analyzer fix

src/gc.c

@@ -2542,18 +2542,20 @@ void gc_drain_all_queues(jl_ptls_t ptls, jl_gc_markqueue_t *mq) JL_NOTSAFEPOINT
     }
 }
 
-void gc_mark_entry_seq(jl_ptls_t ptls)
+int8_t gc_mark_entry_seq(jl_ptls_t ptls) JL_NOTSAFEPOINT
 {
+    uint8_t state0 = jl_atomic_load_relaxed(&ptls->gc_state);
     if (jl_options.parallel_marking) {
         jl_atomic_fetch_add(&nworkers_marking, 1);
-        jl_atomic_exchange(&ptls->gc_state, JL_GC_STATE_PARALLEL);
+        state0 = jl_atomic_exchange(&ptls->gc_state, JL_GC_STATE_PARALLEL);
     }
+    return state0;
 }
 
-void gc_mark_exit_seq(jl_ptls_t ptls)
+void gc_mark_exit_seq(jl_ptls_t ptls, int8_t state0) JL_NOTSAFEPOINT
 {
     if (jl_options.parallel_marking) {
-        jl_atomic_store_release(&ptls->gc_state, JL_GC_STATE_WAITING);
+        jl_atomic_store_release(&ptls->gc_state, state0);
         jl_atomic_fetch_add(&nworkers_marking, -1);
     }
 }
@@ -2564,22 +2566,22 @@ void gc_mark_exit_seq(jl_ptls_t ptls)
 // makes it easier to implement parallel marking via work-stealing
 void gc_mark_loop(jl_ptls_t ptls)
 {
-    gc_mark_entry_seq(ptls);
+    int8_t state0 = gc_mark_entry_seq(ptls);
     gc_mark_loop_(ptls, &ptls->mark_queue);
     gc_drain_own_chunkqueue(ptls, &ptls->mark_queue);
     gc_drain_all_queues(ptls, &ptls->mark_queue);
-    gc_mark_exit_seq(ptls);
+    gc_mark_exit_seq(ptls, state0);
 }
 
 // Mark-loop wrapper. Call workers for parallel marking and mark
 STATIC_INLINE void gc_mark_loop_master(jl_ptls_t ptls)
 {
-    gc_mark_entry_seq(ptls);
+    int8_t state0 = gc_mark_entry_seq(ptls);
     gc_wake_workers(ptls);
     gc_mark_loop_(ptls, &ptls->mark_queue);
     gc_drain_own_chunkqueue(ptls, &ptls->mark_queue);
     gc_drain_all_queues(ptls, &ptls->mark_queue);
-    gc_mark_exit_seq(ptls);
+    gc_mark_exit_seq(ptls, state0);
 }
 
 static void gc_premark(jl_ptls_t ptls2)