edata_cache: Remember the associated base_t.

This will save us some trouble down the line when we stop passing arena pointers
everywhere; we won't have to pass around a base_t pointer either.

include/jemalloc/internal/edata_cache.h

@@ -12,12 +12,13 @@ struct edata_cache_s {
 	edata_tree_t avail;
 	atomic_zu_t count;
 	malloc_mutex_t mtx;
+	base_t *base;
 };
 
-bool edata_cache_init(edata_cache_t *edata_cache);
-edata_t *edata_cache_get(tsdn_t *tsdn, edata_cache_t *edata_cache,
-    base_t *base);
+bool edata_cache_init(edata_cache_t *edata_cache, base_t *base);
+edata_t *edata_cache_get(tsdn_t *tsdn, edata_cache_t *edata_cache);
 void edata_cache_put(tsdn_t *tsdn, edata_cache_t *edata_cache, edata_t *edata);
+
 void edata_cache_prefork(tsdn_t *tsdn, edata_cache_t *edata_cache);
 void edata_cache_postfork_parent(tsdn_t *tsdn, edata_cache_t *edata_cache);
 void edata_cache_postfork_child(tsdn_t *tsdn, edata_cache_t *edata_cache);

src/arena.c

@@ -2052,7 +2052,7 @@ arena_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) {
 		goto label_error;
 	}
 
-	if (edata_cache_init(&arena->edata_cache)) {
+	if (edata_cache_init(&arena->edata_cache, base)) {
 		goto label_error;
 	}
 

src/edata_cache.c

@@ -2,23 +2,29 @@
 #include "jemalloc/internal/jemalloc_internal_includes.h"
 
 bool
-edata_cache_init(edata_cache_t *edata_cache) {
+edata_cache_init(edata_cache_t *edata_cache, base_t *base) {
+	edata_avail_new(&edata_cache->avail);
+	/*
+	 * This is not strictly necessary, since the edata_cache_t is only
+	 * created inside an arena, which is zeroed on creation.  But this is
+	 * handy as a safety measure.
+	 */
+	atomic_store_zu(&edata_cache->count, 0, ATOMIC_RELAXED);
 	if (malloc_mutex_init(&edata_cache->mtx, "edata_cache",
 	    WITNESS_RANK_EDATA_CACHE, malloc_mutex_rank_exclusive)) {
 		return true;
 	}
-
-	edata_avail_new(&edata_cache->avail);
+	edata_cache->base = base;
 	return false;
 }
 
 edata_t *
-edata_cache_get(tsdn_t *tsdn, edata_cache_t *edata_cache, base_t *base) {
+edata_cache_get(tsdn_t *tsdn, edata_cache_t *edata_cache) {
 	malloc_mutex_lock(tsdn, &edata_cache->mtx);
 	edata_t *edata = edata_avail_first(&edata_cache->avail);
 	if (edata == NULL) {
 		malloc_mutex_unlock(tsdn, &edata_cache->mtx);
-		return base_alloc_edata(tsdn, base);
+		return base_alloc_edata(tsdn, edata_cache->base);
 	}
 	edata_avail_remove(&edata_cache->avail, edata);
 	atomic_fetch_sub_zu(&edata_cache->count, 1, ATOMIC_RELAXED);

src/extent2.c

@@ -869,8 +869,7 @@ extent_grow_retained(tsdn_t *tsdn, arena_t *arena, ehooks_t *ehooks,
 		alloc_size = sz_pind2sz(arena->ecache_grow.next + egn_skip);
 	}
 
-	edata_t *edata = edata_cache_get(tsdn, &arena->edata_cache,
-	    arena->base);
+	edata_t *edata = edata_cache_get(tsdn, &arena->edata_cache);
 	if (edata == NULL) {
 		goto label_err;
 	}
@@ -1036,8 +1035,7 @@ extent_alloc_wrapper(tsdn_t *tsdn, arena_t *arena, ehooks_t *ehooks,
 	    WITNESS_RANK_CORE, 0);
 
 	size_t esize = size + pad;
-	edata_t *edata = edata_cache_get(tsdn, &arena->edata_cache,
-	    arena->base);
+	edata_t *edata = edata_cache_get(tsdn, &arena->edata_cache);
 	if (edata == NULL) {
 		return NULL;
 	}
@@ -1430,8 +1428,7 @@ extent_split_impl(tsdn_t *tsdn, arena_t *arena, ehooks_t *ehooks,
 		return NULL;
 	}
 
-	edata_t *trail = edata_cache_get(tsdn, &arena->edata_cache,
-	    arena->base);
+	edata_t *trail = edata_cache_get(tsdn, &arena->edata_cache);
 	if (trail == NULL) {
 		goto label_error_a;
 	}

src/extent_dss.c

@@ -123,7 +123,7 @@ extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size,
 		return NULL;
 	}
 
-	gap = edata_cache_get(tsdn, &arena->edata_cache, arena->base);
+	gap = edata_cache_get(tsdn, &arena->edata_cache);
 	if (gap == NULL) {
 		return NULL;
 	}