Fix | Fix Bulk Copy Async deadlock with custom IDataReader using SqlD…

…ataReader internally. (#779)
dotnet · Nov 4, 2020 · 30f2a4d · 30f2a4d
1 parent a7545de
commit 30f2a4d
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Showing 2 changed files with 57 additions and 39 deletions.
diff --git a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlBulkCopy.cs b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlBulkCopy.cs
@@ -1159,6 +1159,11 @@ private Task ReadFromRowSourceAsync(CancellationToken cts)
             }
             else
             { // This will call Read for DataRows, DataTable and IDataReader (this includes all IDataReader except DbDataReader)
+              // Release lock to prevent possible deadlocks
+                SqlInternalConnectionTds internalConnection = _connection.GetOpenTdsConnection();
+                bool semaphoreLock = internalConnection._parserLock.CanBeReleasedFromAnyThread;
+                internalConnection._parserLock.Release();
+
                 _hasMoreRowToCopy = false;
                 try
                 {
@@ -1175,6 +1180,10 @@ private Task ReadFromRowSourceAsync(CancellationToken cts)
                         throw;
                     }
                 }
+                finally
+                {
+                    internalConnection._parserLock.Wait(canReleaseFromAnyThread: semaphoreLock);
+                }
                 return null;
             }
         }