taskGraph.h

//
// Copyright 2025 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_BASE_WORK_TASK_GRAPH_H
#define PXR_BASE_WORK_TASK_GRAPH_H
 
#include "pxr/pxr.h"
 
#include "pxr/base/work/api.h"
#include "pxr/base/work/dispatcher.h"
#include "pxr/base/work/impl.h"
#include "pxr/base/work/taskGraph_defaultImpl.h"
 
#include <tbb/enumerable_thread_specific.h>
 
#include <utility>
#include <vector>
 
PXR_NAMESPACE_OPEN_SCOPE
 
class WorkTaskGraph 
{
private:
    // Select underlying implementation.
#if defined WORK_IMPL_HAS_TASK_GRAPH
    using _Impl = PXR_WORK_IMPL_NS::WorkImpl_TaskGraph;
#else
    using _Impl = WorkTaskGraph_DefaultImpl;
#endif
 
public:
    WorkTaskGraph() = default;
    ~WorkTaskGraph() noexcept = default;
 
    WorkTaskGraph(WorkTaskGraph const &) = delete;
    WorkTaskGraph &operator=(WorkTaskGraph const &) = delete;
 
    class BaseTask;
 
    using TaskList = std::vector<BaseTask *>;
 
    using TaskLists = tbb::enumerable_thread_specific<TaskList>;
 
    template <typename F, typename ... Args>
    F * AllocateTask(Args&&... args) {
        return _impl.AllocateTask<F>(std::forward<Args>(args)...);
    }
 
    template <typename F>
    inline void RunTask(F * task) {
        _impl.RunTask(task);
    }
 
    WORK_API void RunLists(const TaskLists &taskLists);
 
    inline void Wait() {
        _impl.Wait();
    }
 
private: 
    _Impl _impl;
};
 
class WorkTaskGraph::BaseTask : public WorkTaskGraph::_Impl::BaseTask {
private:
    using _Base = WorkTaskGraph::_Impl::BaseTask;
 
public:
    BaseTask() = default;
    WORK_API virtual ~BaseTask();
 
    virtual BaseTask * execute() = 0;
 
    void AddChildReference() {
        _Base::AddChildReference();
    }
 
    int RemoveChildReference() {
        return _Base::RemoveChildReference();
    }
    
    template <typename F, typename ... Args>
    F * AllocateChild(Args&&... args) {
        return _Base::AllocateChild<F>(std::forward<Args>(args)...);
    }
 
protected:
    void _RecycleAsContinuation() {
        _Base::_RecycleAsContinuation();
    }
 
};
 
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif