Defer creation of internal queues and blits until first needed.

Change-Id: I2e61d7e102f38389d806d9eb24beda910573157b [ROCm/ROCR-Runtime commit: bd5dd47ca1]
2018-01-31 22:48:00 -06:00
parent 27ce54a0aa
commit e844aa939d
4 changed files with 194 additions and 88 deletions
@@ -0,0 +1,125 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// The University of Illinois/NCSA
+// Open Source License (NCSA)
+//
+// Copyright (c) 2014-2015, Advanced Micro Devices, Inc. All rights reserved.
+//
+// Developed by:
+//
+//                 AMD Research and AMD HSA Software Development
+//
+//                 Advanced Micro Devices, Inc.
+//
+//                 www.amd.com
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal with 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:
+//
+//  - Redistributions of source code must retain the above copyright notice,
+//    this list of conditions and the following disclaimers.
+//  - Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimers in
+//    the documentation and/or other materials provided with the distribution.
+//  - Neither the names of Advanced Micro Devices, Inc,
+//    nor the names of its contributors may be used to endorse or promote
+//    products derived from this Software without specific prior written
+//    permission.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIESd OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE CONTRIBUTORS 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 WITH THE SOFTWARE.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef HSA_RUNTIME_CORE_UTIL_LAZY_PTR_H_
+#define HSA_RUNTIME_CORE_UTIL_LAZY_PTR_H_
+
+#include <memory>
+#include <utility>
+#include <functional>
+
+#include "core/util/utils.h"
+
+/*
+ * Wrapper for a std::unique_ptr that initializes its object at first use.
+ */
+template <typename T> class lazy_ptr {
+ public:
+  lazy_ptr() {}
+
+  explicit lazy_ptr(std::function<T*()> Constructor) { Init(Constructor); }
+
+  void reset(std::function<T*()> Constructor = nullptr) {
+    obj.reset();
+    func = Constructor;
+  }
+
+  void reset(T* ptr) {
+    obj.reset(ptr);
+    func = nullptr;
+  }
+
+  bool operator==(T* rhs) const { return obj.get() == rhs; }
+  bool operator!=(T* rhs) const { return obj.get() != rhs; }
+
+  const std::unique_ptr<T>& operator->() const {
+    make(true);
+    return obj;
+  }
+
+  std::unique_ptr<T>& operator*() {
+    make(true);
+    return obj;
+  }
+
+  const std::unique_ptr<T>& operator*() const {
+    make(true);
+    return obj;
+  }
+
+  /*
+   * Ensures that the object is created or is being created.
+   * This is useful when early consruction of the object is required.
+   */
+  void touch() const { make(false); }
+
+ private:
+  mutable std::unique_ptr<T> obj;
+  mutable std::function<T*(void)> func;
+  mutable KernelMutex lock;
+
+  // Separated from make to improve inlining.
+  void make_body(bool block) const {
+    if (block) {
+      lock.Acquire();
+    } else if (!lock.Try()) {
+      return;
+    }
+    MAKE_SCOPE_GUARD([&]() { lock.Release(); });
+    if (obj != nullptr) return;
+    T* ptr = func();
+    std::atomic_thread_fence(std::memory_order_release);
+    obj.reset(ptr);
+    func = nullptr;
+  }
+
+  __forceinline void make(bool block) const {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    if (obj == nullptr) {
+      make_body(block);
+    }
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(lazy_ptr);
+};
+
+#endif  // HSA_RUNTIME_CORE_UTIL_LAZY_PTR_H_