Merged PR 794980: Log more information when bxl failed to open a file for hashing

Log sharing violation and timeout separately
Log current bxl pid when we find a bxl process holds a handle

Public/Src/Engine/Cache/Artifacts/LocalDiskContentStore.cs

@@ -454,7 +454,7 @@ namespace BuildXL.Engine.Cache.Artifacts
                         if (openResult.Status == OpenFileStatus.Timeout ||
                             openResult.Status == OpenFileStatus.SharingViolation)
                         {
-                            Tracing.Logger.Log.TimeoutOpeningFileForHashing(m_loggingContext, expandedPath);
+                            Tracing.Logger.Log.OpeningFileFailedForHashing(m_loggingContext, expandedPath, openResult.Status.ToString());
                             return false; // returning "not done", i.e., do retry
                         }
                         else

Public/Src/Engine/Cache/Tracing/Log.cs

@@ -69,13 +69,14 @@ namespace BuildXL.Engine.Cache.Tracing
         public abstract void FailedOpenHandleToGetKnownHashDuringMaterialization(LoggingContext context, string path, string message);
 
         [GeneratedEvent(
-            (int)LogEventId.TimeoutOpeningFileForHashing,
+            (int)LogEventId.OpeningFileFailedForHashing,
             EventGenerators = EventGenerators.LocalOnly,
             EventLevel = Level.Verbose,
             Keywords = (int)Keywords.UserMessage,
             EventTask = (int)Tasks.Storage,
-            Message = "The path '{0}' could not be opened for hashing because the filesystem returned ERROR_TIMEOUT.")]
-        public abstract void TimeoutOpeningFileForHashing(LoggingContext context, string path);
+            Message = "The path '{0}' could not be opened for hashing because the filesystem returned {error}.")]
+        public abstract void OpeningFileFailedForHashing(LoggingContext context, string path, string error);
+
 
         [GeneratedEvent(
             (int)LogEventId.HashedReparsePointAsTargetPath,

Public/Src/Engine/Cache/Tracing/LogEventId.cs

@@ -29,7 +29,7 @@ namespace BuildXL.Engine.Cache.Tracing
 
         RetryOnLoadingAndDeserializingMetadata = 746,
 
-        TimeoutOpeningFileForHashing = 748,
+        OpeningFileFailedForHashing = 748,
 
         TemporalCacheEntryTrace = 2733,
     }

Public/Src/Utilities/Native/IO/Windows/FileUtilities.Win.cs

@@ -34,6 +34,8 @@ namespace BuildXL.Native.IO.Windows
 
         private static readonly SecurityIdentifier s_worldSid = new SecurityIdentifier(WellKnownSidType.WorldSid, null);
 
+        private static readonly int s_currentBxlPid = Process.GetCurrentProcess().Id;
+
         /// <inheritdoc />
         public PosixDeleteMode PosixDeleteMode { get; set; }
 
@@ -2112,6 +2114,10 @@ namespace BuildXL.Native.IO.Windows
                             Process process = Process.GetProcessById(pid);
 
                             builder.AppendFormat("Handle was used by '{0}' with PID '{1}'.", process.ProcessName, pid);
+                            if (process.ProcessName.Equals("bxl"))
+                            {
+                                builder.AppendFormat(" bxl is holding the handle. Current bxl process PID is {0}.", s_currentBxlPid);
+                            }
                             builder.AppendLine();
                         }
                         catch (Exception ex)