ThreadWeaver

weaver.h
1 /* -*- C++ -*-
2  This file implements the public interfaces of the WeaverImpl class.
3 
4  SPDX-FileCopyrightText: 2005-2013 Mirko Boehm <[email protected]>
5 
6  SPDX-License-Identifier: LGPL-2.0-or-later
7 */
8 
9 #ifndef WeaverImpl_H
10 #define WeaverImpl_H
11 
12 #include "queueapi.h"
13 #include <QObject>
14 
15 namespace ThreadWeaver
16 {
17 class State;
18 class Job;
19 class Thread;
20 class WeaverImplState;
21 class SuspendingState;
22 
23 namespace Private
24 {
25 class Weaver_Private;
26 }
27 
28 /** @brief A Weaver manages worker threads.
29  *
30  * It creates an inventory of Thread objects to which it assigns jobs from its queue.
31  * It extends the API of Queue, hiding methods that need to be public to implement state handling, but
32  * should not be exposed in general.
33  */
34 class THREADWEAVER_EXPORT Weaver : public QueueAPI
35 {
36  Q_OBJECT
37 public:
38  explicit Weaver(QObject *parent = nullptr);
39  ~Weaver() override;
40  void shutDown() override;
41  void shutDown_p() override;
42 
43  const State *state() const override;
44  State *state() override;
45 
46  void setMaximumNumberOfThreads(int cap) override;
47  int maximumNumberOfThreads() const override;
48  int currentNumberOfThreads() const override;
49 
50  void setState(StateId);
51  void enqueue(const QVector<JobPointer> &jobs) override;
52  bool dequeue(const JobPointer &job) override;
53  void dequeue() override;
54  void finish() override;
55  void suspend() override;
56  void resume() override;
57  bool isEmpty() const override;
58  bool isIdle() const override;
59  int queueLength() const override;
60  JobPointer applyForWork(Thread *thread, bool wasBusy) override;
61  void waitForAvailableJob(Thread *th) override;
62  void blockThreadUntilJobsAreBeingAssigned(Thread *th);
63  void blockThreadUntilJobsAreBeingAssigned_locked(Thread *th);
64  void incActiveThreadCount();
65  void decActiveThreadCount();
66  int activeThreadCount();
67 
68  void threadEnteredRun(Thread *thread);
69  JobPointer takeFirstAvailableJobOrSuspendOrWait(Thread *th, bool threadWasBusy, bool suspendIfAllThreadsInactive, bool justReturning);
70  void requestAbort() override;
71  void reschedule() override;
72 
73  // FIXME: rename _p to _locked:
74  friend class WeaverImplState;
75  friend class SuspendingState;
76  void setState_p(StateId);
77  void setMaximumNumberOfThreads_p(int cap) override;
78  int maximumNumberOfThreads_p() const override;
79  int currentNumberOfThreads_p() const override;
80  void enqueue_p(const QVector<JobPointer> &jobs);
81  bool dequeue_p(JobPointer job) override;
82  void dequeue_p() override;
83  void finish_p() override;
84  void suspend_p() override;
85  void resume_p() override;
86  bool isEmpty_p() const override;
87  bool isIdle_p() const override;
88  int queueLength_p() const override;
89  void requestAbort_p() override;
90 
91 Q_SIGNALS:
92  /** @brief A Thread has been created. */
93  void threadStarted(ThreadWeaver::Thread *);
94  /** @brief A thread has exited. */
95  void threadExited(ThreadWeaver::Thread *);
96  /** @brief A thread has been suspended. */
97  void threadSuspended(ThreadWeaver::Thread *);
98 
99 protected:
100  void adjustActiveThreadCount(int diff);
101  virtual Thread *createThread();
102  void adjustInventory(int noOfNewJobs);
103 
104 private:
105  ThreadWeaver::Private::Weaver_Private *d();
106  const ThreadWeaver::Private::Weaver_Private *d() const;
107 };
108 
109 } // namespace ThreadWeaver
110 
111 #endif // WeaverImpl_H
Base class for all WeaverImpl states.
A Weaver manages worker threads.
Definition: weaver.h:34
We use a State pattern to handle the system state in ThreadWeaver.
Definition: state.h:55
void suspend()
Thread represents a worker thread in a Queue's inventory.
Definition: thread.h:27
SuspendingState is the state after suspend() has been called, but before all threads finished executi...
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