feat: Allow profiler to respond to log level changes.

src/Agent/NewRelic/Agent/Core/Config/ConfigurationTracker.cs

@@ -21,8 +21,11 @@ public class ConfigurationTracker : IDisposable
 
         private DateTime _lastWriteTime;
 
-        public ConfigurationTracker(IConfigurationService configurationService)
+        private readonly INativeMethods _nativeMethods;
+
+        public ConfigurationTracker(IConfigurationService configurationService, INativeMethods nativeMethods)
         {
+            _nativeMethods = nativeMethods;
             var fileName = configurationService.Configuration.NewRelicConfigFilePath;
             if (fileName == null)
                 return;
@@ -39,6 +42,7 @@ public ConfigurationTracker(IConfigurationService configurationService)
                     Log.Debug("newrelic.config file changed, reloading.");
                     ConfigurationLoader.Initialize(fileName);
                     _lastWriteTime = lastWriteTime;
+                    _nativeMethods.ReloadConfiguration();
                 }
             }, TimeSpan.FromMinutes(1));
         }

src/Agent/NewRelic/Agent/Core/INativeMethods.cs

@@ -14,6 +14,7 @@ public interface INativeMethods
         void ShutdownNativeThreadProfiler();
 
         int InstrumentationRefresh();
+        int ReloadConfiguration();
         int AddCustomInstrumentation(string fileName, string xml);
         int ApplyCustomInstrumentation();
     }

src/Agent/NewRelic/Agent/Core/NativeMethods.cs

@@ -15,6 +15,9 @@ public class LinuxNativeMethods : INativeMethods
         [DllImport(DllName, EntryPoint = "InstrumentationRefresh", CallingConvention = CallingConvention.Cdecl)]
         private static extern int ExternInstrumentationRefresh();
 
+        [DllImport(DllName, EntryPoint = "ReloadConfiguration", CallingConvention = CallingConvention.Cdecl)]
+        private static extern int ExternReloadConfiguration();
+
         [DllImport(DllName, EntryPoint = "AddCustomInstrumentation", CallingConvention = CallingConvention.Cdecl)]
         private static extern int ExternAddCustomInstrumentation(string fileName, string xml);
 
@@ -34,6 +37,19 @@ public int InstrumentationRefresh()
             }
         }
 
+        public int ReloadConfiguration()
+        {
+            try
+            {
+                return ExternReloadConfiguration();
+            }
+            catch (Exception ex)
+            {
+                Log.Error(ex, "LinuxNativeMethods.ReloadConfiguration() exception");
+                return -1;
+            }
+        }
+
         public int AddCustomInstrumentation(string fileName, string xml)
         {
             return ExternAddCustomInstrumentation(fileName, xml);
@@ -84,6 +100,9 @@ public class WindowsNativeMethods : INativeMethods
         [DllImport(DllName, EntryPoint = "InstrumentationRefresh", CallingConvention = CallingConvention.Cdecl)]
         private static extern int ExternInstrumentationRefresh();
 
+        [DllImport(DllName, EntryPoint = "ReloadConfiguration", CallingConvention = CallingConvention.Cdecl)]
+        private static extern int ExternReloadConfiguration();
+
         [DllImport(DllName, EntryPoint = "AddCustomInstrumentation", CallingConvention = CallingConvention.Cdecl)]
         private static extern int ExternAddCustomInstrumentation(string fileName, string xml);
 
@@ -103,6 +122,19 @@ public int InstrumentationRefresh()
             }
         }
 
+        public int ReloadConfiguration()
+        {
+            try
+            {
+                return ExternReloadConfiguration();
+            }
+            catch (Exception ex)
+            {
+                Log.Error(ex, "WindowsNativeMethods.ReloadConfiguration() exception");
+                return -1;
+            }
+        }
+
         public int AddCustomInstrumentation(string fileName, string xml)
         {
             return ExternAddCustomInstrumentation(fileName, xml);

src/Agent/NewRelic/Profiler/Profiler/CorProfilerCallbackImpl.h

@@ -648,6 +648,15 @@ namespace NewRelic { namespace Profiler {
             return S_OK;
         }
 
+        HRESULT ReloadConfiguration()
+        {
+            LogTrace(L"Enter: ", __func__);
+
+            auto newConfiguration = InitializeConfigAndSetLogLevel();
+
+            return S_OK;
+        }
+
         std::shared_ptr<std::set<mdMethodDef>> GetMethodDefsForAssembly(
             ModuleID moduleId,
             xstring_t assemblyName,
@@ -1314,7 +1323,8 @@ namespace NewRelic { namespace Profiler {
         }
     };
 
-    // called by managed code to get function information from function IDs
+    // Called by managed code to get the profiler to update the which methods
+    // are instrumented at runtime.
     extern "C" __declspec(dllexport) HRESULT __cdecl InstrumentationRefresh()
     {
         LogInfo("Refreshing instrumentation");
@@ -1326,6 +1336,19 @@ namespace NewRelic { namespace Profiler {
         return profiler->InstrumentationRefresh();
     }
 
+    // Called by managed code to get the profiler to reload configuration settings
+    // from the newrelic.config files.
+    extern "C" __declspec(dllexport) HRESULT __cdecl ReloadConfiguration()
+    {
+        LogInfo(L"Reloading newrelic.config files.");
+        auto profiler = CorProfilerCallbackImpl::GetSingletonish();
+        if (profiler == nullptr) {
+            LogError(L"Unable to reload newrelic.config files because the profiler reference is invalid.");
+            return E_FAIL;
+        }
+        return profiler->ReloadConfiguration();
+    }
+
     extern "C" __declspec(dllexport) HRESULT __cdecl AddCustomInstrumentation(const char* fileName, const char* xml)
     {
         LogTrace("Adding custom instrumentation");