Fix hangs at IndexErrors when when TF is imported after TRT

Unpacking an trt.tensorrt.Dims object causes Python to hang when
Tensorflow is imported after TensorRT, only on Windows.

Signed-off-by: samurdhi karunaratne <skarunaratne@nvidia.com>
Signed-off-by: Rajeev Rao <rajeevrao@nvidia.com>

python/include/utils.h

@@ -180,6 +180,8 @@ void doNothingDel(const T& self)
     issueDeprecationWarning("del obj");
 }
 
+void throwPyIndexError(std::string message = "out of bounds");
+
 } // namespace utils
 } // namespace tensorrt
 

python/src/infer/pyCore.cpp

@@ -172,7 +172,9 @@ static const auto engine_getitem = [](ICudaEngine& self, int pyIndex) {
     // Support python's negative indexing
     size_t index = (pyIndex < 0) ? static_cast<int>(self.getNbBindings()) + pyIndex : pyIndex;
     if (index >= self.getNbBindings())
-        throw py::index_error();
+    {
+        utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+    }
     return self.getBindingName(index);
 };
 

python/src/infer/pyFoundationalTypes.cpp

@@ -100,7 +100,9 @@ static const auto dims_getter = [](const Dims& self, int pyIndex) -> const int&
     // Without these bounds checks, horrible infinite looping will occur.
     size_t index = (pyIndex < 0) ? static_cast<int>(self.nbDims) + pyIndex : pyIndex;
     if (index >= self.nbDims)
-        throw py::index_error();
+    {
+        utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+    }
     return self.d[index];
 };
 
@@ -110,7 +112,9 @@ static const auto dims_getter_slice = [](const Dims& self, py::slice slice) {
         throw py::error_already_set();
     // Disallow out-of-bounds things.
     if (stop > self.nbDims)
-        throw py::index_error();
+    {
+        utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+    }
 
     py::tuple ret{slicelength};
     for (int i = start, index = 0; i < stop; i += step, ++index)
@@ -121,7 +125,9 @@ static const auto dims_getter_slice = [](const Dims& self, py::slice slice) {
 static const auto dims_setter = [](Dims& self, int pyIndex, int item) {
     size_t index = (pyIndex < 0) ? static_cast<int>(self.nbDims) + pyIndex : pyIndex;
     if (index >= self.nbDims)
-        throw py::index_error();
+    {
+        utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+    }
     self.d[index] = item;
 };
 
@@ -131,7 +137,9 @@ static const auto dims_setter_slice = [](Dims& self, py::slice slice, const Dims
         throw py::error_already_set();
     // Disallow out-of-bounds things.
     if (stop >= self.nbDims)
-        throw py::index_error();
+    {
+        utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+    }
 
     for (int i = start, index = 0; i < stop; i += step, ++index)
         self.d[i] = other.d[index];

python/src/infer/pyGraph.cpp

@@ -82,14 +82,20 @@ namespace tensorrt
         static const auto permutation_getter = [] (const Permutation& self, int pyIndex) {
             size_t index = (pyIndex < 0) ? static_cast<const int>(Dims::MAX_DIMS) + pyIndex : pyIndex;
             // Static cast is REQUIRED here, or chaos ensues as MAX_DIMS is not pulled in at link time.
-            if (index >= static_cast<const size_t>(Dims::MAX_DIMS)) throw py::index_error();
+            if (index >= static_cast<const size_t>(Dims::MAX_DIMS))
+            {
+                utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+            }
             return self.order[index];
         };
 
         static const auto permutation_setter = [] (Permutation& self, int pyIndex, int item) {
             size_t index = (pyIndex < 0) ? static_cast<const int>(Dims::MAX_DIMS) + pyIndex : pyIndex;
             // Static cast is REQUIRED here, or chaos ensues as MAX_DIMS is not pulled in at link time.
-            if (index >= static_cast<const size_t>(Dims::MAX_DIMS)) throw py::index_error();
+            if (index >= static_cast<const size_t>(Dims::MAX_DIMS))
+            {
+                utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+            }
             self.order[index] = item;
         };
 
@@ -197,7 +203,10 @@ namespace tensorrt
         static const auto network_getitem = [](INetworkDefinition& self, int pyIndex) {
             // Support python's negative indexing
             size_t index = (pyIndex < 0) ? self.getNbLayers() + pyIndex : pyIndex;
-            if (index >= self.getNbLayers()) throw py::index_error();
+            if (index >= self.getNbLayers())
+            {
+                utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+            }
             return self.getLayer(index);
         };
 

python/src/infer/pyPlugin.cpp

@@ -17,6 +17,7 @@
 // This file contains all bindings related to plugins.
 #include "ForwardDeclarations.h"
 #include "infer/pyPluginDoc.h"
+#include "utils.h"
 #include <cuda_runtime_api.h>
 #include <pybind11/stl.h>
 
@@ -217,7 +218,9 @@ void bindPlugin(py::module& m)
         .def("__len__", [](PluginFieldCollection& self) { return self.nbFields; })
         .def("__getitem__", [](PluginFieldCollection& self, int index) {
             if (index >= self.nbFields)
-                throw py::index_error();
+            {
+                utils::throwPyIndexError(); // See definition of throwPyIndexError() for details
+            }
             return self.fields[index];
         });
 

python/src/utils.cpp

@@ -29,5 +29,15 @@ void issueDeprecationWarning(const char* useInstead)
     PyErr_WarnEx(PyExc_DeprecationWarning, msg.c_str(), 1);
 }
 
+// The following is a helper WAR to "throw py::index_error()", which results in an incompatibility
+// with Tensorflow 2.5 and above--on Windows only--when Tensorflow is imported after TensorRT.
+// The TF library fast_module_type.pyd hooks on to IndexErrors thrown through py::index_error()
+// resulting in hangs at unpacking operations and out-of-bounds index accesses.
+void throwPyIndexError(std::string message)
+{
+    PyErr_SetString(PyExc_IndexError, message.data());
+    throw py::error_already_set();
+}
+
 } // namespace utils
 } // namespace tensorrt