[Lazarus] UniqueInstance issue

Giuliano Colla giuliano.colla at fastwebnet.it
Sun Apr 3 13:17:52 CEST 2011

Luiz Americo Pereira Camara ha scritto:
> On 2/4/2011 15:18, Giuliano Colla wrote:
>> In an application I'm currently developing, meant to run under RHEL5, I
>> needed to ensure that no multiple instances were running, so I installed
>> the UniqueInstance component:
>> http://sourceforge.net/projects/lazarus-ccr/files/Unique%20Instance/Unique%20Instance%200.2/ 
> please publish a sample project and a stacktrace
To avoid attachment length problems, my zipped sandbox folder is 
available at:


where you can find project1 and project2, to help sort out the problems, 
together with Trace1.txt and Trace2.txt, which are the stack traces for 
project1 and project2.

Project1 is nothing but a form with only a TUniqueInstance component. If 
the component is enabled at design time, it works perfectly. If the 
component is not enabled at design time, see Trace1.txt. (stack trace of 
the first and only instance running)

In Project2 I tried to put in one by one all the components of my real 
application. Apparently the problem arises with the TMemo component, 
whose presence, together with TUniqueInstance, triggers the access 
violation (see Trace2.txt, which is the trace of the second instance 
running). A TMemo issue or a TUiniqueInstance issue?

Kind regards,


More information about the Lazarus mailing list