Fix possible race condition with unprepare

vonzshik · vonzshik · commit 0190ea1c9228 · 2023-08-26T01:08:45.000+03:00
diff --git a/src/Npgsql/NpgsqlCommand.cs b/src/Npgsql/NpgsqlCommand.cs
@@ -783,11 +783,12 @@ async Task Unprepare(bool async, CancellationToken cancellationToken = default)
 
             foreach (var batchCommand in InternalBatchCommands)
             {
-                if (batchCommand.PreparedStatement?.State == PreparedState.BeingUnprepared)
+                if (batchCommand.IsPrepared)
                 {
                     Expect<CloseCompletedMessage>(await connector.ReadMessage(async).ConfigureAwait(false), connector);
 
                     var pStatement = batchCommand.PreparedStatement;
+                    Debug.Assert(pStatement is not null);
                     pStatement.CompleteUnprepare();
 
                     if (!pStatement.IsExplicit)
@@ -1144,7 +1145,6 @@ async Task SendClose(NpgsqlConnector connector, bool async, CancellationToken ca
                 await new TaskSchedulerAwaitable(ConstrainedConcurrencyScheduler);
 
             await connector.WriteClose(StatementOrPortal.Statement, batchCommand.StatementName, async, cancellationToken).ConfigureAwait(false);
-            batchCommand.PreparedStatement!.State = PreparedState.BeingUnprepared;
             i++;
         }
 

Original file line number	Diff line number	Diff line change
`@@ -783,11 +783,12 @@ async Task Unprepare(bool async, CancellationToken cancellationToken = default)`
`783`	`783`
`784`	`784`	`foreach (var batchCommand in InternalBatchCommands)`
`785`	`785`	`{`
`786`		`- if (batchCommand.PreparedStatement?.State == PreparedState.BeingUnprepared)`
	`786`	`+ if (batchCommand.IsPrepared)`
`787`	`787`	`{`
`788`	`788`	`Expect<CloseCompletedMessage>(await connector.ReadMessage(async).ConfigureAwait(false), connector);`
`789`	`789`
`790`	`790`	`var pStatement = batchCommand.PreparedStatement;`
	`791`	`+ Debug.Assert(pStatement is not null);`
`791`	`792`	`pStatement.CompleteUnprepare();`
`792`	`793`
`793`	`794`	`if (!pStatement.IsExplicit)`
`@@ -1144,7 +1145,6 @@ async Task SendClose(NpgsqlConnector connector, bool async, CancellationToken ca`
`1144`	`1145`	`await new TaskSchedulerAwaitable(ConstrainedConcurrencyScheduler);`
`1145`	`1146`
`1146`	`1147`	`await connector.WriteClose(StatementOrPortal.Statement, batchCommand.StatementName, async, cancellationToken).ConfigureAwait(false);`
`1147`		`- batchCommand.PreparedStatement!.State = PreparedState.BeingUnprepared;`
`1148`	`1148`	`i++;`
`1149`	`1149`	`}`
`1150`	`1150`