Merge branch 'with-gil-context-test' into glopes-dev-linux-support

Author: ncguilbeault

.gitignore

@@ -3,3 +3,6 @@ bin
 obj
 *.user
 *.suo
+.venv
+.bonsai
+*.layout

src/Bonsai.Scripting.Python/PythonInterpreterLock.cs

@@ -0,0 +1,70 @@
+using Bonsai.Expressions;
+using System.Linq.Expressions;
+using System.Collections.Generic;
+using System.Reactive.Linq;
+using System;
+using System.Reflection;
+using System.Linq;
+using Python.Runtime;
+
+namespace Bonsai.Scripting.Python
+{
+    public class PythonInterpreterLock : WorkflowExpressionBuilder
+    {
+        static readonly Range<int> argumentRange = Range.Create(lowerBound: 1, upperBound: 1);
+
+        public PythonInterpreterLock()
+            : this(new ExpressionBuilderGraph())
+        {
+        }
+
+        public PythonInterpreterLock(ExpressionBuilderGraph workflow)
+            : base(workflow)
+        {
+        }
+
+        public override Range<int> ArgumentRange => argumentRange;
+
+        public override Expression Build(IEnumerable<Expression> arguments)
+        {
+            // var source = arguments.Single();
+            // var sourceType = source.Type.GetGenericArguments()[0]; // Get TSource from IObservable<TSource>
+            // var factoryParameter = Expression.Parameter(typeof(IObservable<>).MakeGenericType(sourceType));
+            Console.WriteLine($"here1 args: {arguments}");
+            var source = arguments.FirstOrDefault();
+            if (source == null)
+            {
+                throw new InvalidOperationException("There must be at least one input.");
+            }
+            var sourceType = source.Type.GetGenericArguments()[0]; // Get TSource from IObservable<TSource>
+            Console.WriteLine($"here2 sourceType: {source.Type}");
+            // var factoryParameter = Expression.Parameter(source.Type);
+            var factoryParameter = Expression.Parameter(typeof(IObservable<>).MakeGenericType(sourceType), "factoryParam");
+            Console.WriteLine($"here3 factoryParam: {factoryParameter}");
+            return BuildWorkflow(arguments, factoryParameter, selectorBody =>
+            {
+                Console.WriteLine($"here4 selectorBody: {selectorBody}");
+                var selector = Expression.Lambda(selectorBody, factoryParameter);
+                Console.WriteLine($"here5 selector: {selector}");
+                var resultType = selectorBody.Type.GetGenericArguments()[0];
+                Console.WriteLine($"here6 resultType: {resultType}");
+                // var processMethod = typeof(PythonInterpreterLock).GetMethod(nameof(Process)).MakeGenericMethod(sourceType, resultType);
+                // Console.WriteLine($"here7 processMethod: {processMethod}");
+                // return Expression.Call(processMethod, source, selector);
+                return Expression.Call(GetType(), nameof(Process), new Type[] {sourceType, resultType}, source, selector);
+            });
+        }
+
+        static IObservable<TResult> Process<TSource, TResult>(IObservable<TSource> source, Func<IObservable<TSource>, IObservable<TResult>> selector)
+        {
+            Console.WriteLine("process");
+            return Observable.Defer(() =>
+            {
+                using (Py.GIL())
+                {
+                    return selector(source);
+                }
+            });
+        }
+    }
+}