Add TF_DeleteLibraryHandle, for freeing the memory allocated by TF_LoadLibrary.

This is useful when calling the C API from C++, to avoid memory leaks being
reported.
Change: 132937873

tensorflow/c/BUILD

@@ -7,6 +7,7 @@ load(
     "//tensorflow:tensorflow.bzl",
     "tf_cc_test",
     "tf_cuda_library",
+    "tf_custom_op_library",
 )
 
 # For platform specific build config
@@ -60,6 +61,7 @@ tf_cc_test(
     name = "c_api_test",
     size = "small",
     srcs = ["c_api_test.cc"],
+    data = [":test_op.so"],
     linkopts = select({
         "//tensorflow:darwin": ["-headerpad_max_install_names"],
         "//conditions:default": [],
@@ -81,6 +83,11 @@ tf_cc_test(
     ],
 )
 
+tf_custom_op_library(
+    name = "test_op.so",
+    srcs = ["test_op.cc"],
+)
+
 # -----------------------------------------------------------------------------
 # Google-internal targets.
 

tensorflow/c/c_api.cc

@@ -636,6 +636,11 @@ TF_Library* TF_LoadLibrary(const char* library_filename, TF_Status* status) {
 
 TF_Buffer TF_GetOpList(TF_Library* lib_handle) { return lib_handle->op_list; }
 
+void TF_DeleteLibraryHandle(TF_Library* lib_handle) {
+  free(const_cast<void*>(lib_handle->op_list.data));
+  delete lib_handle;
+}
+
 TF_Buffer* TF_GetAllOpList() {
   std::vector<tensorflow::OpDef> op_defs;
   tensorflow::OpRegistry::Global()->GetRegisteredOps(&op_defs);

tensorflow/c/c_api.h

@@ -958,6 +958,10 @@ extern TF_Library* TF_LoadLibrary(const char* library_filename,
 // ops defined in the library.
 extern TF_Buffer TF_GetOpList(TF_Library* lib_handle);
 
+// Frees the memory associated with the library handle.
+// Does NOT unload the library.
+extern void TF_DeleteLibraryHandle(TF_Library* lib_handle);
+
 // Get the OpList of all OpDefs defined in this address space.
 // Returns a TF_Buffer, ownership of which is transferred to the caller
 // (and can be freed using TF_DeleteBuffer).

tensorflow/c/c_api_test.cc

@@ -91,6 +91,26 @@ TEST(CApi, AllocateTensor) {
   TF_DeleteTensor(t);
 }
 
+TEST(CApi, LibraryLoadFunctions) {
+  // Load the library.
+  TF_Status* status = TF_NewStatus();
+  TF_Library* lib =
+      TF_LoadLibrary("tensorflow/c/test_op.so", status);
+  TF_Code code = TF_GetCode(status);
+  string status_msg(TF_Message(status));
+  TF_DeleteStatus(status);
+  ASSERT_EQ(TF_OK, code) << status_msg;
+
+  // Test op list.
+  TF_Buffer op_list_buf = TF_GetOpList(lib);
+  tensorflow::OpList op_list;
+  EXPECT_TRUE(op_list.ParseFromArray(op_list_buf.data, op_list_buf.length));
+  ASSERT_EQ(op_list.op_size(), 1);
+  EXPECT_EQ("TestCApi", op_list.op(0).name());
+
+  TF_DeleteLibraryHandle(lib);
+}
+
 static void TestEncodeDecode(int line, const std::vector<string>& data) {
   const tensorflow::int64 n = data.size();
   for (const std::vector<tensorflow::int64>& dims :

tensorflow/c/test_op.cc

@@ -0,0 +1,23 @@
+/* Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#include "tensorflow/core/framework/op.h"
+#include "tensorflow/core/framework/op_kernel.h"
+
+namespace tensorflow {
+
+REGISTER_OP("TestCApi").Doc(R"doc(Used to test C API)doc");
+
+}  // namespace tensorflow

tensorflow/core/framework/load_library.cc

@@ -85,7 +85,7 @@ Status LoadLibrary(const char* library_filename, void** result,
   }
   string str;
   op_list.SerializeToString(&str);
-  char* str_buf = reinterpret_cast<char*>(operator new(str.length()));
+  char* str_buf = reinterpret_cast<char*>(malloc(str.length()));
   memcpy(str_buf, str.data(), str.length());
   *buf = str_buf;
   *len = str.length();