changed timing functions to use a monotonic increasing clock

gettimeofday() is subject to be changed on daylight-saving or to ntp-related
(think leap-seconds). even worse, it is subject to be changed BACK in time. this
is hard to fix correctly (see commit 45726d3016e and bug #3560509). it is
irrelevant for timers to know the nano-seconds since the epoch anyways.

1 files changed, 97 insertions, 0 deletions

diff --git a/src/FbTk/FbTime.cc b/src/FbTk/FbTime.cc
new file mode 100644
index 0000000..54eda75
--- /dev/null
+++ b/src/FbTk/FbTime.cc
@@ -0,0 +1,97 @@
+// FbTime.cc for FbTk - Fluxbox Toolkit
+// Copyright (c) 2012 Mathias Gumz (akira at fluxbox dot org)
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the 
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in 
+// all copies or substantial portions of the Software. 
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+// DEALINGS IN THE SOFTWARE.
+
+#include "FbTime.hh"
+
+
+
+#ifdef HAVE_CLOCK_GETTIME // linux|*bsd|solaris
+#include <time.h>
+
+namespace {
+
+uint64_t _now() {
+
+    uint64_t n = 0L;
+    timespec ts;
+
+    if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
+        n = (ts.tv_sec * FbTk::FbTime::IN_SECONDS) + (ts.tv_nsec / 1000L);
+    }
+
+    return n;
+}
+
+}
+
+#endif // HAVE_CLOCK_GETTIME
+
+
+
+
+
+#ifdef HAVE_MACH_ABSOLUTE_TIME // macosx
+
+// http://stackoverflow.com/questions/5167269/clock-gettime-alternative-in-mac-os-x
+// https://github.com/ThomasHabets/monotonic_clock/blob/master/src/monotonic_mach.c
+// http://shiftedbits.org/2008/10/01/mach_absolute_time-on-the-iphone/
+
+
+#include <mach/mach_time.h>
+
+namespace {
+
+uint64_t _now() {
+
+    // mach_absolute_time() * info.numer / info.denom yields
+    // nanoseconds.
+
+    static double micro_scale = 0.001;  // 1000ms == 1ns
+    static bool initial = true;
+
+    if (initial) {
+        initial = false;
+        mach_timebase_info_data_t info;
+        if (mach_timebase_info(&info) == 0) {
+            micro_scale *= static_cast<double>info.numer / static_cast<double>(info.denom);
+        }
+    }
+
+    return static_cast<uint64_t>(mach_absolute_time() * micro_scale);
+}
+
+}
+
+#endif // HAVE_MACH_ABSOLUTE_TIME
+
+
+
+
+
+uint64_t FbTk::FbTime::now() {
+    return ::_now();
+}
+
+
+uint64_t FbTk::FbTime::remainingNext(uint64_t unit) {
+    return (unit - (::_now() % unit) - 1);
+}
+