feat: Use SocketsHttpHandler to configure HttpClient in .NET 6+

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

@@ -325,10 +325,10 @@ public async Task TryInjectBrowserScriptAsync(string contentType, string request
             if (rumBytes == null)
             {
                 transaction.LogFinest("Skipping RUM Injection: No script was available.");
-                await baseStream.WriteAsync(buffer, 0, buffer.Length);
+                await baseStream.WriteAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
             }
             else
-                await BrowserScriptInjectionHelper.InjectBrowserScriptAsync(buffer, baseStream, rumBytes, transaction);
+                await BrowserScriptInjectionHelper.InjectBrowserScriptAsync(buffer, baseStream, rumBytes, transaction).ConfigureAwait(false);
         }
 
         private string TryGetRUMScriptInternal(string contentType, string requestPath)

src/Agent/NewRelic/Agent/Core/AgentShim.cs

@@ -21,14 +21,15 @@ static void Initialize()
         }
 
         private static bool _initialized = false;
-        private static object _initLock = new object();
+        private static SemaphoreSlim _lockSemaphore = new SemaphoreSlim(1, 1);
 
         static bool TryInitialize(string method)
         {
-            if (Monitor.IsEntered(_initLock)) return false;
+            if (_lockSemaphore.CurrentCount == 0) return false;
             if (DeferInitialization(method)) return false;
 
-            lock (_initLock)
+            _lockSemaphore.Wait();
+            try
             {
                 if (!_initialized)
                 {
@@ -38,6 +39,10 @@ static bool TryInitialize(string method)
 
                 return true;
             }
+            finally
+            {
+                _lockSemaphore.Release();
+            }
         }
 
         private static HashSet<string> _deferInitializationOnTheseMethods = new HashSet<string>

src/Agent/NewRelic/Agent/Core/Aggregators/CustomEventAggregator.cs

@@ -89,14 +89,16 @@ protected void InternalHarvest(string transactionId = null)
             var customEvents = originalCustomEvents.Where(node => node != null).Select(node => node.Data).ToList();
 
             // if we don't have any events to publish then don't
-            if (customEvents.Count <= 0)
-                return;
+            var eventCount = customEvents.Count;
+            if (eventCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(customEvents, transactionId);
 
-            var responseStatus = DataTransportService.Send(customEvents, transactionId);
+                HandleResponse(responseStatus, customEvents);
+            }
 
-            HandleResponse(responseStatus, customEvents);
+            Log.Finest($"Custom Event harvest finished. {eventCount} event(s) sent.");
 
-            Log.Finest("Custom Event harvest finished.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/ErrorEventAggregator.cs

@@ -99,14 +99,15 @@ protected void InternalHarvest(string transactionId = null)
             var eventHarvestData = new EventHarvestData(originalErrorEvents.Size, originalErrorEvents.GetAddAttemptsCount());
 
             // if we don't have any events to publish then don't
-            if (aggregatedEvents.Count <= 0)
-                return;
-
-            var responseStatus = DataTransportService.Send(eventHarvestData, aggregatedEvents, transactionId);
+            var eventCount = aggregatedEvents.Count;
+            if (eventCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(eventHarvestData, aggregatedEvents, transactionId);
 
-            HandleResponse(responseStatus, aggregatedEvents);
+                HandleResponse(responseStatus, aggregatedEvents);
+            }
 
-            Log.Finest("Error Event harvest finished.");
+            Log.Finest($"Error Event harvest finished. {eventCount} event(s) sent.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/ErrorTraceAggregator.cs

@@ -79,14 +79,16 @@ protected void InternalHarvest(string transactionId = null)
                 _readerWriterLock.ExitWriteLock();
             }
 
-            if (errorTraceWireModels.Count <= 0)
-                return;
-
-            var responseStatus = DataTransportService.Send(errorTraceWireModels, transactionId);
+            // if we don't have any events to publish then don't
+            var traceCount = errorTraceWireModels.Count;
+            if (traceCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(errorTraceWireModels, transactionId);
 
-            HandleResponse(responseStatus, errorTraceWireModels);
+                HandleResponse(responseStatus, errorTraceWireModels);
+            }
 
-            Log.Finest("Error Trace harvest finished.");
+            Log.Finest($"Error Trace harvest finished. {traceCount} trace(s) sent.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/LogEventAggregator.cs

@@ -88,28 +88,27 @@ protected void InternalHarvest(string transactionId = null)
             Interlocked.Add(ref _logsDroppedCount, originalLogEvents.GetAndResetDroppedItemCount());
 
             // if we don't have any events to publish then don't
-            if (aggregatedEvents.Count <= 0)
+            var eventCount = aggregatedEvents.Count;
+            if (eventCount > 0)
             {
-                return;
-            }
+                // matches metadata so that utilization and this match
+                var hostname = !string.IsNullOrEmpty(_configuration.UtilizationFullHostName)
+                    ? _configuration.UtilizationFullHostName
+                    : _configuration.UtilizationHostName;
 
-            // matches metadata so that utilization and this match
-            var hostname = !string.IsNullOrEmpty(_configuration.UtilizationFullHostName)
-                ? _configuration.UtilizationFullHostName
-                : _configuration.UtilizationHostName;
+                var modelsCollection = new LogEventWireModelCollection(
+                    _configuration.ApplicationNames.ElementAt(0),
+                    _configuration.EntityGuid,
+                    hostname,
+                    _configuration.LabelsEnabled ? _labelsService.GetFilteredLabels(_configuration.LabelsExclude) : [],
+                    aggregatedEvents);
 
-            var modelsCollection = new LogEventWireModelCollection(
-                _configuration.ApplicationNames.ElementAt(0),
-                _configuration.EntityGuid,
-                hostname,
-                _configuration.LabelsEnabled ? _labelsService.GetFilteredLabels(_configuration.LabelsExclude) : [],
-                aggregatedEvents);
+                var responseStatus = DataTransportService.Send(modelsCollection, transactionId);
 
-            var responseStatus = DataTransportService.Send(modelsCollection, transactionId);
-
-            HandleResponse(responseStatus, aggregatedEvents);
+                HandleResponse(responseStatus, aggregatedEvents);
+            }
 
-            Log.Finest("Log Event harvest finished.");
+            Log.Finest($"Log Event harvest finished. {eventCount} event(s) sent.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/MetricAggregator.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using NewRelic.Agent.Core.DataTransport;
 using NewRelic.Agent.Core.Events;
 using NewRelic.Agent.Core.Metrics;
@@ -75,12 +76,16 @@ protected void InternalHarvest(string transactionId = null)
             var oldMetrics = GetStatsCollectionForHarvest();
 
             oldMetrics.MergeUnscopedStats(MetricNames.SupportabilityMetricHarvestTransmit, MetricDataWireModel.BuildCountData());
-            var metricsToSend = oldMetrics.ConvertToJsonForSending(_metricNameService);
+            var metricsToSend = oldMetrics.ConvertToJsonForSending(_metricNameService).ToList();
 
-            var responseStatus = DataTransportService.Send(metricsToSend, transactionId);
-            HandleResponse(responseStatus, metricsToSend);
+            var metricCount = metricsToSend.Count;
+            if (metricCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(metricsToSend, transactionId);
+                HandleResponse(responseStatus, metricsToSend);
+            }
 
-            Log.Debug("Metric harvest finished.");
+            Log.Finest($"Metric harvest finished. {metricCount} metric(s) sent.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/SpanEventAggregator.cs

@@ -123,16 +123,16 @@ protected void InternalHarvest(string transactionId = null)
 
             var eventHarvestData = new EventHarvestData(spanEventsPriorityQueue.Size, spanEventsPriorityQueue.GetAddAttemptsCount());
             var wireModels = spanEventsPriorityQueue.Where(node => null != node).Select(node => node.Data).ToList();
-
-            // if we don't have any events to publish then don't
-            if (wireModels.Count <= 0)
-                return;
-
-            var responseStatus = DataTransportService.Send(eventHarvestData, wireModels, transactionId);
 
-            HandleResponse(responseStatus, wireModels);
+            // if we don't have any events to publish then don't
+            var eventCount = wireModels.Count;
+            if (eventCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(eventHarvestData, wireModels, transactionId);
+                HandleResponse(responseStatus, wireModels);
+            }
 
-            Log.Finest("Span Event harvest finished.");
+            Log.Finest($"Span Event harvest finished. {eventCount} event(s) sent.");
         }
 
         private void ReduceReservoirSize(int newSize)

src/Agent/NewRelic/Agent/Core/Aggregators/SqlTraceAggregator.cs

@@ -66,14 +66,15 @@ protected void InternalHarvest(string transactionId = null)
                 .Take(_configuration.SqlTracesPerPeriod)
                 .ToList();
 
-            if (!slowestTraces.Any())
-                return;
-
-            var responseStatus = DataTransportService.Send(slowestTraces, transactionId);
-
-            HandleResponse(responseStatus, slowestTraces);
+            // if we don't have any traces to publish then don't
+            var traceCount = slowestTraces.Count;
+            if (traceCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(slowestTraces, transactionId);
+                HandleResponse(responseStatus, slowestTraces);
+            }
 
-            Log.Finest("SQL Trace harvest finished.");
+            Log.Finest($"SQL Trace harvest finished. {traceCount} trace(s) sent.");
         }
 
         private void HandleResponse(DataTransportResponseStatus responseStatus, ICollection<SqlTraceWireModel> traces)

src/Agent/NewRelic/Agent/Core/Aggregators/TransactionEventAggregator.cs

@@ -96,14 +96,16 @@ protected void InternalHarvest(string transactionId = null)
             var eventHarvestData = new EventHarvestData(originalTransactionEvents.Size, originalTransactionEvents.GetAddAttemptsCount());
 
             // if we don't have any events to publish then don't
-            if (aggregatedEvents.Count <= 0)
-                return;
+            var eventCount = aggregatedEvents.Count;
+            if (eventCount > 0)
+            {
+                var responseStatus = DataTransportService.Send(eventHarvestData, aggregatedEvents, transactionId);
 
-            var responseStatus = DataTransportService.Send(eventHarvestData, aggregatedEvents, transactionId);
+                HandleResponse(responseStatus, aggregatedEvents);
+            }
 
-            HandleResponse(responseStatus, aggregatedEvents);
+            Log.Finest($"Transaction Event harvest finished. {eventCount} event(s) sent.");
 
-            Log.Finest("Transaction Event harvest finished.");
         }
 
         protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)

src/Agent/NewRelic/Agent/Core/Aggregators/TransactionTraceAggregator.cs

@@ -49,6 +49,8 @@ public override void Collect(TransactionTraceWireModelComponents transactionTrac
 
         protected void InternalHarvest(string transactionId = null)
         {
+            Log.Finest("Transaction Trace harvest starting.");
+
             var traceSamples = _transactionCollectors
                 .Where(t => t != null)
                 .SelectMany(t => t.GetCollectedSamples())
@@ -59,13 +61,17 @@ protected void InternalHarvest(string transactionId = null)
                 .Select(t => t.CreateWireModel())
                 .ToList();
 
-            if (!traceWireModels.Any())
-                return;
+            // if we don't have any traces to publish then don't
+            var traceCount = traceWireModels.Count;
+            if (traceCount > 0)
+            {
+                LogUnencodedTraceData(traceWireModels);
 
-            LogUnencodedTraceData(traceWireModels);
+                var responseStatus = DataTransportService.Send(traceWireModels, transactionId);
+                HandleResponse(responseStatus, traceSamples);
+            }
 
-            var responseStatus = DataTransportService.Send(traceWireModels, transactionId);
-            HandleResponse(responseStatus, traceSamples);
+            Log.Finest($"Transaction Trace harvest finished. {traceCount} trace(s) sent.");
         }
 
         private void HandleResponse(DataTransportResponseStatus responseStatus, ICollection<TransactionTraceWireModelComponents> traceSamples)

src/Agent/NewRelic/Agent/Core/BrowserMonitoring/BrowserScriptInjectionHelper.cs

@@ -25,7 +25,7 @@ public static async Task InjectBrowserScriptAsync(byte[] buffer, Stream baseStre
             {
                 // not found, can't inject anything
                 transaction?.LogFinest("Skipping RUM Injection: No suitable location found to inject script.");
-                await baseStream.WriteAsync(buffer, 0, buffer.Length);
+                await baseStream.WriteAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
                 return;
             }
 
@@ -34,13 +34,13 @@ public static async Task InjectBrowserScriptAsync(byte[] buffer, Stream baseStre
             if (index < buffer.Length) // validate index is less than buffer length
             {
                 // Write everything up to the insertion index
-                await baseStream.WriteAsync(buffer, 0, index);
+                await baseStream.WriteAsync(buffer, 0, index).ConfigureAwait(false);
 
                 // Write the RUM script
                 await baseStream.WriteAsync(rumBytes, 0, rumBytes.Length);
 
                 // Write the rest of the doc, starting after the insertion index
-                await baseStream.WriteAsync(buffer, index, buffer.Length - index);
+                await baseStream.WriteAsync(buffer, index, buffer.Length - index).ConfigureAwait(false);
             }
             else
                 transaction?.LogFinest($"Skipping RUM Injection: Insertion index was invalid.");

src/Agent/NewRelic/Agent/Core/DataTransport/Client/HttpClientBase.cs

@@ -66,7 +66,7 @@ protected void TestConnection()
                     wc.DownloadString(testAddress);
                 }
 #else
-                _lazyHttpClient.Value.GetAsync(testAddress).GetAwaiter().GetResult();
+                _lazyHttpClient.Value.GetAsync(testAddress).ConfigureAwait(false).GetAwaiter().GetResult();
 #endif
                 Log.Info("Connection test to \"{0}\" succeeded", testAddress);
             }

src/Agent/NewRelic/Agent/Core/DataTransport/Client/HttpClientWrapper.cs

@@ -1,14 +1,13 @@
-// Copyright 2020 New Relic, Inc. All rights reserved.
+// Copyright 2020 New Relic, Inc. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 #if !NETFRAMEWORK
 using System;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
-using NewRelic.Agent.Configuration;
-using NewRelic.Agent.Core.Config;
 using NewRelic.Agent.Core.DataTransport.Client.Interfaces;
+using NewRelic.Agent.Extensions.Logging;
 
 namespace NewRelic.Agent.Core.DataTransport.Client
 {
@@ -31,19 +30,20 @@ public void Dispose()
 
         public async Task<IHttpResponseMessageWrapper> SendAsync(HttpRequestMessage message)
         {
-            var cts = new CancellationTokenSource(_timeoutMilliseconds);
-            return new HttpResponseMessageWrapper(await _httpClient.SendAsync(message, cts.Token));
-        }
-
-        public TimeSpan Timeout
-        {
-            get
+            using var cts = new CancellationTokenSource(_timeoutMilliseconds);
+            try
             {
-                return _httpClient.Timeout;
+                // .ConfigureAwait(false) is used to avoid deadlocks.
+                var httpResponseMessage = await _httpClient.SendAsync(message, cts.Token).ConfigureAwait(false);
+                return new HttpResponseMessageWrapper(httpResponseMessage);
             }
-            set
+            catch (Exception e)
             {
-                _httpClient.Timeout = value;
+                Log.Debug(cts.IsCancellationRequested
+                    ? $"HttpClient.SendAsync() timed out after {_timeoutMilliseconds}ms."
+                    : $"HttpClient.SendAsync() threw an unexpected exception: {e}");
+
+                throw;
             }
         }
     }

src/Agent/NewRelic/Agent/Core/DataTransport/Client/HttpContentWrapper.cs

@@ -22,7 +22,7 @@ public HttpContentWrapper(HttpContent httpContent)
 
         public Stream ReadAsStream()
         {
-            return _httpContent.ReadAsStreamAsync().GetAwaiter().GetResult();
+            return _httpContent.ReadAsStreamAsync().ConfigureAwait(false).GetAwaiter().GetResult();
         }
 
         public IHttpContentHeadersWrapper Headers => new HttpContentHeadersWrapper(_httpContent.Headers);

src/Agent/NewRelic/Agent/Core/DataTransport/Client/HttpResponse.cs

@@ -48,7 +48,7 @@ public string GetContent()
                 using (responseStream)
                 using (var reader = new StreamReader(responseStream, Encoding.UTF8))
                 {
-                    var responseBody = reader.ReadLineAsync().GetAwaiter().GetResult();
+                    var responseBody = reader.ReadLineAsync().ConfigureAwait(false).GetAwaiter().GetResult();
 
                     if (responseBody != null)
                     {

src/Agent/NewRelic/Agent/Core/DataTransport/Client/Interfaces/IHttpClientFactory.cs

@@ -1,4 +1,4 @@
-// Copyright 2020 New Relic, Inc. All rights reserved.
+// Copyright 2020 New Relic, Inc. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 using System.Net;
@@ -8,6 +8,6 @@ namespace NewRelic.Agent.Core.DataTransport.Client.Interfaces
 {
     public interface IHttpClientFactory
     {
-        public IHttpClient CreateClient(IWebProxy proxy, IConfiguration configuration);
+        public IHttpClient GetOrCreateClient(IWebProxy proxy, IConfiguration configuration);
     }
 }