Don't warn when deferring an on-demand unload

src/class_loader.cpp

@@ -72,6 +72,16 @@ ClassLoader::~ClassLoader()
     "%s",
     "class_loader.ClassLoader: Destroying class loader, "
     "unloading associated library...\n");
+  {
+    // The deferred on-demand unload in onPluginDeletion() can't happen once this loader is gone.
+    std::lock_guard<std::recursive_mutex> lock(plugin_ref_count_mutex_);
+    if (plugin_ref_count_ > 0 && isOnDemandLoadUnloadEnabled()) {
+      CONSOLE_BRIDGE_logWarn(
+        "%s",
+        "class_loader.ClassLoader: SEVERE WARNING!!! "
+        "Destroying ClassLoader while objects created by it exist in the heap!");
+    }
+  }
   unloadLibrary();  // TODO(mikaelarguedas): while(unloadLibrary() > 0){} ??
 }
 
@@ -123,7 +133,9 @@ int ClassLoader::unloadLibraryInternal(bool lock_plugin_ref_count)
   std::lock_guard<std::recursive_mutex> load_ref_lock(load_ref_count_mutex_);
 
   try {
-    if (plugin_ref_count_ > 0) {
+    if (plugin_ref_count_ > 0 && isOnDemandLoadUnloadEnabled()) {
+      // Expected: onPluginDeletion() unloads the library once the last object is destroyed.
+    } else if (plugin_ref_count_ > 0) {
       CONSOLE_BRIDGE_logWarn(
         "%s",
         "class_loader.ClassLoader: SEVERE WARNING!!! "

test/unique_ptr_test.cpp

@@ -37,6 +37,7 @@
 #include <tuple>
 #include <vector>
 
+#include "console_bridge/console.h"
 #include "gtest/gtest.h"
 
 #include "class_loader/class_loader.hpp"
@@ -48,6 +49,18 @@ const std::string LIBRARY_1 = class_loader::systemLibraryFormat("class_loader_Te
 const std::string LIBRARY_2 = class_loader::systemLibraryFormat("class_loader_TestPlugins2");  // NOLINT
 const std::string LIBRARY_3 = class_loader::systemLibraryFormat("class_loader_TestPlugins3");  // NOLINT
 
+// Collects console_bridge warnings and errors logged while in scope.
+struct WarningCapture : console_bridge::OutputHandler
+{
+  WarningCapture() {console_bridge::useOutputHandler(this);}
+  ~WarningCapture() override {console_bridge::restorePreviousOutputHandler();}
+  void log(const std::string & text, console_bridge::LogLevel level, const char *, int) override
+  {
+    if (level >= console_bridge::CONSOLE_BRIDGE_LOG_WARN) {warnings += text;}
+  }
+  std::string warnings;
+};
+
 using class_loader::ClassLoader;
 
 TEST(ClassLoaderUniquePtrTest, basicLoad) {
@@ -297,6 +310,7 @@ TEST(MultiClassLoaderUniquePtrTest, nonLazyLoad) {
 }
 TEST(MultiClassLoaderUniquePtrTest, noWarningOnLazyLoad) {
   try {
+    WarningCapture capture;
     ClassLoader::UniquePtr<Base> cat, dog, rob;
     {
       class_loader::MultiLibraryClassLoader loader(true);
@@ -310,6 +324,7 @@ TEST(MultiClassLoaderUniquePtrTest, noWarningOnLazyLoad) {
     cat->saySomething();
     dog->saySomething();
     rob->saySomething();
+    EXPECT_EQ("", capture.warnings);
   } catch (class_loader::ClassLoaderException & e) {
     FAIL() << "ClassLoaderException: " << e.what() << "\n";
   }

test/utest.cpp

@@ -44,6 +44,7 @@
 #include "class_loader/class_loader.hpp"
 #include "class_loader/multi_library_class_loader.hpp"
 
+#include "console_bridge/console.h"
 #include "gtest/gtest.h"
 
 #include "./base.hpp"
@@ -57,6 +58,18 @@ const std::string LIBRARY_3 = class_loader::systemLibraryFormat("class_loader_Te
 const std::string GLOBAL_PLUGINS =  // NOLINT
   class_loader::systemLibraryFormat("class_loader_TestGlobalPlugins");
 
+// Collects console_bridge warnings and errors logged while in scope.
+struct WarningCapture : console_bridge::OutputHandler
+{
+  WarningCapture() {console_bridge::useOutputHandler(this);}
+  ~WarningCapture() override {console_bridge::restorePreviousOutputHandler();}
+  void log(const std::string & text, console_bridge::LogLevel level, const char *, int) override
+  {
+    if (level >= console_bridge::CONSOLE_BRIDGE_LOG_WARN) {warnings += text;}
+  }
+  std::string warnings;
+};
+
 TEST(ClassLoaderTest, basicLoad) {
   try {
     class_loader::ClassLoader loader1(LIBRARY_1, false);
@@ -419,6 +432,7 @@ TEST(MultiClassLoaderTest, nonLazyLoad) {
 }
 TEST(MultiClassLoaderTest, noWarningOnLazyLoad) {
   try {
+    WarningCapture capture;
     std::shared_ptr<Base> cat, dog, rob;
     {
       class_loader::MultiLibraryClassLoader loader(true);
@@ -432,6 +446,7 @@ TEST(MultiClassLoaderTest, noWarningOnLazyLoad) {
     cat->saySomething();
     dog->saySomething();
     rob->saySomething();
+    EXPECT_EQ("", capture.warnings);
   } catch (class_loader::ClassLoaderException & e) {
     FAIL() << "ClassLoaderException: " << e.what() << "\n";
   }