From 679d8710635b3c1e17270192293dc112871efdfa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20=C5=81ach?= <mateusza@splunk.com>
Date: Wed, 16 Nov 2022 16:39:41 +0100
Subject: [PATCH] [Instrumentation.Runtime] Reintroduce current heap size
 metric (#683)

---
 src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md      | 3 +++
 src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs | 6 ++++++
 .../RuntimeMetricsTests.cs                                  | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
index 54f797597f..beecf3ca90 100644
--- a/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
@@ -34,6 +34,9 @@
 
   This does not affect applications targeting .NET Framework.
 
+* Add "process.runtime.dotnet.gc.objects.size" metric
+  ([#683](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/683))
+
 ## 1.0.0
 
 Released 2022-Aug-03
diff --git a/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs b/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
index 32bb167ea4..ef294f29bc 100644
--- a/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
+++ b/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
@@ -48,6 +48,12 @@ static RuntimeMetrics()
             () => GetGarbageCollectionCounts(),
             description: "Number of garbage collections that have occurred since process start.");
 
+        MeterInstance.CreateObservableUpDownCounter(
+            "process.runtime.dotnet.gc.objects.size",
+            () => GC.GetTotalMemory(false),
+            unit: "bytes",
+            description: "Count of bytes currently in use by objects in the GC heap that haven't been collected yet. Fragmentation and other GC committed memory pools are excluded.");
+
 #if NET6_0_OR_GREATER
         MeterInstance.CreateObservableCounter(
             "process.runtime.dotnet.gc.allocations.size",
diff --git a/test/OpenTelemetry.Instrumentation.Runtime.Tests/RuntimeMetricsTests.cs b/test/OpenTelemetry.Instrumentation.Runtime.Tests/RuntimeMetricsTests.cs
index 27d71ee87c..d9509a5411 100644
--- a/test/OpenTelemetry.Instrumentation.Runtime.Tests/RuntimeMetricsTests.cs
+++ b/test/OpenTelemetry.Instrumentation.Runtime.Tests/RuntimeMetricsTests.cs
@@ -75,6 +75,9 @@ public void GcMetricsTest()
         var gcCountMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.collections.count");
         Assert.NotNull(gcCountMetric);
 
+        var totalObjectsSize = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.objects.size");
+        Assert.NotNull(totalObjectsSize);
+
 #if NET6_0_OR_GREATER
 
         var gcAllocationSizeMetric = exportedItems.FirstOrDefault(i => i.Name == "process.runtime.dotnet.gc.allocations.size");