as discussed, moving clearing of platform cache to beginning of mock. Also fix the otherwise tautological DeviceRefCounter test.

Signed-off-by: Chris Perkins <[email protected]>

Author: cperkinsintel

sycl/unittests/context_device/DeviceRefCounter.cpp

@@ -5,6 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
+#include <detail/global_handler.hpp>
 #include <gtest/gtest.h>
 #include <helpers/UrMock.hpp>
 #include <sycl/sycl.hpp>
@@ -28,12 +29,10 @@ static ur_result_t redefinedDeviceReleaseAfter(void *) {
   return UR_RESULT_SUCCESS;
 }
 
-#ifndef WIN32
-// This test passes because the UrMock emulates teardown on Linux, but
-// on Windows there is a difference so this test is skipped.
 TEST(DevRefCounter, DevRefCounter) {
   {
     sycl::unittest::UrMock<> Mock;
+    EXPECT_EQ(DevRefCounter, 0);
 
     mock::getCallbacks().set_after_callback("urDeviceGet",
                                             &redefinedDevicesGetAfter);
@@ -44,7 +43,12 @@ TEST(DevRefCounter, DevRefCounter) {
     sycl::platform Plt = sycl::platform();
 
     Plt.get_devices();
-  } // <- ~UrMock destructor called here.
+    EXPECT_NE(DevRefCounter, 0);
+    // This is the behavior that SYCL performs at shutdown, but there
+    // are timing differences Lin/Win and shared/static that make
+    // it not map correctly into our mock.
+    // So for this test, we just do it.
+    sycl::detail::GlobalHandler::instance().getPlatformCache().clear();
+  }
   EXPECT_EQ(DevRefCounter, 0);
 }
-#endif // !WIN32

sycl/unittests/helpers/UrMock.hpp

@@ -596,6 +596,16 @@ template <sycl::backend Backend = backend::opencl> class UrMock {
 
     sycl::detail::ur::initializeUr(UrLoaderConfig);
     urLoaderConfigRelease(UrLoaderConfig);
+
+    // We clear platform cache for each test run, so that tests can have a
+    // different backend. This forces platforms to be reconstructed (and thus
+    // queries about UR backend info to be called again) This also erases each
+    // platform's devices (normally done in the library shutdown) so that
+    // platforms/devices' lifetimes could work in unittests scenario. In SYCL,
+    // this is normally done at shutdown, but between Win/Lin and static/shared
+    // differences, there is no correct parallel in the ~UrMock destructor.
+    // Instead we do it here. Simple and clean.
+    detail::GlobalHandler::instance().getPlatformCache().clear();
   }
 
   UrMock(UrMock<Backend> &&Other) = delete;
@@ -606,18 +616,8 @@ template <sycl::backend Backend = backend::opencl> class UrMock {
     // these between tests
     detail::GlobalHandler::instance().prepareSchedulerToRelease(true);
     detail::GlobalHandler::instance().releaseDefaultContexts();
-#ifndef WIN32
-    // Clear platform cache in case subsequent tests want a different backend.
-    // This forces platforms to be reconstructed (and thus queries about UR
-    // backend info to be called again) This also erases each platform's devices
-    // (normally done in the library shutdown) so that platforms/devices'
-    // lifetimes could work in unittests scenario. But on Windows, because the
-    // shutdown/teardown timing is slightly different, doing this now can cause
-    // a race which will cause errors. At the moment, skipping this on Windows
-    // is fine. If, in the future, we really need to clear this, do it in the
-    // UrMock constructor.
-    detail::GlobalHandler::instance().getPlatformCache().clear();
-#endif // !WIN32
+    // the platform cache is cleared at the BEGINING of the mock.
+
     mock::getCallbacks().resetCallbacks();
   }