Move callback_table.h to the util directory

The CallbackTable utility is shared by multiple APIs, so move it out
of the roctracer directory.

Change-Id: Ie2378dca8a4f90bd334dbe2d39ced37c9e790ed0

src/util/callback_table.h

@@ -0,0 +1,70 @@
+/* Copyright (c) 2018-2022 Advanced Micro Devices, Inc.
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE. */
+
+#ifndef UTIL_CALLBACK_TABLE_H_
+#define UTIL_CALLBACK_TABLE_H_
+
+#include "ext/prof_protocol.h"
+
+#include <array>
+#include <atomic>
+#include <cassert>
+#include <mutex>
+#include <utility>
+
+namespace roctracer::util {
+
+// Generic callbacks table
+template <activity_domain_t Domain, uint32_t N> class CallbackTable {
+ public:
+  CallbackTable()
+      // Zero initialize the callbacks array as the function pointer is used to determine if the
+      // callback is enabled.
+      : callbacks_() {}
+
+  void Set(uint32_t callback_id, activity_rtapi_callback_t callback_function, void* user_arg) {
+    assert(callback_id < N && "callback_id is out of range");
+    std::lock_guard lock(mutex_);
+    auto& callback = callbacks_[callback_id];
+    callback.first.store(callback_function, std::memory_order_relaxed);
+    callback.second = user_arg;
+  }
+
+  auto Get(uint32_t callback_id) const {
+    assert(callback_id < N && "id is out of range");
+    std::lock_guard lock(mutex_);
+    auto& callback = callbacks_[callback_id];
+    return std::make_pair(callback.first.load(std::memory_order_relaxed), callback.second);
+  }
+
+  template <typename... Args> void Invoke(uint32_t callback_id, Args... args) {
+    if (callbacks_[callback_id].first.load(std::memory_order_relaxed) == nullptr) return;
+    if (auto [callback_function, user_arg] = Get(callback_id); callback_function != nullptr)
+      callback_function(Domain, callback_id, std::forward<Args>(args)..., user_arg);
+  }
+
+ private:
+  std::array<std::pair<std::atomic<activity_rtapi_callback_t>, void*>, N> callbacks_;
+  mutable std::mutex mutex_;
+};
+
+}  // namespace roctracer::util
+
+#endif  // UTIL_CALLBACK_TABLE_H_