cec: async writes for CUSBCECAdapterCommunication. less locks and polls, more speed
[deb_libcec.git] / src / lib / platform / util / buffer.h
1 #pragma once
2 /*
3 * This file is part of the libCEC(R) library.
4 *
5 * libCEC(R) is Copyright (C) 2011-2012 Pulse-Eight Limited. All rights reserved.
6 * libCEC(R) is an original work, containing original code.
7 *
8 * libCEC(R) is a trademark of Pulse-Eight Limited.
9 *
10 * This program is dual-licensed; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 *
24 *
25 * Alternatively, you can license this library under a commercial license,
26 * please contact Pulse-Eight Licensing for more information.
27 *
28 * For more information contact:
29 * Pulse-Eight Licensing <license@pulse-eight.com>
30 * http://www.pulse-eight.com/
31 * http://www.pulse-eight.net/
32 */
33
34 #include "../threads/mutex.h"
35 #include <queue>
36
37 namespace PLATFORM
38 {
39 template<typename _BType>
40 struct SyncedBuffer
41 {
42 public:
43 SyncedBuffer(size_t iMaxSize = 100) :
44 m_maxSize(iMaxSize),
45 m_bHasMessages(false) {}
46
47 virtual ~SyncedBuffer(void)
48 {
49 Clear();
50 }
51
52 void Clear(void)
53 {
54 CLockObject lock(m_mutex);
55 while (!m_buffer.empty())
56 m_buffer.pop();
57 m_condition.Broadcast();
58 }
59
60 size_t Size(void)
61 {
62 CLockObject lock(m_mutex);
63 return m_buffer.size();
64 }
65
66 bool IsEmpty(void)
67 {
68 CLockObject lock(m_mutex);
69 return m_buffer.empty();
70 }
71
72 bool Push(_BType entry)
73 {
74 CLockObject lock(m_mutex);
75 if (m_buffer.size() == m_maxSize)
76 return false;
77
78 m_buffer.push(entry);
79 m_bHasMessages = true;
80 m_condition.Signal();
81 return true;
82 }
83
84 bool Pop(_BType &entry, uint32_t iTimeoutMs = 0)
85 {
86 bool bReturn(false);
87 CLockObject lock(m_mutex);
88
89 // wait for a signal if the buffer is empty
90 if (m_buffer.empty() && iTimeoutMs > 0)
91 {
92 if (!m_condition.Wait(m_mutex, m_bHasMessages, iTimeoutMs))
93 return bReturn;
94 }
95
96 // pop the first item
97 if (!m_buffer.empty())
98 {
99 entry = m_buffer.front();
100 m_buffer.pop();
101 m_bHasMessages = !m_buffer.empty();
102 bReturn = true;
103 }
104 return bReturn;
105 }
106
107 bool Peek(_BType &entry)
108 {
109 bool bReturn(false);
110 CLockObject lock(m_mutex);
111 if (!m_buffer.empty())
112 {
113 entry = m_buffer.front();
114 bReturn = true;
115 }
116 return bReturn;
117 }
118
119 private:
120 size_t m_maxSize;
121 std::queue<_BType> m_buffer;
122 CMutex m_mutex;
123 CCondition<bool> m_condition;
124 bool m_bHasMessages;
125 };
126 };