Clean tablet map in gc thread

be/src/olap/tablet_manager.cpp

@@ -615,10 +615,6 @@ OLAPStatus TabletManager::drop_tablets_on_error_root_path(
                     ++it;
                 }
             }
-
-            if (_tablet_map[tablet_id].table_arr.empty()) {
-                _tablet_map.erase(tablet_id);
-            }
         }
     }
 
@@ -923,14 +919,32 @@ OLAPStatus TabletManager::report_all_tablets_info(std::map<TTabletId, TTablet>*
 
 OLAPStatus TabletManager::start_trash_sweep() {
     ReadLock rlock(&_tablet_map_lock);
-    for (const auto& item : _tablet_map) {
+    std::vector<int64_t> tablets_to_clean;
+    for (auto& item : _tablet_map) {
+        // try to clean empty item
+        if (item.second.table_arr.empty()) {
+            // try to get schema change lock if could get schema change lock, then nobody 
+            // own the lock could remove the item
+            // it will core if schema change thread may hold the lock and this thread will deconstruct lock
+            if (item.second.schema_change_lock.trylock() == OLAP_SUCCESS) {
+                item.second.schema_change_lock.unlock();
+                tablets_to_clean.push_back(item.first);
+            }
+        }
         for (TabletSharedPtr tablet : item.second.table_arr) {
             if (tablet == nullptr) {
                 continue;
             }
             tablet->delete_expired_inc_rowsets();
         }
     }
+    // clean empty tablet id item
+    for (const auto& tablet_id_to_clean : tablets_to_clean) {
+        if (_tablet_map[tablet_id_to_clean].table_arr.empty()) {
+            _tablet_map.erase(tablet_id_to_clean);
+        }
+    }
+
     auto it = _shutdown_tablets.begin();
     for (; it != _shutdown_tablets.end();) { 
         // check if the meta has the tablet info and its state is shutdown
@@ -1247,10 +1261,6 @@ OLAPStatus TabletManager::_drop_tablet_directly_unlocked(
         }
     }
 
-    if (_tablet_map[tablet_id].table_arr.empty()) {
-        _tablet_map.erase(tablet_id);
-    }
-
     res = dropped_tablet->deregister_tablet_from_dir();
     if (res != OLAP_SUCCESS) {
         LOG(WARNING) << "fail to unregister from root path. " 

fe/src/main/java/org/apache/doris/common/Config.java

@@ -436,8 +436,9 @@ public class Config extends ConfigBase {
      * After dropping database(table/partition), you can recover it by using RECOVER stmt.
      * And this specifies the maximal data retention time. After time, the data will be deleted permanently.
      */
+    // TODO(ygl): temp modify it for test !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     @ConfField(mutable = true, masterOnly = true)
-    public static long catalog_trash_expire_second = 86400L; // 1day
+    public static long catalog_trash_expire_second = 10L; // 1day
     /*
      * Maximal bytes that a single broker scanner will read.
      * Do not set this if you know what you are doing.