OpenShot Library | libopenshot-audio 0.2.0
juce_TimeSliceThread.h
1
2/** @weakgroup juce_core-threads
3 * @{
4 */
5/*
6 ==============================================================================
7
8 This file is part of the JUCE library.
9 Copyright (c) 2017 - ROLI Ltd.
10
11 JUCE is an open source library subject to commercial or open-source
12 licensing.
13
14 The code included in this file is provided under the terms of the ISC license
15 http://www.isc.org/downloads/software-support-policy/isc-license. Permission
16 To use, copy, modify, and/or distribute this software for any purpose with or
17 without fee is hereby granted provided that the above copyright notice and
18 this permission notice appear in all copies.
19
20 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
21 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
22 DISCLAIMED.
23
24 ==============================================================================
25*/
26
27namespace juce
28{
29
30class TimeSliceThread;
31
32
33//==============================================================================
34/**
35 Used by the TimeSliceThread class.
36
37 To register your class with a TimeSliceThread, derive from this class and
38 use the TimeSliceThread::addTimeSliceClient() method to add it to the list.
39
40 Make sure you always call TimeSliceThread::removeTimeSliceClient() before
41 deleting your client!
42
43 @see TimeSliceThread
44
45 @tags{Core}
46*/
48{
49public:
50 /** Destructor. */
51 virtual ~TimeSliceClient() = default;
52
53 /** Called back by a TimeSliceThread.
54
55 When you register this class with it, a TimeSliceThread will repeatedly call
56 this method.
57
58 The implementation of this method should use its time-slice to do something that's
59 quick - never block for longer than absolutely necessary.
60
61 @returns Your method should return the number of milliseconds which it would like to wait before being called
62 again. Returning 0 will make the thread call again as soon as possible (after possibly servicing
63 other busy clients). If you return a value below zero, your client will be removed from the list of clients,
64 and won't be called again. The value you specify isn't a guaranteee, and is only used as a hint by the
65 thread - the actual time before the next callback may be more or less than specified.
66 You can force the TimeSliceThread to wake up and poll again immediately by calling its notify() method.
67 */
68 virtual int useTimeSlice() = 0;
69
70
71private:
72 friend class TimeSliceThread;
73 Time nextCallTime;
74};
75
76
77//==============================================================================
78/**
79 A thread that keeps a list of clients, and calls each one in turn, giving them
80 all a chance to run some sort of short task.
81
82 @see TimeSliceClient, Thread
83
84 @tags{Core}
85*/
87{
88public:
89 //==============================================================================
90 /**
91 Creates a TimeSliceThread.
92
93 When first created, the thread is not running. Use the startThread()
94 method to start it.
95 */
96 explicit TimeSliceThread (const String& threadName);
97
98 /** Destructor.
99
100 Deleting a Thread object that is running will only give the thread a
101 brief opportunity to stop itself cleanly, so it's recommended that you
102 should always call stopThread() with a decent timeout before deleting,
103 to avoid the thread being forcibly killed (which is a Bad Thing).
104 */
105 ~TimeSliceThread() override;
106
107 //==============================================================================
108 /** Adds a client to the list.
109 The client's callbacks will start after the number of milliseconds specified
110 by millisecondsBeforeStarting (and this may happen before this method has returned).
111 */
112 void addTimeSliceClient (TimeSliceClient* clientToAdd, int millisecondsBeforeStarting = 0);
113
114 /** If the given client is waiting in the queue, it will be moved to the front
115 and given a time-slice as soon as possible.
116 If the specified client has not been added, nothing will happen.
117 */
118 void moveToFrontOfQueue (TimeSliceClient* clientToMove);
119
120 /** Removes a client from the list.
121 This method will make sure that all callbacks to the client have completely
122 finished before the method returns.
123 */
124 void removeTimeSliceClient (TimeSliceClient* clientToRemove);
125
126 /** Removes all the active and pending clients from the list.
127 This method will make sure that all callbacks to clients have finished before the
128 method returns.
129 */
130 void removeAllClients();
131
132 /** Returns the number of registered clients. */
133 int getNumClients() const;
134
135 /** Returns one of the registered clients. */
136 TimeSliceClient* getClient (int index) const;
137
138 //==============================================================================
139 #ifndef DOXYGEN
140 void run() override;
141 #endif
142
143 //==============================================================================
144private:
145 CriticalSection callbackLock, listLock;
147 TimeSliceClient* clientBeingCalled = nullptr;
148
149 TimeSliceClient* getNextClient (int index) const;
150
151 JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (TimeSliceThread)
152};
153
154} // namespace juce
155
156/** @}*/
Holds a resizable array of primitive or copy-by-value objects.
Definition juce_Array.h:60
The JUCE String class!
Definition juce_String.h:43
Encapsulates a thread.
Definition juce_Thread.h:47
Used by the TimeSliceThread class.
virtual int useTimeSlice()=0
Called back by a TimeSliceThread.
virtual ~TimeSliceClient()=default
Destructor.
A thread that keeps a list of clients, and calls each one in turn, giving them all a chance to run so...
Holds an absolute date and time.
Definition juce_Time.h:41
#define JUCE_API
This macro is added to all JUCE public class declarations.