Re: single instance
On 1/16/2013 8:14 PM, Knute Johnson wrote:
On 1/16/2013 10:29 AM, Arne Vajh?j wrote:
On 1/16/2013 1:51 AM, Roedy Green wrote:
On Sat, 05 Jan 2013 19:49:08 -0800, Knute Johnson
<nospam@knutejohnson.com> wrote, quoted or indirectly quoted someone
who said :
The risk is, that in Windows anyway, where the system clock granularity
is 17ms it is possible to start two copies of a program with a batch
I have been studying Knute's code and Peter's commentary hoping to
come up with a canned package for ensuring single Instance.
Using system.nanotime aught to help avoid granularity trouble.
1) It uses a smaller unit, but does not guarantee a smaller
granularity.
At least on my version of Windows, it was much finer.
2) It is only guaranteed to work within the same program as
the base is not fixed.
3) No matter how small a granularity, then it still just reduces
the risk of concurrency problems but does not eliminate the risk.
It doesn't have to be perfect just good enough to stop what you want to
stop. For the application I have, I'm not worried about somebody
starting two copies with a batch file only by clicking on an icon or
typing into a command line. For that it will be more than adequate.
Sure.
But it is not a "canned package for ensuring single instance".
Arne
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