[SYCL] Introduce interop handle for host task

sycl/include/CL/sycl/interop_handle.hpp

@@ -0,0 +1,117 @@
+//==------------ interop_handle.hpp --- SYCL interop handle ----------------==//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <CL/sycl/access/access.hpp>
+#include <CL/sycl/detail/accessor_impl.hpp>
+#include <CL/sycl/detail/common.hpp>
+#include <CL/sycl/detail/defines.hpp>
+#include <CL/sycl/detail/pi.hpp>
+
+#include <memory>
+
+__SYCL_INLINE_NAMESPACE(cl) {
+namespace sycl {
+
+namespace detail {
+class AccessorBaseHost;
+class ExecCGCommand;
+class DispatchHostTask;
+} // namespace detail
+
+template <typename DataT, int Dims, access::mode AccMode,
+          access::target AccTarget, access::placeholder isPlaceholder>
+class accessor;
+
+class interop_handle {
+public:
+  /// Receives a SYCL accessor that has been defined is a requirement for the
+  /// command group, and returns the underlying OpenCL memory object that is
+  /// used by the SYCL runtime. If the accessor passed as parameter is not part
+  /// of the command group requirements (e.g. it is an unregistered placeholder
+  /// accessor), the exception `cl::sycl::invalid_object` is thrown
+  /// asynchronously.
+  template <typename dataT, int dimensions, access::mode accessmode,
+            access::target accessTarget, access::placeholder isPlaceholder>
+  typename std::enable_if<accessTarget != access::target::host_buffer,
+                          cl_mem>::type
+  get_native_mem(const accessor<dataT, dimensions, accessmode, accessTarget,
+                                isPlaceholder> &Acc) const {
+#ifndef __SYCL_DEVICE_ONLY__
+    // employ reinterpret_cast instead of static_cast due to cycle in includes
+    // involving CL/sycl/accessor.hpp
+    auto *AccBase = const_cast<detail::AccessorBaseHost *>(
+        reinterpret_cast<const detail::AccessorBaseHost *>(&Acc));
+    return getMemImpl(detail::getSyclObjImpl(*AccBase).get());
+#else
+    (void)Acc;
+    // we believe this won't be ever called on device side
+    return static_cast<cl_mem>(0x0);
+#endif
+  }
+
+  template <typename dataT, int dimensions, access::mode accessmode,
+            access::target accessTarget, access::placeholder isPlaceholder>
+  typename std::enable_if<accessTarget == access::target::host_buffer,
+                          cl_mem>::type
+  get_native_mem(const accessor<dataT, dimensions, accessmode, accessTarget,
+                                isPlaceholder> &) const {
+    throw invalid_object_error("Getting memory object out of host accessor is "
+                               "not allowed",
+                               PI_INVALID_MEM_OBJECT);
+  }
+
+  /// Returns an underlying OpenCL queue for the SYCL queue used to submit the
+  /// command group, or the fallback queue if this command-group is re-trying
+  /// execution on an OpenCL queue. The OpenCL command queue returned is
+  /// implementation-defined in cases where the SYCL queue maps to multiple
+  /// underlying OpenCL objects. It is responsibility of the SYCL runtime to
+  /// ensure the OpenCL queue returned is in a state that can be used to
+  /// dispatch work, and that other potential OpenCL command queues associated
+  /// with the same SYCL command queue are not executing commands while the host
+  /// task is executing.
+  cl_command_queue get_native_queue() const noexcept { return MQueue; }
+
+  /// Returns an underlying OpenCL device associated with the SYCL queue used
+  /// to submit the command group, or the fallback queue if this command-group
+  /// is re-trying execution on an OpenCL queue.
+  cl_device_id get_native_device() const noexcept { return MDeviceId; }
+
+  /// Returns an underlying OpenCL context associated with the SYCL queue used
+  /// to submit the command group, or the fallback queue if this command-group
+  /// is re-trying execution on an OpenCL queue.
+  cl_context get_native_context() const noexcept { return MContext; }
+
+private:
+  using ReqToMem = std::pair<detail::Requirement *, pi_mem>;
+
+  template <typename DataT, int Dims, access::mode AccMode,
+            access::target AccTarget, access::placeholder isPlaceholder>
+  friend class accessor;
+  friend class detail::ExecCGCommand;
+  friend class detail::DispatchHostTask;
+
+public:
+  // TODO set c-tor private
+  interop_handle(std::vector<ReqToMem> MemObjs, cl_command_queue Queue,
+                 cl_device_id DeviceId, cl_context Context)
+      : MQueue(Queue), MDeviceId(DeviceId), MContext(Context),
+        MMemObjs(std::move(MemObjs)) {}
+
+private:
+  cl_mem getMemImpl(detail::Requirement *Req) const;
+
+  cl_command_queue MQueue;
+  cl_device_id MDeviceId;
+  cl_context MContext;
+  std::vector<ReqToMem> MMemObjs;
+};
+
+} // namespace sycl
+} // __SYCL_INLINE_NAMESPACE(cl)

sycl/source/CMakeLists.txt

@@ -150,6 +150,7 @@ set(SYCL_SOURCES
     "sampler.cpp"
     "stream.cpp"
     "spirv_ops.cpp"
+    "interop_handle.cpp"
     "$<$<PLATFORM_ID:Windows>:detail/windows_pi.cpp>"
     "$<$<OR:$<PLATFORM_ID:Linux>,$<PLATFORM_ID:Darwin>>:detail/posix_pi.cpp>"
 )

sycl/source/interop_handle.cpp

@@ -0,0 +1,28 @@
+//==------------ interop_handle.cpp --- SYCL interop handle ----------------==//
+//
+// 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 <CL/sycl/detail/accessor_impl.hpp>
+#include <CL/sycl/interop_handle.hpp>
+
+#include <algorithm>
+
+__SYCL_INLINE_NAMESPACE(cl) {
+namespace sycl {
+
+cl_mem interop_handle::getMemImpl(detail::Requirement *Req) const {
+  auto Iter = std::find_if(std::begin(MMemObjs), std::end(MMemObjs),
+                           [=](ReqToMem Elem) { return (Elem.first == Req); });
+
+  if (Iter == std::end(MMemObjs))
+    throw("Invalid memory object used inside interop");
+
+  return detail::pi::cast<cl_mem>(Iter->second);
+}
+
+} // namespace sycl
+} // __SYCL_INLINE_NAMESPACE(cl)