[llvm] [libsycl] Add sycl::queue stub (PR #184110)

[Sergey Semenov via llvm-commits]

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@@ -0,0 +1,159 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the declaration of the SYCL queue class, which
+/// schedules kernels on a device.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBSYCL___IMPL_QUEUE_HPP
+#define _LIBSYCL___IMPL_QUEUE_HPP
+
+#include <sycl/__impl/detail/config.hpp>
+#include <sycl/__impl/detail/default_async_handler.hpp>
+#include <sycl/__impl/detail/obj_utils.hpp>
+
+#include <sycl/__impl/async_handler.hpp>
+#include <sycl/__impl/device.hpp>
+#include <sycl/__impl/property_list.hpp>
+
+_LIBSYCL_BEGIN_NAMESPACE_SYCL
+
+class context;
+
+namespace detail {
+class QueueImpl;
+} // namespace detail
+
+// SYCL 2020 4.6.5. Queue class.
+class _LIBSYCL_EXPORT queue {
+public:
+  queue(const queue &rhs) = default;
+
+  queue(queue &&rhs) = default;
+
+  queue &operator=(const queue &rhs) = default;
+
+  queue &operator=(queue &&rhs) = default;
+
+  friend bool operator==(const queue &lhs, const queue &rhs) {
+    return lhs.impl == rhs.impl;
+  }
+
+  friend bool operator!=(const queue &lhs, const queue &rhs) {
+    return !(lhs == rhs);
+  }
+
+  /// Constructs a SYCL queue instance using the device returned by an instance
+  /// of default_selector.
+  ///
+  /// \param propList is a list of properties for queue construction.
+  explicit queue(const property_list &propList = {})
+      : queue(detail::SelectDevice(default_selector_v),
+              detail::defaultAsyncHandler, propList) {}
+
+  /// Constructs a SYCL queue instance with an async_handler using the device
+  /// returned by an instance of default_selector.
+  ///
+  /// \param asyncHandler is a SYCL asynchronous exception handler.
+  /// \param propList is a list of properties for queue construction.
+  explicit queue(const async_handler &asyncHandler,
+                 const property_list &propList = {})
+      : queue(detail::SelectDevice(default_selector_v), asyncHandler,
+              propList) {}
+
+  /// Constructs a SYCL queue instance using the device identified by the
+  /// device selector provided.
+  /// \param deviceSelector is SYCL 2020 Device Selector, a simple callable that
+  /// takes a device and returns an int
+  /// \param propList is a list of properties for queue construction.
+  template <
+      typename DeviceSelector,
+      typename = detail::EnableIfDeviceSelectorIsInvocable<DeviceSelector>>
+  explicit queue(const DeviceSelector &deviceSelector,
+                 const property_list &propList = {})
+      : queue(detail::SelectDevice(deviceSelector), detail::defaultAsyncHandler,
+              propList) {}
+
+  /// Constructs a SYCL queue instance using the device identified by the
+  /// device selector provided.
+  /// \param deviceSelector is SYCL 2020 Device Selector, a simple callable that
+  /// takes a device and returns an int
+  /// \param asyncHandler is a SYCL asynchronous exception handler.
+  /// \param propList is a list of properties for queue construction.
+  template <
+      typename DeviceSelector,
+      typename = detail::EnableIfDeviceSelectorIsInvocable<DeviceSelector>>
+  explicit queue(const DeviceSelector &deviceSelector,
+                 const async_handler &asyncHandler,
+                 const property_list &propList = {})
+      : queue(detail::SelectDevice(deviceSelector), asyncHandler, propList) {}
+
+  /// Constructs a SYCL queue instance using the device provided.
+  ///
+  /// \param syclDevice is an instance of SYCL device.
+  /// \param propList is a list of properties for queue construction.
+  explicit queue(const device &syclDevice, const property_list &propList = {})
+      : queue(syclDevice, detail::defaultAsyncHandler, propList) {}
+
+  /// Constructs a SYCL queue instance with an async_handler using the device
+  /// provided.
+  ///
+  /// \param syclDevice is an instance of SYCL device.
+  /// \param asyncHandler is a SYCL asynchronous exception handler.
+  /// \param propList is a list of properties for queue construction.
+  explicit queue(const device &syclDevice, const async_handler &asyncHandler,
+                 const property_list &propList = {});
+
+  /// Returns the SYCL backend that is associated with this queue.
+  ///
+  /// \return the backend associated with this queue.
+  backend get_backend() const noexcept;
+
+  /// Returns context that is associated with this queue.
+  ///
+  /// \return an associated SYCL context.
----------------
sergey-semenov wrote:

```suggestion
  /// \return the associated SYCL context.
```

https://github.com/llvm/llvm-project/pull/184110