Hi,
Le ven. 1 mars 2019 à 02:12, Neil Schemenauer <nas-pyt...@arctrix.com> a écrit :
> I believe the correct fix is to use PEP 3121 per-interpreter module
> state. I created a new issue:
>
> https://github.com/psycopg/psycopg2/issues/854
>
> I think the fix is not trival as the psycopgmodule.c source code has
> change a fair bit to use the PEP 3121 APIs.
The problem is this function:
/* Return nonzero if the current one is the main interpreter */
static int
psyco_is_main_interp(void)
{
static PyInterpreterState *main_interp = NULL; /* Cached reference */
PyInterpreterState *interp;
if (main_interp) {
return (main_interp == PyThreadState_Get()->interp);
}
/* No cached value: cache the proper value and try again. */
interp = PyInterpreterState_Head();
while (interp->next)
interp = interp->next;
main_interp = interp;
assert (main_interp);
return psyco_is_main_interp();
}
https://github.com/psycopg/psycopg2/blob/599432552aae4941c2b282e9251330f1357b2a45/psycopg/utils.c#L407
I'm not sure that this code is safe. In CPython, iterating on
interp->next is protected by a lock:
HEAD_LOCK();
...
HEAD_UNLOCK();
We already expose the main interpreter since Python 3.7:
PyInterpreterState_Main(). psycopg can be modified to use directly
this function rather than playing black magic with CPython internals.
IMHO it's a good thing that the compilation failed: that such bug is found :-)
Victor
--
Night gathers, and now my watch begins. It shall not end until my death.
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