Introduce SerialQueue to track in flight resources

src/backend/CMakeLists.txt

@@ -60,6 +60,7 @@ list(APPEND BACKEND_SOURCES
     ${COMMON_DIR}/RefCounted.h
     ${COMMON_DIR}/Sampler.cpp
     ${COMMON_DIR}/Sampler.h
+    ${COMMON_DIR}/SerialQueue.h
     ${COMMON_DIR}/ShaderModule.cpp
     ${COMMON_DIR}/ShaderModule.h
     ${COMMON_DIR}/Texture.cpp

src/backend/common/SerialQueue.h

@@ -0,0 +1,217 @@
+// Copyright 2017 The NXT Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef BACKEND_COMMON_SERIALQUEUE_H_
+#define BACKEND_COMMON_SERIALQUEUE_H_
+
+#include "Forward.h"
+
+#include <cstdint>
+#include <vector>
+
+namespace backend {
+
+    using Serial = uint64_t;
+
+    template<typename T>
+    class SerialQueue {
+        private:
+            using SerialPair = std::pair<Serial, std::vector<T>>;
+            using Storage = std::vector<SerialPair>;
+            using StorageIterator = typename Storage::const_iterator;
+
+        public:
+            class Iterator {
+                public:
+                    Iterator(StorageIterator start);
+                    Iterator& operator++();
+
+                    bool operator==(const Iterator& other) const;
+                    bool operator!=(const Iterator& other) const;
+                    const T& operator*() const;
+
+                private:
+                    StorageIterator storageIterator;
+                    // Special case the serialIterator when it should be equal to storageIterator.begin()
+                    // otherwise we could ask storageIterator.begin() when storageIterator is storage.end()
+                    // which is invalid. storageIterator.begin() is tagged with a nullptr.
+                    const T* serialIterator;
+            };
+
+            class BeginEnd {
+                public:
+                    BeginEnd(StorageIterator start, StorageIterator end);
+
+                    Iterator begin() const;
+                    Iterator end() const;
+
+                private:
+                    StorageIterator startIt;
+                    StorageIterator endIt;
+            };
+
+            // The serial must be given in (not strictly) increasing order.
+            void Enqueue(const T& value, Serial serial);
+            void Enqueue(T&& value, Serial serial);
+            void Enqueue(const std::vector<T>& values, Serial serial);
+            void Enqueue(std::vector<T>&& values, Serial serial);
+
+            bool Empty() const;
+
+            // The UpTo variants of Iterate and Clear affect all values associated to a serial
+            // that is smaller OR EQUAL to the given serial. Iterating is done like so:
+            //     for (const T& value : queue.IterateAll()) { stuff(T); }
+            BeginEnd IterateAll() const;
+            BeginEnd IterateUpTo(Serial serial) const;
+
+            void Clear();
+            void ClearUpTo(Serial serial);
+
+        private:
+            // Returns the first StorageIterator that a serial bigger than serial.
+            StorageIterator FindUpTo(Serial serial) const;
+            Storage storage;
+    };
+
+    // SerialQueue
+
+    template<typename T>
+    void SerialQueue<T>::Enqueue(const T& value, Serial serial) {
+        ASSERT(Empty() || storage.back().first <= serial);
+
+        if (Empty() || storage.back().first < serial) {
+            storage.emplace_back(SerialPair(serial, {}));
+        }
+        storage.back().second.push_back(value);
+    }
+
+    template<typename T>
+    void SerialQueue<T>::Enqueue(T&& value, Serial serial) {
+        ASSERT(Empty() || storage.back().first <= serial);
+
+        if (Empty() || storage.back().first < serial) {
+            storage.emplace_back(SerialPair(serial, {}));
+        }
+        storage.back().second.push_back(value);
+    }
+
+    template<typename T>
+    void SerialQueue<T>::Enqueue(const std::vector<T>& values, Serial serial) {
+        ASSERT(Empty() || storage.back().first <= serial);
+        storage.emplace_back(SerialPair(serial, {values}));
+    }
+
+    template<typename T>
+    void SerialQueue<T>::Enqueue(std::vector<T>&& values, Serial serial) {
+        ASSERT(Empty() || storage.back().first <= serial);
+        storage.emplace_back(SerialPair(serial, {values}));
+    }
+
+    template<typename T>
+    bool SerialQueue<T>::Empty() const {
+        return storage.empty();
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::BeginEnd SerialQueue<T>::IterateAll() const {
+        return {storage.begin(), storage.end()};
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::BeginEnd SerialQueue<T>::IterateUpTo(Serial serial) const {
+        return {storage.begin(), FindUpTo(serial)};
+    }
+
+    template<typename T>
+    void SerialQueue<T>::Clear() {
+        storage.clear();
+    }
+
+    template<typename T>
+    void SerialQueue<T>::ClearUpTo(Serial serial) {
+        storage.erase(storage.begin(), FindUpTo(serial));
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::StorageIterator SerialQueue<T>::FindUpTo(Serial serial) const {
+        auto it = storage.begin();
+        while (it != storage.end() && it->first <= serial) {
+            it ++;
+        }
+        return it;
+    }
+
+    // SerialQueue::BeginEnd
+
+    template<typename T>
+    SerialQueue<T>::BeginEnd::BeginEnd(typename SerialQueue<T>::StorageIterator start, typename SerialQueue<T>::StorageIterator end)
+        : startIt(start), endIt(end) {
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::Iterator SerialQueue<T>::BeginEnd::begin() const {
+        return {startIt};
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::Iterator SerialQueue<T>::BeginEnd::end() const {
+        return {endIt};
+    }
+
+    // SerialQueue::Iterator
+
+    template<typename T>
+    SerialQueue<T>::Iterator::Iterator(typename SerialQueue<T>::StorageIterator start)
+        : storageIterator(start), serialIterator(nullptr) {
+    }
+
+    template<typename T>
+    typename SerialQueue<T>::Iterator& SerialQueue<T>::Iterator::operator++() {
+        const T* vectorData = storageIterator->second.data();
+
+        if (serialIterator == nullptr) {
+            serialIterator = vectorData + 1;
+        } else {
+            serialIterator ++;
+        }
+
+        if (serialIterator >= vectorData + storageIterator->second.size()) {
+            serialIterator = nullptr;
+            storageIterator ++;
+        }
+
+        return *this;
+    }
+
+    template<typename T>
+    bool SerialQueue<T>::Iterator::operator==(const typename SerialQueue<T>::Iterator& other) const {
+        return other.storageIterator == storageIterator && other.serialIterator == serialIterator;
+    }
+
+    template<typename T>
+    bool SerialQueue<T>::Iterator::operator!=(const typename SerialQueue<T>::Iterator& other) const {
+        return !(*this == other);
+    }
+
+    template<typename T>
+    const T& SerialQueue<T>::Iterator::operator*() const {
+        if (serialIterator == nullptr) {
+            return *storageIterator->second.begin();
+        }
+        return *serialIterator;
+    }
+
+}
+
+#endif // BACKEND_COMMON_SERIALQUEUE_H_