From 0772d9a4a3320fa44927cb4565af0a758bdb8cb2 Mon Sep 17 00:00:00 2001
From: Hans Gaiser <j.c.gaiser@delftrobotics.com>
Date: Fri, 9 Jun 2017 23:20:11 +0200
Subject: [PATCH 1/2] Add try/catch around python function calls.

---
 src/caffe/net.cpp | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/caffe/net.cpp b/src/caffe/net.cpp
index 353c2f95b9e..a7d63307058 100644
--- a/src/caffe/net.cpp
+++ b/src/caffe/net.cpp
@@ -5,6 +5,11 @@
 #include <utility>
 #include <vector>
 
+#ifdef WITH_PYTHON_LAYER
+#include <boost/python.hpp>
+namespace bp = boost::python;
+#endif
+
 #include "hdf5.h"
 
 #include "caffe/common.hpp"
@@ -118,7 +123,16 @@ void Net<Dtype>::Init(const NetParameter& in_param) {
       }
     }
     // After this layer is connected, set it up.
-    layers_[layer_id]->SetUp(bottom_vecs_[layer_id], top_vecs_[layer_id]);
+#ifdef WITH_PYTHON_LAYER
+    try {
+#endif
+      layers_[layer_id]->SetUp(bottom_vecs_[layer_id], top_vecs_[layer_id]);
+#ifdef WITH_PYTHON_LAYER
+    } catch (bp::error_already_set) {
+      PyErr_Print();
+      throw;
+    }
+#endif
     LOG_IF(INFO, Caffe::root_solver())
         << "Setting up " << layer_names_[layer_id];
     for (int top_id = 0; top_id < top_vecs_[layer_id].size(); ++top_id) {
@@ -521,7 +535,17 @@ Dtype Net<Dtype>::ForwardFromTo(int start, int end) {
     for (int c = 0; c < before_forward_.size(); ++c) {
       before_forward_[c]->run(i);
     }
-    Dtype layer_loss = layers_[i]->Forward(bottom_vecs_[i], top_vecs_[i]);
+    Dtype layer_loss;
+#ifdef WITH_PYTHON_LAYER
+    try {
+#endif
+      layer_loss = layers_[i]->Forward(bottom_vecs_[i], top_vecs_[i]);
+#ifdef WITH_PYTHON_LAYER
+    } catch (bp::error_already_set) {
+      PyErr_Print();
+      throw;
+    }
+#endif
     loss += layer_loss;
     if (debug_info_) { ForwardDebugInfo(i); }
     for (int c = 0; c < after_forward_.size(); ++c) {
@@ -572,8 +596,17 @@ void Net<Dtype>::BackwardFromTo(int start, int end) {
       before_backward_[c]->run(i);
     }
     if (layer_need_backward_[i]) {
-      layers_[i]->Backward(
-          top_vecs_[i], bottom_need_backward_[i], bottom_vecs_[i]);
+#ifdef WITH_PYTHON_LAYER
+      try {
+#endif
+        layers_[i]->Backward(
+            top_vecs_[i], bottom_need_backward_[i], bottom_vecs_[i]);
+#ifdef WITH_PYTHON_LAYER
+      } catch (bp::error_already_set) {
+        PyErr_Print();
+        throw;
+      }
+#endif
       if (debug_info_) { BackwardDebugInfo(i); }
     }
     for (int c = 0; c < after_backward_.size(); ++c) {
@@ -725,7 +758,16 @@ void Net<Dtype>::Backward() {
 template <typename Dtype>
 void Net<Dtype>::Reshape() {
   for (int i = 0; i < layers_.size(); ++i) {
+#ifdef WITH_PYTHON_LAYER
+    try {
+#endif
     layers_[i]->Reshape(bottom_vecs_[i], top_vecs_[i]);
+#ifdef WITH_PYTHON_LAYER
+    } catch (bp::error_already_set) {
+      PyErr_Print();
+      throw;
+    }
+#endif
   }
 }
 

From 74073c921093f626b73c8c740b147519c6b405c5 Mon Sep 17 00:00:00 2001
From: Hans Gaiser <j.c.gaiser@delftrobotics.com>
Date: Thu, 29 Jun 2017 10:12:40 +0200
Subject: [PATCH 2/2] Restore python error after printing.

---
 src/caffe/net.cpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/caffe/net.cpp b/src/caffe/net.cpp
index a7d63307058..ea8d49a43fd 100644
--- a/src/caffe/net.cpp
+++ b/src/caffe/net.cpp
@@ -8,6 +8,14 @@
 #ifdef WITH_PYTHON_LAYER
 #include <boost/python.hpp>
 namespace bp = boost::python;
+
+void PrintPyError() {
+  PyObject * ptype, * pvalue, * ptraceback;
+  PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+  PyErr_Print();
+  PyErr_Restore(ptype, pvalue, ptraceback);
+}
+
 #endif
 
 #include "hdf5.h"
@@ -128,8 +136,8 @@ void Net<Dtype>::Init(const NetParameter& in_param) {
 #endif
       layers_[layer_id]->SetUp(bottom_vecs_[layer_id], top_vecs_[layer_id]);
 #ifdef WITH_PYTHON_LAYER
-    } catch (bp::error_already_set) {
-      PyErr_Print();
+    } catch (bp::error_already_set const &) {
+      PrintPyError();
       throw;
     }
 #endif
@@ -542,7 +550,7 @@ Dtype Net<Dtype>::ForwardFromTo(int start, int end) {
       layer_loss = layers_[i]->Forward(bottom_vecs_[i], top_vecs_[i]);
 #ifdef WITH_PYTHON_LAYER
     } catch (bp::error_already_set) {
-      PyErr_Print();
+      PrintPyError();
       throw;
     }
 #endif
@@ -603,7 +611,7 @@ void Net<Dtype>::BackwardFromTo(int start, int end) {
             top_vecs_[i], bottom_need_backward_[i], bottom_vecs_[i]);
 #ifdef WITH_PYTHON_LAYER
       } catch (bp::error_already_set) {
-        PyErr_Print();
+        PrintPyError();
         throw;
       }
 #endif