr, "error: ");
             fputs(message.Buffer(), stderr);
@@ -383,7 +388,7 @@ void TestContext::outputSummary()
                 printf("---\n");
                 for (const auto& testInfo : m_testInfos)
                 {
-                    if (testInfo.testResult == TestResult::eFail)
+                    if (testInfo.testResult == TestResult::Fail)
                     {
                         printf("%s\n", testInfo.name.Buffer());
                     }
@@ -392,7 +397,7 @@ void TestContext::outputSummary()
             }
             break;
         }
-        case TestOutputMode::eXUnit:
+        case TestOutputMode::XUnit:
         {
             // xUnit 1.0 format  
 
@@ -402,11 +407,11 @@ void TestContext::outputSummary()
 
             for (const auto& testInfo : m_testInfos)
             {
-                const int numFailed = (testInfo.testResult == TestResult::eFail);
-                const int numIgnored = (testInfo.testResult == TestResult::eIgnored);
+                const int numFailed = (testInfo.testResult == TestResult::Fail);
+                const int numIgnored = (testInfo.testResult == TestResult::Ignored);
                 //int numPassed = (testInfo.testResult == TestResult::ePass);
 
-                if (testInfo.testResult == TestResult::ePass)
+                if (testInfo.testResult == TestResult::Pass)
                 {
                     printf("    <testcase name=\"%s\" status=\"run\"/>\n", testInfo.name.Buffer());
                 }
@@ -415,7 +420,7 @@ void TestContext::outputSummary()
                     printf("    <testcase name=\"%s\" status=\"run\">\n", testInfo.name.Buffer());
                     switch (testInfo.testResult)
                     {
-                        case TestResult::eFail:
+                        case TestResult::Fail:
                         {
                             StringBuilder buf;
                             appendXmlEncode(testInfo.message, buf);
@@ -425,7 +430,7 @@ void TestContext::outputSummary()
                             printf("      </error>\n");
                             break;
                         }
-                        case TestResult::eIgnored:
+                        case TestResult::Ignored:
                         {
                             printf("      <skip>Ignored</skip>\n");
                             break;
@@ -440,7 +445,7 @@ void TestContext::outputSummary()
             printf("</testSuites>\n");
             break;
         }
-        case TestOutputMode::eXUnit2:
+        case TestOutputMode::XUnit2:
         {
             // https://xunit.github.io/docs/format-xml-v2
             assert("Not currently supported");
diff --git a/tools/slang-test/test-context.h b/tools/slang-test/test-context.h
index 22042a4e6..853bd3015 100644
--- a/tools/slang-test/test-context.h
+++ b/tools/slang-test/test-context.h
@@ -27,25 +27,27 @@ struct TestRegister
 
 enum class TestOutputMode
 {
-    eDefault = 0,   ///< Default mode is to write test results to the console
-    eAppVeyor,      ///< For AppVeyor continuous integration 
-    eTravis,        ///< We currently don't specialize for Travis, but maybe we should.
-    eXUnit,         ///< xUnit original format  https://nose.readthedocs.io/en/latest/plugins/xunit.html
-    eXUnit2,        ///< https://xunit.github.io/docs/format-xml-v2
+    Default = 0,   ///< Default mode is to write test results to the console
+    AppVeyor,      ///< For AppVeyor continuous integration 
+    Travis,        ///< We currently don't specialize for Travis, but maybe we should.
+    XUnit,         ///< xUnit original format  https://nose.readthedocs.io/en/latest/plugins/xunit.html
+    XUnit2,        ///< https://xunit.github.io/docs/format-xml-v2
 };
 
 enum class TestResult
 {
-    eIgnored,
-    ePass,
-    eFail,
+    // NOTE! Must keep in order such that combine is meaningful. That is larger values are higher precident - and a series of tests that has lots of passes
+    // and a fail, is still a fail overall. 
+    Ignored,
+    Pass,
+    Fail,
 };
 
 enum class TestMessageType
 {
-    eInfo,                   ///< General info (may not be shown depending on verbosity setting)
-    eTestFailure,           ///< Describes how a test failure took place
-    eRunError,              ///< Describes an error that caused a test not to actually correctly run
+    Info,                   ///< General info (may not be shown depending on verbosity setting)
+    TestFailure,           ///< Describes how a test failure took place
+    RunError,              ///< Describes an error that caused a test not to actually correctly run
 };
 
 class TestContext
@@ -54,7 +56,7 @@ class TestContext
 
     struct TestInfo
     {
-        TestResult testResult = TestResult::eIgnored;
+        TestResult testResult = TestResult::Ignored;
         Slang::String name;
         Slang::String message;                 ///< Message that is specific for the testResult
     };
@@ -118,9 +120,9 @@ class TestContext
     int m_failedTestCount;
     int m_ignoredTestCount;
 
-    int m_maxTestResults;                   ///< Maximum amount of results per test. If 0 it's infinite.
+    int m_maxFailTestResults;                   ///< Maximum amount of results per test. If 0 it's infinite.
 
-    TestOutputMode m_outputMode = TestOutputMode::eDefault;
+    TestOutputMode m_outputMode = TestOutputMode::Default;
     bool m_dumpOutputOnFailure;
     bool m_isVerbose;
 
@@ -130,6 +132,7 @@ protected:
     Slang::StringBuilder m_currentMessage;
     TestInfo m_currentInfo;
     int m_numCurrentResults;
+    int m_numFailResults;
 
     bool m_inTest;
     
diff --git a/tools/slang-test/unit-test-memory-arena.cpp b/tools/slang-test/unit-test-memory-arena.cpp
index 69eed520a..20a7e047d 100644
--- a/tools/slang-test/unit-test-memory-arena.cpp
+++ b/tools/slang-test/unit-test-memory-arena.cpp
@@ -123,15 +123,23 @@ static void memoryArenaUnitTest()
         blocks.Add(arena.allocate(blockSize * 2));
         blocks.Add(arena.allocate(100));
 
-        while (blocks.Count())
+        arena.deallocateAll();
+        blocks.Add(arena.allocate(100));
+        blocks.Add(arena.allocate(blockSize * 2));
+
+        arena.reset();
+
         {
-            arena.deallocateLast(blocks.Last());
-            blocks.RemoveLast();
+            uint32_t data[] = { 1, 2, 3 };
+
+            const uint32_t* copy = arena.allocateAndCopyArray(data, SLANG_COUNT_OF(data));
+
+            SLANG_CHECK(::memcmp(copy, data, sizeof(data)) == 0);
         }
     }
 
     {
-
+        int count = 0;
         const size_t blockSize = 1024;
 
         for (TestMode mode = TestMode(0); int(mode) < int(TestMode::eCount); mode = TestMode(int(mode) + 1))
@@ -143,32 +151,30 @@ static void memoryArenaUnitTest()
 
             List<Block> blocks;
 
-            for (int i = 0; i < 1000; i++)
+            for (int i = 0; i < 10000; i++)
             {
-                int var = randGen.nextInt32() & 0x3ff;
+                count++;
+
+                const int var = randGen.nextInt32() & 0x3ff;
                 if (var < 3 && blocks.Count() > 0)
                 {
-                    if (var == 0)
-                    {
-                        // Do a single dealloc
-                        arena.deallocateLast(blocks.Last().m_data);
-                        blocks.RemoveLast();
-                    }
-                    else if (var == 1)
+                    if (var == 1)
                     {
                         // Deallocate everything
                         arena.deallocateAll();
                         blocks.Clear();
+                    }   
+                    else if (var == 2)
+                    {
+                        arena.reset();
+                        blocks.Clear();
                     }
                     else
                     {
-                        // Do a multiple dealloc
-                        int index = randGen.nextInt32UpTo(int(blocks.Count()));
+                        size_t usedMemory = arena.calcTotalMemoryUsed();
+                        size_t allocatedMemory = arena.calcTotalMemoryAllocated();
 
-                        // Deallocate all afterwards
-                        arena.deallocateAllFrom(blocks[index].m_data);
-
-                        blocks.SetSize(index);
+                        SLANG_CHECK(allocatedMemory >= usedMemory);
                     }
                 }
                 else
@@ -180,6 +186,11 @@ static void memoryArenaUnitTest()
                     {
                         sizeInBytes += blockSize;
                     }
+                    else if ((randGen.nextInt32() & 0xff) < 2)
+                    {
+                        // Let's try for a block that's awkwardly sized 
+                        sizeInBytes = blockSize / 3 + 10;
+                    }
 
                     const uint8_t value = uint8_t(randGen.nextInt32());