address comments

tensorflow/c/c_api_experimental.cc

@@ -37,7 +37,9 @@ limitations under the License.
 #include "tensorflow/core/graph/node_builder.h"
 #include "tensorflow/core/platform/blocking_counter.h"
 #include "tensorflow/core/platform/casts.h"
+#include "tensorflow/core/platform/env.h"
 #include "tensorflow/core/platform/init_main.h"
+#include "tensorflow/core/platform/mutex.h"
 #include "tensorflow/core/platform/net.h"
 #include "tensorflow/core/platform/platform.h"
 #include "tensorflow/core/platform/strcat.h"
@@ -747,6 +749,14 @@ void TF_ImportGraphDefOptionsSetValidateColocationConstraints(
   opts->opts.validate_colocation_constraints = enable;
 }
 
+// Load a Pluggable Device library
+// On sucess, returns the handle to library in result and return OK from the
+// function. Otherwise return nullptr in result and error Status from the
+// function.
+//
+// If `library_filename` has already been loaded, we return a cached handle.
+// Device and Kernels/Ops are registered as globals when a library is loaded
+// for the first time.
 TF_Library* TF_LoadPluggableDeviceLibrary(const char* library_filename,
                                           TF_Status* status) {
 #if defined(IS_MOBILE_PLATFORM) || defined(IS_SLIM_BUILD)
@@ -755,17 +765,28 @@ TF_Library* TF_LoadPluggableDeviceLibrary(const char* library_filename,
   return nullptr;
 #else
   TF_Library* lib_handle = new TF_Library;
-  status->status = tensorflow::LoadPluggableDeviceLibrary(
+  static tensorflow::mutex mu(tensorflow::LINKER_INITIALIZED);
-      library_filename, &lib_handle->lib_handle);
+  static std::unordered_map<std::string, void*> loaded_libs;
-  if (!status->status.ok()) {
+  tensorflow::Env* env = tensorflow::Env::Default();
-    delete lib_handle;
+  {
-    return nullptr;
+    tensorflow::mutex_lock lock(mu);
+    if (loaded_libs.find(library_filename) != loaded_libs.end()) {
+      lib_handle->lib_handle = loaded_libs[library_filename];
+    } else {
+      status->status =
+          env->LoadDynamicLibrary(library_filename, &lib_handle->lib_handle);
+      if (status->status.ok()) {
+        // Init PluggableDevice Plugin
+      } else {
+        delete lib_handle;
+        return nullptr;
+      }
+    }
+    return lib_handle;
   }
-  return lib_handle;
 #endif
 }
 
 void TF_DeletePluggableDeviceLibraryHandle(TF_Library* lib_handle) {
-  if (lib_handle == nullptr) return;
   delete lib_handle;
 }

tensorflow/c/c_api_experimental.h

@@ -308,7 +308,7 @@ TF_ImportGraphDefOptionsSetValidateColocationConstraints(
 // device and related kernels present in that library.
 //
 // Pass "library_filename" to a platform-specific mechanism for dynamically
-// loading a library. The reles for determining the exact location of the
+// loading a library. The rules for determining the exact location of the
 // library are platform-specific and are not documented here
 //
 // On success, place OK in status and return the newly created library handle.

tensorflow/c/experimental/stream_executor/BUILD

@@ -60,11 +60,3 @@ tf_cc_test(
         "//tensorflow/stream_executor:stream_executor_pimpl",
     ],
 )
-
-exports_files(
-    srcs = [
-        "stream_executor.h",
-        "stream_executor_internal.h",
-    ],
-    visibility = ["//visibility:public"],
-)

tensorflow/c/experimental/stream_executor/test/BUILD

@@ -2,20 +2,12 @@
 # test for stream_executor
 load(
     "//tensorflow:tensorflow.bzl",
-    "tf_custom_op_library",
+    "tf_cc_shared_object",
 )
 
-cc_library(
+tf_cc_shared_object(
-    name = "test_pluggable_device_impl",
-    srcs = ["test_pluggable_device.cc"],
-    hdrs = [
-        "//tensorflow/c:headers",
-        "//tensorflow/c/experimental/stream_executor:stream_executor.h",
-    ],
-)
-
-tf_custom_op_library(
     name = "test_pluggable_device.so",
+    srcs = ["test_pluggable_device.cc"],
     visibility = ["//tensorflow/c:__subpackages__"],
-    deps = [":test_pluggable_device_impl"],
+    deps = ["//tensorflow/c/experimental/stream_executor:stream_executor_hdrs"],
 )

tensorflow/c/kernels.h

@@ -134,12 +134,13 @@ TF_CAPI_EXPORT extern void TF_DeleteKernelBuilder(TF_KernelBuilder* builder);
 // --------------------------------------------------------------------------
 // OpKernelContext routines
 
-// TF_GetStream returns the SP_Stream available in ctx
+// TF_GetStream returns the SP_Stream available in ctx.
 // This function returns a stream only for devices registered using the
 // StreamExecutor C API
 // (tensorflow/c/experimental/stream_executor/stream_executor.h). It will return
-// nullptr in all other cases. Experimental: this function doesn't have
+// nullptr in all other cases.
-// compatibility guarantees and subject to change at any time."
+// Experimental: this function doesn't have compatibility guarantees and subject
+// to change at any time."
 TF_CAPI_EXPORT extern SP_Stream TF_GetStream(TF_OpKernelContext* ctx);
 
 // TF_NumInputs returns the number of inputs available in ctx.

tensorflow/c/test_pluggable_device.cc

@@ -1,24 +0,0 @@
-
-/* Copyright 2020 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/c/experimental/stream_executor/stream_executor.h"
-
-void SE_InitPlugin(SE_PlatformRegistrationParams* const params,
-                   TF_Status* const status) {
-  params->platform->struct_size = SP_PLATFORM_STRUCT_SIZE;
-  params->platform->name = "GPU";
-  params->platform->type = "XGPU";
-}

tensorflow/core/framework/load_library.cc

@@ -101,35 +101,4 @@ Status LoadDynamicLibrary(const char* library_filename, void** result,
   return Status::OK();
 }
 
-// Load a Pluggable Device library
-// On sucess, returns the handle to library in result and return OK from the
-// function. Otherwise return nullptr in result and error Status from the
-// function.
-//
-// If `library_filename` has already been loaded, we return a cached handle.
-// Device and Kernels/Ops are registered as globals when a library is laoded
-// for the first time.
-Status LoadPluggableDeviceLibrary(const char* library_filename, void** result) {
-  static mutex mu(LINKER_INITIALIZED);
-  static std::unordered_map<string, Library> loaded_libs;
-  Env* env = Env::Default();
-  Library library;
-  {
-    mutex_lock lock(mu);
-    if (loaded_libs.find(library_filename) != loaded_libs.end()) {
-      library = loaded_libs[library_filename];
-    } else {
-      Status s = env->LoadDynamicLibrary(library_filename, &library.handle);
-      if (s.ok()) {
-        // Init PluggableDevice Plugin
-      } else {
-        return s;
-      }
-
-      loaded_libs[library_filename] = library;
-    }
-    *result = library.handle;
-    return Status::OK();
-  }
-}
 }  // namespace tensorflow

tensorflow/python/eager/context.py

@@ -1244,12 +1244,12 @@ class Context(object):
   def invoking_op_callbacks(self, value):
     self._thread_local_data.invoking_op_callbacks = value
 
-  def _initialize_physical_devices(self):
+  def _initialize_physical_devices(self, reinitialize=False):
     """Get local devices visible to the system."""
     # We lazy initialize self._physical_devices since we do not want to do this
     # the constructor since the backend may not be initialized yet.
     with self._device_lock:
-      if self._physical_devices is not None:
+      if reinitialize is False and self._physical_devices is not None:
         return
 
       devs = pywrap_tfe.TF_ListPhysicalDevices()
@@ -1267,29 +1267,12 @@ class Context(object):
 
     # Import device settings that may have been passed into the constructor
     self._import_config()
-
+  
   def reinitialize_physical_devices(self):
     """Get local devices visible to the system."""
-    # We lazy initialize self._physical_devices since we do not want to do this
+    # Reinitialize the physical device list after registering
-    # the constructor since the backend may not be initialized yet.
+    # the pluggable device.
-    with self._device_lock:
+    self._initialize_physical_devices(True)
-      devs = pywrap_tfe.TF_ListPhysicalDevices()
-      self._physical_devices = [
-          PhysicalDevice(name=d.decode(),
-                         device_type=d.decode().split(":")[1]) for d in devs]
-      self._physical_device_to_index = {
-          p: i for i, p in enumerate(self._physical_devices)
-      }
-
-      self._visible_device_list = list(self._physical_devices)
-      self._memory_growth_map = {
-          d: None for d in self._physical_devices if d.device_type == "GPU"
-      }
-
-    # Import device settings that may have been passed into the constructor
-    self._import_config()
-
-
 
   def list_physical_devices(self, device_type=None):
     """List local devices visible to the system.