private static void ThreadProc()
{
#if NET20
localOffset = (int)TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.UtcNow).TotalMinutes;
#else
localOffset = (int)TimeZoneInfo.Local.GetUtcOffset(DateTime.UtcNow).TotalMinutes;
#endif
// Only check for offset changes every new minute (plus 1 second safety margin) to save
// resources for clearing the TimeZoneInfo cache
nextOffsetCheck = DateTime.UtcNow.Ticks / 600000000 * 600000000 + 610000000;
do
{
try
{
Thread.Sleep(CheckInterval);
}
catch (ThreadInterruptedException)
{
// That's fine.
}
// Check for UTC time changes
TimeSpan offset = DateTime.UtcNow - FL.UtcNow;
if (Math.Abs(offset.TotalMilliseconds) >= FL.CheckTimeThreshold)
{
FL.RebaseTime();
string msg = "System time changed by " + offset.TotalMilliseconds.ToString("0.0", CultureInfo.InvariantCulture) + " ms";
var item = new FieldLogTextItem(FieldLogPriority.Notice, msg, "Changes less than " + FL.CheckTimeThreshold + " ms are not reported.");
// Discard this log item if there was no other item logged within the last
// 10 seconds because it wouldn't be interesting anyway. If no other log items
// may have discontinuous timestamps, the time recalibration can occur silently.
FL.LogInternal(item, TimeSpan.FromSeconds(10));
Debug.WriteLine(msg);
prevLoggedOffset = 0;
}
else if (FL.LogTimeThreshold >= 0 &&
Math.Abs(offset.TotalMilliseconds - prevLoggedOffset) > FL.LogTimeThreshold)
{
FL.TraceData("System time offset", offset.TotalMilliseconds);
prevLoggedOffset = offset.TotalMilliseconds;
}
// Check for local time zone changes
if (DateTime.UtcNow.Ticks >= nextOffsetCheck)
{
// Clear the cache to get the real current setting
#if NET20
int newLocalOffset = (int)TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.UtcNow).TotalMinutes;
#else
TimeZoneInfo.ClearCachedData();
int newLocalOffset = (int)TimeZoneInfo.Local.GetUtcOffset(DateTime.UtcNow).TotalMinutes;
#endif
if (newLocalOffset != localOffset)
{
int hours = localOffset / 60;
int mins = Math.Abs(localOffset) % 60;
int newHours = newLocalOffset / 60;
int newMins = Math.Abs(newLocalOffset) % 60;
localOffset = newLocalOffset;
string msg = "Local time UTC offset changed from " +
hours.ToString("+00;-00;+00") + ":" + mins.ToString("00") + " to " +
newHours.ToString("+00;-00;+00") + ":" + newMins.ToString("00");
string details = "\u0001UtcOffset=" + newLocalOffset;
FL.Notice(msg, details);
Debug.WriteLine(msg);
}
nextOffsetCheck = DateTime.UtcNow.Ticks / 600000000 * 600000000 + 610000000;
}
}while (!cancelPending);
}