indexamajig: Add fallback for clock_gettime()

4 files changed, 106 insertions, 11 deletions

diff --git a/config.h.in b/config.h.in
index 1dd5de50..ea2b3689 100644
--- a/config.h.in
+++ b/config.h.in
@@ -18,6 +18,9 @@
 /* Define to 1 if Cairo is available */
 #undef HAVE_CAIRO
 
+/* Define to 1 if clock_gettime is available. */
+#undef HAVE_CLOCK_GETTIME
+
 /* Define to 1 if CL/cl.h should be used */
 #undef HAVE_CL_CL_H
 
diff --git a/configure b/configure
index 339d4902..d5f96eb3 100755
--- a/configure
+++ b/configure
@@ -7481,6 +7481,60 @@ fi
 
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clock_gettime in -lrt" >&5
+$as_echo_n "checking for clock_gettime in -lrt... " >&6; }
+if test "${ac_cv_lib_rt_clock_gettime+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lrt  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char clock_gettime ();
+int
+main ()
+{
+return clock_gettime ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_rt_clock_gettime=yes
+else
+  ac_cv_lib_rt_clock_gettime=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_rt_clock_gettime" >&5
+$as_echo "$ac_cv_lib_rt_clock_gettime" >&6; }
+if test "x$ac_cv_lib_rt_clock_gettime" = x""yes; then :
+
+
+$as_echo "#define HAVE_CLOCK_GETTIME 1" >>confdefs.h
+
+   TIMER_LIBS="-lrt"
+
+else
+
+   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Falling back on gettimeofday()." >&5
+$as_echo "$as_me: WARNING: Falling back on gettimeofday()." >&2;}
+   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Time intervals may not be correct in certain circumstances." >&5
+$as_echo "$as_me: WARNING: Time intervals may not be correct in certain circumstances." >&2;}
+
+fi
+
+
+
  if test x$have_opencl = xtrue; then
   HAVE_OPENCL_TRUE=
   HAVE_OPENCL_FALSE='#'
@@ -7574,9 +7628,10 @@ $as_echo "$gl_cv_prog_c_ignore_unused_libraries" >&6; }
 CFLAGS="$CFLAGS $HDF5_CFLAGS $GSL_CFLAGS $OPENCL_CFLAGS -pthread $GTK_CFLAGS"
 CFLAGS="$CFLAGS $LIBTIFF_CFLAGS -D_GNU_SOURCE $libPNG_CFLAGS $Cairo_CFLAGS"
 CFLAGS="$CFLAGS $GDK_pixbuf_CFLAGS $GDK_pixbuf_2_CFLAGS"
-LIBS="$LIBS $HDF5_LIBS -lm -lz $GSL_LIBS $GTK_LIBS $OPENCL_LIBS -pthread -lrt"
+
+LIBS="$LIBS $HDF5_LIBS -lm -lz $GSL_LIBS $GTK_LIBS $OPENCL_LIBS -pthread"
 LIBS="$LIBS $LIBTIFF_LIBS $libPNG_LIBS $Cairo_LIBS $GDK_pixbuf_LIBS"
-LIBS="$LIBS $GDK_pixbuf_2_LIBS $LDFLAGS"
+LIBS="$LIBS $GDK_pixbuf_2_LIBS $TIMER_LIBS $LDFLAGS"
 
 
 
diff --git a/configure.ac b/configure.ac
index 83078536..eaac7a4b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -219,6 +219,16 @@ AC_CHECK_LIB([pthread], [sched_setaffinity], [
 ])
 
 
+AC_CHECK_LIB([rt], [clock_gettime], [
+   AC_DEFINE([HAVE_CLOCK_GETTIME], [1],
+             [Define to 1 if clock_gettime is available.])
+   TIMER_LIBS="-lrt"
+], [
+   AC_MSG_WARN([Falling back on gettimeofday().])
+   AC_MSG_WARN([Time intervals may not be correct in certain circumstances.])
+])
+
+
 dnl Conditionals...
 AM_CONDITIONAL([HAVE_OPENCL], test x$have_opencl = xtrue)
 
@@ -236,9 +246,10 @@ gl_IGNORE_UNUSED_LIBRARIES
 CFLAGS="$CFLAGS $HDF5_CFLAGS $GSL_CFLAGS $OPENCL_CFLAGS -pthread $GTK_CFLAGS"
 CFLAGS="$CFLAGS $LIBTIFF_CFLAGS -D_GNU_SOURCE $libPNG_CFLAGS $Cairo_CFLAGS"
 CFLAGS="$CFLAGS $GDK_pixbuf_CFLAGS $GDK_pixbuf_2_CFLAGS"
-LIBS="$LIBS $HDF5_LIBS -lm -lz $GSL_LIBS $GTK_LIBS $OPENCL_LIBS -pthread -lrt"
+
+LIBS="$LIBS $HDF5_LIBS -lm -lz $GSL_LIBS $GTK_LIBS $OPENCL_LIBS -pthread"
 LIBS="$LIBS $LIBTIFF_LIBS $libPNG_LIBS $Cairo_LIBS $GDK_pixbuf_LIBS"
-LIBS="$LIBS $GDK_pixbuf_2_LIBS $LDFLAGS"
+LIBS="$LIBS $GDK_pixbuf_2_LIBS $TIMER_LIBS $LDFLAGS"
 
 
 GTK_DOC_CHECK([1.11],[--flavour no-tmpl])
diff --git a/src/indexamajig.c b/src/indexamajig.c
index 953fd81d..093738da 100644
--- a/src/indexamajig.c
+++ b/src/indexamajig.c
@@ -23,7 +23,12 @@
 #include <hdf5.h>
 #include <gsl/gsl_errno.h>
 #include <pthread.h>
+
+#ifdef HAVE_CLOCK_GETTIME
 #include <time.h>
+#else
+#include <sys/time.h>
+#endif
 
 #include "utils.h"
 #include "hdf5-file.h"
@@ -401,17 +406,40 @@ static void *get_image(void *qp)
 }
 
 
+#ifdef HAVE_CLOCK_GETTIME
+
+static time_t get_monotonic_seconds()
+{
+	struct timespec tp;
+	clock_gettime(CLOCK_MONOTONIC, &tp);
+	return tp.tv_sec;
+}
+
+#else
+
+/* Fallback version of the above.  The time according to gettimeofday() is not
+ * monotonic, so measuring intervals based on it will screw up if there's a
+ * timezone change (e.g. daylight savings) while the program is running. */
+static time_t get_monotonic_seconds()
+{
+	struct timeval tp;
+	gettimeofday(&tp, NULL);
+	return tp.tv_sec;
+}
+
+#endif
+
 static void finalise_image(void *qp, void *pp)
 {
 	struct queue_args *qargs = qp;
 	struct index_args *pargs = pp;
-	struct timespec tp;
+	time_t monotonic_seconds;
 
 	qargs->n_indexable += pargs->indexable;
 	qargs->n_processed++;
 
-	clock_gettime(CLOCK_REALTIME, &tp);
-	if ( tp.tv_sec >= qargs->t_last_stats+STATS_EVERY_N_SECONDS ) {
+	monotonic_seconds = get_monotonic_seconds();
+	if ( monotonic_seconds >= qargs->t_last_stats+STATS_EVERY_N_SECONDS ) {
 
 		STATUS("%i out of %i indexed so far,"
 		       " %i out of %i since the last message.\n",
@@ -421,7 +449,7 @@ static void finalise_image(void *qp, void *pp)
 
 		qargs->n_processed_last_stats = qargs->n_processed;
 		qargs->n_indexable_last_stats = qargs->n_indexable;
-		qargs->t_last_stats = tp.tv_sec;
+		qargs->t_last_stats = monotonic_seconds;
 
 	}
 
@@ -475,7 +503,6 @@ int main(int argc, char *argv[])
 	char *element = NULL;
 	double nominal_photon_energy;
 	int stream_flags = STREAM_INTEGRATED;
-	struct timespec tp;
 	int cpu_num = 0;
 	int cpu_groupsize = 1;
 	int cpu_offset = 0;
@@ -847,8 +874,7 @@ int main(int argc, char *argv[])
 	qargs.n_processed = 0;
 	qargs.n_indexable_last_stats = 0;
 	qargs.n_processed_last_stats = 0;
-	clock_gettime(CLOCK_REALTIME, &tp);
-	qargs.t_last_stats = tp.tv_sec;
+	qargs.t_last_stats = get_monotonic_seconds();
 
 	n_images = run_threads(nthreads, process_image, get_image,
 	                       finalise_image, &qargs, 0,