Parallel.ForEach中的二进制序列化/反序列化（BinaryFormatter）

Question

Perhaps this is a duplication(( But I have not found any sample code of the using of binnaryformatter in Parallel.Foreach. Could anyone provide a sample of it? Sample of code

Parralel.ForEach(files, fileCurr=>
                  {
                      using(lib.Accesser("fileType", fileNameSpec))
                      {
                        LoadFileData(fileNameSpec,fileCurr,cancellationToken, progressCallback);
                      }
                   });
and

LoadFileData(fileNameSpec,fileCurr,cancellationToken, progressCallback)
{
 using(lib2.load(fileCurr.name))
{
 foreach(var v in fileCurr.include)
 {
   var objectForSerialization = loadObj(v);
   //my code goes below
   System.IO.Stream stream = System.IO.File.Open("J:\\volume", FileMode.OpenOrCreate);
                    System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bformatter = new BinaryFormatter();
                    bformatter.Serialize(stream, objectForSerialization);
                    stream.Close();
  //but this fil will be locked by multyply writes

 }
}
}

Answer 1

One part of your problem is that

reading and writing or executing multiple writes in the same file in parallel is not realistically possible.

Once you implement a locking mechanism for the file reads / writes, there is no longer any need to execute your iteration in parallel because its operations cannot be executed in parallel .

If you are only deserialising , (just reading from the files) it's a different story.

Read-only access can be done in parallel because it does not require locking of the file per sé.

see : How can I read a text file without locking it?

Another thing you could do, is preload the text files (if this is possible) and deserialise them straight from the resulting strings.

::edit::

one more thing :

You appear to always be writing to the same file on your J: drive (a file called volume with no extention).

If you are serialising multiple objects, you will want them to be serialised to different files...

If you can assure yourself that all objects are serialised to different files, you can make the operation parallel.

This would be someting like this:

 System.IO.Stream stream = System.IO.File.Open("J:\\volume\\" + GenerateFileName(v), FileMode.OpenOrCreate);

Then make sure GenerateFileName generates a unique file name as string.