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author | Mike Buland <eichlan@xagasoft.com> | 2023-07-29 00:19:13 -0700 |
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committer | Mike Buland <eichlan@xagasoft.com> | 2023-07-29 00:19:13 -0700 |
commit | 412173a23c88a49ebaeb982e0c7eeddc5662b8cc (patch) | |
tree | b00519e715b3ffecd342746e433d8e2dc0eb308e /src/stable/counterevent.h | |
parent | 915005e218b5d00939b548de65ce6354f7acb487 (diff) | |
download | libbu++-412173a23c88a49ebaeb982e0c7eeddc5662b8cc.tar.gz libbu++-412173a23c88a49ebaeb982e0c7eeddc5662b8cc.tar.bz2 libbu++-412173a23c88a49ebaeb982e0c7eeddc5662b8cc.tar.xz libbu++-412173a23c88a49ebaeb982e0c7eeddc5662b8cc.zip |
Many bugfixes. It's almost working!
Diffstat (limited to '')
-rw-r--r-- | src/stable/counterevent.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/stable/counterevent.h b/src/stable/counterevent.h new file mode 100644 index 0000000..e7ad7a1 --- /dev/null +++ b/src/stable/counterevent.h | |||
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1 | /* | ||
2 | * Copyright (C) 2007-2019 Xagasoft, All rights reserved. | ||
3 | * | ||
4 | * This file is part of the libbu++ library and is released under the | ||
5 | * terms of the license contained in the file LICENSE. | ||
6 | */ | ||
7 | |||
8 | #ifndef BU_COUNTER_EVENT_H | ||
9 | #define BU_COUNTER_EVENT_H | ||
10 | |||
11 | #include <pthread.h> | ||
12 | |||
13 | #include "bu/mutex.h" | ||
14 | #include "bu/condition.h" | ||
15 | |||
16 | namespace Bu | ||
17 | { | ||
18 | /** | ||
19 | * Represents a true/false state that controls thread synchronization. This | ||
20 | * is primarilly intended to control the synchronization state of | ||
21 | * multithreaded services. For example, telling all threads when to exit. | ||
22 | * | ||
23 | * An Event is either set or unset. If the Event is unset then it can be | ||
24 | * waited on for something to happen. As soon as the Event is set all | ||
25 | * waiting threads are released and new requests to wait are ignored until | ||
26 | * the Event is cleared again. | ||
27 | * | ||
28 | * Threads can also be woken up without setting the Event, which may be | ||
29 | * handy in certain circumstances. | ||
30 | *@ingroup Threading | ||
31 | */ | ||
32 | class CounterEvent | ||
33 | { | ||
34 | public: | ||
35 | CounterEvent() : | ||
36 | iCount( 0 ) | ||
37 | { | ||
38 | } | ||
39 | |||
40 | ~CounterEvent() | ||
41 | { | ||
42 | } | ||
43 | |||
44 | /** | ||
45 | * Wait indefinitely for the Event to trigger. If the event is already | ||
46 | * set, then return immediately. It's important to note that this may | ||
47 | * return at any time, not only when the Event is set, so examining the | ||
48 | * return value is important. | ||
49 | *@returns the set status of the Event. | ||
50 | */ | ||
51 | int wait() | ||
52 | { | ||
53 | cBlock.lock(); | ||
54 | if( iCount == 0 ) | ||
55 | { | ||
56 | cBlock.unlock(); | ||
57 | return iCount; | ||
58 | } | ||
59 | cBlock.wait(); | ||
60 | int iRet = iCount; | ||
61 | cBlock.unlock(); | ||
62 | return iRet; | ||
63 | } | ||
64 | |||
65 | /** | ||
66 | * Wait for up to nSec seconds and nUSec nanoseconds for the event to | ||
67 | * trigger. If the Event is already set then return immediately. | ||
68 | *@returns the set status of the Event. | ||
69 | */ | ||
70 | int wait( int nSec, int nUSec ) | ||
71 | { | ||
72 | cBlock.lock(); | ||
73 | if( iCount == 0 ) | ||
74 | { | ||
75 | cBlock.unlock(); | ||
76 | return iCount; | ||
77 | } | ||
78 | cBlock.wait( nSec, nUSec ); | ||
79 | bool iRet = iCount; | ||
80 | cBlock.unlock(); | ||
81 | return iRet; | ||
82 | } | ||
83 | |||
84 | /** | ||
85 | * Allow one of the waiting threads to unlock without updating the set | ||
86 | * state of the Event. | ||
87 | */ | ||
88 | void unblockOne() | ||
89 | { | ||
90 | cBlock.lock(); | ||
91 | cBlock.signal(); | ||
92 | cBlock.unlock(); | ||
93 | } | ||
94 | |||
95 | /** | ||
96 | * Allow all waiting threads to unlock and proceed without updating the | ||
97 | * set state of the Event. | ||
98 | */ | ||
99 | void unblockAll() | ||
100 | { | ||
101 | cBlock.lock(); | ||
102 | cBlock.broadcast(); | ||
103 | cBlock.unlock(); | ||
104 | } | ||
105 | |||
106 | /** | ||
107 | * Find out if the Event is in the set state or not. | ||
108 | *@returns True if set, false otherwise. | ||
109 | */ | ||
110 | bool isZero() | ||
111 | { | ||
112 | cBlock.lock(); | ||
113 | bool bRet = (iCount == 0); | ||
114 | cBlock.unlock(); | ||
115 | return bRet; | ||
116 | } | ||
117 | |||
118 | /** | ||
119 | * Sets the Event's state to true and triggers all waiting threads. | ||
120 | */ | ||
121 | void decrement() | ||
122 | { | ||
123 | cBlock.lock(); | ||
124 | iCount--; if( iCount < 0 ) iCount = 0; | ||
125 | if( iCount == 0 ) | ||
126 | cBlock.broadcast(); | ||
127 | cBlock.unlock(); | ||
128 | } | ||
129 | |||
130 | void increment() | ||
131 | { | ||
132 | cBlock.lock(); | ||
133 | iCount++; | ||
134 | cBlock.unlock(); | ||
135 | } | ||
136 | |||
137 | /** | ||
138 | * Sets the Event's state to false. This does NOT trigger any waiting | ||
139 | * threads. | ||
140 | */ | ||
141 | void clear() | ||
142 | { | ||
143 | cBlock.lock(); | ||
144 | iCount = 0; | ||
145 | cBlock.unlock(); | ||
146 | } | ||
147 | |||
148 | private: | ||
149 | Condition cBlock; /**< The condition for blocking dequeues. */ | ||
150 | int iCount; | ||
151 | }; | ||
152 | } | ||
153 | |||
154 | #endif | ||