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We are using mono 126.96.36.199-0xamarin1 on ubuntu.
After the dispose of a System.Diagnostics.Process the VM often crashes with the following stack trace:
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Stream has been closed'.
at System.IO.FileStream.BeginRead (System.Byte array, Int32 offset, Int32 numBytes, System.AsyncCallback userCallback, System.Object stateObject) <0x7f5f73f0c1a0 + 0x00235> in <filename unknown>:0
at System.Diagnostics.AsyncStreamReader.ReadBuffer (IAsyncResult ar) <0x4135bee0 + 0x00425> in <filename unknown>:0
at System.IO.Stream+ReadWriteTask.InvokeAsyncCallback (System.Object completedTask) <0x7f5f73d6b920 + 0x0004f> in <filename unknown>:0
at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, Boolean preserveSyncCtx) <0x7f5f73e5a990 + 0x00178> in <filename unknown>:0
at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, Boolean preserveSyncCtx) <0x7f5f73e5a960 + 0x00020> in <filename unknown>:0
at System.IO.Stream+ReadWriteTask.System.Threading.Tasks.ITaskCompletionAction.Invoke (System.Threading.Tasks.Task completingTask) <0x7f5f73d6b990 + 0x00103> in <filename unknown>:0
at System.Threading.Tasks.Task.FinishContinuations () <0x7f5f73e497e0 + 0x00214> in <filename unknown>:0
at System.Threading.Tasks.Task.FinishStageThree () <0x7f5f73e47bf0 + 0x00068> in <filename unknown>:0
at System.Threading.Tasks.Task.FinishStageTwo () <0x7f5f73e47a90 + 0x00133> in <filename unknown>:0
at System.Threading.Tasks.Task.Finish (Boolean bUserDelegateExecuted) <0x7f5f73e478f0 + 0x0008d> in <filename unknown>:0
at System.Threading.Tasks.Task.ExecuteWithThreadLocal (System.Threading.Tasks.Task& currentTaskSlot) <0x7f5f73e48620 + 0x00131> in <filename unknown>:0
at System.Threading.Tasks.Task.ExecuteEntry (Boolean bPreventDoubleExecution) <0x7f5f73e484c0 + 0x000ee> in <filename unknown>:0
at System.Threading.Tasks.Task.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () <0x7f5f73e48440 + 0x0000e> in <filename unknown>:0
at System.Threading.ThreadPoolWorkQueue.Dispatch () <0x7f5f73e5f2e0 + 0x001d6> in <filename unknown>:0
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () <0x7f5f73e60bf0 + 0x00008> in <filename unknown>:0
This behaviour could not be confirmed for Mono "Stable 188.8.131.52/832de4b".
Maybe the process dispose, which only sets the streams to null, leaves the responsibility for the dispose of the streams to the GC which leads to a wrong dispose sequence of the streams. This might allow the AsyncStreamReader to read more data after the underlying stream has already been closed by the GC.
standardOutput = null;
standardInput = null;
standardError = null;
output = null; // AsyncStreamReader
error = null; // AsyncStreamReader
Maybe this PR which was merged into the mono-4.3.2-branch is related to this behaviour:
Could you provide some steps how to reproduce the issue?
We have not received the requested information. If you are still experiencing this issue please provide all the requested information and reopen the bug report.