free more thread state in jl_delete_thread and GC

Author: JeffBezanson

src/gc-stacks.c

@@ -223,6 +223,9 @@ void sweep_stack_pools(void)
                 void *stk = small_arraylist_pop(al);
                 free_stack(stk, pool_sizes[p]);
             }
+            if (jl_atomic_load_relaxed(&ptls2->current_task) == NULL) {
+                small_arraylist_free(al);
+            }
         }
 
         small_arraylist_t *live_tasks = &ptls2->heap.live_tasks;

src/gc.c

@@ -3499,6 +3499,22 @@ static int _jl_gc_collect(jl_ptls_t ptls, jl_gc_collection_t collection)
         else {
             ptls2->heap.remset->len = 0;
         }
+        // free empty GC state for threads that have exited
+        if (ptls2->current_task == NULL) {
+            jl_thread_heap_t *heap = &ptls2->heap;
+            if (heap->weak_refs.len == 0)
+                small_arraylist_free(&heap->weak_refs);
+            if (heap->live_tasks.len == 0)
+                small_arraylist_free(&heap->live_tasks);
+            if (heap->remset->len == 0)
+                arraylist_free(heap->remset);
+            if (heap->last_remset->len == 0)
+                arraylist_free(heap->last_remset);
+            if (ptls2->finalizers.len == 0)
+                arraylist_free(&ptls->finalizers);
+            if (ptls2->sweep_objs.len == 0)
+                arraylist_free(&ptls->sweep_objs);
+        }
     }
 
 #ifdef __GLIBC__
@@ -3708,6 +3724,18 @@ void jl_init_thread_heap(jl_ptls_t ptls)
     jl_atomic_store_relaxed(&ptls->gc_num.allocd, -(int64_t)gc_num.interval);
 }
 
+void jl_free_thread_gc_state(jl_ptls_t ptls)
+{
+    jl_gc_markqueue_t *mq = &ptls->mark_queue;
+    ws_queue_t *cq = &mq->chunk_queue;
+    free_ws_array(jl_atomic_load_relaxed(&cq->array));
+    jl_atomic_store_relaxed(&cq->array, NULL);
+    ws_queue_t *q = &mq->ptr_queue;
+    free_ws_array(jl_atomic_load_relaxed(&q->array));
+    jl_atomic_store_relaxed(&q->array, NULL);
+    arraylist_free(&mq->reclaim_set);
+}
+
 // System-wide initializations
 void jl_gc_init(void)
 {

src/threading.c

@@ -510,6 +510,11 @@ static void jl_delete_thread(void *value) JL_NOTSAFEPOINT_ENTER
 #else
     pthread_mutex_unlock(&in_signal_lock);
 #endif
+    free(ptls->bt_data);
+    // allow the page root_task is on to be freed
+    ptls->root_task = NULL;
+    void jl_free_thread_gc_state(jl_ptls_t ptls);
+    jl_free_thread_gc_state(ptls);
     // then park in safe-region
     (void)jl_gc_safe_enter(ptls);
 }

src/work-stealing-queue.h

@@ -34,6 +34,12 @@ static inline ws_array_t *create_ws_array(size_t capacity, int32_t eltsz) JL_NOT
     return a;
 }
 
+static inline void free_ws_array(ws_array_t *a)
+{
+    free(a->buffer);
+    free(a);
+}
+
 typedef struct {
     _Atomic(int64_t) top;
     _Atomic(int64_t) bottom;