process tags for profiler

profiler/src/ProfilerEngine/Datadog.Profiler.Native.Windows/Datadog.Profiler.Native.def

@@ -9,6 +9,7 @@
   SetApplicationInfoForAppDomain PRIVATE
   SetEndpointForTrace PRIVATE
   SetGitMetadataForApplication PRIVATE
+  SetProcessTagsForApplication PRIVATE
   FlushProfile PRIVATE
   CreateCrashReport PRIVATE
   SetConfiguration PRIVATE

profiler/src/ProfilerEngine/Datadog.Profiler.Native/ApplicationInfo.h

@@ -10,4 +10,5 @@ struct ApplicationInfo
     std::string Version;
     std::string RepositoryUrl;
     std::string CommitSha;
+    std::string ProcessTags;
 };

profiler/src/ProfilerEngine/Datadog.Profiler.Native/ApplicationStore.cpp

@@ -65,6 +65,13 @@ void ApplicationStore::SetGitMetadata(std::string runtimeId, std::string reposit
     // no need to create worker, it has already been created
 }
 
+void ApplicationStore::SetProcessTags(std::string runtimeId, std::string processTags)
+{
+    std::lock_guard lock(_infosLock);
+    auto& info = _infos[std::move(runtimeId)];
+    info.ProcessTags = std::move(processTags);
+}
+
 const char* ApplicationStore::GetName()
 {
     return _serviceName;

profiler/src/ProfilerEngine/Datadog.Profiler.Native/ApplicationStore.h

@@ -30,6 +30,7 @@ class ApplicationStore
     ApplicationInfo GetApplicationInfo(const std::string& runtimeId) override;
     void SetApplicationInfo(const std::string& runtimeId, const std::string& serviceName, const std::string& environment, const std::string& version) override;
     void SetGitMetadata(std::string runtimeId, std::string repositoryUrl, std::string commitSha) override;
+    void SetProcessTags(std::string runtimeId, std::string processTags) override;
 
     const char* GetName() override;
 

profiler/src/ProfilerEngine/Datadog.Profiler.Native/IApplicationStore.h

@@ -14,4 +14,5 @@ class IApplicationStore
 
     virtual void SetApplicationInfo(const std::string& runtimeId, const std::string& serviceName, const std::string& environment, const std::string& version) = 0;
     virtual void SetGitMetadata(std::string runtimeId, std::string repositoryUrl, std::string commitSha) = 0;
+    virtual void SetProcessTags(std::string runtimeId, std::string processTags) = 0;
 };

profiler/src/ProfilerEngine/Datadog.Profiler.Native/PInvoke.cpp

@@ -170,6 +170,33 @@ extern "C" void __stdcall SetGitMetadataForApplication(const char* runtimeId, co
     );
 }
 
+extern "C" void __stdcall SetProcessTagsForApplication(const char* runtimeId, const char* processTags)
+{
+    const auto profiler = CorProfilerCallback::GetInstance();
+
+    if (profiler == nullptr)
+    {
+        Log::Error("SetProcessTagsForApplication is called BEFORE CLR initialize");
+        return;
+    }
+
+    if (!profiler->GetClrLifetime()->IsRunning())
+    {
+        return;
+    }
+
+    if (runtimeId == nullptr)
+    {
+        Log::Error("SetProcessTagsForApplication was called with an empty runtime id");
+        return;
+    }
+
+    profiler->GetApplicationStore()->SetProcessTags(
+        runtimeId,
+        processTags != nullptr ? processTags : std::string()
+    );
+}
+
 extern "C" void __stdcall FlushProfile()
 {
     const auto profiler = CorProfilerCallback::GetInstance();

profiler/src/ProfilerEngine/Datadog.Profiler.Native/ProfileExporter.cpp

@@ -645,6 +645,10 @@ bool ProfileExporter::Export(bool lastCall)
         {
             additionalTags.Add("git.commit.sha", applicationInfo.CommitSha);
         }
+        if (!applicationInfo.ProcessTags.empty())
+        {
+            additionalTags.Add("_dd.tags.process", applicationInfo.ProcessTags);
+        }
 
         auto filesToSend = std::vector<std::pair<std::string, std::string>>{};
 

tracer/src/Datadog.Trace/ContinuousProfiler/NativeInterop.cs

@@ -48,6 +48,12 @@ public static void SetGitMetadata(string runtimeId, string repositoryUrl, string
             NativeMethods.SetGitMetadata(runtimeId, repositoryUrl, commitSha);
         }
 
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        public static void SetProcessTags(string runtimeId, string processTagsValue)
+        {
+            NativeMethods.SetProcessTags(runtimeId, processTagsValue);
+        }
+
         [MethodImpl(MethodImplOptions.NoInlining)]
         public static void FlushProfile()
         {
@@ -103,6 +109,9 @@ private static class NativeMethods
             [DllImport(dllName: "Datadog.Profiler.Native", EntryPoint = "SetGitMetadataForApplication")]
             public static extern void SetGitMetadata(string runtimeId, string repositoryUrl, string commitSha);
 
+            [DllImport(dllName: "Datadog.Profiler.Native", EntryPoint = "SetProcessTagsForApplication")]
+            public static extern void SetProcessTags(string runtimeId, string processTagsValue);
+
             [DllImport(dllName: "Datadog.Profiler.Native", EntryPoint = "FlushProfile")]
             public static extern void FlushProfile();
 

tracer/src/Datadog.Trace/ProcessTags.cs

@@ -8,15 +8,18 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Text;
 using Datadog.Trace.Configuration;
+using Datadog.Trace.ContinuousProfiler;
+using Datadog.Trace.Logging;
 using Datadog.Trace.Processors;
 using Datadog.Trace.Util;
 
 namespace Datadog.Trace;
 
 internal static class ProcessTags
 {
+    private static readonly IDatadogLogger Log = DatadogLogging.GetLoggerFor(typeof(ProcessTags));
+
     public const string EntrypointName = "entrypoint.name";
     public const string EntrypointBasedir = "entrypoint.basedir";
     public const string EntrypointWorkdir = "entrypoint.workdir";
@@ -60,7 +63,12 @@ private static string GetSerializedTags()
         }
 
         serializedTags.Remove(serializedTags.Length - 1, length: 1); // remove last comma
-        return StringBuilderCache.GetStringAndRelease(serializedTags);
+        var tagsValues = StringBuilderCache.GetStringAndRelease(serializedTags);
+
+        // also send the tags to the profiler to tag profiles
+        PropagateProcessTagsToProfiler(tagsValues);
+
+        return tagsValues;
     }
 
     private static string NormalizeTagValue(string tagValue)
@@ -69,4 +77,20 @@ private static string NormalizeTagValue(string tagValue)
         // which we don't want because we use it as a key/value separator.
         return TraceUtil.NormalizeTag(tagValue).Replace(oldChar: ':', newChar: '_');
     }
+
+    private static void PropagateProcessTagsToProfiler(string values)
+    {
+        try
+        {
+            // Avoid P/Invoke if the profiler is not ready
+            if (Profiler.Instance.Status.IsProfilerReady && !string.IsNullOrEmpty(values))
+            {
+                NativeInterop.SetProcessTags(RuntimeId.Get(), values);
+            }
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Failed to share process tags with the Continuous Profiler.");
+        }
+    }
 }