MDEV-7962 wsrep_on() takes 0.14% in OLTP RO

The reason why we have wsrep_on() at all is that the macro WSREP(thd)
depends on the definition of THD, and that is intentionally an opaque
data type for InnoDB. So, we cannot avoid invoking wsrep_on(), but
we can evaluate the less expensive conditions thd && WSREP_ON before
calling the function.

Global_read_lock: Use WSREP_NNULL(thd) instead of wsrep_on(thd)
because we not only know the definition of THD but also that
the pointer is not null.

wsrep_open(): Use WSREP(thd) instead of wsrep_on(thd).

InnoDB: Replace thd && wsrep_on(thd) with wsrep_on(thd), now that
the condition has been merged to the definition of the macro
wsrep_on().

1 files changed, 9 insertions, 4 deletions

diff --git a/sql/lock.cc b/sql/lock.cc
index 94e0d2733c7..8b8dd6fbed1 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -1,5 +1,6 @@
 /*
    Copyright (c) 2000, 2011, Oracle and/or its affiliates.
+   Copyright (c) 2020, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1102,13 +1103,15 @@ void Global_read_lock::unlock_global_read_lock(THD *thd)
   {
     Wsrep_server_state& server_state= Wsrep_server_state::instance();
     if (server_state.state() == Wsrep_server_state::s_donor ||
-        (wsrep_on(thd) && server_state.state() != Wsrep_server_state::s_synced))
+        (WSREP_NNULL(thd) &&
+         server_state.state() != Wsrep_server_state::s_synced))
     {
       /* TODO: maybe redundant here?: */
       wsrep_locked_seqno= WSREP_SEQNO_UNDEFINED;
       server_state.resume();
     }
-    else if (wsrep_on(thd) && server_state.state() == Wsrep_server_state::s_synced)
+    else if (WSREP_NNULL(thd) &&
+             server_state.state() == Wsrep_server_state::s_synced)
     {
       server_state.resume_and_resync();
     }
@@ -1164,11 +1167,13 @@ bool Global_read_lock::make_global_read_lock_block_commit(THD *thd)
   Wsrep_server_state& server_state= Wsrep_server_state::instance();
   wsrep::seqno paused_seqno;
   if (server_state.state() == Wsrep_server_state::s_donor ||
-      (wsrep_on(thd) && server_state.state() != Wsrep_server_state::s_synced))
+      (WSREP_NNULL(thd) &&
+       server_state.state() != Wsrep_server_state::s_synced))
   {
     paused_seqno= server_state.pause();
   }
-  else if (wsrep_on(thd) && server_state.state() == Wsrep_server_state::s_synced)
+  else if (WSREP_NNULL(thd) &&
+           server_state.state() == Wsrep_server_state::s_synced)
   {
     paused_seqno= server_state.desync_and_pause();
   }