remove connection reference in gc

Author: DifferentialOrange

mysql/init.lua

@@ -30,13 +30,13 @@ end
 -- channel put is immediate or pool is doomed.
 local CONN_GC_HOOK_TIMEOUT = 0
 
-local function conn_gc_hook(pool, conn)
+local function conn_gc_hook(pool, conn_id)
     local success = pool.queue:put(POOL_EMPTY_SLOT, CONN_GC_HOOK_TIMEOUT)
     if not success then
         log.error('mysql pool %s internal queue unexpected state: there are no ' ..
                   'empty slots, connection %s cannot be put back. It is likely ' ..
                   'that someone had messed with pool.queue manually. Closing ' ..
-                  'the pool...', pool, conn)
+                  'the pool...', pool, conn_id)
         log.error(debug.traceback)
 
         pool:close()
@@ -62,6 +62,7 @@ local function conn_get(pool, timeout)
     end
 
     local conn = conn_create(mysql_conn)
+    local conn_id = tostring(conn)
     -- we can use ffi gc to return mysql connection to pool
     conn.__gc_hook = ffi.gc(ffi.new('void *'),
             function(self)
@@ -71,7 +72,7 @@ local function conn_get(pool, timeout)
                 -- * 2.5.1-105-gc690b3337
                 -- * 2.4.2-89-g83037df15
                 -- * 1.10.7-47-g8099cb053
-                fiber.new(conn_gc_hook, pool, conn)
+                fiber.new(conn_gc_hook, pool, conn_id)
             end)
     -- If the connection belongs to a connection pool, it must be returned to
     -- the pool when calling "close" without actually closing the connection.