[fpc-devel] Suggestion: reference counted objects

Hans-Peter Diettrich DrDiettrich1 at aol.com
Sun Sep 21 07:22:51 CEST 2014

Boian Mitov schrieb:
> That is easy. it gets incremented when it gets assigned. The running 
> threads have no way of accessing it if there is no reference 
> (assignment) already in place.

The problem arises when an object is destroyed, or even elected for 
destruction in _Release, while another thread starts using the same 

> Indeed that is how it works in Delphi, and BTW: that is how Strings work 
> in Delphi and FPC the last time I checked ;-) .

With strings it's possible to create another (unique) copy, when a 
string is modified, and it does no harm when that copy is destroyed 
later - every user will find an valid (empty) string. Not so with 
objects, which cannot be copied nor reused after destruction.


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