{$ifdef Has_EventWait}
procedure TFPTimerThread.Execute;
var
WakeTime, StartTime: TDateTime;
WakeInterval: Integer;
Counter: int64; { use Int64 to avoid overflow with Counter*fInterval (~49 days)}
AInterval: int64;
Diff: Extended;
Const
wrSignaled = 0;
wrTimeout = 1;
wrAbandoned= 2;
wrError = 3;
begin
WakeInterval := MaxInt;
Counter := 1;
AInterval := fInterval;
FStartTime := Now;
while not Terminated do
begin
if GetWakeTime(AInterval,Counter,WakeInterval,WakeTime) then
Continue;
if not Terminated then
case BasicEventWaitFor(WakeInterval,fWaitEvent) of
wrTimeout:
begin
if Terminated then
Break
else
begin
try
if not Timer.UseTimerThread then
// If terminate is called while here, then the Synchronize will be
// queued while the stoptimer is being processed.
// StopTimer cannot wait until thread completion as this would deadlock
Synchronize(@Timer.Timer) // Call user event
else
Timer.Timer;
except
// Trap errors to prevent this thread from terminating
end;
Inc(Counter); // Next interval
end;
end;
wrSignaled:
begin
if Terminated then
Break
else
begin // Interval has changed
Counter := 1; // Restart timer without creating new thread
AInterval := fInterval;
FStartTime := Now;
end;
end;
else
Break;
end
end;
BasicEventDestroy(fWaitEvent);
end;
{$ELSE Has_EventWait}
procedure TFPTimerThread.Execute;
var
WakeTime, StartTime: TDateTime;
WakeInterval: Integer;
Counter: int64; { use Int64 to avoid overflow with Counter*fInterval (~49 days)}
AInterval: int64;
Diff: Extended;
S,Last: Cardinal;
RecheckTimeCounter: integer;
const
cSleepTime = 500; // 0.5 second, better than every 5 milliseconds
cRecheckTimeCount = 120; // Recheck clock every minute, as the sleep loop can loose time
begin
WakeInterval := MaxInt;
Counter := 1;
AInterval := fInterval;
FStartTime := Now;
while not Terminated do
begin
if GetWakeTime(AInterval,Counter,WakeInterval,WakeTime) then
Continue;
if not Terminated then
begin
RecheckTimeCounter := cRecheckTimeCount;
s := cSleepTime;
repeat
if s > WakeInterval then
s := WakeInterval;
sleep(s);
if fSignaled then // Terminated or interval has changed
begin
if not Terminated then
begin
fSignaled := False;
Counter := 1; // Restart timer
AInterval := fInterval;
StartTime := Now;
end;
break; // Need to break out of sleep loop
end;
dec(WakeInterval,s); // Update total wait time
dec(RecheckTimeCounter); // Do we need to recheck current time
if (RecheckTimeCounter < 0) and (WakeInterval > 0) then
begin
Diff := (WakeTime - Now);
WakeInterval := Trunc(Diff * cMilliSecs);
RecheckTimeCounter := cRecheckTimeCount;
s := cSleepTime;
end;
until (WakeInterval<=0) or Terminated;
if WakeInterval <= 0 then
try
inc(Counter);
if not Timer.UseTimerThread then
// If terminate is called while here, then the Synchronize will be
// queued while the stoptimer is being processed.
// StopTimer cannot wait until thread completion as this would deadlock
Synchronize(@Timer.Timer) // Call user event
else
Timer.Timer;
except
// Trap errors to prevent this thread from terminating
end;
end
end;
end;
{$ENDIF Has_EventWait}
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