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[chaz/yoink] / src / Moof / Timer.cc
1
2 /*******************************************************************************
3
4 Copyright (c) 2009, Charles McGarvey
5 All rights reserved.
6
7 Redistribution and use in source and binary forms, with or without
8 modification, are permitted provided that the following conditions are met:
9
10 * Redistributions of source code must retain the above copyright notice,
11 this list of conditions and the following disclaimer.
12 * Redistributions in binary form must reproduce the above copyright notice,
13 this list of conditions and the following disclaimer in the documentation
14 and/or other materials provided with the distribution.
15
16 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
20 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27 *******************************************************************************/
28
29 #include <cerrno>
30 #include <ctime>
31 #include <limits>
32
33 #include <SDL/SDL.h>
34
35 #include "Log.hh"
36 #include "Timer.hh"
37
38 #if HAVE_CONFIG_H
39 #include "config.h"
40 #endif
41
42
43 namespace Mf {
44
45
46 Scalar Timer::gNextFire = std::numeric_limits<Scalar>::max();
47 std::map<unsigned,Timer&> Timer::gTimers;
48
49
50 unsigned Timer::getNewID()
51 {
52 static unsigned id = 1;
53 return id++;
54 }
55
56
57 void Timer::init(const Function& function, Scalar seconds, Mode mode)
58 {
59 invalidate();
60
61 mMode = mode;
62
63 if (mMode != INVALID)
64 {
65 mFunction = function;
66
67 if (mode == ABSOLUTEE)
68 {
69 mAbsolute = seconds;
70 }
71 else
72 {
73 mAbsolute = seconds - getTicks();
74 mInterval = seconds;
75 }
76
77 mId = getNewID();
78 gTimers.insert(std::pair<unsigned,Timer&>(mId, *this));
79
80 if (mAbsolute < gNextFire) gNextFire = mAbsolute;
81 }
82 }
83
84
85 bool Timer::isValid() const
86 {
87 return mMode != INVALID;
88 }
89
90 void Timer::invalidate()
91 {
92 if (mMode != INVALID)
93 {
94 gTimers.erase(mId);
95 mMode = INVALID;
96
97 if (isEqual(mAbsolute, gNextFire)) gNextFire = findNextFire();
98 }
99 }
100
101
102 void Timer::fire()
103 {
104 Scalar t = getTicks();
105
106 if (mFunction) mFunction(*this, t);
107
108 if (isRepeating())
109 {
110 Scalar absolute = mAbsolute;
111
112 if (isEqual(mAbsolute, t, 1.0)) mAbsolute += mInterval;
113 else mAbsolute = mInterval + t;
114
115 if (isEqual(absolute, gNextFire)) gNextFire = findNextFire();
116 }
117 else
118 {
119 invalidate();
120 }
121 }
122
123
124 Scalar Timer::findNextFire()
125 {
126 std::map<unsigned,Timer&>::iterator it;
127 Scalar nextFire = std::numeric_limits<Scalar>::max();
128
129 for (it = gTimers.begin(); it != gTimers.end(); ++it)
130 {
131 Scalar absolute = (*it).second.mAbsolute;
132 if (absolute < nextFire) nextFire = absolute;
133 }
134
135 return nextFire;
136 }
137
138
139 Scalar Timer::getSecondsRemaining() const
140 {
141 return mAbsolute - getTicks();
142 }
143
144 bool Timer::isExpired() const
145 {
146 return getSecondsRemaining() < 0.0;
147 }
148
149 bool Timer::isRepeating() const
150 {
151 return mMode == REPEAT;
152 }
153
154
155 void Timer::fireIfExpired(Scalar t)
156 {
157 std::map<unsigned,Timer&>::iterator it;
158
159 if (gNextFire > t) return;
160
161 for (it = gTimers.begin(); it != gTimers.end(); ++it)
162 {
163 Timer& timer = (*it).second;
164 if (timer.isExpired()) timer.fire();
165 }
166 }
167
168
169 #if HAVE_CLOCK_GETTIME
170
171 // Since the monotonic clock will provide us with the time since the computer
172 // started, the number of seconds since that time could easily become so large
173 // that it cannot be accurately stored in a float (even with as little two days
174 // uptime), therefore we need to start from a more recent reference (when the
175 // program starts). Of course this isn't much of an issue if scalar is a
176 // double-precision number.
177
178 static time_t setReference_()
179 {
180 struct timespec ts;
181
182 if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
183 {
184 return 0;
185 }
186
187 return ts.tv_sec;
188 }
189
190 static const time_t reference = setReference_();
191
192
193 Scalar Timer::getTicks()
194 {
195 struct timespec ts;
196
197 int result = clock_gettime(CLOCK_MONOTONIC, &ts);
198 ASSERT(result == 0 && "cannot access clock");
199
200 return Scalar(ts.tv_sec - reference) + Scalar(ts.tv_nsec) / 1000000000.0;
201 }
202
203 void Timer::sleep(Scalar seconds, bool absolute)
204 {
205 struct timespec ts;
206 int ret;
207
208 if (absolute) seconds -= getTicks();
209 ts.tv_sec = time_t(seconds);
210 ts.tv_nsec = long((seconds - Scalar(ts.tv_sec)) * 1000000000.0);
211
212 do
213 {
214 ret = nanosleep(&ts, &ts);
215 }
216 while (ret == -1 && errno == EINTR);
217 }
218
219
220 #else // ! HAVE_CLOCK_GETTIME
221
222
223 // If we don't have posix timers, we'll have to use a different timing method.
224 // SDL only promises centisecond accuracy, but that's better than a kick in the
225 // butt.
226
227 Scalar Timer::getTicks()
228 {
229 Uint32 ms = SDL_GetTicks();
230 return Scalar(ms / 1000) + Scalar(ms % 1000) / 1000.0;
231 }
232
233 void Timer::sleep(Scalar seconds, bool absolute)
234 {
235 if (absolute) seconds -= getTicks();
236 SDL_Delay(Uint32(cml::clamp(int(seconds * 1000.0), 0, 1000)));
237 }
238
239 #endif // HAVE_CLOCK_GETTIME
240
241
242 } // namespace Mf
243
244 /** vim: set ts=4 sw=4 tw=80: *************************************************/
245
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