git-svn-id: https://casparcg.svn.sourceforge.net/svnroot/casparcg/server/branches...

[casparcg] / common / utility / timer.h

diff --git a/common/utility/timer.h b/common/utility/timer.h
index 574391682d057b98d3ea59b3d66a07268721583e..122d0eaaf7033d6868ab64bd8939484ad759c943 100644 (file)
--- a/common/utility/timer.h
+++ b/common/utility/timer.h
@@ -1,26 +1,86 @@
+/*\r
+* copyright (c) 2010 Sveriges Television AB <info@casparcg.com>\r
+*\r
+*  This file is part of CasparCG.\r
+*\r
+*    CasparCG is free software: you can redistribute it and/or modify\r
+*    it under the terms of the GNU General Public License as published by\r
+*    the Free Software Foundation, either version 3 of the License, or\r
+*    (at your option) any later version.\r
+*\r
+*    CasparCG is distributed in the hope that it will be useful,\r
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
+*    GNU General Public License for more details.\r
+\r
+*    You should have received a copy of the GNU General Public License\r
+*    along with CasparCG.  If not, see <http://www.gnu.org/licenses/>.\r
+*\r
+*/\r
 #pragma once\r
 \r
+#define NOMINMAX\r
+\r
 #include <windows.h>\r
 \r
 namespace caspar {\r
        \r
-class timer\r
+class high_prec_timer\r
 {\r
 public:\r
-       timer() : time_(timeGetTime()){}\r
-\r
-       double elapsed()\r
-       {\r
-               return static_cast<double>(timeGetTime() - time_)/1000.0;\r
-       }\r
-       \r
-       void reset()\r
+       high_prec_timer()\r
        {\r
-               time_ = timeGetTime();\r
+               QueryPerformanceFrequency(&freq_);\r
+               QueryPerformanceCounter(&time_);\r
        }\r
-       \r
+\r
+       // Author: Ryan M. Geiss\r
+       // http://www.geisswerks.com/ryan/FAQS/timing.html\r
+       void tick(double interval)\r
+       {       \r
+               LARGE_INTEGER t;\r
+               QueryPerformanceCounter(&t);\r
+\r
+               if (time_.QuadPart != 0)\r
+               {\r
+                       __int64 ticks_to_wait = static_cast<int>(static_cast<double>(freq_.QuadPart) * interval);\r
+                       __int64 done = 0;\r
+                       do\r
+                       {\r
+                               QueryPerformanceCounter(&t);\r
+                               \r
+                               __int64 ticks_passed = static_cast<__int64>(t.QuadPart) - static_cast<__int64>(time_.QuadPart);\r
+                               __int64 ticks_left = ticks_to_wait - ticks_passed;\r
+\r
+                               if (t.QuadPart < time_.QuadPart)    // time wrap\r
+                                       done = 1;\r
+                               if (ticks_passed >= ticks_to_wait)\r
+                                       done = 1;\r
+                               \r
+                               if (!done)\r
+                               {\r
+                                       // if > 0.002s left, do Sleep(1), which will actually sleep some \r
+                                       //   steady amount, probably 1-2 ms,\r
+                                       //   and do so in a nice way (cpu meter drops; laptop battery spared).\r
+                                       // otherwise, do a few Sleep(0)'s, which just give up the timeslice,\r
+                                       //   but don't really save cpu or battery, but do pass a tiny\r
+                                       //   amount of time.\r
+                                       if (ticks_left > static_cast<__int64>((freq_.QuadPart*2)/1000))\r
+                                               Sleep(1);\r
+                                       else                        \r
+                                               for (int i = 0; i < 10; ++i) \r
+                                                       Sleep(0);  // causes thread to give up its timeslice\r
+                               }\r
+                       }\r
+                       while (!done);            \r
+               }\r
+\r
+               time_ = t;\r
+       }               \r
 private:       \r
-       DWORD time_;\r
+       LARGE_INTEGER freq_;\r
+       LARGE_INTEGER time_;\r
 };\r
 \r
+\r
 }
\ No newline at end of file