I expect it is because on most systems, some of the C libraries are not re-entrant; particularly, memory allocation and I/O routines. This sounds like the same issue with signal handlers not being re-entrant covered in perlipc. The problems will likely manifest as core dumps.

NB: A re-entrant (thread safe) library protects its internal data structures from corruption due to the potential for simultaneous access.

cheers

tachyon

In reply to Re: perlembed: perl_run twice? by tachyon
in thread perlembed: perl_run twice? by BUU

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