diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/pystate.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/Python/pystate.c b/Python/pystate.c index 642d680..a11f162 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -810,7 +810,15 @@ new_threadstate(PyInterpreterState *interp) { PyThreadState *tstate; _PyRuntimeState *runtime = interp->runtime; - + // We don't need to allocate a thread state for the main interpreter + // (the common case), but doing it later for the other case revealed a + // reentrancy problem (deadlock). So for now we always allocate before + // taking the interpreters lock. See GH-96071. + PyThreadState *new_tstate = alloc_threadstate(); + int used_newtstate; + if (new_tstate == NULL) { + return NULL; + } /* We serialize concurrent creation to protect global state. */ HEAD_LOCK(runtime); @@ -822,18 +830,15 @@ new_threadstate(PyInterpreterState *interp) if (old_head == NULL) { // It's the interpreter's initial thread state. assert(id == 1); - + used_newtstate = 0; tstate = &interp->_initial_thread; } else { // Every valid interpreter must have at least one thread. assert(id > 1); assert(old_head->prev == NULL); - - tstate = alloc_threadstate(); - if (tstate == NULL) { - goto error; - } + used_newtstate = 1; + tstate = new_tstate; // Set to _PyThreadState_INIT. memcpy(tstate, &initial._main_interpreter._initial_thread, @@ -844,11 +849,11 @@ new_threadstate(PyInterpreterState *interp) init_threadstate(tstate, interp, id, old_head); HEAD_UNLOCK(runtime); + if (!used_newtstate) { + // Must be called with lock unlocked to avoid re-entrancy deadlock. + PyMem_RawFree(new_tstate); + } return tstate; - -error: - HEAD_UNLOCK(runtime); - return NULL; } PyThreadState * |