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Why did dlclose not unload the library? (2023)

(kishoreganesh.com)
39 points mattrighetti | 1 comments | 27 Aug 25 00:45 UTC | HN request time: 0.218s | source
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sgbeal ◴[30 Aug 25 13:34 UTC] No.45074556[source]▶
There is no safe, reliable, cross-environment way to deal with closing a DLL. A DLL initialization function can allocate arbitrary resources, some of which may be in use by clients of the DLL when it is closed.

The only safe, consistent, reliable approach is not to close DLLs.

replies(6): >>45074649 #>>45074720 #>>45075478 #>>45075558 #>>45075726 #>>45080214 #
1. kazinator ◴[31 Aug 25 03:48 UTC] No.45080214[source]▶
The DLL consists of code and static data. If nothing needs the code or the static data, it can be blown away. If that library allocated something which it is responsible for freeing, but that something still exists even though that library's very code is no longer referenced (nobody will call into it), it almost certainly means there is a memory leak.

A memory leak caused by a library isn't necessarily something that should prevent it from being unloaded. Unless it is the leaked objects that are holding a reference! (Then we need a full blown GC system to detect cycles.)