Remove Net452 from API project

src/OpenTelemetry.Api/.publicApi/net461/PublicAPI.Unshipped.txt

@@ -0,0 +1,4 @@
+override OpenTelemetry.Context.AsyncLocalRuntimeContextSlot<T>.Get() -> T
+override OpenTelemetry.Context.AsyncLocalRuntimeContextSlot<T>.Set(T value) -> void
+OpenTelemetry.Context.AsyncLocalRuntimeContextSlot<T>
+OpenTelemetry.Context.AsyncLocalRuntimeContextSlot<T>.AsyncLocalRuntimeContextSlot(string name) -> void

src/OpenTelemetry.Api/CHANGELOG.md

@@ -9,6 +9,9 @@ please check the latest changes
 
 ## Unreleased
 
+* Removes .NET Framework 4.5.2 support. The minimum .NET Framework
+  version supported is .NET 4.6.1. ([#2138](https://github.com/open-telemetry/opentelemetry-dotnet/issues/2138))
+
 ## 1.1.0
 
 Released 2021-Jul-12

src/OpenTelemetry.Api/Context/AsyncLocalRuntimeContextSlot.cs

@@ -14,7 +14,6 @@
 // limitations under the License.
 // </copyright>
 
-#if !NET452
 using System.Runtime.CompilerServices;
 using System.Threading;
 
@@ -53,4 +52,3 @@ public override void Set(T value)
         }
     }
 }
-#endif

src/OpenTelemetry.Api/Context/RemotingRuntimeContextSlot.cs

@@ -14,7 +14,7 @@
 // limitations under the License.
 // </copyright>
 
-#if NET452
+#if NET461
 using System.Collections;
 using System.Reflection;
 using System.Runtime.CompilerServices;

src/OpenTelemetry.Api/Context/RuntimeContext.cs

@@ -30,11 +30,7 @@ public static class RuntimeContext
         /// <summary>
         /// Gets or sets the actual context carrier implementation.
         /// </summary>
-#if !NET452
         public static Type ContextSlotType { get; set; } = typeof(AsyncLocalRuntimeContextSlot<>);
-#else
-        public static Type ContextSlotType { get; set; } = typeof(RemotingRuntimeContextSlot<>);
-#endif
 
         /// <summary>
         /// Register a named context slot.

src/OpenTelemetry.Api/OpenTelemetry.Api.csproj

@@ -1,13 +1,19 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <Description>OpenTelemetry .NET API</Description>
     <RootNamespace>OpenTelemetry</RootNamespace>
 
     <NoWarn>$(NoWarn),CS0618</NoWarn>
     <MinVerTagPrefix>core-</MinVerTagPrefix>
   </PropertyGroup>
 
+  <!--Do not run ApiCopmat for net461 as this is newly added. There is no existing contract for net461 against which we could compare the implementation.
+  Remove this property once we have released a stable net461 version.-->
+  <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
+    <RunApiCompat>false</RunApiCompat>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="$(SystemDiagnosticSourcePkgVer)" />
     <PackageReference Include="System.Reflection.Emit.Lightweight" Version="$(SystemReflectionEmitLightweightPkgVer)" />

src/OpenTelemetry.Exporter.Zipkin/OpenTelemetry.Exporter.Zipkin.csproj

@@ -22,7 +22,7 @@
 
   <ItemGroup>
     <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry\OpenTelemetry.csproj" />
-    <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonPkgVer)" Condition="'$(TargetFramework)' != 'net452'" />
+    <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonPkgVer)" />
   </ItemGroup>
 
 </Project>

src/OpenTelemetry.Exporter.Zipkin/ZipkinExporter.cs

@@ -22,11 +22,7 @@
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Net.Sockets;
-#if NET452
-using Newtonsoft.Json;
-#else
 using System.Text.Json;
-#endif
 using System.Threading;
 using System.Threading.Tasks;
 using OpenTelemetry.Exporter.Zipkin.Implementation;
@@ -40,9 +36,7 @@ namespace OpenTelemetry.Exporter
     public class ZipkinExporter : BaseExporter<Activity>
     {
         private readonly ZipkinExporterOptions options;
-#if !NET452
         private readonly int maxPayloadSizeInBytes;
-#endif
         private readonly HttpClient httpClient;
 
         /// <summary>
@@ -53,9 +47,7 @@ public class ZipkinExporter : BaseExporter<Activity>
         public ZipkinExporter(ZipkinExporterOptions options, HttpClient client = null)
         {
             this.options = options ?? throw new ArgumentNullException(nameof(options));
-#if !NET452
             this.maxPayloadSizeInBytes = (!options.MaxPayloadSizeInBytes.HasValue || options.MaxPayloadSizeInBytes <= 0) ? ZipkinExporterOptions.DefaultMaxPayloadSizeInBytes : options.MaxPayloadSizeInBytes.Value;
-#endif
             this.httpClient = client ?? new HttpClient();
         }
 
@@ -196,12 +188,7 @@ private class JsonContent : HttpContent
 
             private readonly ZipkinExporter exporter;
             private readonly Batch<Activity> batch;
-
-#if NET452
-            private JsonWriter writer;
-#else
             private Utf8JsonWriter writer;
-#endif
 
             public JsonContent(ZipkinExporter exporter, in Batch<Activity> batch)
             {
@@ -213,10 +200,6 @@ public JsonContent(ZipkinExporter exporter, in Batch<Activity> batch)
 
             protected override Task SerializeToStreamAsync(Stream stream, TransportContext context)
             {
-#if NET452
-                StreamWriter streamWriter = new StreamWriter(stream);
-                this.writer = new JsonTextWriter(streamWriter);
-#else
                 if (this.writer == null)
                 {
                     this.writer = new Utf8JsonWriter(stream);
@@ -225,7 +208,6 @@ protected override Task SerializeToStreamAsync(Stream stream, TransportContext c
                 {
                     this.writer.Reset(stream);
                 }
-#endif
 
                 this.writer.WriteStartArray();
 
@@ -236,23 +218,16 @@ protected override Task SerializeToStreamAsync(Stream stream, TransportContext c
                     zipkinSpan.Write(this.writer);
 
                     zipkinSpan.Return();
-#if !NET452
                     if (this.writer.BytesPending >= this.exporter.maxPayloadSizeInBytes)
                     {
                         this.writer.Flush();
                     }
-#endif
                 }
 
                 this.writer.WriteEndArray();
 
                 this.writer.Flush();
-
-#if NET452
-                return Task.FromResult(true);
-#else
                 return Task.CompletedTask;
-#endif
             }
 
             protected override bool TryComputeLength(out long length)

src/OpenTelemetry.Exporter.Zipkin/ZipkinExporterOptions.cs

@@ -24,9 +24,7 @@ namespace OpenTelemetry.Exporter
     /// </summary>
     public sealed class ZipkinExporterOptions
     {
-#if !NET452
         internal const int DefaultMaxPayloadSizeInBytes = 4096;
-#endif
 
         /// <summary>
         /// Gets or sets Zipkin endpoint address. See https://zipkin.io/zipkin-api/#/default/post_spans.
@@ -39,12 +37,10 @@ public sealed class ZipkinExporterOptions
         /// </summary>
         public bool UseShortTraceIds { get; set; }
 
-#if !NET452
         /// <summary>
         /// Gets or sets the maximum payload size in bytes. Default value: 4096.
         /// </summary>
         public int? MaxPayloadSizeInBytes { get; set; } = DefaultMaxPayloadSizeInBytes;
-#endif
 
         /// <summary>
         /// Gets or sets the export processor type to be used with Zipkin Exporter.