B4J Question [Solved] Is datatime conversion reliable in webapp concurrent threads

[billzhan]

Hi,

In my webapp, datetime conversion are used quite a lot in concurrent threads.

'For all threads,datetime conversion config:
DateTime.SetTimeZone(0)
DateTime.DateFormat="yyyy-MM-dd"
DateTime.TimeFormat="HH:mm:ss"
'conversion or get hour/minute
Dim tick As Long=DateTime.DateParse(datestr)
Dim minute As Int=DateTime.GetMinute(DateTime.Now)
Dim hour As Int=DateTime.GetHour(ticks)
   

'But I also need to use DateUtils.SetDateAndTime2 with different time-zones.
Public Sub SetDateAndTime2(Years As Int, Months As Int, Days As Int, Hours As Int, Minutes As Int, Seconds As Int, timezone As Double) As Long
    Dim df As String = DateTime.DateFormat
    DateTime.DateFormat = "GGyyyyMMddHHmmssz"
    ...
    Try
        Dim ticks As Long = DateTime.DateParse(d)
    Catch
    ....
    End Try
    DateTime.DateFormat = df
    Return ticks
End Sub

I know that conversions are done within very short time(1ms).
But it's possible that two concurrent threads use different DateFormat/SetTimeZone for conversion at the "same" time. Is this reliable?

One more question:
Do I have to set DateTime.SetTimeZone/DateFormat/TimeFormat every time before conversion, or just once in the main thread?


Best regards,
bz

 

[Erel]

Good questions. The answer is yes. B4J DateTime object is thread safe (unlike B4A DateTime).

Do I have to set DateTime.SetTimeZone/DateFormat/TimeFormat every time before conversion, or just once in the main thread?

Each thread works with his own DateTime instance so you need to call DateTime.SetTimeZone in the servlet module.