Is JsonTransformer thread-safe?

[joshidp]

Hello JUST.net,

I am using JsonTransformer with single instance and when in multi-thread environment I am doing transform then results are not expected. Below code fails when jsonTransformer is declared outside the parallel loop but it works if jsonTransformer is declared inside loop context. How are we suppose to use JsonTransformer ? is it thread-safe?

var jsonTransformer = new JsonTransformer();

            var data = new List<THreadTestData>();

            data.Add(new THreadTestData()
            {
                Transformer = File.ReadAllText("atomicTX.json"),
                Input = File.ReadAllText("atomic.json"),
                Expected = "{\r\n  \"alias\": \"abc\",\r\n  \"eou\": null,\r\n  \"resourceType\": null,\r\n  \"resourceCategory\": \"FFF\",  \"reportsTo\": \"pqr\"\r\n}"
            });

            data.Add(new THreadTestData()
            {
                Transformer = File.ReadAllText("bulkTX.json"),
                Input = File.ReadAllText("bulk.json"),
                Expected = "[\r\n  {\r\n    \"alias\": \"abc\"\r\n  },\r\n  {\r\n    \"alias\": \"xyz\"\r\n  }\r\n]"
            });

            // Execute the loop in parallel
            Parallel.For(0, 100, i =>
            {
                THreadTestData threadTestData = null;
                {
                    threadTestData = data.First();
                    // var jsonTransformer = new JsonTransformer();
                    var tx = jsonTransformer.Transform(JObject.Parse(threadTestData.Transformer), threadTestData.Input);

                    if (tx.ToString() != threadTestData.Expected)
                    {

                    }
                    else
                    {

                    }
                }
                {
                    threadTestData = data.Last();
                    //  var jsonTransformer = new JsonTransformer();
                    var tx = jsonTransformer.Transform(JObject.Parse(threadTestData.Transformer), threadTestData.Input);

                    if (tx.ToString() != threadTestData.Expected)
                    {

                    }
                }


                Task.Delay(2 * 100).Wait();
            });

Thanks

[Courela]

Current version should be thread-safe.
#260

[joshidp]

I am using latest 4.3.0 and its not acting thread-safe, above code snippet scenario can validate it.

[Courela]

You're right, different instances of JsonTransformer work fine, but the same instance does not, there's a property, JUSTContext, that is read and set throughout the code...

[joshidp]

JUSTContext have setting values, transformer and inputs are not part of it, so how JUSTContext can help here? Is it a bug?

JUSTContext context = new JUSTContext 
{ 
  EvaluationMode = EvaluationMode.Strict,
  DefaultDecimalPlaces = 4
};

[Courela]

Input is a property of JUSTContext (internal), it is set at the beginning of the tranformation, and it is changed whenever is needed (for example, multiple transformations use it, I'm not sure but maybe #applyover and loops also...)

[joshidp]

So, sounds like JsonTransformer is not thread-safe in true sense and we should re-instantiate JsonTransformer for each transformation.

[Courela]

Not thread-safe at all... One thing to check

[s-summers]

Are there any plans to release this fix to nuget?