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 /* -*- C++ -*-
     This file implements the DependencyPolicy class.
 
     SPDX-FileCopyrightText: 2004-2013 Mirko Boehm <mirko@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 
     $Id: DebuggingAids.cpp 20 2005-08-08 21:02:51Z mirko $
 */
 
 #ifndef DEPENDENCYPOLICY_H
 #define DEPENDENCYPOLICY_H
 
 #include <QtGlobal>
 
 // template <typename T> class QList;
 
 #include "queuepolicy.h"
 
 namespace ThreadWeaver
 {
 class JobInterface;
 class Dependency;
 
 /** @brief DependencyPolicy implements execution-time dependencies dependencies between Jobs.
  *
  *  To declare that Job B can only be executed when Job A is finished, call addDependency.
  *
  *  Be aware of circular dependencies. All dependencies on a Job will be removed if the Job object is destructed.
  *  Sequence uses dependencies to implement the ordered execution of the sequence elements.
  */
 class THREADWEAVER_EXPORT DependencyPolicy : public QueuePolicy
 {
 public:
     /** Destructor. */
     ~DependencyPolicy() override;
 
     /** @brief Add jobB as a dependency of jobA.
      *  jobA will only be executed after jobB has been successfully processed.
      *  @param jobA the depending job
      *  @param jobB the job jobA depends on
      */
     void addDependency(JobPointer jobA, JobPointer jobB);
     void addDependency(const Dependency &dep);
 
     /** @brief Remove a dependency.
      *  The dependency of jobA on jobB is removed. If no dependencies are left for jobA, canRun will return true.
      *  Returns false if the given object is not dependency of this job.
      *  @param jobA the depending job
      *  @param jobB the job jobA depends on
      *  @return true if dependency existed, false otherwise
      */
     bool removeDependency(JobPointer jobA, JobPointer jobB);
     bool removeDependency(const Dependency &dep);
 
     /** @brief Resolve all dependencies for a job.
      *  This method is called after the Job has been finished, or when it is deleted without being executed (performed by the
      *  destructor). The method will remove all entries stating that another Job depends on this one.
      */
     void resolveDependencies(JobPointer);
 
     // FIXME remove
     //    /** @brief Retrieve a list of dependencies of this job. */
     //    QList<JobPointer> getDependencies(JobPointer) const;
 
     static DependencyPolicy &instance();
 
     bool canRun(JobPointer) override;
 
     void free(JobPointer) override;
 
     void release(JobPointer) override;
 
     void destructed(JobInterface *job) override;
 
     bool isEmpty() const;
 
 protected:
     /** @brief Query whether the job has an unresolved dependency.
      *  In case it does, the policy will return false from canRun().
      */
     bool hasUnresolvedDependencies(JobPointer) const;
 
 private:
     DependencyPolicy();
     class Private;
     Private *const d;
 };
 
 }
 
 #endif