diff options
author | Mike Buland <eichlan@xagasoft.com> | 2012-03-25 20:00:08 +0000 |
---|---|---|
committer | Mike Buland <eichlan@xagasoft.com> | 2012-03-25 20:00:08 +0000 |
commit | 469bbcf0701e1eb8a6670c23145b0da87357e178 (patch) | |
tree | b5b062a16e46a6c5d3410b4e574cd0cc09057211 /src/stable/condition.h | |
parent | ee1b79396076edc4e30aefb285fada03bb45e80d (diff) | |
download | libbu++-469bbcf0701e1eb8a6670c23145b0da87357e178.tar.gz libbu++-469bbcf0701e1eb8a6670c23145b0da87357e178.tar.bz2 libbu++-469bbcf0701e1eb8a6670c23145b0da87357e178.tar.xz libbu++-469bbcf0701e1eb8a6670c23145b0da87357e178.zip |
Code is all reorganized. We're about ready to release. I should write up a
little explenation of the arrangement.
Diffstat (limited to 'src/stable/condition.h')
-rw-r--r-- | src/stable/condition.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/src/stable/condition.h b/src/stable/condition.h new file mode 100644 index 0000000..71634f5 --- /dev/null +++ b/src/stable/condition.h | |||
@@ -0,0 +1,90 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2007-2011 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_CONDITION_H | ||
9 | #define BU_CONDITION_H | ||
10 | |||
11 | #include <pthread.h> | ||
12 | |||
13 | #include "bu/mutex.h" | ||
14 | |||
15 | namespace Bu | ||
16 | { | ||
17 | /** | ||
18 | * Ito condition. This is a fairly simple condition mechanism. As you may | ||
19 | * notice this class inherits from the Mutex class, this is because all | ||
20 | * conditions must be within a locked block. The standard usage of a | ||
21 | * condition is to pause one thread, perhaps indefinately, until another | ||
22 | * thread signals that it is alright to procede. | ||
23 | * <br> | ||
24 | * Standard usage for the thread that wants to wait is as follows: | ||
25 | * <pre> | ||
26 | * Condition cond; | ||
27 | * ... // Perform setup and enter your run loop | ||
28 | * cond.lock(); | ||
29 | * while( !isFinished() ) // Could be anything you're waiting for | ||
30 | * cond.wait(); | ||
31 | * ... // Take care of what you have to. | ||
32 | * cond.unlock(); | ||
33 | * </pre> | ||
34 | * The usage for the triggering thread is much simpler, when it needs to | ||
35 | * tell the others that it's time to grab some data it calls either signal | ||
36 | * or broadcast. See both of those functions for the difference. | ||
37 | *@ingroup Threading | ||
38 | */ | ||
39 | class Condition : public Mutex | ||
40 | { | ||
41 | public: | ||
42 | /** | ||
43 | * Create a condition. | ||
44 | */ | ||
45 | Condition(); | ||
46 | |||
47 | /** | ||
48 | * Destroy a condition. | ||
49 | */ | ||
50 | ~Condition(); | ||
51 | |||
52 | /** | ||
53 | * Wait forever, or until signalled. This has to be called from within | ||
54 | * a locked section, i.e. before calling this this object's lock | ||
55 | * function should be called. | ||
56 | */ | ||
57 | int wait(); | ||
58 | |||
59 | /** | ||
60 | * Wait for a maximum of nSec seconds and nUSec micro-seconds or until | ||
61 | * signalled. This is a little more friendly function if you want to | ||
62 | * perform other operations in the thrad loop that calls this function. | ||
63 | * Like the other wait function, this must be inside a locked section. | ||
64 | *@param nSec The seconds to wait. | ||
65 | *@param nUSec the micro-seconds to wait. | ||
66 | */ | ||
67 | int wait( int nSec, int nUSec ); | ||
68 | |||
69 | /** | ||
70 | * Notify the next thread waiting on this condition that they can go | ||
71 | * ahead. This only signals one thread, the next one in the condition | ||
72 | * queue, that it is safe to procede with whatever operation was being | ||
73 | * waited on. | ||
74 | */ | ||
75 | int signal(); | ||
76 | |||
77 | /** | ||
78 | * Notify all threads waiting on this condition that they can go ahead | ||
79 | * now. This function is slower than signal, but more effective in | ||
80 | * certain situations where you may not know how many threads should be | ||
81 | * activated. | ||
82 | */ | ||
83 | int broadcast(); | ||
84 | |||
85 | private: | ||
86 | pthread_cond_t cond; /**< Internal condition reference. */ | ||
87 | }; | ||
88 | } | ||
89 | |||
90 | #endif | ||