Modify extent hook functions to take an (extent_t *) argument.

This facilitates the application accessing its own extent allocator
metadata during hook invocations.

This resolves #259.

include/jemalloc/internal/arena.h

@@ -240,11 +240,15 @@ struct arena_s {
 	 */
 	extent_heap_t		extents_cached[NPSIZES];
 	extent_heap_t		extents_retained[NPSIZES];
-	/* User-configurable extent hook functions. */
-	extent_hooks_t		extent_hooks;
-	/* Protects extents_cached, extents_retained, and extent_hooks. */
+	/* Protects extents_cached and extents_retained. */
 	malloc_mutex_t		extents_mtx;
 
+	/* User-configurable extent hook functions. */
+	union {
+		extent_hooks_t		*extent_hooks;
+		void			*extent_hooks_pun;
+	};
+
 	/* Cache of extent structures that were allocated via base_alloc(). */
 	ql_head(extent_t)	extent_cache;
 	malloc_mutex_t		extent_cache_mtx;
@@ -279,10 +283,10 @@ extern ssize_t		opt_decay_time;
 extern const arena_bin_info_t	arena_bin_info[NBINS];
 
 extent_t	*arena_extent_cache_alloc(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, void *new_addr, size_t size, size_t alignment,
-    bool *zero);
+    extent_hooks_t **r_extent_hooks, void *new_addr, size_t size,
+    size_t alignment, bool *zero);
 void	arena_extent_cache_dalloc(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent);
+    extent_hooks_t **r_extent_hooks, extent_t *extent);
 void	arena_extent_cache_maybe_insert(arena_t *arena, extent_t *extent,
     bool cache);
 void	arena_extent_cache_maybe_remove(arena_t *arena, extent_t *extent,

include/jemalloc/internal/extent.h

@@ -3,15 +3,7 @@
 
 typedef struct extent_s extent_t;
 
-#define	EXTENT_HOOKS_INITIALIZER {					\
-    NULL,								\
-    NULL,								\
-    NULL,								\
-    NULL,								\
-    NULL,								\
-    NULL,								\
-    NULL								\
-}
+#define	EXTENT_HOOKS_INITIALIZER	NULL
 
 #endif /* JEMALLOC_H_TYPES */
 /******************************************************************************/
@@ -93,9 +85,8 @@ extern const extent_hooks_t	extent_hooks_default;
 extent_t	*extent_alloc(tsdn_t *tsdn, arena_t *arena);
 void	extent_dalloc(tsdn_t *tsdn, arena_t *arena, extent_t *extent);
 
-extent_hooks_t	extent_hooks_get(tsdn_t *tsdn, arena_t *arena);
-extent_hooks_t	extent_hooks_set(tsdn_t *tsdn, arena_t *arena,
-    const extent_hooks_t *extent_hooks);
+extent_hooks_t	*extent_hooks_get(arena_t *arena);
+extent_hooks_t	*extent_hooks_set(arena_t *arena, extent_hooks_t *extent_hooks);
 
 #ifdef JEMALLOC_JET
 typedef size_t (extent_size_quantize_t)(size_t);
@@ -109,29 +100,29 @@ size_t	extent_size_quantize_ceil(size_t size);
 ph_proto(, extent_heap_, extent_heap_t, extent_t)
 
 extent_t	*extent_alloc_cache(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, void *new_addr, size_t usize, size_t pad,
+    extent_hooks_t **r_extent_hooks, void *new_addr, size_t usize, size_t pad,
     size_t alignment, bool *zero, bool slab);
 extent_t	*extent_alloc_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, void *new_addr, size_t usize, size_t pad,
+    extent_hooks_t **r_extent_hooks, void *new_addr, size_t usize, size_t pad,
     size_t alignment, bool *zero, bool *commit, bool slab);
 void	extent_dalloc_cache(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent);
+    extent_hooks_t **r_extent_hooks, extent_t *extent);
 void	extent_dalloc_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent);
+    extent_hooks_t **r_extent_hooks, extent_t *extent);
 bool	extent_commit_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent, size_t offset,
+    extent_hooks_t **r_extent_hooks, extent_t *extent, size_t offset,
     size_t length);
 bool	extent_decommit_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent, size_t offset,
+    extent_hooks_t **r_extent_hooks, extent_t *extent, size_t offset,
     size_t length);
 bool	extent_purge_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent, size_t offset,
+    extent_hooks_t **r_extent_hooks, extent_t *extent, size_t offset,
     size_t length);
 extent_t	*extent_split_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *extent, size_t size_a,
+    extent_hooks_t **r_extent_hooks, extent_t *extent, size_t size_a,
     size_t usize_a, size_t size_b, size_t usize_b);
 bool	extent_merge_wrapper(tsdn_t *tsdn, arena_t *arena,
-    extent_hooks_t *extent_hooks, extent_t *a, extent_t *b);
+    extent_hooks_t **r_extent_hooks, extent_t *a, extent_t *b);
 void	extent_prefork(tsdn_t *tsdn);
 void	extent_postfork_parent(tsdn_t *tsdn);
 void	extent_postfork_child(tsdn_t *tsdn);

include/jemalloc/jemalloc_typedefs.h.in

@@ -1,53 +1,61 @@
+typedef struct extent_hooks_s extent_hooks_t;
+
 /*
  * void *
  * extent_alloc(void *new_addr, size_t size, size_t alignment, bool *zero,
  *     bool *commit, unsigned arena_ind);
  */
-typedef void *(extent_alloc_t)(void *, size_t, size_t, bool *, bool *,
-    unsigned);
+typedef void *(extent_alloc_t)(extent_hooks_t *, void *, size_t, size_t, bool *,
+    bool *, unsigned);
 
 /*
  * bool
  * extent_dalloc(void *addr, size_t size, bool committed, unsigned arena_ind);
  */
-typedef bool (extent_dalloc_t)(void *, size_t, bool, unsigned);
+typedef bool (extent_dalloc_t)(extent_hooks_t *, void *, size_t, bool,
+    unsigned);
 
 /*
  * bool
  * extent_commit(void *addr, size_t size, size_t offset, size_t length,
  *     unsigned arena_ind);
  */
-typedef bool (extent_commit_t)(void *, size_t, size_t, size_t, unsigned);
+typedef bool (extent_commit_t)(extent_hooks_t *, void *, size_t, size_t, size_t,
+    unsigned);
 
 /*
  * bool
  * extent_decommit(void *addr, size_t size, size_t offset, size_t length,
  *     unsigned arena_ind);
  */
-typedef bool (extent_decommit_t)(void *, size_t, size_t, size_t, unsigned);
+typedef bool (extent_decommit_t)(extent_hooks_t *, void *, size_t, size_t,
+    size_t, unsigned);
 
 /*
  * bool
  * extent_purge(void *addr, size_t size, size_t offset, size_t length,
  *     unsigned arena_ind);
  */
-typedef bool (extent_purge_t)(void *, size_t, size_t, size_t, unsigned);
+typedef bool (extent_purge_t)(extent_hooks_t *, void *, size_t, size_t, size_t,
+    unsigned);
 
 /*
  * bool
  * extent_split(void *addr, size_t size, size_t size_a, size_t size_b,
  *     bool committed, unsigned arena_ind);
  */
-typedef bool (extent_split_t)(void *, size_t, size_t, size_t, bool, unsigned);
+typedef bool (extent_split_t)(extent_hooks_t *, void *, size_t, size_t, size_t,
+    bool, unsigned);
 
 /*
  * bool
  * extent_merge(void *addr_a, size_t size_a, void *addr_b, size_t size_b,
  *     bool committed, unsigned arena_ind);
  */
-typedef bool (extent_merge_t)(void *, size_t, void *, size_t, bool, unsigned);
+typedef bool (extent_merge_t)(extent_hooks_t *, void *, size_t, void *, size_t,
+    bool, unsigned);
 
-typedef struct {
+struct extent_hooks_s {
 	extent_alloc_t		*alloc;
 	extent_dalloc_t		*dalloc;
 	extent_commit_t		*commit;
@@ -55,4 +63,4 @@ typedef struct {
 	extent_purge_t		*purge;
 	extent_split_t		*split;
 	extent_merge_t		*merge;
-} extent_hooks_t;
+};