Thread ID assertion in pystate.c failing under WASI

[brettcannon]

Bug report

Bug description:

The following assert fails under a debug build with WASI:

cpython/Python/pystate.c

Line 269 in a155f9f

assert(tstate->thread_id > 0);

It's probably due to the pthread stubs always returning 0 as the thread ID:

cpython/Python/thread_pthread_stubs.h

Lines 97 to 100 in a155f9f

	PyAPI_FUNC(pthread_t) pthread_self(void)
	{
	return 0;
	}

It can probably be solved by making the assertion conditional on `HAVE_PTHREAD_STUBS not being defined:

cpython/Include/cpython/pthread_stubs.h

Line 4 in a155f9f

#if !defined(HAVE_PTHREAD_STUBS)

CPython versions tested on:

CPython main branch

Operating systems tested on:

Other

Linked PRs

• GH-110455: Guard assert(tstate->thread_id > 0) with #ifndef HAVE_PTHREAD_STUBS #110487
• [3.12] GH-110455: Guard assert(tstate->thread_id > 0) with GH-ifndef HAVE_PTHREAD_STUBS (GH-110487) #110491

[brettcannon]

This fixes it:

diff --git a/Python/pystate.c b/Python/pystate.c
index dcc6c11221..f7042d0e21 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -270,7 +270,9 @@ unbind_tstate(PyThreadState *tstate)
     // XXX assert(tstate_is_alive(tstate));
     assert(tstate_is_bound(tstate));
     // XXX assert(!tstate->_status.active);
+#ifndef HAVE_PTHREAD_STUBS
     assert(tstate->thread_id > 0);
+#endif
 #ifdef PY_HAVE_THREAD_NATIVE_ID
     assert(tstate->native_thread_id > 0);
 #endif