Buddy pools: Add check for available allocations

src/buddy.c

@@ -2823,6 +2823,8 @@ t_pool_fill(struct buddy_reqs *reqs, const void *priv)
 
 // defines t_pool_s_get()
 BUDDY_POOL_GET_FUNC(t_pool_s, static)
+// defines t_pool_s_avail()
+BUDDY_POOL_AVAIL_FUNC(t_pool_s, static)
 
 /*
  * get allocations from a pool and return them
@@ -2847,6 +2849,7 @@ t_pool(void)
 
 	for (u = 0; u < 42; u++) {
 		reqs = t_pool_s_get(pool, NULL);
+		AN(t_pool_s_avail(pool));
 		alloc = buddy_get_next_ptr_page(reqs);
 		assert(alloc.ptr > 0);
 		do {

src/buddy.h

@@ -626,6 +626,23 @@ name ## _get(struct name *poolp, const void *priv)		\
 	WRONG("Expected second return() to be hit");		\
 }
 
+// return available allocations, does not block
+#define BUDDY_POOL_AVAIL_FUNC(name, decl)			\
+decl unsigned							\
+name ## _avail(struct name *poolp)				\
+{								\
+	struct buddy_reqs *reqs;				\
+	unsigned u, avail = 0;					\
+								\
+	CHECK_OBJ_NOTNULL(poolp, BUDDY_POOL_MAGIC);		\
+	for (u = 0; u < 2; u++) {				\
+		reqs = &((poolp)->reqs[u].reqs);		\
+		CHECK_OBJ_NOTNULL(reqs, BUDDY_REQS_MAGIC);	\
+		avail += buddy_reqs_next_ready(reqs);		\
+	}							\
+	return (avail);						\
+}
+
 #define BUDDY_POOL_INIT(poolp, b, f, p) do {				\
 	INIT_OBJ(poolp, BUDDY_POOL_MAGIC);				\
 	poolp->fill = f;						\