Johannes Sixt wrote: > On Wednesday 07 March 2007 19:25, Christian Thaeter wrote: >>> Remove the Garbage collector in favor of boost::shared_ptr, the GC has >>> some nasty bugs, partially together with threads. By replacing ALL >>> Asset* with boost::shared_ptr<Asset> these should be fixed on expanse of >>> some performance. > > Is boost::shared_ptr thread safe? If not, this replacement does not fix > anything, in particular not the thread related bugs.
http://www.boost.org/libs/smart_ptr/shared_ptr.htm#ThreadSafety so its not fully, but it employs the locking which already exists. The only problem could be when the internal use-count drops to zero and the thread prepares to delete a object, if then a context switch occurs and another thread increments the use count to 1 we have a problem. But this case is avoided because ALL pointers are shared pointers now. This costs little performance but guards against that case. I have Cinelerra running under valgrind for hours here now, loading some hundred assets and valgrind didnt report a single error with asset handling, thats at least far better than before :). Even if there is some corner case left where thread safety play against us, it's now possible to replace the shared_ptr easily with something else. But as long I don't observe such glitches I concentrate on improving a debugging frameworks which aids in finding race conditions, deadlocks and unspecified ownership of objects. The shared_ptr transistion is only a prelimary step, somewhat better than a bandaid to fix some bugs, later to be optimized mostly out again. Christian _______________________________________________ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
