Polish marshalling of MF model and MF problem and enable 32-bit tests (#3227)

Author: wschin

src/Microsoft.ML.Recommender/SafeTrainingAndModelBuffer.cs

@@ -17,31 +17,50 @@ namespace Microsoft.ML.Recommender.Internal
     /// </summary>
     internal sealed class SafeTrainingAndModelBuffer : IDisposable
     {
-        [StructLayout(LayoutKind.Explicit)]
+        [StructLayout(LayoutKind.Sequential)]
         private struct MFNode
         {
-            [FieldOffset(0)]
+            /// <summary>
+            /// Row index.
+            /// </summary>
             public int U;
-            [FieldOffset(4)]
+
+            /// <summary>
+            /// Column index;
+            /// </summary>
             public int V;
-            [FieldOffset(8)]
+
+            /// <summary>
+            /// Matrix element's value at <see cref="U"/>-th row and <see cref="V"/>-th column.
+            /// </summary>
             public float R;
         }
 
-        [StructLayout(LayoutKind.Explicit)]
+        [StructLayout(LayoutKind.Sequential)]
         private unsafe struct MFProblem
         {
-            [FieldOffset(0)]
+            /// <summary>
+            /// Number of rows.
+            /// </summary>
             public int M;
-            [FieldOffset(4)]
+
+            /// <summary>
+            /// Number of columns.
+            /// </summary>
             public int N;
-            [FieldOffset(8)]
+
+            /// <summary>
+            /// Number of specified matrix elements in <see cref="R"/>.
+            /// </summary>
             public long Nnz;
-            [FieldOffset(16)]
+
+            /// <summary>
+            /// Specified matrix elements.
+            /// </summary>
             public MFNode* R;
         }
 
-        [StructLayout(LayoutKind.Explicit)]
+        [StructLayout(LayoutKind.Sequential)]
         private struct MFParameter
         {
             /// <summary>
@@ -58,130 +77,117 @@ private struct MFParameter
             /// Fun 12 is solved by a coordinate descent method while other functions invoke
             /// a stochastic gradient method.
             /// </summary>
-            [FieldOffset(0)]
             public int Fun;
 
             /// <summary>
             /// Rank of factor matrices.
             /// </summary>
-            [FieldOffset(4)]
             public int K;
 
             /// <summary>
             /// Number of threads which can be used for training.
             /// </summary>
-            [FieldOffset(8)]
             public int NrThreads;
 
             /// <summary>
             /// Number of blocks that the training matrix is divided into. The parallel stochastic gradient
             /// method in LIBMF processes assigns each thread a block at one time. The ratings in one block
             /// would be sequentially accessed (not randomaly accessed like standard stochastic gradient methods).
             /// </summary>
-            [FieldOffset(12)]
             public int NrBins;
 
             /// <summary>
             /// Number of training iteration. At one iteration, all values in the training matrix are roughly accessed once.
             /// </summary>
-            [FieldOffset(16)]
             public int NrIters;
 
             /// <summary>
             /// L1-norm regularization coefficient of left factor matrix.
             /// </summary>
-            [FieldOffset(20)]
             public float LambdaP1;
 
             /// <summary>
             /// L2-norm regularization coefficient of left factor matrix.
             /// </summary>
-            [FieldOffset(24)]
             public float LambdaP2;
 
             /// <summary>
             /// L1-norm regularization coefficient of right factor matrix.
             /// </summary>
-            [FieldOffset(28)]
             public float LambdaQ1;
 
             /// <summary>
             /// L2-norm regularization coefficient of right factor matrix.
             /// </summary>
-            [FieldOffset(32)]
             public float LambdaQ2;
 
             /// <summary>
             /// Learning rate of LIBMF's stochastic gradient method.
             /// </summary>
-            [FieldOffset(36)]
             public float Eta;
 
             /// <summary>
             /// Coefficient of loss function on unobserved entries in the training matrix. It's used only with fun=12.
             /// </summary>
-            [FieldOffset(40)]
             public float Alpha;
 
             /// <summary>
             /// Desired value of unobserved entries in the training matrix. It's used only with fun=12.
             /// </summary>
-            [FieldOffset(44)]
             public float C;
 
             /// <summary>
             /// Specify if the factor matrices should be non-negative.
             /// </summary>
-            [FieldOffset(48)]
             public byte DoNmf;
 
             /// <summary>
             /// Set to true so that LIBMF may produce less information to STDOUT.
             /// </summary>
-            [FieldOffset(49)]
             public byte Quiet;
 
             /// <summary>
             /// Set to false so that LIBMF may reuse and modifiy the data passed in.
             /// </summary>
-            [FieldOffset(50)]
             public byte CopyData;
         }
 
-        [StructLayout(LayoutKind.Explicit)]
+        [StructLayout(LayoutKind.Sequential)]
         private unsafe struct MFModel
         {
-            [FieldOffset(0)]
+            /// <summary>
+            /// See <see cref="MFParameter.Fun"/>.
+            /// </summary>
             public int Fun;
+
             /// <summary>
             /// Number of rows in the training matrix.
             /// </summary>
-            [FieldOffset(4)]
             public int M;
+
             /// <summary>
             /// Number of columns in the training matrix.
             /// </summary>
-            [FieldOffset(8)]
             public int N;
+
             /// <summary>
             /// Rank of factor matrices.
             /// </summary>
-            [FieldOffset(12)]
             public int K;
+
             /// <summary>
             /// Average value in the training matrix.
             /// </summary>
-            [FieldOffset(16)]
             public float B;
+
             /// <summary>
             /// Left factor matrix. Its shape is M-by-K stored in row-major format.
             /// </summary>
-            [FieldOffset(24)] // pointer is 8-byte on 64-bit machine.
             public float* P;
+
             /// <summary>
             /// Right factor matrix. Its shape is N-by-K stored in row-major format.
             /// </summary>
-            [FieldOffset(32)] // pointer is 8-byte on 64-bit machine.
             public float* Q;
         }
 

src/Native/MatrixFactorizationNative/UnmanagedMemory.cpp

@@ -9,7 +9,7 @@
 
 using namespace mf;
 
-mf_parameter make_param(const mf_parameter_bridge *param_bridge)
+inline mf_parameter TranslateToParam(const mf_parameter_bridge *param_bridge)
 {
     mf_parameter param;
     param.fun = param_bridge->fun;
@@ -30,30 +30,97 @@ mf_parameter make_param(const mf_parameter_bridge *param_bridge)
     return param;
 }
 
-EXPORT_API(void) MFDestroyModel(mf_model *&model)
+inline mf_problem TranslateToProblem(const mf_problem_bridge *prob_bridge)
 {
-    return mf_destroy_model(&model);
+    mf_problem prob;
+    prob.m = prob_bridge->m;
+    prob.n = prob_bridge->n;
+    prob.nnz = prob_bridge->nnz;
+    prob.R = prob_bridge->R;
+    return prob;
 }
 
-EXPORT_API(mf_model*) MFTrain(const mf_problem *prob, const mf_parameter_bridge *param_bridge)
+inline void TranslateToModelBridge(const mf_model *model, mf_model_bridge *model_bridge)
 {
-    auto param = make_param(param_bridge);
-    return mf_train(prob, param);
+    model_bridge->fun = model->fun;
+    model_bridge->m = model->m;
+    model_bridge->n = model->n;
+    model_bridge->k = model->k;
+    model_bridge->b = model->b;
+    model_bridge->P = model->P;
+    model_bridge->Q = model->Q;
 }
 
-EXPORT_API(mf_model*) MFTrainWithValidation(const mf_problem *tr, const mf_problem *va, const mf_parameter_bridge *param_bridge)
+inline void TranslateToModel(const mf_model_bridge *model_bridge, mf_model *model)
 {
-    auto param = make_param(param_bridge);
-    return mf_train_with_validation(tr, va, param);
+    model->fun = model_bridge->fun;
+    model->m = model_bridge->m;
+    model->n = model_bridge->n;
+    model->k = model_bridge->k;
+    model->b = model_bridge->b;
+    model->P = model_bridge->P;
+    model->Q = model_bridge->Q;
 }
 
-EXPORT_API(float) MFCrossValidation(const mf_problem *prob, int nr_folds, const mf_parameter_bridge *param_bridge)
+EXPORT_API(void) MFDestroyModel(mf_model_bridge *&model_bridge)
 {
-    auto param = make_param(param_bridge);
-    return mf_cross_validation(prob, nr_folds, param);
+    // Transfer the ownership of P and Q back to the original LIBMF class, so that
+    // mf_destroy_model can be called.
+    auto model = new mf_model;
+    model->P = model_bridge->P;
+    model->Q = model_bridge->Q;
+    mf_destroy_model(&model); // delete model, model->P, amd model->Q.
+
+    // Delete bridge class allocated in MFTrain, MFTrainWithValidation, or MFCrossValidation.
+    delete model_bridge;
+	model_bridge = nullptr;
+}
+
+EXPORT_API(mf_model_bridge*) MFTrain(const mf_problem_bridge *prob_bridge, const mf_parameter_bridge *param_bridge)
+{
+    // Convert objects created outside LIBMF. Notice that the called LIBMF function doesn't take the ownership of
+    // allocated memory in those external objects.
+    auto prob = TranslateToProblem(prob_bridge);
+    auto param = TranslateToParam(param_bridge);
+
+    // The model contains 3 allocated things --- itself, P, and Q.
+    // We will delete itself and transfer the ownership of P and Q to the associated bridge class. The bridge class
+    // will then be sent to C#.
+    auto model = mf_train(&prob, param);
+    auto model_bridge = new mf_model_bridge;
+    TranslateToModelBridge(model, model_bridge);
+    delete model;
+    return model_bridge; // To clean memory up, we need to delete model_bridge, model_bridge->P, and model_bridge->Q.
+}
+
+EXPORT_API(mf_model_bridge*) MFTrainWithValidation(const mf_problem_bridge *tr_bridge, const mf_problem_bridge *va_bridge, const mf_parameter_bridge *param_bridge)
+{
+    // Convert objects created outside LIBMF. Notice that the called LIBMF function doesn't take the ownership of
+    // allocated memory in those external objects.
+    auto tr = TranslateToProblem(tr_bridge);
+    auto va = TranslateToProblem(va_bridge);
+    auto param = TranslateToParam(param_bridge);
+
+    // The model contains 3 allocated things --- itself, P, and Q.
+    // We will delete itself and transfer the ownership of P and Q to the associated bridge class. The bridge class
+    // will then be sent to C#.
+    auto model = mf_train_with_validation(&tr, &va, param);
+    auto model_bridge = new mf_model_bridge;
+    TranslateToModelBridge(model, model_bridge);
+    delete model;
+    return model_bridge; // To clean memory up, we need to delete model_bridge, model_bridge->P, and model_bridge->Q.
+}
+
+EXPORT_API(float) MFCrossValidation(const mf_problem_bridge *prob_bridge, int32_t nr_folds, const mf_parameter_bridge *param_bridge)
+{
+    auto param = TranslateToParam(param_bridge);
+    auto prob = TranslateToProblem(prob_bridge);
+    return mf_cross_validation(&prob, nr_folds, param);
 }
 
-EXPORT_API(float) MFPredict(const mf_model *model, int p_idx, int q_idx)
+EXPORT_API(float) MFPredict(const mf_model_bridge *model_bridge, int32_t p_idx, int32_t q_idx)
 {
-    return mf_predict(model, p_idx, q_idx);
+    mf_model model;
+    TranslateToModel(model_bridge, &model);
+    return mf_predict(&model, p_idx, q_idx);
 }

src/Native/MatrixFactorizationNative/UnmanagedMemory.h

@@ -27,12 +27,31 @@ struct mf_parameter_bridge
     uint8_t copy_data;
 };
 
-EXPORT_API(void) MFDestroyModel(mf_model *&model);
+struct mf_problem_bridge
+{
+    int32_t m;
+    int32_t n;
+    int64_t nnz;
+    struct mf_node *R;
+};
+
+struct mf_model_bridge
+{
+    int32_t fun;
+    int32_t m;
+    int32_t n;
+    int32_t k;
+    float b;
+    float *P;
+    float *Q;
+};
+
+EXPORT_API(void) MFDestroyModel(mf_model_bridge *&model);
 
-EXPORT_API(mf_model*) MFTrain(const mf_problem *prob, const mf_parameter_bridge *parameter_bridge);
+EXPORT_API(mf_model_bridge*) MFTrain(const mf_problem_bridge *prob_bridge, const mf_parameter_bridge *parameter_bridge);
 
-EXPORT_API(mf_model*) MFTrainWithValidation(const mf_problem *tr, const mf_problem *va, const mf_parameter_bridge *parameter_bridge);
+EXPORT_API(mf_model_bridge*) MFTrainWithValidation(const mf_problem_bridge *tr, const mf_problem_bridge *va, const mf_parameter_bridge *parameter_bridge);
 
-EXPORT_API(float) MFCrossValidation(const mf_problem *prob, int nr_folds, const mf_parameter_bridge* parameter_bridge);
+EXPORT_API(float) MFCrossValidation(const mf_problem_bridge *prob, int32_t nr_folds, const mf_parameter_bridge* parameter_bridge);
 
-EXPORT_API(float) MFPredict(const mf_model *model, int p_idx, int q_idx);
+EXPORT_API(float) MFPredict(const mf_model_bridge *model, int32_t p_idx, int32_t q_idx);

test/Microsoft.ML.TestFramework/Attributes/MatrixFactorizationFactAttribute.cs

@@ -10,14 +10,14 @@ namespace Microsoft.ML.TestFramework.Attributes
     /// </summary>
     public sealed class MatrixFactorizationFactAttribute : EnvironmentSpecificFactAttribute
     {
-        public MatrixFactorizationFactAttribute() : base("Disabled - this test is being fixed as part of https://github.com/dotnet/machinelearning/issues/1441")
+        public MatrixFactorizationFactAttribute() : base("")
         {
         }
 
         /// <inheritdoc />
         protected override bool IsEnvironmentSupported()
         {
-            return Environment.Is64BitProcess;
+            return true;
         }
     }
 }