MDEV-10569: Add RELEASE_ALL_LOCKS function. Implementing the SQL

function to release all named locks

5 files changed, 237 insertions, 29 deletions

diff --git a/mysql-test/main/func_misc.result b/mysql-test/main/func_misc.result
index ae6686ecadc..311b9c083fa 100644
--- a/mysql-test/main/func_misc.result
+++ b/mysql-test/main/func_misc.result
@@ -1641,3 +1641,94 @@ DROP TABLE t1;
 #
 # End of 10.4 tests
 #
+#
+# MDEV-10569 Add RELEASE_ALL_LOCKS SQL-function 
+# 
+# Test function without any locks
+SELECT RELEASE_ALL_LOCKS();
+RELEASE_ALL_LOCKS()
+0
+# Test function with one lock only
+SELECT GET_LOCK('l1',10);
+GET_LOCK('l1',10)
+1
+SELECT RELEASE_ALL_LOCKS();
+RELEASE_ALL_LOCKS()
+1
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA
+# Test function with multiple locks
+SELECT GET_LOCK('l01',10),
+GET_LOCK('l02',10),
+GET_LOCK('l03',10),
+GET_LOCK('l04',10),
+GET_LOCK('l05',10),
+GET_LOCK('l06',10),
+GET_LOCK('l07',10),
+GET_LOCK('l08',10),
+GET_LOCK('l09',10),
+GET_LOCK('l10',10),
+GET_LOCK('l11',10),
+GET_LOCK('l12',10),
+GET_LOCK('l13',10),
+GET_LOCK('l14',10),
+GET_LOCK('l15',10);
+GET_LOCK('l01',10)	GET_LOCK('l02',10)	GET_LOCK('l03',10)	GET_LOCK('l04',10)	GET_LOCK('l05',10)	GET_LOCK('l06',10)	GET_LOCK('l07',10)	GET_LOCK('l08',10)	GET_LOCK('l09',10)	GET_LOCK('l10',10)	GET_LOCK('l11',10)	GET_LOCK('l12',10)	GET_LOCK('l13',10)	GET_LOCK('l14',10)	GET_LOCK('l15',10)
+1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA
+MDL_SHARED_NO_WRITE	User lock	l01
+MDL_SHARED_NO_WRITE	User lock	l02
+MDL_SHARED_NO_WRITE	User lock	l03
+MDL_SHARED_NO_WRITE	User lock	l04
+MDL_SHARED_NO_WRITE	User lock	l05
+MDL_SHARED_NO_WRITE	User lock	l06
+MDL_SHARED_NO_WRITE	User lock	l07
+MDL_SHARED_NO_WRITE	User lock	l08
+MDL_SHARED_NO_WRITE	User lock	l09
+MDL_SHARED_NO_WRITE	User lock	l10
+MDL_SHARED_NO_WRITE	User lock	l11
+MDL_SHARED_NO_WRITE	User lock	l12
+MDL_SHARED_NO_WRITE	User lock	l13
+MDL_SHARED_NO_WRITE	User lock	l14
+MDL_SHARED_NO_WRITE	User lock	l15
+SELECT RELEASE_ALL_LOCKS();
+RELEASE_ALL_LOCKS()
+15
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA
+# Test function with recursive locks
+SELECT GET_LOCK('l1',10),
+GET_LOCK('l2',10),
+GET_LOCK('l2',10),
+GET_LOCK('l3',10),
+GET_LOCK('l3',10),
+GET_LOCK('l3',10),
+GET_LOCK('l4',10),
+GET_LOCK('l4',10),
+GET_LOCK('l4',10),
+GET_LOCK('l4',10),
+GET_LOCK('l5',10),
+GET_LOCK('l5',10),
+GET_LOCK('l5',10),
+GET_LOCK('l5',10),
+GET_LOCK('l5',10);
+GET_LOCK('l1',10)	GET_LOCK('l2',10)	GET_LOCK('l2',10)	GET_LOCK('l3',10)	GET_LOCK('l3',10)	GET_LOCK('l3',10)	GET_LOCK('l4',10)	GET_LOCK('l4',10)	GET_LOCK('l4',10)	GET_LOCK('l4',10)	GET_LOCK('l5',10)	GET_LOCK('l5',10)	GET_LOCK('l5',10)	GET_LOCK('l5',10)	GET_LOCK('l5',10)
+1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA
+MDL_SHARED_NO_WRITE	User lock	l1
+MDL_SHARED_NO_WRITE	User lock	l2
+MDL_SHARED_NO_WRITE	User lock	l3
+MDL_SHARED_NO_WRITE	User lock	l4
+MDL_SHARED_NO_WRITE	User lock	l5
+SELECT RELEASE_ALL_LOCKS();
+RELEASE_ALL_LOCKS()
+15
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA
diff --git a/mysql-test/main/func_misc.test b/mysql-test/main/func_misc.test
index 7d19c9e58af..951553705ab 100644
--- a/mysql-test/main/func_misc.test
+++ b/mysql-test/main/func_misc.test
@@ -1,7 +1,7 @@
 #
 # Testing of misc functions
 #
-
+--source include/have_metadata_lock_info.inc
 --source include/default_optimizer_switch.inc
 --disable_warnings
 DROP TABLE IF EXISTS t1, t2;
@@ -1278,3 +1278,60 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.4 tests
 --echo #
+
+--echo #
+--echo # MDEV-10569 Add RELEASE_ALL_LOCKS SQL-function 
+--echo # 
+
+--echo # Test function without any locks
+SELECT RELEASE_ALL_LOCKS();
+
+--echo # Test function with one lock only
+SELECT GET_LOCK('l1',10);
+SELECT RELEASE_ALL_LOCKS();
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+                                                         
+--echo # Test function with multiple locks
+SELECT GET_LOCK('l01',10),
+       GET_LOCK('l02',10),
+       GET_LOCK('l03',10),
+       GET_LOCK('l04',10),
+       GET_LOCK('l05',10),
+       GET_LOCK('l06',10),
+       GET_LOCK('l07',10),
+       GET_LOCK('l08',10),
+       GET_LOCK('l09',10),
+       GET_LOCK('l10',10),
+       GET_LOCK('l11',10),
+       GET_LOCK('l12',10),
+       GET_LOCK('l13',10),
+       GET_LOCK('l14',10),
+       GET_LOCK('l15',10);  
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+SELECT RELEASE_ALL_LOCKS();
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+
+--echo # Test function with recursive locks
+SELECT GET_LOCK('l1',10),
+       GET_LOCK('l2',10),
+       GET_LOCK('l2',10),
+       GET_LOCK('l3',10),
+       GET_LOCK('l3',10),
+       GET_LOCK('l3',10),
+       GET_LOCK('l4',10),
+       GET_LOCK('l4',10),
+       GET_LOCK('l4',10),
+       GET_LOCK('l4',10),
+       GET_LOCK('l5',10),
+       GET_LOCK('l5',10),
+       GET_LOCK('l5',10),
+       GET_LOCK('l5',10),
+       GET_LOCK('l5',10);  
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
+SELECT RELEASE_ALL_LOCKS();
+SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA 
+FROM information_schema.metadata_lock_info WHERE thread_id>0 ORDER BY TABLE_SCHEMA;
\ No newline at end of file
diff --git a/sql/item_create.cc b/sql/item_create.cc
index 486f4fc591e..57e402999ea 100644
--- a/sql/item_create.cc
+++ b/sql/item_create.cc
@@ -1765,6 +1765,15 @@ protected:
 };
 
 
+class Create_func_release_all_locks : public Create_func_arg0
+{
+public:
+  virtual Item *create_builder(THD *thd);
+
+  static Create_func_release_all_locks s_singleton;
+};
+
+
 class Create_func_release_lock : public Create_func_arg1
 {
 public:
@@ -4762,6 +4771,17 @@ Create_func_rand::create_native(THD *thd, LEX_CSTRING *name,
 }
 
 
+Create_func_release_all_locks Create_func_release_all_locks::s_singleton;
+
+Item*
+Create_func_release_all_locks::create_builder(THD *thd)
+{
+  thd->lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_FUNCTION);
+  thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
+  return new (thd->mem_root) Item_func_release_all_locks(thd);
+}
+
+
 Create_func_release_lock Create_func_release_lock::s_singleton;
 
 Item*
@@ -5525,6 +5545,8 @@ static Native_func_registry func_array[] =
   { { STRING_WITH_LEN("REGEXP_SUBSTR") }, BUILDER(Create_func_regexp_substr)},
   { { STRING_WITH_LEN("RADIANS") }, BUILDER(Create_func_radians)},
   { { STRING_WITH_LEN("RAND") }, BUILDER(Create_func_rand)},
+  { { STRING_WITH_LEN("RELEASE_ALL_LOCKS") },
+      BUILDER(Create_func_release_all_locks)},
   { { STRING_WITH_LEN("RELEASE_LOCK") }, BUILDER(Create_func_release_lock)},
   { { STRING_WITH_LEN("REPLACE_ORACLE") },
       BUILDER(Create_func_replace_oracle)},
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 0419d55cc58..14a17bd09de 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -4028,7 +4028,7 @@ longlong Item_func_get_lock::val_int()
   MDL_request ull_request;
   ull_request.init(MDL_key::USER_LOCK, res->c_ptr_safe(), "",
                    MDL_SHARED_NO_WRITE, MDL_EXPLICIT);
-  MDL_key *ull_key = &ull_request.key;
+  MDL_key *ull_key= &ull_request.key;
 
 
   if ((ull= (User_level_lock*)
@@ -4036,7 +4036,7 @@ longlong Item_func_get_lock::val_int()
   {
     /* Recursive lock */
     ull->refs++;
-    null_value = 0;
+    null_value= 0;
     DBUG_PRINT("info", ("recursive lock, ref-count: %d", (int) ull->refs));
     DBUG_RETURN(1);
   }
@@ -4076,6 +4076,30 @@ longlong Item_func_get_lock::val_int()
 
 
 /**
+  Release all user level locks.
+  @return
+    - N if N-lock released
+    - 0 if lock wasn't held
+*/
+longlong Item_func_release_all_locks::val_int()
+{
+  DBUG_ASSERT(fixed == 1);
+  THD *thd= current_thd;
+  ulong num_unlocked= 0;
+  DBUG_ENTER("Item_func_release_all_locks::val_int");
+  for (size_t i= 0; i < thd->ull_hash.records; i++)
+  {
+    auto ull= (User_level_lock *) my_hash_element(&thd->ull_hash, i);
+    thd->mdl_context.release_lock(ull->lock);
+    num_unlocked+= ull->refs;
+    my_free(ull);
+  }
+  my_hash_free(&thd->ull_hash);
+  DBUG_RETURN(num_unlocked);
+}
+
+
+/**
   Release a user level lock.
   @return
     - 1 if lock released
diff --git a/sql/item_func.h b/sql/item_func.h
index dced158bb86..2ff806492cf 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -2654,19 +2654,13 @@ public:
 void mysql_ull_cleanup(THD *thd);
 void mysql_ull_set_explicit_lock_duration(THD *thd);
 
-class Item_func_get_lock :public Item_long_func
+
+class Item_func_lock :public Item_long_func
 {
-  bool check_arguments() const
-  {
-    return args[0]->check_type_general_purpose_string(func_name()) ||
-           args[1]->check_type_can_return_real(func_name());
-  }
-  String value;
  public:
-  Item_func_get_lock(THD *thd, Item *a, Item *b) :Item_long_func(thd, a, b) {}
-  longlong val_int();
-  const char *func_name() const { return "get_lock"; }
-  bool fix_length_and_dec() { max_length=1; maybe_null=1; return FALSE; }
+  Item_func_lock(THD *thd): Item_long_func(thd) { }
+  Item_func_lock(THD *thd, Item *a): Item_long_func(thd, a) {}
+  Item_func_lock(THD *thd, Item *a, Item *b): Item_long_func(thd, a, b) {}
   table_map used_tables() const
   {
     return used_tables_cache | RAND_TABLE_BIT;
@@ -2677,34 +2671,54 @@ class Item_func_get_lock :public Item_long_func
   {
     return mark_unsupported_function(func_name(), "()", arg, VCOL_IMPOSSIBLE);
   }
-  Item *get_copy(THD *thd)
+};
+
+
+class Item_func_get_lock final :public Item_func_lock
+{
+  bool check_arguments() const
+  {
+    return args[0]->check_type_general_purpose_string(func_name()) ||
+           args[1]->check_type_can_return_real(func_name());
+  }
+  String value;
+ public:
+  Item_func_get_lock(THD *thd, Item *a, Item *b) :Item_func_lock(thd, a, b) {}
+  longlong val_int() final;
+  const char *func_name() const final { return "get_lock"; }
+  bool fix_length_and_dec() { max_length= 1; maybe_null= 1; return FALSE; }
+  Item *get_copy(THD *thd) final
   { return get_item_copy<Item_func_get_lock>(thd, this); }
 };
 
-class Item_func_release_lock :public Item_long_func
+
+class Item_func_release_all_locks final :public Item_func_lock 
+{
+public:
+  Item_func_release_all_locks(THD *thd): Item_func_lock(thd)
+  { unsigned_flag= 1; }
+  longlong val_int() final;
+  const char *func_name() const final { return "release_all_locks"; }
+  Item *get_copy(THD *thd) final
+  { return get_item_copy<Item_func_release_all_locks>(thd, this); }
+};
+
+
+class Item_func_release_lock final :public Item_func_lock
 {
   bool check_arguments() const
   { return args[0]->check_type_general_purpose_string(func_name()); }
   String value;
 public:
-  Item_func_release_lock(THD *thd, Item *a): Item_long_func(thd, a) {}
-  longlong val_int();
+  Item_func_release_lock(THD *thd, Item *a): Item_func_lock(thd, a) {}
+  longlong val_int() final;
   const char *func_name() const { return "release_lock"; }
   bool fix_length_and_dec() { max_length= 1; maybe_null= 1; return FALSE; }
-  table_map used_tables() const
-  {
-    return used_tables_cache | RAND_TABLE_BIT;
-  }
-  bool const_item() const { return 0; }
-  bool is_expensive() { return 1; }
-  bool check_vcol_func_processor(void *arg)
-  {
-    return mark_unsupported_function(func_name(), "()", arg, VCOL_IMPOSSIBLE);
-  }
-  Item *get_copy(THD *thd)
+  Item *get_copy(THD *thd) final
   { return get_item_copy<Item_func_release_lock>(thd, this); }
 };
 
+
 /* replication functions */
 
 class Item_master_pos_wait :public Item_longlong_func