Allow using libneuralnetworks.so on non-Android platforms.

PiperOrigin-RevId: 230957760

tensorflow/lite/nnapi/BUILD

@@ -15,13 +15,26 @@ cc_library(
 
 cc_library(
     name = "nnapi_implementation",
-    srcs = [
-        "nnapi_implementation.cc",
-    ],
+    srcs = select({
+        "//tensorflow:ios": [
+            "nnapi_implementation_disabled.cc",
+        ],
+        "//tensorflow:windows": [
+            "nnapi_implementation_disabled.cc",
+        ],
+        "//conditions:default": [
+            "nnapi_implementation.cc",
+        ],
+    }),
     hdrs = [
         "nnapi_implementation.h",
     ],
-    linkopts = ["-ldl"],
+    linkopts = ["-ldl"] + select({
+        "//tensorflow:android": [],
+        "//tensorflow:ios": [],
+        "//tensorflow:windows": [],
+        "//conditions:default": ["-lrt"],
+    }),
     deps = [
         "//tensorflow/lite/nnapi:nnapi_lib",
     ],

tensorflow/lite/nnapi/nnapi_implementation.cc

@@ -14,14 +14,17 @@ limitations under the License.
 ==============================================================================*/
 #include "tensorflow/lite/nnapi/nnapi_implementation.h"
 
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #include <cstdlib>
 
 #ifdef __ANDROID__
-#include <dlfcn.h>
-#include <sys/mman.h>
 #include <sys/system_properties.h>
-#include <unistd.h>
-#endif
+#endif  // __ANDROID__
 
 #define NNAPI_LOG(format, ...) fprintf(stderr, format "\n", __VA_ARGS__);
 
@@ -46,6 +49,7 @@ int32_t GetAndroidSdkVersion() {
   }
   return 0;
 }
+#endif  // __ANDROID__
 
 void* LoadFunction(void* handle, const char* name) {
   if (handle == nullptr) {
@@ -58,43 +62,48 @@ void* LoadFunction(void* handle, const char* name) {
   return fn;
 }
 
+#ifndef __ANDROID__
+// Add /dev/shm implementation of shared memory for non-Android platforms
+int ASharedMemory_create(const char* name, size_t size) {
+  int fd = shm_open(name, O_RDWR | O_CREAT, 0644);
+  if (fd >= 0) {
+    ftruncate(fd, size);
+  }
+  return fd;
+}
+#endif  // __ANDROID__
+
 #define LOAD_FUNCTION(handle, name) \
   nnapi.name = reinterpret_cast<name##_fn>(LoadFunction(handle, #name));
 
-#else
-
-#define LOAD_FUNCTION(handle, name) nnapi.name = nullptr;
-
-#endif
-
 const NnApi LoadNnApi() {
   NnApi nnapi = {};
+  nnapi.android_sdk_version = 0;
 
 #ifdef __ANDROID__
-  void* libneuralnetworks = nullptr;
   void* libandroid = nullptr;
   nnapi.android_sdk_version = GetAndroidSdkVersion();
   if (nnapi.android_sdk_version < 27) {
     NNAPI_LOG("nnapi error: requires android sdk version to be at least %d",
               27);
-  } else {
-    // TODO: change RTLD_LOCAL? Assumes there can be multiple instances of nn
-    // api RT
-    libneuralnetworks = dlopen("libneuralnetworks.so", RTLD_LAZY | RTLD_LOCAL);
-    if (libneuralnetworks == nullptr) {
-      NNAPI_LOG("nnapi error: unable to open library %s",
-                "libneuralnetworks.so");
-    }
-    libandroid = dlopen("libandroid.so", RTLD_LAZY | RTLD_LOCAL);
-    if (libandroid == nullptr) {
-      NNAPI_LOG("nnapi error: unable to open library %s", "libandroid.so");
-    }
+    nnapi.nnapi_exists = false;
+    return nnapi;
   }
+  libandroid = dlopen("libandroid.so", RTLD_LAZY | RTLD_LOCAL);
+  if (libandroid == nullptr) {
+    NNAPI_LOG("nnapi error: unable to open library %s", "libandroid.so");
+  }
+#endif  // __ANDROID__
+
+  void* libneuralnetworks = nullptr;
+  // TODO(b/123243014): change RTLD_LOCAL? Assumes there can be multiple
+  // instances of nn api RT
+  libneuralnetworks = dlopen("libneuralnetworks.so", RTLD_LAZY | RTLD_LOCAL);
+  if (libneuralnetworks == nullptr) {
+    NNAPI_LOG("nnapi error: unable to open library %s", "libneuralnetworks.so");
+  }
+
   nnapi.nnapi_exists = libneuralnetworks != nullptr;
-#else
-  nnapi.nnapi_exists = false;
-  nnapi.android_sdk_version = 0;
-#endif
 
   LOAD_FUNCTION(libneuralnetworks, ANeuralNetworksMemory_createFromFd);
   LOAD_FUNCTION(libneuralnetworks, ANeuralNetworksMemory_free);
@@ -124,7 +133,11 @@ const NnApi LoadNnApi() {
   LOAD_FUNCTION(libneuralnetworks, ANeuralNetworksExecution_startCompute);
   LOAD_FUNCTION(libneuralnetworks, ANeuralNetworksEvent_wait);
   LOAD_FUNCTION(libneuralnetworks, ANeuralNetworksEvent_free);
+#ifdef __ANDROID__
   LOAD_FUNCTION(libandroid, ASharedMemory_create);
+#else
+  nnapi.ASharedMemory_create = ASharedMemory_create;
+#endif  // __ANDROID__
 
   return nnapi;
 }

tensorflow/lite/nnapi/nnapi_implementation_disabled.cc

@@ -0,0 +1,20 @@
+/* Copyright 2019 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/lite/nnapi/nnapi_implementation.h"
+
+const NnApi* NnApiImplementation() {
+  static const NnApi nnapi = {};
+  return &nnapi;
+}

tensorflow/lite/nnapi/nnapi_implementation_test.cc

@@ -113,7 +113,7 @@ TEST(NnapiLibTest, NnApiImplementation) {
   EXPECT_EQ(nnapi->ANeuralNetworksExecution_startCompute, nullptr);
   EXPECT_EQ(nnapi->ANeuralNetworksEvent_wait, nullptr);
   EXPECT_EQ(nnapi->ANeuralNetworksEvent_free, nullptr);
-  EXPECT_EQ(nnapi->ASharedMemory_create, nullptr);
+  EXPECT_NE(nnapi->ASharedMemory_create, nullptr);
 #endif
 }