Make base_t's extent_hooks field C11-atomic

2 files changed, 9 insertions, 15 deletions

diff --git a/include/jemalloc/internal/base_structs.h b/include/jemalloc/internal/base_structs.h
index bad37c0..13d5bd4 100644
--- a/include/jemalloc/internal/base_structs.h
+++ b/include/jemalloc/internal/base_structs.h
@@ -17,11 +17,11 @@ struct base_s {
 	/* Associated arena's index within the arenas array. */
 	unsigned	ind;
 
-	/* User-configurable extent hook functions. */
-	union {
-		extent_hooks_t	*extent_hooks;
-		void		*extent_hooks_pun;
-	};
+	/*
+	 * User-configurable extent hook functions.  Points to an
+	 * extent_hooks_t.
+	 */
+	atomic_p_t extent_hooks;
 
 	/* Protects base_alloc() and base_stats_get() operations. */
 	malloc_mutex_t	mtx;
diff --git a/src/base.c b/src/base.c
index b1a4ae3..4275259 100644
--- a/src/base.c
+++ b/src/base.c
@@ -227,7 +227,7 @@ base_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) {
 	base = (base_t *)base_extent_bump_alloc_helper(&block->extent,
 	    &gap_size, base_size, base_alignment);
 	base->ind = ind;
-	base->extent_hooks = extent_hooks;
+	atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELAXED);
 	if (malloc_mutex_init(&base->mtx, "base", WITNESS_RANK_BASE)) {
 		base_unmap(extent_hooks, ind, block, block->size);
 		return NULL;
@@ -264,20 +264,14 @@ base_delete(base_t *base) {
 
 extent_hooks_t *
 base_extent_hooks_get(base_t *base) {
-	return (extent_hooks_t *)atomic_read_p(&base->extent_hooks_pun);
+	return (extent_hooks_t *)atomic_load_p(&base->extent_hooks,
+	    ATOMIC_ACQUIRE);
 }
 
 extent_hooks_t *
 base_extent_hooks_set(base_t *base, extent_hooks_t *extent_hooks) {
 	extent_hooks_t *old_extent_hooks = base_extent_hooks_get(base);
-	union {
-		extent_hooks_t	**h;
-		void		**v;
-	} u;
-
-	u.h = &base->extent_hooks;
-	atomic_write_p(u.v, extent_hooks);
-
+	atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELEASE);
 	return old_extent_hooks;
 }