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Postings from May 2003
It seems a bunch of globals that are neither constants nor mutexes-that-protect-truly-global-state have snuck into perlvars.h. This breaks concurrency safety pretty badly, so they need to get moved into intrpvars.h. If any of these variables need to point to common memory, that needs to be done through a well-defined protocol (i.e. a set of API functions that can be called on the interpreter that needs its state changed). Take the case of PL_threadhook, for instance. If there are multiple interpreters within the application (could be as simple as the examples from perlembed.pod) and one of these interpreters does a "use threads" which sets PL_threadhook, it affects all the other interpreters that may be executing in different threads at a random spot in their lifetime. If the first interpreter is then destroyed, it unloads threads.so, and now PL_threadhook is pointing at invalid memory and at that point trying to destroy the other interpreters will provoke a coredump. Sarathy gsar@ActiveState.comThread Next