From a123130cb3d9d7dd09875d29beffd8c37249f2c5 Mon Sep 17 00:00:00 2001
From: Jeff Donahue <jeff.donahue@gmail.com>
Date: Fri, 21 Mar 2014 13:05:59 -0700
Subject: [PATCH] loss in forward pass fix for window data layer

---
 include/caffe/vision_layers.hpp        | 12 ++++++------
 src/caffe/layers/window_data_layer.cpp | 17 +++--------------
 2 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/include/caffe/vision_layers.hpp b/include/caffe/vision_layers.hpp
index 2c471fa..91a2324 100644
--- a/include/caffe/vision_layers.hpp
+++ b/include/caffe/vision_layers.hpp
@@ -637,14 +637,14 @@ class WindowDataLayer : public Layer<Dtype> {
       vector<Blob<Dtype>*>* top);
 
  protected:
-  virtual void Forward_cpu(const vector<Blob<Dtype>*>& bottom,
+  virtual Dtype Forward_cpu(const vector<Blob<Dtype>*>& bottom,
       vector<Blob<Dtype>*>* top);
-  virtual void Forward_gpu(const vector<Blob<Dtype>*>& bottom,
+  virtual Dtype Forward_gpu(const vector<Blob<Dtype>*>& bottom,
       vector<Blob<Dtype>*>* top);
-  virtual Dtype Backward_cpu(const vector<Blob<Dtype>*>& top,
-      const bool propagate_down, vector<Blob<Dtype>*>* bottom);
-  virtual Dtype Backward_gpu(const vector<Blob<Dtype>*>& top,
-      const bool propagate_down, vector<Blob<Dtype>*>* bottom);
+  virtual void Backward_cpu(const vector<Blob<Dtype>*>& top,
+      const bool propagate_down, vector<Blob<Dtype>*>* bottom) { return; }
+  virtual void Backward_gpu(const vector<Blob<Dtype>*>& top,
+      const bool propagate_down, vector<Blob<Dtype>*>* bottom) { return; }
 
   pthread_t thread_;
   shared_ptr<Blob<Dtype> > prefetch_data_;
diff --git a/src/caffe/layers/window_data_layer.cpp b/src/caffe/layers/window_data_layer.cpp
index 87fb541..a288403 100644
--- a/src/caffe/layers/window_data_layer.cpp
+++ b/src/caffe/layers/window_data_layer.cpp
@@ -403,7 +403,7 @@ void WindowDataLayer<Dtype>::SetUp(const vector<Blob<Dtype>*>& bottom,
 }
 
 template <typename Dtype>
-void WindowDataLayer<Dtype>::Forward_cpu(const vector<Blob<Dtype>*>& bottom,
+Dtype WindowDataLayer<Dtype>::Forward_cpu(const vector<Blob<Dtype>*>& bottom,
       vector<Blob<Dtype>*>* top) {
   // First, join the thread
   CHECK(!pthread_join(thread_, NULL)) << "Pthread joining failed.";
@@ -415,10 +415,11 @@ void WindowDataLayer<Dtype>::Forward_cpu(const vector<Blob<Dtype>*>& bottom,
   // Start a new prefetch thread
   CHECK(!pthread_create(&thread_, NULL, WindowDataLayerPrefetch<Dtype>,
       reinterpret_cast<void*>(this))) << "Pthread execution failed.";
+  return Dtype(0.);
 }
 
 template <typename Dtype>
-void WindowDataLayer<Dtype>::Forward_gpu(const vector<Blob<Dtype>*>& bottom,
+Dtype WindowDataLayer<Dtype>::Forward_gpu(const vector<Blob<Dtype>*>& bottom,
       vector<Blob<Dtype>*>* top) {
   // First, join the thread
   CHECK(!pthread_join(thread_, NULL)) << "Pthread joining failed.";
@@ -432,18 +433,6 @@ void WindowDataLayer<Dtype>::Forward_gpu(const vector<Blob<Dtype>*>& bottom,
   // Start a new prefetch thread
   CHECK(!pthread_create(&thread_, NULL, WindowDataLayerPrefetch<Dtype>,
       reinterpret_cast<void*>(this))) << "Pthread execution failed.";
-}
-
-// The backward operations are dummy - they do not carry any computation.
-template <typename Dtype>
-Dtype WindowDataLayer<Dtype>::Backward_cpu(const vector<Blob<Dtype>*>& top,
-      const bool propagate_down, vector<Blob<Dtype>*>* bottom) {
-  return Dtype(0.);
-}
-
-template <typename Dtype>
-Dtype WindowDataLayer<Dtype>::Backward_gpu(const vector<Blob<Dtype>*>& top,
-      const bool propagate_down, vector<Blob<Dtype>*>* bottom) {
   return Dtype(0.);
 }
 
-- 
2.7.4