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ConcurrentBag and FormatterServices

    Question

  • Hello, I've been struggling a bit using some of the methods in the FormatterServices class in conjunction with a ConcurrentBag.

    Dim OriginalBag As New Concurrent.ConcurrentBag(Of Double)
    OriginalBag.Add(1.0)
    OriginalBag.Add(1.1)
    OriginalBag.Add(1.2)
    
    Dim BagFields As System.Reflection.MemberInfo() = FormatterServices.GetSerializableMembers(OriginalBag.GetType)
    Dim OriginalBagData As Object() = FormatterServices.GetObjectData(OriginalBag, BagFields)
    Dim NewBag As Concurrent.ConcurrentBag(Of Double) = FormatterServices.GetSafeUninitializedObject(GetType(Concurrent.ConcurrentBag(Of Double)))
    FormatterServices.PopulateObjectMembers(NewBag, BagFields, OriginalBagData)
    
    CollectionAssert.AreEquivalent(OriginalBag, NewBag)

    The intended result the above is a new concurrent bag of doubles containing the same values as the original bag (similar to how using binary formatter to serialize/deserialize an object would work) however, the object NewList, in the end, has no members.

    Tracing the issue back further, the GetSerializableMembers call only returns one member called "m_serializationArray".  The GetObjectData method cannot find any fields named "m_serializationArray", returning only a list with a single Nothing in it.

    I guess, with that in mind, my question is: is ConcurrentBag not intended to be used with the FormatterServices methods?  I had just assumed that a ConcurrentBag would behave similarly to (for example) a List in this situation, but from the code above this appears to not be the case.


    Monday, February 25, 2013 4:31 PM

Answers

  • ConcurrentBag uses the OnSerializing/OnDeserialized mechanism for serialization, which means that its implementation actually provides code that runs to assist in the serialization/deserialization, rather than just specifying certain fields to be serialized/deserialized that completely represent its data.  Just copying its serializable fields from one instance to another will not correctly populate the new instance.
    Friday, March 08, 2013 12:51 AM
    Owner