Switch to AllocationSampled Event

Even after switching to just enabling GCKeyword,
the 1s tracee app had a 1% failure rate locally.
On the other hand, AllocationSampled had no
failures after 1000 runs.

Author: mdh1418

src/tests/tracing/eventpipe/userevents/dotnet-common.script

@@ -1,2 +1,2 @@
 let Microsoft_Windows_DotNETRuntime_flags = new_dotnet_provider_flags();
-record_dotnet_provider("Microsoft-Windows-DotNETRuntime", 0x1, 4, Microsoft_Windows_DotNETRuntime_flags);
+record_dotnet_provider("Microsoft-Windows-DotNETRuntime", 0x80000000000, 4, Microsoft_Windows_DotNETRuntime_flags);

src/tests/tracing/eventpipe/userevents/userevents.cs

@@ -132,26 +132,22 @@ public static int TestEntryPoint()
         private static bool ValidateTraceeEvents(string traceFilePath)
         {
             using EventPipeEventSource source = new EventPipeEventSource(traceFilePath);
-            bool startEventFound = false;
-            bool stopEventFound = false;
+            bool allocationSampledEventFound = false;
 
+            // TraceEvent's ClrTraceEventParser does not know about the AllocationSampled Event, so it shows up as "Unknown(303)"
             source.Dynamic.All += (TraceEvent e) =>
             {
                 if (e.ProviderName == "Microsoft-Windows-DotNETRuntime")
                 {
-                    if (e.EventName == "GC/Start" || (e.ID == (TraceEventID)1 && e.EventName.StartsWith("Unknown")))
+                    if (e.EventName == "AllocationSampled" || (e.ID == (TraceEventID)303 && e.EventName.StartsWith("Unknown")))
                     {
-                        startEventFound = true;
-                    }
-                    else if (e.EventName == "GC/Stop" || (e.ID == (TraceEventID)2 && e.EventName.StartsWith("Unknown")))
-                    {
-                        stopEventFound = true;
+                        allocationSampledEventFound = true;
                     }
                 }
             };
 
             source.Process();
-            return startEventFound && stopEventFound;
+            return allocationSampledEventFound;
         }
     }
 }

src/tests/tracing/eventpipe/userevents/usereventstracee.cs

@@ -18,12 +18,7 @@ public static void Run()
 
             while (Stopwatch.GetTimestamp() - startTimestamp < targetTicks)
             {
-                for (int i = 0; i < 100; i++)
-                {
-                    s_array = new byte[1024 * 10];
-                }
-
-                GC.Collect();
+                s_array = new byte[1024 * 100];
                 Thread.Sleep(100);
             }
         }