diff options
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2020-03-02-20-12-33.bpo-39776.fNaxi_.rst | 6 | ||||
| -rw-r--r-- | Python/pystate.c | 3 |
2 files changed, 7 insertions, 2 deletions
diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-03-02-20-12-33.bpo-39776.fNaxi_.rst b/Misc/NEWS.d/next/Core and Builtins/2020-03-02-20-12-33.bpo-39776.fNaxi_.rst new file mode 100644 index 0000000..e5a00bd --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-03-02-20-12-33.bpo-39776.fNaxi_.rst @@ -0,0 +1,6 @@ +Fix race condition where threads created by PyGILState_Ensure() could get a +duplicate id. + +This affects consumers of tstate->id like the contextvar caching machinery, +which could return invalid cached objects under heavy thread load (observed +in embedded scenarios). diff --git a/Python/pystate.c b/Python/pystate.c index ebc17ea..4001c63 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -606,13 +606,12 @@ new_threadstate(PyInterpreterState *interp, int init) tstate->context = NULL; tstate->context_ver = 1; - tstate->id = ++interp->tstate_next_unique_id; - if (init) { _PyThreadState_Init(tstate); } HEAD_LOCK(runtime); + tstate->id = ++interp->tstate_next_unique_id; tstate->prev = NULL; tstate->next = interp->tstate_head; if (tstate->next) |