Add cfutimer which uses more accurate functions if available

This is some code I had previously written, adapted to (mostly)
libcfu coding style. The API is very similar to that of the
existing (to be eventually removed) cfutime.

configure.ac

@@ -27,6 +27,12 @@ AC_FUNC_MALLOC
 AC_FUNC_MEMCMP
 AC_CHECK_FUNCS([gettimeofday memset snprintf strcasecmp strncasecmp vsnprintf])
 
+# Check for clock_gettime()
+AC_CHECK_FUNCS([clock_gettime], [],
+               [AC_CHECK_LIB([rt], [clock_gettime],
+                             [AC_DEFINE(HAVE_CLOCK_GETTIME, 1)
+                              AC_SUBST([REALTIME_LIBS], [-lrt])])])
+
 # Check for pthread support
 AC_CHECK_LIB([pthread],
              [pthread_create],

examples/Makefile.am

@@ -2,4 +2,4 @@ noinst_PROGRAMS = hash_usage large_hash strings conf_example \
                   conf_example2 opt_example
 
 AM_CFLAGS = -I$(top_srcdir)/src
-LDADD = $(top_builddir)/src/libcfu.la @PTHREAD_LIBS@
+LDADD = $(top_builddir)/src/libcfu.la @PTHREAD_LIBS@ @REALTIME_LIBS@

libcfu.pc.in

@@ -6,5 +6,5 @@ includedir=@includedir@
 Name: @PACKAGE_NAME@
 Description: Portable C data structure and utility library
 Version: @PACKAGE_VERSION@
-Libs.private: @PTHREAD_LIBS@
+Libs.private: @PTHREAD_LIBS@ @REALTIME_LIBS@
 Cflags: -I${includedir}/cfu

src/Makefile.am

@@ -1,12 +1,13 @@
 lib_LTLIBRARIES = libcfu.la
 
-libcfu_la_SOURCES = cfuhash.c cfutime.c cfustring.c cfulist.c \
-                    cfuconf.c cfu.c cfuopt.c snprintf.c
+libcfu_la_SOURCES = cfuhash.c cfutime.c cfutimer.c cfustring.c \
+                    cfulist.c cfuconf.c cfu.c cfuopt.c snprintf.c
 
+libcfu_la_LIBADD = @PTHREAD_LIBS@ @REALTIME_LIBS@
 
 libcfuincdir = $(includedir)/cfu
-libcfuinc_HEADERS = cfu.h cfuhash.h cfutime.h cfustring.h cfulist.h \
-                    cfuconf.h cfuopt.h
+libcfuinc_HEADERS = cfu.h cfuhash.h cfutime.h cfutimer.h cfustring.h \
+                    cfulist.h cfuconf.h cfuopt.h
 
 if USE_PTHREADS
 libcfu_la_SOURCES += cfuthread_queue.c

src/cfu.c

@@ -71,6 +71,14 @@ cfu_is_time(void *item) {
 	return 0;
 }
 
+int
+cfu_is_timer(void *item)
+{
+	if (cfu_get_type(item) == libcfu_t_time)
+		return 1;
+	return 0;
+}
+
 extern int
 cfu_is_conf(void *item) {
 	if (cfu_get_type(item) == libcfu_t_conf) return 1;

src/cfu.h

@@ -59,7 +59,7 @@ CFU_BEGIN_DECLS
 #define LIBCFU_VERSION "0.04"
 
 typedef enum { libcfu_t_none = 0, libcfu_t_hash_table, libcfu_t_list, libcfu_t_string,
-			   libcfu_t_time, libcfu_t_conf } libcfu_type;
+			   libcfu_t_time, libcfu_t_timer, libcfu_t_conf } libcfu_type;
 
 typedef struct libcfu_item libcfu_item_t;
 
@@ -68,6 +68,7 @@ extern int cfu_is_hash(void *item);
 extern int cfu_is_list(void *item);
 extern int cfu_is_string(void *item);
 extern int cfu_is_time(void *item);
+int cfu_is_timer(void *item);
 extern int cfu_is_conf(void *item);
 
 CFU_END_DECLS

src/cfutimer.c

@@ -0,0 +1,101 @@
+/*
+ * cfutimer.c - This file is part of the libcfu library
+ *
+ * Copyright (c) Matthew Brush <mbrush@codebrainz.ca>.
+ * All rights reserved.
+ *
+ * This code is released under the BSD license, see COPYING file
+ * for full license text.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "cfu.h"
+#include "cfutimer.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <time.h>
+
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+/* For Windows, use a fairly accurate timer. This could probably be
+ * improved quite a bit (if it even works at all), by using performance
+ * counters stuff or thread cycle time from the API. Setting the afinity
+ * mask is probably also helpful. Note: not tested at all. */
+#ifdef _WIN32
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# define TIMEVALUE_TYPE    FILETIME
+# define TIMEVALUE_NOW(tv) GetSystemTimeAsFileTime(&(tv))
+# define TIMEVALUE_SEC(tv) ((double)(((uint64_t)(tv).dwHighDataTime << 32) + (tv).dwLowDateTime) * 10000000.0)
+/* another option for windows, also untested
+#define TIMEVALUE_TYPE LARGE_INTEGER
+// future: set thread afinity mask
+#define TIMEVALUE_NOW(tv) QueryPerformanceCounter(&(tv))
+static INLINE double timevalue_sec_(TIMEVALUE_TYPE *tv) {
+  LARGE_INTEGER freq;
+  QueryPerformanceFrequency(&freq);
+  return (double) tv->QuadPart / (double) freq.QuadPart;
+}
+#define TIMEVALUE_SEC(tv) timevalue_sec_(&(tv))
+*/
+#else
+/* For non-Windows systems check to see if the nano-second timer is
+ * available from POSIX. Note: must also be linked with -lrt.*/
+# if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
+#  define TIMEVALUE_TYPE    struct timespec
+#  define TIMEVALUE_NOW(tv) clock_gettime(CLOCK_MONOTONIC, &(tv))
+#  define TIMEVALUE_SEC(tv) ((double)(tv).tv_sec + ((double) (tv).tv_nsec / 1000000000.0))
+/* For non-Windows systems that don't have the more accurate clock_gettime()
+ * then use the gettimeofday() function from POSIX if available. */
+# elif defined(HAVE_GETTIMEOFDAY)
+#  define TIMEVALUE_TYPE    struct timeval
+#  define TIMEVALUE_NOW(tv) gettimeofday(&(tv), NULL)
+#  define TIMEVALUE_SEC(tv) ((double)(tv).tv_sec + ((double) (tv).tv_usec / 1000000.0))
+# else /* Fall-back to time() from stdlib */
+#  define TIMEVALUE_TYPE    time_t
+#  define TIMEVALUE_NOW(tv) time(&(tv))
+#  define TIMEVALUE_SEC(tv) ((double)(tv))
+# endif
+#endif
+
+struct cfutimer
+{
+	libcfu_type type;
+	TIMEVALUE_TYPE t1;
+	TIMEVALUE_TYPE t2;
+};
+
+cfutimer_t *cfutimer_new(void)
+{
+	cfutimer_t *timer = calloc(1, sizeof(cfutimer_t));
+	timer->type = libcfu_t_time;
+	return timer;
+}
+
+void cfutimer_start(cfutimer_t *timer)
+{
+	memset(&(timer->t2), 0, sizeof(TIMEVALUE_TYPE));
+	TIMEVALUE_NOW(timer->t1);
+}
+
+void cfutimer_stop(cfutimer_t *timer)
+{
+	TIMEVALUE_NOW(timer->t2);
+}
+
+double cfutimer_elapsed(cfutimer_t *timer)
+{
+	return TIMEVALUE_SEC(timer->t2) - TIMEVALUE_SEC(timer->t1);
+}
+
+void cfutimer_free(cfutimer_t *timer)
+{
+	free(timer);
+}

src/cfutimer.h

@@ -0,0 +1,37 @@
+/*
+ * cfutimer.h - This file is part of the libcfu library
+ *
+ * Copyright (c) Matthew Brush <mbrush@codebrainz.ca>.
+ * All rights reserved.
+ *
+ * This code is released under the BSD license, see COPYING file
+ * for full license text.
+ */
+
+#ifndef CFU_TIMER_H_
+#define CFU_TIMER_H_
+
+#include <cfu.h>
+
+CFU_BEGIN_DECLS
+
+typedef struct cfutimer cfutimer_t;
+
+/* Return a new cfutimer structure. */
+cfutimer_t *cfutimer_new(void);
+
+/* Start the timer. */
+void cfutimer_start(cfutimer_t *timer);
+
+/* Stop the timer. */
+void cfutimer_stop(cfutimer_t *timer);
+
+/* Return the number of seconds elapsed as a double. */
+double cfutimer_elapsed(cfutimer_t *timer);
+
+/* Deallocate resources allocated for time. */
+void cfutimer_free(cfutimer_t *timer);
+
+CFU_END_DECLS
+
+#endif /* CFU_TIMER_H_ */