changed signal by fd close to signal by vio_close

added support for kill expr
fixed coredump in set @A := foo;
added testcase for user_var
added testcase for kill


sql/slave.cc:
  fd -> vio
sql/sql_class.cc:
  fd->vio, fixed coredump on set @A := foo;
sql/sql_class.h:
  fd -> vio
sql/sql_repl.cc:
  fd -> vio
sql/sql_yacc.yy:
  added support for kill expr - needed this for a clean test case of kill

mysql-test/r/kill.result

+((@id := kill_id) - kill_id)
+0
+4
+4

mysql-test/r/user_var.result

+@a - connection_id()
+3

mysql-test/t/kill.test

+connect (con1, localhost, root,,test,0, mysql-master.sock);
+connect (con2, localhost, root,,test,0, mysql-master.sock);
+
+#remember id of con1
+connection con1;
+drop table if exists connection_kill;
+create table connection_kill (kill_id int);
+insert into connection_kill values(connection_id());
+
+#kill con1
+connection con2;
+select ((@id := kill_id) - kill_id) from connection_kill; 
+kill @id;
+
+# verify that con1 is really dead
+connection con1;
+error 2013;
+select 1;
+
+#make sure the server is still alive
+connection con2;
+select 4;
+drop table connection_kill;

mysql-test/t/user_var.test

+error 1204;
+set @a := foo;
+set @a := connection_id() + 3;
+select @a - connection_id();
+

sql/slave.cc

@@ -1381,8 +1381,8 @@ static int safe_connect(THD* thd, MYSQL* mysql, MASTER_INFO* mi)
     {
       mysql_log.write(thd, COM_CONNECT_OUT, "%s@%s:%d",
 		  mi->user, mi->host, mi->port);
-#ifdef STOP_IO_WITH_FD_CLOSE
-      thd->set_active_fd(vio_fd(mysql->net.vio));
+#ifdef SIGNAL_WITH_VIO_CLOSE
+      thd->set_active_vio(mysql->net.vio);
 #endif      
     }
   
@@ -1417,8 +1417,8 @@ replication resumed in log '%s' at position %s", glob_mi.user,
 		    glob_mi.host, glob_mi.port,
 		    RPL_LOG_NAME,
 		    llstr(glob_mi.pos,llbuff));
-#ifdef STOP_IO_WITH_FD_CLOSE
-      thd->set_active_fd(vio_fd(mysql->net.vio));
+#ifdef SIGNAL_WITH_VIO_CLOSE
+      thd->set_active_vio(mysql->net.vio);
 #endif      
     }
 

sql/sql_class.cc

@@ -30,6 +30,7 @@
 #include "sql_acl.h"
 #include <m_ctype.h>
 #include <sys/stat.h>
+#include <thr_alarm.h>
 #ifdef	__WIN__
 #include <io.h>
 #endif
@@ -79,14 +80,15 @@ THD::THD():user_time(0),fatal_error(0),last_insert_id_used(0),
 	   global_read_lock(0),bootstrap(0)
 {
   proc_info="login";
+  where="field list";
   host=user=priv_user=db=query=ip=0;
   locked=killed=count_cuted_fields=some_tables_deleted=no_errors=password=
     query_start_used=0;
   query_length=col_access=0;
   query_error=0;
-#ifdef STOP_IO_WITH_FD_CLOSE
-  active_fd = -1;
-  pthread_mutex_init(&active_fd_lock, NULL);
+#ifdef SIGNAL_WITH_VIO_CLOSE
+  active_vio = 0;
+  pthread_mutex_init(&active_vio_lock, NULL);
 #endif  
   server_id = ::server_id;
   server_status=SERVER_STATUS_AUTOCOMMIT;
@@ -186,12 +188,34 @@ THD::~THD()
   safeFree(ip);
   free_root(&mem_root,MYF(0));
   mysys_var=0;					// Safety (shouldn't be needed)
-#ifdef STOP_IO_WITH_FD_CLOSE
-  pthread_mutex_destroy(&active_fd_lock);
+#ifdef SIGNAL_WITH_VIO_CLOSE
+  pthread_mutex_destroy(&active_vio_lock);
 #endif  
   DBUG_VOID_RETURN;
 }
 
+void THD::prepare_to_die()
+{
+  thr_alarm_kill(real_id);
+  killed = 1;
+#ifdef SIGNAL_WITH_VIO_CLOSE
+  close_active_vio();
+#endif    
+  if (mysys_var)
+    {
+      pthread_mutex_lock(&mysys_var->mutex);
+      if (!system_thread)		// Don't abort locks
+	mysys_var->abort=1;
+      if (mysys_var->current_mutex)
+	{
+	  pthread_mutex_lock(mysys_var->current_mutex);
+	  pthread_cond_broadcast(mysys_var->current_cond);
+	  pthread_mutex_unlock(mysys_var->current_mutex);
+	}
+      pthread_mutex_unlock(&mysys_var->mutex);
+    }
+}
+
 // remember the location of thread info, the structure needed for
 // sql_alloc() and the structure for the net buffer
 

sql/sql_class.h

@@ -21,8 +21,6 @@
 #pragma interface			/* gcc class implementation */
 #endif
 
-#include <thr_alarm.h>
-
 class Query_log_event;
 class Load_log_event;
 
@@ -258,9 +256,9 @@ class THD :public ilink {
 #ifndef __WIN__
   sigset_t signals,block_signals;
 #endif
-#ifdef STOP_IO_WITH_FD_CLOSE
-  int active_fd;
-  pthread_mutex_t active_fd_lock;
+#ifdef SIGNAL_WITH_VIO_CLOSE
+  Vio* active_vio;
+  pthread_mutex_t active_vio_lock;
 #endif  
   ulonglong  next_insert_id,last_insert_id,current_insert_id;
   ha_rows select_limit,offset_limit,default_select_limit,cuted_fields,
@@ -285,59 +283,39 @@ class THD :public ilink {
   // each thread that is using LOG_INFO needs to adjust the pointer to it
 
   ulong slave_proxy_id; // in slave thread we need to know in behalf of which
-  // thread the query is being run to replicate temp tables properly 
+  // thread the query is being run to replicate temp tables properly
 
   // thread-specific state map for lex parser
   uchar state_map[256];
-
+  
   THD();
   ~THD();
   bool store_globals();
-#ifdef STOP_IO_WITH_FD_CLOSE
-  inline void set_active_fd(int fd)
+#ifdef SIGNAL_WITH_VIO_CLOSE
+  inline void set_active_vio(Vio* vio)
   {
-    pthread_mutex_lock(&active_fd_lock);
-    active_fd = fd;
-    pthread_mutex_unlock(&active_fd_lock);
+    pthread_mutex_lock(&active_vio_lock);
+    active_vio = vio;
+    pthread_mutex_unlock(&active_vio_lock);
   }
-  inline void clear_active_fd()
+  inline void clear_active_vio()
   {
-    pthread_mutex_lock(&active_fd_lock);
-    active_fd = -1;
-    pthread_mutex_unlock(&active_fd_lock);
+    pthread_mutex_lock(&active_vio_lock);
+    active_vio = 0;
+    pthread_mutex_unlock(&active_vio_lock);
   }
-  inline void close_active_fd()
+  inline void close_active_vio()
   {
-    pthread_mutex_lock(&active_fd_lock);
-    if(active_fd >= 0)
+    pthread_mutex_lock(&active_vio_lock);
+    if(active_vio)
       {
-	my_close(active_fd, MYF(MY_WME));
-        active_fd = -1;
+	vio_close(active_vio);
+        active_vio = 0;
       }
-    pthread_mutex_unlock(&active_fd_lock);
+    pthread_mutex_unlock(&active_vio_lock);
   }
 #endif  
-  inline void prepare_to_die()
-  {
-    thr_alarm_kill(real_id);
-    killed = 1;
-#ifdef STOP_IO_WITH_FD_CLOSE
-    close_active_fd();
-#endif    
-    if (mysys_var)
-      {
-	pthread_mutex_lock(&mysys_var->mutex);
-	if (!system_thread)		// Don't abort locks
-	  mysys_var->abort=1;
-	if (mysys_var->current_mutex)
-	  {
-	    pthread_mutex_lock(mysys_var->current_mutex);
-	    pthread_cond_broadcast(mysys_var->current_cond);
-	    pthread_mutex_unlock(mysys_var->current_mutex);
-	  }
-	pthread_mutex_unlock(&mysys_var->mutex);
-      }
-  }
+  void prepare_to_die();
   inline const char* enter_cond(pthread_cond_t *cond, pthread_mutex_t* mutex,
 			  const char* msg)
   {

sql/sql_repl.cc

@@ -572,8 +572,8 @@ int stop_slave(THD* thd, bool net_report )
   {
     abort_slave = 1;
     thr_alarm_kill(slave_real_id);
-#ifdef STOP_IO_WITH_FD_CLOSE
-    slave_thd->close_active_fd();
+#ifdef SIGNAL_WITH_VIO_CLOSE
+    slave_thd->close_active_vio();
 #endif    
     // do not abort the slave in the middle of a query, so we do not set
     // thd->killed for the slave thread

sql/sql_yacc.yy

@@ -2293,10 +2293,15 @@ purge:
 /* kill threads */
 
 kill:
-	KILL_SYM NUM
+	KILL_SYM expr
 	{
-	  Lex->sql_command=SQLCOM_KILL;
-	  Lex->thread_id= (ulong) strtoul($2.str,NULL,10);
+	  if ($2->fix_fields(current_thd,0))
+	     { 
+		send_error(&current_thd->net, ER_SET_CONSTANTS_ONLY);
+	        YYABORT;
+	     }
+          Lex->sql_command=SQLCOM_KILL;
+	  Lex->thread_id= (ulong) $2->val_int();
 	}
 
 /* change database */