Allow mutexes to take a lock ordering enum at construction.

This lets us specify whether and how mutexes of the same rank are allowed to be
acquired.  Currently, we only allow two polices (only a single mutex at a given
rank at a time, and mutexes acquired in ascending order), but we can plausibly
allow more (e.g. the "release uncontended mutexes before blocking").

1 files changed, 2 insertions, 1 deletions

diff --git a/src/base.c b/src/base.c
index 3de6e3b..7502a65 100644
--- a/src/base.c
+++ b/src/base.c
@@ -238,7 +238,8 @@ base_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) {
 	    &gap_size, base_size, base_alignment);
 	base->ind = ind;
 	atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELAXED);
-	if (malloc_mutex_init(&base->mtx, "base", WITNESS_RANK_BASE)) {
+	if (malloc_mutex_init(&base->mtx, "base", WITNESS_RANK_BASE,
+	    malloc_mutex_rank_exclusive)) {
 		base_unmap(extent_hooks, ind, block, block->size);
 		return NULL;
 	}