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| 1 | +// Licensed to the .NET Foundation under one or more agreements. |
| 2 | +// The .NET Foundation licenses this file to you under the MIT license. |
| 3 | + |
| 4 | +using System; |
| 5 | +using System.Collections.Generic; |
| 6 | +using System.Diagnostics; |
| 7 | +using System.Diagnostics.Tracing; |
| 8 | +using System.Linq; |
| 9 | +using System.Threading; |
| 10 | +using System.Threading.Tasks; |
| 11 | +using Microsoft.Diagnostics.NETCore.Client; |
| 12 | +using Microsoft.Diagnostics.Tracing; |
| 13 | +using Xunit; |
| 14 | + |
| 15 | +namespace BasicEventSourceTests |
| 16 | +{ |
| 17 | + /// <summary> |
| 18 | + /// Implementation of Listener for EventPipe (in-process collection using DiagnosticsClient + EventPipeEventSource). |
| 19 | + /// </summary> |
| 20 | + internal sealed class EventPipeListener : Listener |
| 21 | + { |
| 22 | + private readonly List<(string eventSourceName, EventCommand command, FilteringOptions options)> _pendingCommands = new(); |
| 23 | + private readonly Dictionary<string, FilteringOptions> _enabled = new(StringComparer.Ordinal); |
| 24 | + private EventPipeSession _session; |
| 25 | + private Task _processingTask; |
| 26 | + private bool _disposed; |
| 27 | + |
| 28 | + public override bool IsDynamicConfigChangeSupported => false; |
| 29 | + |
| 30 | + /// <summary> |
| 31 | + /// EventPipe NetTrace V5 format can't emit the metadata for a Boolean8 HasValue field that self-describing events use. |
| 32 | + /// </summary> |
| 33 | + public override bool IsSelfDescribingNullableSupported => false; |
| 34 | + |
| 35 | + public override bool IsEventPipe => true; |
| 36 | + |
| 37 | + public EventPipeListener() { } |
| 38 | + |
| 39 | + public override void EventSourceCommand(string eventSourceName, EventCommand command, FilteringOptions options = null) |
| 40 | + { |
| 41 | + if (eventSourceName is null) |
| 42 | + { |
| 43 | + throw new ArgumentNullException(nameof(eventSourceName)); |
| 44 | + } |
| 45 | + |
| 46 | + if (_session != null) |
| 47 | + { |
| 48 | + throw new InvalidOperationException("EventPipeEventListener does not support dynamic configuration changes after Start()."); |
| 49 | + } |
| 50 | + _pendingCommands.Add((eventSourceName, command, options)); |
| 51 | + } |
| 52 | + |
| 53 | + public override void Start() |
| 54 | + { |
| 55 | + if (_session != null) |
| 56 | + { |
| 57 | + return; // already started |
| 58 | + } |
| 59 | + |
| 60 | + // Build provider enable list from pending commands |
| 61 | + foreach (var (eventSourceName, command, options) in _pendingCommands) |
| 62 | + { |
| 63 | + if (command == EventCommand.Enable) |
| 64 | + { |
| 65 | + var effective = options ?? new FilteringOptions(); |
| 66 | + _enabled[eventSourceName] = effective; |
| 67 | + } |
| 68 | + else if (command == EventCommand.Disable) |
| 69 | + { |
| 70 | + _enabled.Remove(eventSourceName); |
| 71 | + } |
| 72 | + else |
| 73 | + { |
| 74 | + throw new NotImplementedException(); |
| 75 | + } |
| 76 | + } |
| 77 | + |
| 78 | + var providers = new List<EventPipeProvider>(); |
| 79 | + foreach (var kvp in _enabled) |
| 80 | + { |
| 81 | + var opt = kvp.Value; |
| 82 | + providers.Add(new EventPipeProvider(kvp.Key, (EventLevel)opt.Level, (long)opt.Keywords, opt.Args)); |
| 83 | + } |
| 84 | + |
| 85 | + var client = new DiagnosticsClient(Environment.ProcessId); |
| 86 | + _session = client.StartEventPipeSession(providers, false); |
| 87 | + |
| 88 | + _processingTask = Task.Factory.StartNew(() => ProcessEvents(_session), TaskCreationOptions.LongRunning); |
| 89 | + } |
| 90 | + |
| 91 | + private void ProcessEvents(EventPipeSession session) |
| 92 | + { |
| 93 | + using var source = new EventPipeEventSource(session.EventStream); |
| 94 | + source.Dynamic.All += traceEvent => |
| 95 | + { |
| 96 | + // EventPipe adds extra events we didn't ask for, ignore them. |
| 97 | + if (traceEvent.ProviderName == "Microsoft-DotNETCore-EventPipe") |
| 98 | + { |
| 99 | + return; |
| 100 | + } |
| 101 | + |
| 102 | + OnEvent?.Invoke(new EventPipeEvent(traceEvent)); |
| 103 | + }; |
| 104 | + source.Process(); |
| 105 | + } |
| 106 | + |
| 107 | + public override void Dispose() |
| 108 | + { |
| 109 | + if (_disposed) |
| 110 | + { |
| 111 | + return; |
| 112 | + } |
| 113 | + |
| 114 | + try |
| 115 | + { |
| 116 | + _disposed = true; |
| 117 | + _session?.Stop(); |
| 118 | + |
| 119 | + if (_processingTask != null && !_processingTask.Wait(TimeSpan.FromSeconds(5))) |
| 120 | + { |
| 121 | + // If the session is still streaming data then session.Dispose() below will disconnect the stream |
| 122 | + // and likely cause the thread running source.Process() to throw. |
| 123 | + Assert.Fail("EventPipeEventListener processing task failed to complete in 5 seconds."); |
| 124 | + } |
| 125 | + } |
| 126 | + finally |
| 127 | + { |
| 128 | + _session?.Dispose(); |
| 129 | + } |
| 130 | + } |
| 131 | + |
| 132 | + public override string ToString() => "EventPipeListener"; |
| 133 | + |
| 134 | + /// <summary> |
| 135 | + /// Wrapper mapping TraceEvent (EventPipe) to harness Event abstraction. |
| 136 | + /// </summary> |
| 137 | + private sealed class EventPipeEvent : Event |
| 138 | + { |
| 139 | + private readonly TraceEvent _data; |
| 140 | + private readonly IList<string> _payloadNames; |
| 141 | + private readonly IList<object> _payloadValues; |
| 142 | + |
| 143 | + public EventPipeEvent(TraceEvent data) |
| 144 | + { |
| 145 | + _data = data; |
| 146 | + // EventPipe has a discrepancy with ETW for self-describing events - it exposes a single top-level object whereas ETW considers each of the fields within |
| 147 | + // that object as top-level named fields. To workaround that we unwrap any top-level object at payload index 0. |
| 148 | + if(data.PayloadNames.Length > 0 && data.PayloadValue(0) is IDictionary<string,object> d) |
| 149 | + { |
| 150 | + _payloadNames = d.Select(kv => kv.Key).ToList(); |
| 151 | + _payloadValues = d.Select(kv => kv.Value).ToList(); |
| 152 | + } |
| 153 | + else |
| 154 | + { |
| 155 | + _payloadNames = data.PayloadNames; |
| 156 | + _payloadValues = new List<object>(); |
| 157 | + for(int i = 0; i < _payloadNames.Count; i++) |
| 158 | + { |
| 159 | + _payloadValues.Add(data.PayloadValue(i)); |
| 160 | + } |
| 161 | + } |
| 162 | + } |
| 163 | + |
| 164 | + public override string ProviderName => _data.ProviderName; |
| 165 | + public override string EventName => _data.EventName; |
| 166 | + public override int PayloadCount => _payloadNames.Count; |
| 167 | + public override IList<string> PayloadNames => _payloadNames; |
| 168 | + |
| 169 | + public override object PayloadValue(int propertyIndex, string propertyName) |
| 170 | + { |
| 171 | + if (propertyName != null) |
| 172 | + { |
| 173 | + Assert.Equal(propertyName, _payloadNames[propertyIndex]); |
| 174 | + } |
| 175 | + return _payloadValues[propertyIndex]; |
| 176 | + } |
| 177 | + } |
| 178 | + } |
| 179 | +} |
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