[llvm] [Offload] Add GenericProfilerTy abstraction and APITypes extensions (PR #225639)

[Jan Patrick Lehr via llvm-commits]

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+//===- GenericProfiler.h - GenericProfiler interface for use in Plugins ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// The GenericProfiler interface allows to implement profiler logic for various
+// backends, such as OMPT or other tracing mechanisms.
+// This enables the plugins to be agnostic of the actual high-level language
+// that is implemented.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef OFFLOAD_PLUGINS_NEXTGEN_COMMON_INCLUDE_GENERICPROFILER_H
+#define OFFLOAD_PLUGINS_NEXTGEN_COMMON_INCLUDE_GENERICPROFILER_H
+
+#include "Shared/APITypes.h"
+
+#include <cstdint>
+#include <functional>
+#include <tuple>
+
+class OmptTracingBufferMgr;
+
+namespace llvm {
+namespace omp {
+namespace target {
+namespace plugin {
+
+struct GenericDeviceTy;
+struct GenericPluginTy;
+class GenericProfilerTy;
+
+template <typename FunT, typename... ArgsT, size_t... IdxSequence>
+void callViaIndexSeq(FunT F, GenericProfilerTy *P, uint64_t StartNanos,
+                     uint64_t EndNanos, std::tuple<ArgsT...> Args,
+                     std::index_sequence<IdxSequence...>) {
+  F(P, StartNanos, EndNanos, std::get<IdxSequence>(Args)...);
+}
+
+template <typename FunT, typename... ArgsT>
+void callViaUnpack(FunT F, GenericProfilerTy *P, uint64_t StartNanos,
+                   uint64_t EndNanos, std::tuple<ArgsT...> Tup) {
+  callViaIndexSeq(F, P, StartNanos, EndNanos, Tup,
+                  std::index_sequence_for<ArgsT...>{});
+}
+
+/// Abstraction layer to implement different profiler backends.
+///
+/// The plugins call into the GenericProfilerTy to handle the specific events
+/// with whatever specific backend was instantiated. For now, the supported
+/// backends are limited to an OMPT implementation.
+class GenericProfilerTy {
+public:
+  GenericProfilerTy() = default;
+  virtual ~GenericProfilerTy() = default;
+
+  /// Obtain a pointer to profiler-specific data, if any.
+  virtual void *getProfilerSpecificData() { return nullptr; }
+
+  /// Obtain the trace record manager owned by this profiler, if any. Profilers
+  /// that produce trace records own the manager so that the records handed out
+  /// cannot outlive the buffers they point into.
+  virtual OmptTracingBufferMgr *getTraceRecordManager() { return nullptr; }
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jplehr wrote:

No. In fact, after some more thinking, the trace buffer manager is an implementation detail that should not be exposed at all. I'm currently working on a refactoring of it, which would move that fully into the `OmptProfilerTy` and remove this public API.

https://github.com/llvm/llvm-project/pull/225639