[llvm-branch-commits] [llvm] [libsycl] add single_task (PR #188797)

[Sergey Semenov via llvm-branch-commits]

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@@ -0,0 +1,135 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 helper functions used to wrap kernel arguments to
+/// typeless collection.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBSYCL___IMPL_DETAIL_ARG_WRAPPER_HPP
+#define _LIBSYCL___IMPL_DETAIL_ARG_WRAPPER_HPP
+
+#include <sycl/__impl/detail/config.hpp>
+#include <sycl/__impl/exception.hpp>
+
+#include <cassert>
+#include <memory>
+
+_LIBSYCL_BEGIN_NAMESPACE_SYCL
+
+namespace detail {
+
+/// Base class is needed for unification, we pass arguments through ABI
+/// boundary.
+class ArgWrapperBase {
+public:
+  ArgWrapperBase(const ArgWrapperBase &) = delete;
+  ArgWrapperBase &operator=(const ArgWrapperBase &) = delete;
+  virtual ~ArgWrapperBase() = default;
+
+  virtual void deepCopy() = 0;
+  virtual size_t getSize() const = 0;
+  virtual const void *getPtr() const = 0;
+
+protected:
+  ArgWrapperBase() = default;
+};
+
+/// Helps to manage arguments in a typeless way.
+template <typename Type> class ArgWrapper : public ArgWrapperBase {
+public:
+  ArgWrapper(Type &Arg) { Ptr = &Arg; }
+  ArgWrapper(const ArgWrapper &) = delete;
+  ArgWrapper &operator=(const ArgWrapper &) = delete;
+
+  /// \return size of argument in bytes.
+  size_t getSize() const override { return sizeof(Type); }
+
+  /// Returns raw pointer to the corresponding argument.
+  /// No copy is done by this method. It works with pointer to the memory whose
+  /// existence must be guaranteed by class user or with copy that must be
+  /// explicitly requested by class user via deepCopy method.
+  /// \return pointer to the argument.
+  const void *getPtr() const override {
+    assert((!DeepCopy || (DeepCopy.get()) == Ptr) &&
+           "Incorrect state of copied argument");
+    return Ptr;
+  }
+
+  /// Copies agrument to RT owned storage.
+  void deepCopy() override {
+    if (DeepCopy)
+      return;
+
+    DeepCopy.reset(new Type(*Ptr));
+    Ptr = DeepCopy.get();
+  }
+
+private:
+  Type *Ptr;
+  std::unique_ptr<Type> DeepCopy;
+};
+
+/// Collection of arguments. Provides functionality to accumulate all arguments
+/// data to pass through ABI boundary.
+class ArgCollection {
+public:
+  /// Adds argument to the collection. Don't own the memory. Argument lifetime
+  /// must be guaranteed by class user. If extended lifetime is needed (copy),
+  /// deepCopy must be called.
----------------
sergey-semenov wrote:

```suggestion
  /// Adds an argument to the collection. Doesn't own the memory, the argument lifetime
  /// must be guaranteed by the class user. If extended lifetime is needed (copy),
  /// deepCopy must be called.
```

https://github.com/llvm/llvm-project/pull/188797