Implement gettime function as a separate module.

Author: kostrzewa

gettime.c

@@ -0,0 +1,52 @@
+/***********************************************************************                                                             
+ * Copyright (C) 2002,2003,2004,2005,2006,2007,2008 Carsten Urbach
+ * Copyright (C) 2012 Bartosz Kostrzewa (gettime.[c,h])
+ *
+ * This file is part of tmLQCD.
+ *
+ * tmLQCD is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * tmLQCD is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with tmLQCD.  If not, see <http://www.gnu.org/licenses/>.
+***********************************************************************/
+
+
+#ifdef HAVE_CONFIG_H
+# include<config.h>
+#endif
+#include <time.h>
+#if (defined BGL && !defined BGP)
+#  include <rts.h>
+#endif
+#ifdef MPI
+# include <mpi.h>
+#endif
+
+#include "gettime.h"
+
+double gettime(void) {
+  double t;
+#if (defined BGL && !defined BGP)
+  const double clockspeed=1.0e-6/700.0;
+  t = rts_get_timebase() * clockspeed;
+#elif defined MPI
+  t = MPI_Wtime();
+  /* clock_gettime is detected on BGL/BGP but it is an unsupported system call so we can't use it! */
+#elif (defined HAVE_CLOCK_GETTIME && !defined BGL)
+  struct timespec ts;
+  clock_gettime(CLOCK_MONOTONIC,&ts);
+  t = ts.tv_sec + 1.0e-9*ts.tv_nsec;
+#else
+  t = (double)clock()/(CLOCKS_PER_SEC);
+#endif
+  return t;
+}
+

gettime.h

@@ -0,0 +1,32 @@
+/***********************************************************************                                                             
+ * Copyright (C) 2002,2003,2004,2005,2006,2007,2008 Carsten Urbach
+ * Copyright (C) 2012 Bartosz Kostrzewa (gettime.[c,h])
+ *
+ * This file is part of tmLQCD.
+ *
+ * tmLQCD is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * tmLQCD is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with tmLQCD.  If not, see <http://www.gnu.org/licenses/>.
+***********************************************************************/
+
+#ifndef _GETTIME_H
+#define _GETTIME_H
+
+/* gettime provides a time measurement with the BGL real time ticker,
+   MPI_Wtime, clock_gettime and clock in decreasing order of preference
+   depending on availability. Except for clock(), all these measurements
+   are good representations of walltime */
+
+double gettime(void);
+
+#endif /* _GETTIME_H */
+