more predicatable slave behaviour with wait_for_slave_stop in mysqltest

fixed a couple of bugs with SEQ_READ_APPEND cache
rpl000016 still has non-deterministic result, but I am going to commit and
push since what I have is now better than what is in the main repository


client/mysqltest.c:
  added wait_for_slave_to_stop
  cleaned up TODO and comments
include/my_sys.h:
  fixed race in flush_io_cache in SEQ_READ_APPEND cache
mysql-test/r/rpl000016.result:
  updated result
mysql-test/t/rpl000016.test:
  use wait_for_slave_to_stop to have deterministic slave behaviour for the test
mysys/mf_iocache.c:
  fixed race in flush_io_cache()
  fixed failure to unlock mutex in my_b_append()
sql/log.cc:
  be compatible with 3.23 master
sql/log_event.cc:
  3.23 master compat
sql/slave.cc:
  3.23 master compat
sql/sql_class.h:
  compat with 3.23 master

1 files changed, 4 insertions, 1 deletions

diff --git a/include/my_sys.h b/include/my_sys.h
index f899e4f9324..1d7c0b7ddb1 100644
--- a/include/my_sys.h
+++ b/include/my_sys.h
@@ -643,7 +643,10 @@ extern int _my_b_write(IO_CACHE *info,const byte *Buffer,uint Count);
 extern int my_b_append(IO_CACHE *info,const byte *Buffer,uint Count);
 extern int my_block_write(IO_CACHE *info, const byte *Buffer,
 			  uint Count, my_off_t pos);
-extern int flush_io_cache(IO_CACHE *info);
+extern int _flush_io_cache(IO_CACHE *info, int need_append_buffer_lock);
+
+#define flush_io_cache(info) _flush_io_cache((info),1)
+
 extern int end_io_cache(IO_CACHE *info);
 extern uint my_b_fill(IO_CACHE *info);
 extern void my_b_seek(IO_CACHE *info,my_off_t pos);