Added functions :

* binary XOR
* logical XOR
* CHECK_LOCK("lock_name")

Docs/manual.texi

@@ -49578,6 +49578,39 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
 
 @itemize @bullet
 @item
+Added binary XOR. 
+
+The one that with a query like :
+
+select 11 ^ 3;
+
+returns 8.
+
+Based on the code originated  by Hartmut Holzgraefe <hartmut@six.de>.
+@item
+
+Added logical XOR.
+
+The one that with a query like:
+
+select 1 XOR 1;
+
+returns 0;
+
+Based on the code originated by Hartmut Holzgraefe <hartmut@six.de>.
+@item
+Add function CHEDK_LOCK("lock_name"). 
+This function checks if the lock of the certain name is available or not. 
+This function does not attempt to take a look.
+It is used like this:
+
+   SELECT CHECK_LOCK("some_lock");
+
+it will return 1 if the lock is held by a process (including by
+itself), 0 if it is currently not held by anyone and NULL on
+errors.
+Based on the code originated  by Hartmut Holzgraefe <hartmut@six.de>.
+@item
 Removed @code{mysql_ssl_clear()}, as this was not needed.
 @item
 @code{DECIMAL} and @code{NUMERIC} types can now read exponential numbers.

mysql-test/r/func_test.result

@@ -40,6 +40,12 @@ select 2 in (3,2,5,9,5,1),"monty" in ("david","monty","allan"), 1.2 in (1.4,1.2,
 select -1.49 or -1.49,0.6 or 0.6;
 -1.49 or -1.49	0.6 or 0.6
 1	1
+select 3 ^ 11;
+3 ^ 11
+8
+select 1 XOR 0;
+1 XOR 0
+1
 select 5 between 0 and 10 between 0 and 1,(5 between 0 and 10) between 0 and 1;
 5 between 0 and 10 between 0 and 1	(5 between 0 and 10) between 0 and 1
 0	1

mysql-test/r/rpl_get_lock.result

@@ -17,4 +17,7 @@ get_lock("lock",3)
 select * from t1;
 n
 1
+select check_lock("lock");
+check_lock("lock")
+1
 drop table t1;

mysql-test/t/func_test.test

@@ -15,7 +15,8 @@ select 2 between 1 and 3, "monty" between "max" and "my",2=2 and "monty" between
 select 'b' between 'a' and 'c', 'B' between 'a' and 'c';
 select 2 in (3,2,5,9,5,1),"monty" in ("david","monty","allan"), 1.2 in (1.4,1.2,1.0);
 select -1.49 or -1.49,0.6 or 0.6;
-
+select 3 ^ 11;
+select 1 XOR 0;
 #
 # Wrong usage of functions
 #

mysql-test/t/rpl_get_lock.test

@@ -22,6 +22,7 @@ sync_with_master;
 select get_lock("lock",3);
 select * from t1;
 connection master1;
+select check_lock("lock");
 drop table t1;
 save_master_pos;
 connection slave;

sql/item_cmpfunc.cc

@@ -1624,3 +1624,18 @@ bool Item_func_like::turboBM_matches(const char* text, int text_len) const
     return false;
   }
 }
+
+longlong Item_cond_xor::val_int()
+{
+  List_iterator<Item> li(list);
+  Item *item;
+  int result=0;	
+  null_value=1;
+  while ((item=li++))
+  {
+    result ^= (item->val_int() != 0);
+    if (!item->null_value)
+      null_value=0;
+  }
+  return result;
+}

sql/item_cmpfunc.h

@@ -596,3 +596,13 @@ inline Item *and_conds(Item *a,Item *b)
     cond->update_used_tables();
   return cond;
 }
+
+class Item_cond_xor :public Item_cond
+{
+public:
+  Item_cond_xor() :Item_cond() {}
+  Item_cond_xor(Item *i1,Item *i2) :Item_cond(i1,i2) {}
+  enum Functype functype() const { return COND_XOR_FUNC; }
+  longlong val_int();
+  const char *func_name() const { return "xor"; }
+};

sql/item_create.cc

@@ -428,3 +428,10 @@ Item *create_func_cast(Item *a, Item_cast cast_type)
   }
   return res;
 }
+
+Item *create_func_check_lock(Item* a)
+{
+  current_thd->safe_to_cache_query=0;
+  return new Item_func_check_lock(a);
+}
+

sql/item_create.h

@@ -91,3 +91,4 @@ Item *create_func_version(void);
 Item *create_func_weekday(Item* a);
 Item *create_load_file(Item* a);
 Item *create_wait_for_master_pos(Item* a, Item* b);
+Item *create_func_check_lock(Item* a);

sql/item_func.cc

@@ -2257,6 +2257,24 @@ double Item_func_match::val()
     return ft_handler->please->find_relevance(ft_handler, record, 0);
 }
 
+longlong Item_func_bit_xor::val_int()
+{
+  ulonglong arg1= (ulonglong) args[0]->val_int();
+  if (args[0]->null_value)
+  {
+    null_value=1;
+    return 0;
+  }
+  ulonglong arg2= (ulonglong) args[1]->val_int();
+  if (args[1]->null_value)
+  {
+    null_value=1;
+    return 0;
+  }
+  null_value=0;
+  return (longlong) (arg1 ^ arg2);
+}
+
 
 /***************************************************************************
   System variables
@@ -2274,3 +2292,40 @@ Item *get_system_var(LEX_STRING name)
   net_printf(&current_thd->net, ER_UNKNOWN_SYSTEM_VARIABLE, name.str);
   return 0;
 }
+
+/*
+  Check a user level lock.
+  Returns 1: available
+  Returns 0: already taken
+  Returns NULL: Error
+*/
+
+longlong Item_func_check_lock::val_int()
+{
+  String *res=args[0]->val_str(&value);
+  struct timespec abstime;
+  THD *thd=current_thd;
+  ULL *ull;
+  int error=0;
+
+  null_value=0;
+
+  if (/* check_global_access(thd,SUPER_ACL) ||*/ !res || !res->length())
+  {
+    null_value=1;
+    return 0;
+  }
+  
+  pthread_mutex_lock(&LOCK_user_locks);
+
+  
+  ull= (ULL*) hash_search(&hash_user_locks,(byte*) res->ptr(),
+			  res->length());
+
+  pthread_mutex_unlock(&LOCK_user_locks);
+  
+  if (!ull || !ull->locked)
+    return 1;
+  
+  return 0;
+}

sql/item_func.h

@@ -39,7 +39,7 @@ public:
   enum Functype { UNKNOWN_FUNC,EQ_FUNC,EQUAL_FUNC,NE_FUNC,LT_FUNC,LE_FUNC,
 		  GE_FUNC,GT_FUNC,FT_FUNC,
 		  LIKE_FUNC,NOTLIKE_FUNC,ISNULL_FUNC,ISNOTNULL_FUNC,
-		  COND_AND_FUNC,COND_OR_FUNC,BETWEEN,IN_FUNC,INTERVAL_FUNC};
+		  COND_AND_FUNC,COND_OR_FUNC,COND_XOR_FUNC,BETWEEN,IN_FUNC,INTERVAL_FUNC};
   enum optimize_type { OPTIMIZE_NONE,OPTIMIZE_KEY,OPTIMIZE_OP, OPTIMIZE_NULL };
   enum Type type() const { return FUNC_ITEM; }
   virtual enum Functype functype() const   { return UNKNOWN_FUNC; }
@@ -989,3 +989,23 @@ enum Item_cast
 };
 
 Item *create_func_cast(Item *a, Item_cast cast_type);
+
+
+class Item_func_bit_xor : public Item_int_func
+{
+public:
+  Item_func_bit_xor(Item *a,Item *b) :Item_int_func(a,b) {}
+  longlong val_int();
+  const char *func_name() const { return "^"; }
+  void fix_length_xor_dec() { unsigned_flag=1; }
+};
+
+class Item_func_check_lock :public Item_int_func
+{
+  String value;
+public:
+  Item_func_check_lock(Item *a) :Item_int_func(a) {}
+  longlong val_int();
+  const char *func_name() const { return "check_lock"; }
+  void fix_length_and_dec() { decimals=0; max_length=1; maybe_null=1;}
+};

sql/lex.h

@@ -384,6 +384,7 @@ static SYMBOL symbols[] = {
   { "WRITE",		SYM(WRITE_SYM),0,0},
   { "WHEN",		SYM(WHEN_SYM),0,0},
   { "WHERE",		SYM(WHERE),0,0},
+  { "XOR",		SYM(XOR),0,0},
   { "X509",		SYM(X509_SYM),0,0},
   { "YEAR",		SYM(YEAR_SYM),0,0},
   { "YEAR_MONTH",	SYM(YEAR_MONTH_SYM),0,0},
@@ -412,6 +413,7 @@ static SYMBOL sql_functions[] = {
   { "BIT_LENGTH",	SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_bit_length)},
   { "CHAR_LENGTH",	SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_char_length)},
   { "CHARACTER_LENGTH", SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_char_length)},
+  { "CHECK_LOCK",	SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_check_lock)},
   { "COALESCE",		SYM(COALESCE),0,0},
   { "CONCAT",		SYM(CONCAT),0,0},
   { "CONCAT_WS",	SYM(CONCAT_WS),0,0},

sql/sql_yacc.yy

@@ -339,6 +339,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token	WITH
 %token	WRITE_SYM
 %token	X509_SYM
+%token  XOR
 %token	COMPRESSED_SYM
 
 %token	BIGINT
@@ -496,6 +497,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %left	'-' '+'
 %left	'*' '/' '%'
 %left	NEG '~'
+%left   XOR
+%left   '^'
 %right	NOT
 %right	BINARY
 
@@ -1524,6 +1527,7 @@ expr_expr:
 	  { $$= new Item_func_not(new Item_func_between($1,$4,$6)); }
 	| expr OR_OR_CONCAT expr { $$= or_or_concat($1,$3); }
 	| expr OR expr		{ $$= new Item_cond_or($1,$3); }
+        | expr XOR expr		{ $$= new Item_cond_xor($1,$3); }
 	| expr AND expr		{ $$= new Item_cond_and($1,$3); }
 	| expr LIKE simple_expr opt_escape { $$= new Item_func_like($1,$3,$4); }
 	| expr NOT LIKE simple_expr opt_escape	{ $$= new Item_func_not(new Item_func_like($1,$4,$5));}
@@ -1545,6 +1549,7 @@ expr_expr:
 	| expr '*' expr		{ $$= new Item_func_mul($1,$3); }
 	| expr '/' expr		{ $$= new Item_func_div($1,$3); }
 	| expr '|' expr		{ $$= new Item_func_bit_or($1,$3); }
+        | expr '^' expr		{ $$= new Item_func_bit_xor($1,$3); }	
 	| expr '&' expr		{ $$= new Item_func_bit_and($1,$3); }
 	| expr '%' expr		{ $$= new Item_func_mod($1,$3); }
 	| expr '+' INTERVAL_SYM expr interval
@@ -1560,6 +1565,7 @@ no_in_expr:
 	  { $$= new Item_func_not(new Item_func_between($1,$4,$6)); }
 	| no_in_expr OR_OR_CONCAT expr	{ $$= or_or_concat($1,$3); }
 	| no_in_expr OR expr		{ $$= new Item_cond_or($1,$3); }
+        | no_in_expr XOR expr		{ $$= new Item_cond_xor($1,$3); }
 	| no_in_expr AND expr		{ $$= new Item_cond_and($1,$3); }
 	| no_in_expr LIKE simple_expr opt_escape { $$= new Item_func_like($1,$3,$4); }
 	| no_in_expr NOT LIKE simple_expr opt_escape { $$= new Item_func_not(new Item_func_like($1,$4,$5)); }
@@ -1581,6 +1587,7 @@ no_in_expr:
 	| no_in_expr '*' expr		{ $$= new Item_func_mul($1,$3); }
 	| no_in_expr '/' expr		{ $$= new Item_func_div($1,$3); }
 	| no_in_expr '|' expr		{ $$= new Item_func_bit_or($1,$3); }
+        | no_in_expr '^' expr		{ $$= new Item_func_bit_xor($1,$3); }
 	| no_in_expr '&' expr		{ $$= new Item_func_bit_and($1,$3); }
 	| no_in_expr '%' expr		{ $$= new Item_func_mod($1,$3); }
 	| no_in_expr '+' INTERVAL_SYM expr interval
@@ -1601,6 +1608,7 @@ no_and_expr:
 	  { $$= new Item_func_not(new Item_func_between($1,$4,$6)); }
 	| no_and_expr OR_OR_CONCAT expr	{ $$= or_or_concat($1,$3); }
 	| no_and_expr OR expr		{ $$= new Item_cond_or($1,$3); }
+        | no_and_expr XOR expr		{ $$= new Item_cond_xor($1,$3); }
 	| no_and_expr LIKE simple_expr opt_escape { $$= new Item_func_like($1,$3,$4); }
 	| no_and_expr NOT LIKE simple_expr opt_escape	{ $$= new Item_func_not(new Item_func_like($1,$4,$5)); }
 	| no_and_expr REGEXP expr { $$= new Item_func_regex($1,$3); }
@@ -1621,6 +1629,7 @@ no_and_expr:
 	| no_and_expr '*' expr		{ $$= new Item_func_mul($1,$3); }
 	| no_and_expr '/' expr		{ $$= new Item_func_div($1,$3); }
 	| no_and_expr '|' expr		{ $$= new Item_func_bit_or($1,$3); }
+        | no_and_expr '^' expr		{ $$= new Item_func_bit_xor($1,$3); }
 	| no_and_expr '&' expr		{ $$= new Item_func_bit_and($1,$3); }
 	| no_and_expr '%' expr		{ $$= new Item_func_mod($1,$3); }
 	| no_and_expr '+' INTERVAL_SYM expr interval