[UR][Offload] Native handle wrappers for device and platform (#19563)

And also a small comment explaining why context isn't supported.

Author: RossBrunton

unified-runtime/source/adapters/offload/context.cpp

@@ -59,6 +59,7 @@ urContextRelease(ur_context_handle_t hContext) {
   return UR_RESULT_SUCCESS;
 }
 
+// Offload currently doesn't have an equivalent to context handles
 UR_APIEXPORT ur_result_t UR_APICALL
 urContextGetNativeHandle(ur_context_handle_t, ur_native_handle_t *) {
   return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;

unified-runtime/source/adapters/offload/device.cpp

@@ -12,6 +12,7 @@
 #include <ur/ur.hpp>
 #include <ur_api.h>
 
+#include "adapters/offload/adapter.hpp"
 #include "device.hpp"
 #include "platform.hpp"
 #include "ur2offload.hpp"
@@ -211,14 +212,32 @@ UR_APIEXPORT ur_result_t UR_APICALL urDeviceSelectBinary(
   return UR_RESULT_ERROR_INVALID_BINARY;
 }
 
-UR_APIEXPORT ur_result_t UR_APICALL
-urDeviceGetNativeHandle(ur_device_handle_t, ur_native_handle_t *) {
-  return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
+UR_APIEXPORT ur_result_t UR_APICALL urDeviceGetNativeHandle(
+    ur_device_handle_t UrDevice, ur_native_handle_t *Handle) {
+  *Handle = reinterpret_cast<ur_native_handle_t>(UrDevice->OffloadDevice);
+  return UR_RESULT_SUCCESS;
 }
 
 UR_APIEXPORT ur_result_t UR_APICALL urDeviceCreateWithNativeHandle(
-    ur_native_handle_t, ur_adapter_handle_t,
-    const ur_device_native_properties_t *, ur_device_handle_t *) {
+    ur_native_handle_t hNativeDevice, ur_adapter_handle_t hAdapter,
+    const ur_device_native_properties_t *, ur_device_handle_t *phDevice) {
+  ol_device_handle_t OlDevice =
+      reinterpret_cast<ol_device_handle_t>(hNativeDevice);
+
+  // Currently, all devices are found at initialization, there is no way to
+  // create sub devices yet
+  for (auto &P : hAdapter->Platforms) {
+    auto Found =
+        std::find_if(P->Devices.begin(), P->Devices.end(),
+                     [&](std::unique_ptr<ur_device_handle_t_> &PDevice) {
+                       return PDevice->OffloadDevice == OlDevice;
+                     });
+    if (Found != P->Devices.end()) {
+      *phDevice = Found->get();
+      return UR_RESULT_SUCCESS;
+    }
+  }
+
   return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
 }
 

unified-runtime/source/adapters/offload/platform.cpp

@@ -95,14 +95,27 @@ urPlatformGetBackendOption(ur_platform_handle_t, const char *pFrontendOption,
   return UR_RESULT_ERROR_INVALID_VALUE;
 }
 
-UR_APIEXPORT ur_result_t UR_APICALL
-urPlatformGetNativeHandle(ur_platform_handle_t, ur_native_handle_t *) {
-  return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
+UR_APIEXPORT ur_result_t UR_APICALL urPlatformGetNativeHandle(
+    ur_platform_handle_t hAdapter, ur_native_handle_t *phNativePlatform) {
+  *phNativePlatform =
+      reinterpret_cast<ur_native_handle_t>(hAdapter->OffloadPlatform);
+  return UR_RESULT_SUCCESS;
 }
 
 UR_APIEXPORT ur_result_t UR_APICALL urPlatformCreateWithNativeHandle(
-    ur_native_handle_t, ur_adapter_handle_t,
-    const ur_platform_native_properties_t *, ur_platform_handle_t *) {
+    ur_native_handle_t hNativePlatform, ur_adapter_handle_t hAdapter,
+    const ur_platform_native_properties_t *, ur_platform_handle_t *phPlatform) {
+
+  auto Found = std::find_if(
+      hAdapter->Platforms.begin(), hAdapter->Platforms.end(), [&](auto &P) {
+        return P->OffloadPlatform ==
+               reinterpret_cast<ol_platform_handle_t>(hNativePlatform);
+      });
+  if (Found != hAdapter->Platforms.end()) {
+    *phPlatform = Found->get();
+    return UR_RESULT_SUCCESS;
+  }
+
   return UR_RESULT_ERROR_UNSUPPORTED_FEATURE;
 }