Support listing resource pool resources

knots/resource-pool.scm

@@ -567,6 +567,16 @@
                waiters
                resources-last-used))
 
+        (('list-resources reply)
+         (spawn-fiber
+          (lambda ()
+            (put-message reply (list-copy resources))))
+
+         (loop resources
+               available
+               waiters
+               resources-last-used))
+
         (('stats reply)
          (let ((stats
                 `((resources              . ,(length resources))
@@ -965,3 +975,8 @@ available.  Return the resource once PROC has returned."
           (raise-exception
            (make-resource-pool-timeout-error pool))))))
 
+(define (resource-pool-list-resources pool)
+  (let ((reply (make-channel)))
+    (put-message (resource-pool-channel pool)
+                 (list 'list-resources reply))
+    (get-message reply)))