introduce clockNow()

this will be useful for converting some of the nanosleep calls into
scrotSleepFor().

src/scrot.c

@@ -109,7 +109,7 @@ int main(int argc, char *argv[])
     struct tm *tm;
 
     /* Get the time ASAP to reduce the timing error in case --delay is used. */
-    clock_gettime(CONTINUOUS_CLOCK, &opt.delayStart);
+    opt.delayStart = clockNow();
 
     atexit(uninitXAndImlib);
 
@@ -351,6 +351,21 @@ static long miliToNanoSec(int ms)
     return ms * 1000L * 1000L;
 }
 
+/* clockNow() has the exact same semantics as CLOCK_MONOTONIC. Except that on
+ * Linux, CLOCK_MONOTONIC does not progress while the system is suspended, so
+ * the non-standard CLOCK_BOOTTIME is used instead to avoid this bug.
+ */
+struct timespec clockNow(void)
+{
+    struct timespec ret;
+#if defined(__linux__)
+    clock_gettime(CLOCK_BOOTTIME, &ret);
+#else
+    clock_gettime(CLOCK_MONOTONIC, &ret);
+#endif
+    return ret;
+}
+
 /* scrotWaitUntil: clock_nanosleep with a simpler interface and no EINTR nagging
  */
 static void scrotWaitUntil(const struct timespec *time)
@@ -360,7 +375,7 @@ static void scrotWaitUntil(const struct timespec *time)
      */
     struct timespec tmp;
     do {
-        clock_gettime(CONTINUOUS_CLOCK, &tmp);
+        tmp = clockNow();
 
         /* XXX: Use timespecsub(). OS X doesn't have that BSD macro, and libbsd
          * doesn't support OS X save for an unmaintained fork. libobsd supports

src/scrot.h

@@ -28,6 +28,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #pragma once
 
+#include <time.h>
+
 #include <X11/Xlib.h>
 #include <Imlib2.h>
 
@@ -39,5 +41,6 @@ extern Screen *scr;
 Window scrotGetWindow(Display *, Window, int, int);
 int scrotGetGeometry(Window, int *, int *, int *, int *);
 void scrotNiceClip(int *, int *, int *, int *);
+struct timespec clockNow(void);
 void scrotDoDelay(void);
 void scrotGrabMousePointer(const Imlib_Image, const int, const int);

src/scrot_selection.c

@@ -433,7 +433,7 @@ Imlib_Image scrotSelectionSelectMode(void)
             return NULL;
 
     if (!opt.delaySelection) {
-        clock_gettime(CONTINUOUS_CLOCK, &opt.delayStart);
+        opt.delayStart = clockNow();
         scrotDoDelay();
     }
 

src/util.h

@@ -26,21 +26,9 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #pragma once
 
-#include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-/* On Linux, CLOCK_MONOTONIC does not progress while the system is suspended,
- * and an alternative non-standard clock which does not suffer from this problem
- * called CLOCK_BOOTTIME is available. Scrot's CONTINUOUS_CLOCK has the exact
- * same semantics as CLOCK_MONOTONIC, only it avoids this bug.
- */
-#if defined(__linux__)
-    #define CONTINUOUS_CLOCK CLOCK_BOOTTIME
-#else
-    #define CONTINUOUS_CLOCK CLOCK_MONOTONIC
-#endif
-
 #ifdef DEBUG
     #define scrotAssert(X) do { \
         if (!(X)) { \