Drizzled Public API Documentation

drop_table.cc
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20 
21 #include <config.h>
22 #include <drizzled/show.h>
23 #include <drizzled/session.h>
24 #include <drizzled/lock.h>
25 #include <drizzled/statement/drop_table.h>
26 #include <drizzled/sql_table.h>
27 #include <drizzled/sql_lex.h>
28 
29 namespace drizzled
30 {
31 
32 
33 /*
34  delete (drop) tables.
35 
36  SYNOPSIS
37  rm_table()
38  session Thread handle
39  tables List of tables to delete
40  if_exists If 1, don't give error if one table doesn't exists
41 
42  NOTES
43  Will delete all tables that can be deleted and give a compact error
44  messages for tables that could not be deleted.
45  If a table is in use, we will wait for all users to free the table
46  before dropping it
47 
48  Wait if global_read_lock (FLUSH TABLES WITH READ LOCK) is set, but
49  not if under LOCK TABLES.
50 
51  RETURN
52  false OK. In this case ok packet is sent to user
53  true Error
54 
55 */
56 
57 static bool rm_table(Session *session, TableList *tables, bool if_exists, bool drop_temporary)
58 {
59  bool need_start_waiting= false;
60 
61  /* mark for close and remove all cached entries */
62 
63  if (not drop_temporary)
64  {
65  if (not (need_start_waiting= not session->wait_if_global_read_lock(false, true)))
66  return true;
67  }
68 
69  /*
70  Acquire table::Cache::mutex() after wait_if_global_read_lock(). If we would hold
71  table::Cache::mutex() during wait_if_global_read_lock(), other threads could not
72  close their tables. This would make a pretty deadlock.
73  */
74  bool error= rm_table_part2(session, tables, if_exists, drop_temporary);
75 
76  if (need_start_waiting)
77  {
78  session->startWaitingGlobalReadLock();
79  }
80 
81  if (error)
82  return true;
83 
84  session->my_ok();
85 
86  return false;
87 }
88 
90 {
91  TableList *first_table= (TableList *) lex().select_lex.table_list.first;
92  TableList *all_tables= lex().query_tables;
93  assert(first_table == all_tables && first_table != 0);
94 
95  if (not drop_temporary)
96  {
97  if (session().inTransaction())
98  {
99  my_error(ER_TRANSACTIONAL_DDL_NOT_SUPPORTED, MYF(0));
100  return true;
101  }
102  }
103 
104  return rm_table(&session(), first_table, drop_if_exists, drop_temporary);
105 }
106 
107 } /* namespace drizzled */