Merge pull request #762 from Sebastian-roko/random_seed

Random seed handling more simular to python

Author: Esther2013

src/TensorFlowNET.Core/APIs/tf.random.cs

@@ -93,7 +93,12 @@ public Tensor random_shuffle(Tensor value, int? seed = null, string name = null)
             => random_ops.random_shuffle(value, seed: seed, name: name);
 
         public void set_random_seed(int seed)
-            => ops.get_default_graph().seed = seed;
+        {
+            if (executing_eagerly())
+                Context.set_global_seed(seed);
+            else
+                ops.get_default_graph().seed = seed;
+        }
 
         public Tensor multinomial(Tensor logits, int num_samples, int? seed = null,
             string name = null, TF_DataType output_dtype = TF_DataType.DtInvalid)

src/TensorFlowNET.Core/Contexts/Context.cs

@@ -42,6 +42,9 @@ public sealed partial class Context : IDisposable
         SafeContextHandle _handle;
         public SafeContextHandle Handle => _handle;
 
+        int? _seed;
+        Random _rng;
+
         public Context()
         {
             _device_policy = ContextDevicePlacementPolicy.DEVICE_PLACEMENT_SILENT;
@@ -71,6 +74,24 @@ public void ensure_initialized()
             initialized = true;
         }
 
+        public void set_global_seed(int? seed)
+        {
+            _seed = seed;
+            if (seed.HasValue)
+                _rng = new Random(seed.Value);
+            else
+                _rng = null;
+            // Also clear the kernel cache, to reset any existing seeds
+            if (_handle != null)
+                c_api.TFE_ContextClearCaches(_handle);
+        }
+
+        public int? global_seed()
+            => _seed;
+
+        public int? internal_operation_seed()
+            => _rng?.Next(0, int.MaxValue);
+
         public void start_step()
             => c_api.TFE_ContextStartStep(_handle);
 
@@ -86,7 +107,7 @@ public bool executing_eagerly()
         {
             if(context_switches.Count() == 0)
                 tf.enable_eager_execution();
-            
+
             return context_switches.Current().EagerMode;
         }
 

src/TensorFlowNET.Core/Framework/random_seed.py.cs

@@ -14,16 +14,43 @@ You may obtain a copy of the License at
    limitations under the License.
 ******************************************************************************/
 
+using System.Collections.Generic;
+using static Tensorflow.Binding;
+
 namespace Tensorflow
 {
     public class random_seed
     {
         private static int DEFAULT_GRAPH_SEED = 87654321;
+        private static Dictionary<string, int> _graph_to_seed_dict = new Dictionary<string, int>();
 
         public static (int?, int?) get_seed(int? op_seed = null)
         {
+            int? global_seed;
+
+            if (tf.executing_eagerly())
+                global_seed = tf.Context.global_seed();
+            else
+                global_seed = ops.get_default_graph().seed;
+
+            if (global_seed.HasValue)
+            {
+                if (!op_seed.HasValue)
+                    if (tf.executing_eagerly())
+                        op_seed = tf.Context.internal_operation_seed();
+                    else
+                    {
+                        if (!_graph_to_seed_dict.TryGetValue(ops.get_default_graph().graph_key, out int seed))
+                            seed = 0;
+                        _graph_to_seed_dict[ops.get_default_graph().graph_key] = seed + 1;
+                        op_seed = seed;
+                    }
+
+                return (global_seed, op_seed);
+            }
+
             if (op_seed.HasValue)
-                return (DEFAULT_GRAPH_SEED, 0);
+                return (DEFAULT_GRAPH_SEED, op_seed);
             else
                 return (null, null);
         }

src/TensorFlowNET.Core/Operations/gen_random_ops.cs

@@ -79,7 +79,8 @@ public static Tensor random_uniform(Tensor shape, TF_DataType dtype, int? seed =
         /// <returns></returns>
         public static Tensor random_shuffle(Tensor value, int seed = 0, int seed2 = 0,
             string name = null)
-                => tf.Context.ExecuteOp("RandomShuffle", name, new ExecuteOpArgs(value, seed, seed2));
+               => tf.Context.ExecuteOp("RandomShuffle", name, new ExecuteOpArgs(value)
+                   .SetAttributes(new { seed = seed, seed2 = seed2 }));
 
         /// <summary>
         /// Outputs random values from a truncated normal distribution.

test/TensorFlowNET.UnitTest/Basics/RandomTest.cs

@@ -14,7 +14,7 @@ public class RandomTest
         /// Test the function of setting random seed
         /// This will help regenerate the same result
         /// </summary>
-        [TestMethod, Ignore]
+        [TestMethod]
         public void TFRandomSeedTest()
         {
             var initValue = np.arange(6).reshape(3, 2);
@@ -60,7 +60,7 @@ public void TFRandomSeedTest2()
         /// <summary>
         /// This part we use funcs in tf.random rather than only tf
         /// </summary>
-        [TestMethod, Ignore]
+        [TestMethod]
         public void TFRandomRaodomSeedTest()
         {
             tf.set_random_seed(1234);

test/TensorFlowNET.UnitTest/Dataset/DatasetTest.cs

@@ -151,5 +151,25 @@ public void Cardinality()
             var cardinality = dataset.dataset_cardinality();
             Assert.AreEqual(new long[] { 10 }, cardinality.numpy());
         }
+
+        [TestMethod]
+        public void Shuffle()
+        {
+            tf.set_random_seed(1234);
+
+            var dataset = tf.data.Dataset.range(3);
+            var shuffled = dataset.shuffle(3);
+
+            var zipped = tf.data.Dataset.zip(dataset, shuffled);
+
+            bool allEqual = true;
+            foreach (var item in zipped)
+            {
+                if (item.Item1 != item.Item2)
+                    allEqual = false;
+            }
+
+            Assert.IsFalse(allEqual);
+        }
     }
 }