add sigar_time_now_millis util

include/sigar_private.h

@@ -117,6 +117,7 @@
 #endif
 
 #define SIGAR_MSEC 1000L
+#define SIGAR_USEC 1000000L
 #define SIGAR_NSEC 1000000000L
 
 #define SIGAR_SEC2NANO(s) \

include/sigar_util.h

@@ -62,6 +62,8 @@
 #define PROCP_FS_ROOT "/proc/"
 #endif
 
+sigar_int64_t sigar_time_now_millis(void);
+
 char *sigar_uitoa(char *buf, unsigned int n, int *len);
 
 int sigar_inet_ntoa(sigar_t *sigar,

src/sigar_util.c

@@ -812,3 +812,13 @@ SIGAR_DECLARE(void) sigar_log_impl_file(sigar_t *sigar, void *data,
     FILE *fp = (FILE*)data;
     fprintf(fp, "[%s] %s\n", log_levels[level], message);
 }
+
+sigar_int64_t sigar_time_now_millis(void)
+{
+#ifdef WIN32
+#else
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return ((tv.tv_sec * SIGAR_USEC) + tv.tv_usec) / SIGAR_MSEC;
+#endif
+}