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39 #ifndef QXCBEVENTQUEUE_H
40 #define QXCBEVENTQUEUE_H
41
42 #include <QtCore/QThread>
43 #include <QtCore/QHash>
44 #include <QtCore/QEventLoop>
45 #include <QtCore/QVector>
46 #include <QtCore/QMutex>
47 #include <QtCore/QWaitCondition>
48
49 #include <xcb/xcb.h>
50
51 #include <atomic>
52
53 QT_BEGIN_NAMESPACE
54
55 struct QXcbEventNode {
56 QXcbEventNode(xcb_generic_event_t *e = nullptr)
eventQXcbEventNode57 : event(e) { }
58
59 xcb_generic_event_t *event;
60 QXcbEventNode *next = nullptr;
61 bool fromHeap = false;
62 };
63
64 class QXcbConnection;
65 class QAbstractEventDispatcher;
66
67 class QXcbEventQueue : public QThread
68 {
69 Q_OBJECT
70 public:
71 QXcbEventQueue(QXcbConnection *connection);
72 ~QXcbEventQueue();
73
74 enum { PoolSize = 100 }; // 2.4 kB with 100 nodes
75
76 enum PeekOption {
77 PeekDefault = 0, // see qx11info_x11.h for docs
78 PeekFromCachedIndex = 1,
79 PeekRetainMatch = 2,
80 PeekRemoveMatch = 3,
81 PeekRemoveMatchContinue = 4
82 };
83 Q_DECLARE_FLAGS(PeekOptions, PeekOption)
84
85 void run() override;
86
isEmpty()87 bool isEmpty() const { return m_head == m_flushedTail && !m_head->event; }
88 xcb_generic_event_t *takeFirst(QEventLoop::ProcessEventsFlags flags);
89 xcb_generic_event_t *takeFirst();
90 void flushBufferedEvents();
91 void wakeUpDispatcher();
92
93 // ### peek() and peekEventQueue() could be unified. Note that peekEventQueue()
94 // is public API exposed via QX11Extras/QX11Info.
95 template<typename Peeker>
peek(Peeker && peeker)96 xcb_generic_event_t *peek(Peeker &&peeker) {
97 return peek(PeekRemoveMatch, std::forward<Peeker>(peeker));
98 }
99 template<typename Peeker>
100 inline xcb_generic_event_t *peek(PeekOption config, Peeker &&peeker);
101
102 qint32 generatePeekerId();
103 bool removePeekerId(qint32 peekerId);
104
105 using PeekerCallback = bool (*)(xcb_generic_event_t *event, void *peekerData);
106 bool peekEventQueue(PeekerCallback peeker, void *peekerData = nullptr,
107 PeekOptions option = PeekDefault, qint32 peekerId = -1);
108
flushedTail()109 const QXcbEventNode *flushedTail() const { return m_flushedTail; }
110 void waitForNewEvents(const QXcbEventNode *sinceFlushedTail,
111 unsigned long time = ULONG_MAX);
112
113 private:
114 QXcbEventNode *qXcbEventNodeFactory(xcb_generic_event_t *event);
115 void dequeueNode();
116
117 void sendCloseConnectionEvent() const;
118 bool isCloseConnectionEvent(const xcb_generic_event_t *event);
119
120 QXcbEventNode *m_head = nullptr;
121 QXcbEventNode *m_flushedTail = nullptr;
122 std::atomic<QXcbEventNode *> m_tail { nullptr };
123 std::atomic_uint m_nodesRestored { 0 };
124
125 QXcbConnection *m_connection = nullptr;
126 bool m_closeConnectionDetected = false;
127
128 uint m_freeNodes = PoolSize;
129 uint m_poolIndex = 0;
130
131 qint32 m_peekerIdSource = 0;
132 bool m_queueModified = false;
133 bool m_peekerIndexCacheDirty = false;
134 QHash<qint32, QXcbEventNode *> m_peekerToNode;
135
136 QVector<xcb_generic_event_t *> m_inputEvents;
137
138 // debug stats
139 quint64 m_nodesOnHeap = 0;
140
141 QMutex m_newEventsMutex;
142 QWaitCondition m_newEventsCondition;
143 };
144
145 template<typename Peeker>
peek(PeekOption option,Peeker && peeker)146 xcb_generic_event_t *QXcbEventQueue::peek(PeekOption option, Peeker &&peeker)
147 {
148 flushBufferedEvents();
149 if (isEmpty())
150 return nullptr;
151
152 QXcbEventNode *node = m_head;
153 do {
154 xcb_generic_event_t *event = node->event;
155 if (event && peeker(event, event->response_type & ~0x80)) {
156 if (option == PeekRemoveMatch || option == PeekRemoveMatchContinue)
157 node->event = nullptr;
158 if (option != PeekRemoveMatchContinue)
159 return event;
160 }
161 if (node == m_flushedTail)
162 break;
163 node = node->next;
164 } while (true);
165
166 return nullptr;
167 }
168
169 QT_END_NAMESPACE
170
171 #endif
172