[Lazarus] Synchronize problem in linux

[michael.vancanneyt at wisa.be]

On Wed, 25 May 2011, Giuliano Colla wrote:

> michael.vancanneyt at wisa.be ha scritto:
>> 
>> 
>> On Wed, 25 May 2011, Vincent Snijders wrote:
>> 
>>> 2011/5/25  <michael.vancanneyt at wisa.be>:
>>>>>> No. You should use a TMultiReadExclusiveWriteSynchronizer object to
>>>>>> synchronize access to your object, or use a critical section.
>>>>> 
>>>>> Ehm, he made sure that only one thread accesses the TStringList at a
>>>>> time.
>>>> 
>>>> To me, this is not obvious from his mail ?
>>> 
>>> I thought it was obvious from:
>>> "The logic of the application itself made it sure that there was no
>>> conflict whatsoever. "
>>> 
>>> But maybe that was not not what Giuliano meant by "no conflict".
>> 
>> This is what was not clear to me...
>> 
>> If no conflict can mean 'it adds only', then there is a conflict at a lower
>> level, because adding can mean a reallocation of the array of strings.
>> 
> The full picture is:
> 1) The main thread creates the String List, and doesn't touch it any more.
> 2) The other thread is activated and it is the only one which appends strings 
> to the list.
> 3) When the other thread is terminated, the main thread processes the list.
>
> I would expect that whatever activity occurs as an effect of appending 
> strings (such as reallocating the array) would occur in the context of the 
> thread performing the action, that all pertinent information is stored in 
> fields of the object itself, and that the main thread is never involved.  Am 
> I wrong on this aspect?

No, you are right. If it is designed as described above, then it should
work.

Michael.