new classes; yajl library

[chaz/yoink] / src / timer.cc

diff --git a/src/timer.cc b/src/timer.cc
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+++ b/src/timer.cc
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+
+/*******************************************************************************
+
+ Copyright (c) 2009, Charles McGarvey
+ All rights reserved.
+ 
+ Redistribution   and   use  in  source  and  binary  forms,  with  or  without
+ modification, are permitted provided that the following conditions are met:
+ 
+   * Redistributions  of  source  code  must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+   * Redistributions  in binary form must reproduce the above copyright notice,
+     this  list of conditions and the following disclaimer in the documentation
+     and/or other materials provided with the distribution.
+ 
+ THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES  (INCLUDING,  BUT  NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES;  LOSS  OF  USE,  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*******************************************************************************/
+
+#include <stdexcept>
+#include <ctime>
+#include <cerrno>
+
+#include <SDL/SDL.h>
+
+#include "timer.hh"
+
+
+namespace dc {
+
+
+#if HAVE_LIBRT
+
+scalar ticks()
+{
+       struct timespec ts;
+
+       if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
+       {
+               throw std::runtime_error("cannot access monotonic clock");
+       }
+
+       return scalar(ts.tv_sec) + scalar(ts.tv_nsec) / 1000000000.0;
+}
+
+void sleep(scalar seconds, bool absolute)
+{
+       struct timespec ts;
+       int ret;
+
+       if (!absolute) seconds += ticks();
+       ts.tv_sec = time_t(seconds);
+       ts.tv_nsec = time_t((seconds - scalar(ts.tv_sec)) * 1000000000.0);
+
+       do
+       {
+               ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &ts, 0);
+       }
+       while (ret == -1 && errno == EINTR);
+}
+
+#else // ! HAVE_LIBRT
+
+// If we don't have librt, we'll have to use different timing methods.
+
+scalar ticks()
+{
+       unsigned ms = SDL_GetTicks();
+       return scalar(ms / 1000) + scalar(ms % 1000) / 1000.0;
+}
+
+void sleep(scalar seconds, bool absolute)
+{
+       struct timespec ts;
+       int ret;
+
+       if (absolute) seconds -= ticks();
+       ts.tv_sec = time_t(seconds);
+       ts.tv_nsec = time_t((seconds - scalar(ts.tv_sec)) * 1000000000.0);
+
+       do
+       {
+               ret = nanosleep(&ts, &ts);
+       }
+       while (ret == -1 && errno == EINTR);
+}
+
+#endif // HAVE_LIBRT
+
+
+} // namespace dc
+