feat: godot-engine-source-4.3-stable

engine/thirdparty/thorvg/src/renderer/tvgTaskScheduler.cpp

@@ -0,0 +1,229 @@
+/*
+ * Copyright (c) 2020 - 2024 the ThorVG project. All rights reserved.
+
+ * 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.
+ */
+
+#include "tvgArray.h"
+#include "tvgInlist.h"
+#include "tvgTaskScheduler.h"
+
+#ifdef THORVG_THREAD_SUPPORT
+    #include <thread>
+    #include <atomic>
+#endif
+
+/************************************************************************/
+/* Internal Class Implementation                                        */
+/************************************************************************/
+
+namespace tvg {
+
+struct TaskSchedulerImpl;
+static TaskSchedulerImpl* inst = nullptr;
+
+#ifdef THORVG_THREAD_SUPPORT
+
+static thread_local bool _async = true;
+
+struct TaskQueue {
+    Inlist<Task>             taskDeque;
+    mutex                    mtx;
+    condition_variable       ready;
+    bool                     done = false;
+
+    bool tryPop(Task** task)
+    {
+        unique_lock<mutex> lock{mtx, try_to_lock};
+        if (!lock || taskDeque.empty()) return false;
+        *task = taskDeque.front();
+        return true;
+    }
+
+    bool tryPush(Task* task)
+    {
+        {
+            unique_lock<mutex> lock{mtx, try_to_lock};
+            if (!lock) return false;
+            taskDeque.back(task);
+        }
+        ready.notify_one();
+        return true;
+    }
+
+    void complete()
+    {
+        {
+            lock_guard<mutex> lock{mtx};
+            done = true;
+        }
+        ready.notify_all();
+    }
+
+    bool pop(Task** task)
+    {
+        unique_lock<mutex> lock{mtx};
+
+        while (taskDeque.empty() && !done) {
+            ready.wait(lock);
+        }
+
+        if (taskDeque.empty()) return false;
+
+        *task = taskDeque.front();
+        return true;
+    }
+
+    void push(Task* task)
+    {
+        {
+            lock_guard<mutex> lock{mtx};
+            taskDeque.back(task);
+        }
+        ready.notify_one();
+    }
+};
+
+
+struct TaskSchedulerImpl
+{
+    Array<thread*>                 threads;
+    Array<TaskQueue*>              taskQueues;
+    atomic<uint32_t>               idx{0};
+
+    TaskSchedulerImpl(uint32_t threadCnt)
+    {
+        threads.reserve(threadCnt);
+        taskQueues.reserve(threadCnt);
+
+        for (uint32_t i = 0; i < threadCnt; ++i) {
+            taskQueues.push(new TaskQueue);
+            threads.push(new thread);
+        }
+        for (uint32_t i = 0; i < threadCnt; ++i) {
+            *threads.data[i] = thread([&, i] { run(i); });
+        }
+    }
+
+    ~TaskSchedulerImpl()
+    {
+        for (auto tq = taskQueues.begin(); tq < taskQueues.end(); ++tq) {
+            (*tq)->complete();
+        }
+        for (auto thread = threads.begin(); thread < threads.end(); ++thread) {
+            (*thread)->join();
+            delete(*thread);
+        }
+        for (auto tq = taskQueues.begin(); tq < taskQueues.end(); ++tq) {
+            delete(*tq);
+        }
+    }
+
+    void run(unsigned i)
+    {
+        Task* task;
+
+        //Thread Loop
+        while (true) {
+            auto success = false;
+            for (uint32_t x = 0; x < threads.count * 2; ++x) {
+                if (taskQueues[(i + x) % threads.count]->tryPop(&task)) {
+                    success = true;
+                    break;
+                }
+            }
+
+            if (!success && !taskQueues[i]->pop(&task)) break;
+            (*task)(i + 1);
+        }
+    }
+
+    void request(Task* task)
+    {
+        //Async
+        if (threads.count > 0 && _async) {
+            task->prepare();
+            auto i = idx++;
+            for (uint32_t n = 0; n < threads.count; ++n) {
+                if (taskQueues[(i + n) % threads.count]->tryPush(task)) return;
+            }
+            taskQueues[i % threads.count]->push(task);
+        //Sync
+        } else {
+            task->run(0);
+        }
+    }
+
+    uint32_t threadCnt()
+    {
+        return threads.count;
+    }
+};
+
+#else //THORVG_THREAD_SUPPORT
+
+static bool _async = true;
+
+struct TaskSchedulerImpl
+{
+    TaskSchedulerImpl(TVG_UNUSED uint32_t threadCnt) {}
+    void request(Task* task) { task->run(0); }
+    uint32_t threadCnt() { return 0; }
+};
+
+#endif //THORVG_THREAD_SUPPORT
+
+} //namespace
+
+/************************************************************************/
+/* External Class Implementation                                        */
+/************************************************************************/
+
+void TaskScheduler::init(uint32_t threads)
+{
+    if (inst) return;
+    inst = new TaskSchedulerImpl(threads);
+}
+
+
+void TaskScheduler::term()
+{
+    delete(inst);
+    inst = nullptr;
+}
+
+
+void TaskScheduler::request(Task* task)
+{
+    if (inst) inst->request(task);
+}
+
+
+uint32_t TaskScheduler::threads()
+{
+    if (inst) return inst->threadCnt();
+    return 0;
+}
+
+
+void TaskScheduler::async(bool on)
+{
+    //toggle async tasking for each thread on/off
+    _async = on;
+}