[OpenMP] Add unit tests for nextgen plugins (#74398)

This patch add three GTest unit tests that test plugin read and write
operations. Tests can be compiled with `ninja -C runtimes/runtimes-bins
LibomptUnitTests`.

openmp/libomptarget/CMakeLists.txt

@@ -150,3 +150,9 @@ add_subdirectory(${LIBOMPTARGET_SRC_DIR})
 
 # Add tests.
 add_subdirectory(test)
+
+# Add unit tests if GMock/GTest is present
+if (EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest)
+  add_subdirectory(${LLVM_THIRD_PARTY_DIR}/unittest ${CMAKE_CURRENT_BINARY_DIR}/third-party/unittest)
+  add_subdirectory(unittests)
+endif()

openmp/libomptarget/unittests/CMakeLists.txt

@@ -0,0 +1,8 @@
+add_custom_target(LibomptUnitTests)
+set_target_properties(LibomptUnitTests PROPERTIES FOLDER "Tests/UnitTests")
+
+function(add_libompt_unittest test_dirname)
+  add_unittest(LibomptUnitTests ${test_dirname} ${ARGN})
+endfunction()
+
+add_subdirectory(Plugins)

openmp/libomptarget/unittests/Plugins/CMakeLists.txt

@@ -0,0 +1,11 @@
+set(PLUGINS_TEST_COMMON omptarget OMPT omptarget.devicertl)
+set(PLUGINS_TEST_SOURCES NextgenPluginsTest.cpp)
+set(PLUGINS_TEST_INCLUDE ${LIBOMPTARGET_INCLUDE_DIR})
+
+foreach(PLUGIN IN LISTS LIBOMPTARGET_TESTED_PLUGINS)
+  libomptarget_say("Building plugin unit tests for ${PLUGIN}")
+  add_libompt_unittest("${PLUGIN}.unittests" ${PLUGINS_TEST_SOURCES})
+  add_dependencies("${PLUGIN}.unittests" ${PLUGINS_TEST_COMMON} ${PLUGIN})
+  target_link_libraries("${PLUGIN}.unittests" PRIVATE ${PLUGINS_TEST_COMMON} ${PLUGIN})
+  target_include_directories("${PLUGIN}.unittests" PRIVATE ${PLUGINS_TEST_INCLUDE})
+endforeach()

openmp/libomptarget/unittests/Plugins/NextgenPluginsTest.cpp

@@ -0,0 +1,168 @@
+//===------- unittests/Plugins/NextgenPluginsTest.cpp - Plugin tests ------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Shared/PluginAPI.h"
+#include "omptarget.h"
+#include "gtest/gtest.h"
+
+#include <unordered_set>
+
+const int DEVICE_ID = 0;
+std::unordered_set<int> setup_map;
+
+int init_test_device(int ID) {
+  if (setup_map.find(ID) != setup_map.end()) {
+    return OFFLOAD_SUCCESS;
+  }
+  if (__tgt_rtl_init_plugin() == OFFLOAD_FAIL ||
+      __tgt_rtl_init_device(ID) == OFFLOAD_FAIL) {
+    return OFFLOAD_FAIL;
+  }
+  setup_map.insert(ID);
+  return OFFLOAD_SUCCESS;
+}
+
+// Test plugin initialization
+TEST(NextgenPluginsTest, PluginInit) {
+  EXPECT_EQ(OFFLOAD_SUCCESS, init_test_device(DEVICE_ID));
+}
+
+// Test GPU allocation and R/W
+TEST(NextgenPluginsTest, PluginAlloc) {
+  int32_t test_value = 23;
+  int32_t host_value = -1;
+  int64_t var_size = sizeof(int32_t);
+
+  // Init plugin and device
+  EXPECT_EQ(OFFLOAD_SUCCESS, init_test_device(DEVICE_ID));
+
+  // Allocate memory
+  void *device_ptr =
+      __tgt_rtl_data_alloc(DEVICE_ID, var_size, nullptr, TARGET_ALLOC_DEFAULT);
+
+  // Check that the result is not null
+  EXPECT_NE(device_ptr, nullptr);
+
+  // Submit data to device
+  EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_submit(DEVICE_ID, device_ptr,
+                                                   &test_value, var_size));
+
+  // Read data from device
+  EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_retrieve(DEVICE_ID, &host_value,
+                                                     device_ptr, var_size));
+
+  // Compare values
+  EXPECT_EQ(host_value, test_value);
+
+  // Cleanup data
+  EXPECT_EQ(OFFLOAD_SUCCESS,
+            __tgt_rtl_data_delete(DEVICE_ID, device_ptr, TARGET_ALLOC_DEFAULT));
+}
+
+// Test async GPU allocation and R/W
+TEST(NextgenPluginsTest, PluginAsyncAlloc) {
+  int32_t test_value = 47;
+  int32_t host_value = -1;
+  int64_t var_size = sizeof(int32_t);
+  __tgt_async_info *info;
+
+  // Init plugin and device
+  EXPECT_EQ(OFFLOAD_SUCCESS, init_test_device(DEVICE_ID));
+
+  // Check if device supports async
+  // Platforms like x86_64 don't support it
+  if (__tgt_rtl_init_async_info(DEVICE_ID, &info) == OFFLOAD_SUCCESS) {
+    // Allocate memory
+    void *device_ptr = __tgt_rtl_data_alloc(DEVICE_ID, var_size, nullptr,
+                                            TARGET_ALLOC_DEFAULT);
+
+    // Check that the result is not null
+    EXPECT_NE(device_ptr, nullptr);
+
+    // Submit data to device asynchronously
+    EXPECT_EQ(OFFLOAD_SUCCESS,
+              __tgt_rtl_data_submit_async(DEVICE_ID, device_ptr, &test_value,
+                                          var_size, info));
+
+    // Wait for async request to process
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_synchronize(DEVICE_ID, info));
+
+    // Read data from device
+    EXPECT_EQ(OFFLOAD_SUCCESS,
+              __tgt_rtl_data_retrieve_async(DEVICE_ID, &host_value, device_ptr,
+                                            var_size, info));
+
+    // Wait for async request to process
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_synchronize(DEVICE_ID, info));
+
+    // Compare values
+    EXPECT_EQ(host_value, test_value);
+
+    // Cleanup data
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_delete(DEVICE_ID, device_ptr,
+                                                     TARGET_ALLOC_DEFAULT));
+  }
+}
+
+// Test GPU data exchange
+TEST(NextgenPluginsTest, PluginDataSwap) {
+  int32_t test_value = 23;
+  int32_t host_value = -1;
+  int64_t var_size = sizeof(int32_t);
+
+  // Look for compatible device
+  int DEVICE_TWO = -1;
+  for (int i = 1; i < __tgt_rtl_number_of_devices(); i++) {
+    if (__tgt_rtl_is_data_exchangable(DEVICE_ID, i)) {
+      DEVICE_TWO = i;
+      break;
+    }
+  }
+
+  // Only run test if we have multiple GPUs to test
+  // GPUs must be compatible for test to work
+  if (DEVICE_TWO >= 1) {
+    // Init both GPUs
+    EXPECT_EQ(OFFLOAD_SUCCESS, init_test_device(DEVICE_ID));
+    EXPECT_EQ(OFFLOAD_SUCCESS, init_test_device(DEVICE_TWO));
+
+    // Allocate memory on both GPUs
+    // DEVICE_ID will be the source
+    // DEVICE_TWO will be the destination
+    void *source_ptr = __tgt_rtl_data_alloc(DEVICE_ID, var_size, nullptr,
+                                            TARGET_ALLOC_DEFAULT);
+    void *dest_ptr = __tgt_rtl_data_alloc(DEVICE_TWO, var_size, nullptr,
+                                          TARGET_ALLOC_DEFAULT);
+
+    // Check for success in allocation
+    EXPECT_NE(source_ptr, nullptr);
+    EXPECT_NE(dest_ptr, nullptr);
+
+    // Write data to source
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_submit(DEVICE_ID, source_ptr,
+                                                     &test_value, var_size));
+
+    // Transfer data between devices
+    EXPECT_EQ(OFFLOAD_SUCCESS,
+              __tgt_rtl_data_exchange(DEVICE_ID, source_ptr, DEVICE_TWO,
+                                      dest_ptr, var_size));
+
+    // Read from destination device (DEVICE_TWO) memory
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_retrieve(DEVICE_TWO, &host_value,
+                                                       dest_ptr, var_size));
+
+    // Ensure match
+    EXPECT_EQ(host_value, test_value);
+
+    // Cleanup
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_delete(DEVICE_ID, source_ptr,
+                                                     TARGET_ALLOC_DEFAULT));
+    EXPECT_EQ(OFFLOAD_SUCCESS, __tgt_rtl_data_delete(DEVICE_TWO, dest_ptr,
+                                                     TARGET_ALLOC_DEFAULT));
+  }
+}