New submission from Tom Lane <t...@sss.pgh.pa.us>:
Assorted code in the Python core supposes that the result of pthread_self() cannot be equal to PYTHREAD_INVALID_THREAD_ID, ie (void *) -1. If it is, you get a crash at interpreter startup. Unfortunately, this supposition is directly contrary to the POSIX specification for pthread_self(), which defines no failure return value; and it is violated by NetBSD's implementation in some circumstances. In particular, we (the Postgres project) are observing that libpython.so fails when dynamically loaded into a host executable that does not itself link libpthread. NetBSD's code always returns -1 if libpthread was not present at main program start, as they do not support forking new threads in that case. They assert (and I can't disagree) that their implementation conforms to POSIX. A lazy man's solution might be to change PYTHREAD_INVALID_THREAD_ID to some other value like -3, but that's not fixing the core problem that you're violating POSIX by testing for any specific value at all. Details and background info can be found in this email thread: https://www.postgresql.org/message-id/flat/25662.1560896200%40sss.pgh.pa.us ---------- components: Interpreter Core messages: 355723 nosy: tgl priority: normal severity: normal status: open title: Invalid check on the result of pthread_self() leads to libpython startup failure type: crash versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue38646> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
