Revert "pythongh-117657: TSAN fix race on gstate->young.count (pyth…

…on#118313)"

This reverts commit 2ba1aed.

Python/gc_free_threading.c

@@ -1090,20 +1090,9 @@ record_deallocation(PyThreadState *tstate)
 }
 
 static void
-gc_collect_internal(PyInterpreterState *interp, struct collection_state *state, int generation)
+gc_collect_internal(PyInterpreterState *interp, struct collection_state *state)
 {
     _PyEval_StopTheWorld(interp);
-
-    // update collection and allocation counters
-    if (generation+1 < NUM_GENERATIONS) {
-        state->gcstate->old[generation].count += 1;
-    }
-
-    state->gcstate->young.count = 0;
-    for (int i = 1; i <= generation; ++i) {
-        state->gcstate->old[i-1].count = 0;
-    }
-
     // merge refcounts for all queued objects
     merge_all_queued_objects(interp, state);
     process_delayed_frees(interp);
@@ -1169,6 +1158,7 @@ gc_collect_internal(PyInterpreterState *interp, struct collection_state *state,
 static Py_ssize_t
 gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
 {
+    int i;
     Py_ssize_t m = 0; /* # objects collected */
     Py_ssize_t n = 0; /* # unreachable objects that couldn't be collected */
     PyTime_t t1 = 0;   /* initialize to prevent a compiler warning */
@@ -1215,14 +1205,23 @@ gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
         PyDTrace_GC_START(generation);
     }
 
+    /* update collection and allocation counters */
+    if (generation+1 < NUM_GENERATIONS) {
+        gcstate->old[generation].count += 1;
+    }
+    gcstate->young.count = 0;
+    for (i = 1; i <= generation; i++) {
+        gcstate->old[i-1].count = 0;
+    }
+
     PyInterpreterState *interp = tstate->interp;
 
     struct collection_state state = {
         .interp = interp,
         .gcstate = gcstate,
     };
 
-    gc_collect_internal(interp, &state, generation);
+    gc_collect_internal(interp, &state);
 
     m = state.collected;
     n = state.uncollectable;