MDEV-23855: Shrink fil_space_t

Merge n_pending_ios, n_pending_ops to std::atomic<uint32_t> n_pending.
Change some more fil_space_t members to uint32_t to reduce
the memory footprint.

fil_space_t::add(), fil_ibd_create(): Attach the already opened
handle to the tablespace, and enforce the fil_system.n_open limit.

dict_boot(): Initialize fil_system.max_assigned_id.

srv_boot(): Call srv_thread_pool_init() before anything else,
so that files should be opened in the correct mode on Windows.

fil_ibd_create(): Create the file in OS_FILE_AIO mode, just like
fil_node_open_file_low() does it.

dict_table_t::is_accessible(): Replaces fil_table_accessible().

Reviewed by: Vladislav Vaintroub

1 files changed, 5 insertions, 5 deletions

diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index 39025862276..c05677b8810 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -3094,10 +3094,10 @@ xb_load_single_table_tablespace(
 
 		ut_a(space != NULL);
 
-		space->add(file->filepath(), OS_FILE_CLOSED, 0, false, false);
-		/* by opening the tablespace we forcing node and space objects
-		in the cache to be populated with fields from space header */
-		space->get_size();
+		space->add(file->filepath(), file->detach(), 0, false, false);
+		mutex_enter(&fil_system.mutex);
+		space->read_page0();
+		mutex_exit(&fil_system.mutex);
 
 		if (srv_operation == SRV_OPERATION_RESTORE_DELTA
 		    || xb_close_files) {
@@ -3402,7 +3402,7 @@ xb_load_tablespaces()
 /** Destroy the tablespace memory cache. */
 static void xb_data_files_close()
 {
-  fil_close_all_files();
+  fil_space_t::close_all();
   buf_dblwr.close();
 }