Merge work:/home/bk/mysql-4.0

into mysql.sashanet.com:/reiser-data/mysql-4.0
2002-03-26 22:23:51 -07:00 · 2002-03-26 22:23:51 -07:00 · ab1fdbdeac
commit ab1fdbdeac
parent 6e4b213654 f28f8d086d
20 changed files with 274 additions and 29 deletions
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@ -21,7 +21,8 @@
 *	all copies and derivative works.  Thank you.			      *
 *									      *
 *	The author makes no warranty of any kind  with	respect  to  this     *
- *	product  and  explicitly disclaims any implied warranties of mer-     *
+ *	product  and  explicitly disclaims any implied warranties of mer-     *ct_lex.table_list.first=0;
+  thd->lex.selec
 *	chantability or fitness for any particular purpose.		      *
 *									      *
 ******************************************************************************
@ -58,7 +59,7 @@
 *	seismo!bpa!sjuvax!bbanerje
 *
 *	Michael Widenius:
- *	DBUG_DUMP	- To dump a pice of memory.
+ *	DBUG_DUMP	- To dump a block of memory.
 *	PUSH_FLAG "O"	- To be used insted of "o" if we don't
 *			  want flushing (for slow systems)
 *	PUSH_FLAG "A"	- as 'O', but we will append to the out file instead
@ -707,7 +708,13 @@ char ***_sframep_ __attribute__((unused)))
    int save_errno=errno;
    if (!init_done)
      _db_push_ (_DBUG_START_CONDITION_);
-    state=code_state();
+    /* Sasha: the test below is so we could call functions with DBUG_ENTER
+       before my_thread_init(). I needed this because I suspected corruption
+       of a block allocated by my_thread_init() itself, so I wanted to use
+       my_malloc()/my_free() in my_thread_init()/my_thread_end()
+    */
+    if (!(state=code_state()))
+      return;

    *_sfunc_ = state->func;
    *_sfile_ = state->file;
@ -855,6 +862,9 @@ uint _line_,
 const char *keyword)
 {
  CODE_STATE *state=code_state();
+  /* Sasha: pre-my_thread_init() safety */
+  if (!state)
+    return;
  state->u_line = _line_;
  state->u_keyword = (char*) keyword;
 }
@ -890,7 +900,9 @@ void _db_doprnt_ (const char *format,...)
 {
  va_list args;
  CODE_STATE *state;
-  state=code_state();
+  /* Sasha: pre-my_thread_init() safety */
+  if (!(state=code_state()))
+    return;

  va_start(args,format);

@ -942,7 +954,9 @@ uint length)
  int pos;
  char dbuff[90];
  CODE_STATE *state;
-  state=code_state();
+  /* Sasha: pre-my_thread_init() safety */
+  if (!(state=code_state()))
+    return;

  if (_db_keyword_ ((char*) keyword))
  {
@ -1224,7 +1238,9 @@ const char *keyword)

  if (!init_done)
    _db_push_ ("");
-  state=code_state();
+  /* Sasha: pre-my_thread_init() safety */
+  if (!(state=code_state()))
+    return FALSE;
  result = FALSE;
  if (DEBUGGING &&
      state->level <= stack -> maxdepth &&
--- a/include/my_sys.h
+++ b/include/my_sys.h
@ -137,6 +137,10 @@ extern int NEAR my_errno;		/* Last error in mysys */
 #define NORMAL_SAFEMALLOC sf_malloc_quick=0
 extern uint sf_malloc_prehunc,sf_malloc_endhunc,sf_malloc_quick;
 extern ulonglong safemalloc_mem_limit;
+/* keep track of shutdown,signal, and main threads so that my_end() will not
+   report errors with them
+*/
+extern pthread_t shutdown_th, main_th,signal_th;
 #define CALLER_INFO_PROTO   , const char *sFile, uint uLine
 #define CALLER_INFO         , __FILE__, __LINE__
 #define ORIG_CALLER_INFO    , sFile, uLine
--- a/mysql-test/r/multi_update.result
+++ b/mysql-test/r/multi_update.result
@ -2,7 +2,34 @@ drop table if exists t1,t2,t3;
 create table t1(id1 int not null auto_increment primary key, t char(12));
 create table t2(id2 int not null, t char(12));
 create table t3(id3 int not null, t char(12), index(id3));
+select count(*) from t1 where id1 > 95;
+count(*)
+5
+select count(*) from t2 where id2 > 95;
+count(*)
+25
+select count(*) from t3 where id3 > 95;
+count(*)
+250
 update t1,t2,t3 set t1.t="aaa", t2.t="bbb", t3.t="cc" where  t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 90;
+select count(*) from t1 where t = "aaa";
+count(*)
+10
+select count(*) from t1 where id1 > 90;
+count(*)
+10
+select count(*) from t2 where t = "bbb";
+count(*)
+10
+select count(*) from t2 where id2 > 90;
+count(*)
+50
+select count(*) from t3 where t = "cc";
+count(*)
+500
+select count(*) from t3 where id3 > 90;
+count(*)
+500
 delete t1.*, t2.*, t3.*  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 95;
 check table t1, t2, t3;
 Table	Op	Msg_type	Msg_text
--- a/mysql-test/r/rpl000015.result
+++ b/mysql-test/r/rpl000015.result
@ -9,16 +9,16 @@ Master_Host	Master_User	Master_Port	Connect_retry	Master_Log_File	Read_Master_Lo
 change master to master_host='127.0.0.1';
 show slave status;
 Master_Host	Master_User	Master_Port	Connect_retry	Master_Log_File	Read_Master_Log_Pos	Relay_Log_File	Relay_Log_Pos	Relay_Master_Log_File	Slave_IO_Running	Slave_SQL_Running	Replicate_do_db	Replicate_ignore_db	Last_errno	Last_error	Skip_counter	Exec_master_log_pos
-127.0.0.1	test	MASTER_PORT	60		4	slave-relay-bin.001	4		No	No			0		0	0
+127.0.0.1	test	MASTER_PORT	7		4	slave-relay-bin.001	4		No	No			0		0	0
 change master to master_host='127.0.0.1',master_user='root',
 master_password='',master_port=MASTER_PORT;
 show slave status;
 Master_Host	Master_User	Master_Port	Connect_retry	Master_Log_File	Read_Master_Log_Pos	Relay_Log_File	Relay_Log_Pos	Relay_Master_Log_File	Slave_IO_Running	Slave_SQL_Running	Replicate_do_db	Replicate_ignore_db	Last_errno	Last_error	Skip_counter	Exec_master_log_pos
-127.0.0.1	root	MASTER_PORT	60		4	slave-relay-bin.001	4		No	No			0		0	0
+127.0.0.1	root	MASTER_PORT	7		4	slave-relay-bin.001	4		No	No			0		0	0
 slave start;
 show slave status;
 Master_Host	Master_User	Master_Port	Connect_retry	Master_Log_File	Read_Master_Log_Pos	Relay_Log_File	Relay_Log_Pos	Relay_Master_Log_File	Slave_IO_Running	Slave_SQL_Running	Replicate_do_db	Replicate_ignore_db	Last_errno	Last_error	Skip_counter	Exec_master_log_pos
-127.0.0.1	root	MASTER_PORT	60	master-bin.001	79	slave-relay-bin.001	120	master-bin.001	Yes	Yes			0		0	79
+127.0.0.1	root	MASTER_PORT	7	master-bin.001	79	slave-relay-bin.001	120	master-bin.001	Yes	Yes			0		0	79
 drop table if exists t1;
 create table t1 (n int);
 insert into t1 values (10),(45),(90);
--- a/mysql-test/t/multi_update.test
+++ b/mysql-test/t/multi_update.test
@ -29,7 +29,18 @@ while ($1)
  dec $1;
 }
 enable_query_log;
+
+select count(*) from t1 where id1 > 95;
+select count(*) from t2 where id2 > 95;
+select count(*) from t3 where id3 > 95;
+
 update t1,t2,t3 set t1.t="aaa", t2.t="bbb", t3.t="cc" where  t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 90;
+select count(*) from t1 where t = "aaa";
+select count(*) from t1 where id1 > 90;
+select count(*) from t2 where t = "bbb";
+select count(*) from t2 where id2 > 90;
+select count(*) from t3 where t = "cc";
+select count(*) from t3 where id3 > 90;
 delete t1.*, t2.*, t3.*  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 95;

 check table t1, t2, t3;
--- a/mysql-test/t/rpl000014.test
+++ b/mysql-test/t/rpl000014.test
@ -8,6 +8,7 @@ sync_with_master;
 show slave status;
 change master to master_log_pos=73;
 slave stop;
+
 change master to master_log_pos=73;
 --replace_result 3306 MASTER_PORT 9306 MASTER_PORT 3334 MASTER_PORT 3336 MASTER_PORT
 show slave status;
--- a/mysql-test/t/rpl000015-slave-master-info.opt
+++ b/mysql-test/t/rpl000015-slave-master-info.opt
@ -1 +1 @@
--server-id=2
+--server-id=22 --master-connect-retry=7
--- a/mysql-test/t/rpl000015.test
+++ b/mysql-test/t/rpl000015.test
@ -8,6 +8,7 @@ connection slave;
 reset slave;
 --replace_result $MASTER_MYPORT MASTER_PORT
 show slave status;
+
 change master to master_host='127.0.0.1';
 # The following needs to be cleaned up when change master is fixed
 --replace_result $MASTER_MYPORT MASTER_PORT 3306 MASTER_PORT 3334 MASTER_PORT
--- a/mysys/my_static.h
+++ b/mysys/my_static.h
@ -38,6 +38,7 @@ struct irem {
    my_string _sFileName;		/* File in which memory was new'ed */
    uint _uLineNum;			/* Line number in above file	   */
    uint _uDataSize;			/* Size requested		   */
+    pthread_t thread_id;
    long _lSpecialValue;		/* Underrun marker value	   */
 };

@ -56,6 +57,11 @@ extern const char *soundex_map;
 extern USED_MEM* my_once_root_block;
 extern uint	 my_once_extra;

+/* these threads are exept from safemalloc leak scrutiny unless
+   PEDANTIC_SAFEMALLOC is defined
+*/
+extern pthread_t signal_thread,kill_thread;
+
 #ifndef HAVE_TEMPNAM
 extern int	_my_tempnam_used;
 #endif
--- a/mysys/my_thr_init.c
+++ b/mysys/my_thr_init.c
@ -105,19 +105,33 @@ static long thread_id=0;
 my_bool my_thread_init(void)
 {
  struct st_my_thread_var *tmp;
+#ifdef EXTRA_DEBUG
+  fprintf(stderr,"my_thread_init(): thread_id=%ld\n",pthread_self());
+#endif  
 #if !defined(__WIN__) || defined(USE_TLS) || ! defined(SAFE_MUTEX)
  pthread_mutex_lock(&THR_LOCK_lock);
 #endif
 #if !defined(__WIN__) || defined(USE_TLS)
  if (my_pthread_getspecific(struct st_my_thread_var *,THR_KEY_mysys))
  {
+#ifdef EXTRA_DEBUG
+    fprintf(stderr,"my_thread_init() called more than once in thread %ld\n",
+	    pthread_self());
+#endif    
    pthread_mutex_unlock(&THR_LOCK_lock);
    return 0;						/* Safequard */
  }
    /* We must have many calloc() here because these are freed on
       pthread_exit */
+    /*
+      Sasha: the above comment does not make sense. I have changed calloc() to
+      equivalent my_malloc() but it was calloc() before. It seems like the
+      comment is out of date - we always call my_thread_end() before
+      pthread_exit() to clean up. Note that I have also fixed up DBUG
+      code to be able to call it from my_thread_init()
+     */
  if (!(tmp=(struct st_my_thread_var *)
-	calloc(1,sizeof(struct st_my_thread_var))))
+	my_malloc(sizeof(struct st_my_thread_var),MYF(MY_WME|MY_ZEROFILL))))
  {
    pthread_mutex_unlock(&THR_LOCK_lock);
    return 1;
@ -125,6 +139,9 @@ my_bool my_thread_init(void)
  pthread_setspecific(THR_KEY_mysys,tmp);

 #else
+  /* Sasha: TODO - explain what exactly we are doing on Windows
+     At first glance, I have a hard time following the code
+   */
  if (THR_KEY_mysys.id)   /* Already initialized */
  {
 #if !defined(__WIN__) || defined(USE_TLS) || ! defined(SAFE_MUTEX)
@ -146,9 +163,18 @@ my_bool my_thread_init(void)
 void my_thread_end(void)
 {
  struct st_my_thread_var *tmp=my_thread_var;
+#ifdef EXTRA_DEBUG
+  fprintf(stderr,"my_thread_end(): tmp=%p,thread_id=%ld\n",
+	  tmp,pthread_self());
+#endif  
  if (tmp)
  {
 #if !defined(DBUG_OFF)
+    /* Sasha:  tmp->dbug is allocated inside DBUG library
+       so for now we will not mess with trying to use my_malloc()/
+       my_free(), but in the future it would be nice to figure out a
+       way to do it
+    */
    if (tmp->dbug)
    {
      free(tmp->dbug);
@ -160,12 +186,15 @@ void my_thread_end(void)
 #endif
    pthread_mutex_destroy(&tmp->mutex);
 #if (!defined(__WIN__) && !defined(OS2)) || defined(USE_TLS)
-    free(tmp);
+    /* we need to setspecific to 0 BEFORE we call my_free, as my_free
+       uses some DBUG_ macros that will use the follow the specific
+       pointer after the block it is pointing to has been freed if
+       specific does not get reset first
+    */
+    pthread_setspecific(THR_KEY_mysys,0);
+    my_free((gptr)tmp,MYF(MY_WME));
 #endif
  }
-#if (!defined(__WIN__) && !defined(OS2)) || defined(USE_TLS)
-  pthread_setspecific(THR_KEY_mysys,0);
-#endif
 }

 struct st_my_thread_var *_my_thread_var(void)
--- a/mysys/safemalloc.c
+++ b/mysys/safemalloc.c
@ -73,14 +73,25 @@
 #include "mysys_err.h"

 ulonglong safemalloc_mem_limit = ~(ulonglong)0;
+pthread_t shutdown_th=0,main_th=0,signal_th=0;

 #define pNext		tInt._pNext
 #define pPrev		tInt._pPrev
 #define sFileName	tInt._sFileName
 #define uLineNum	tInt._uLineNum
 #define uDataSize	tInt._uDataSize
+#define thread_id       tInt.thread_id
 #define lSpecialValue	tInt._lSpecialValue

+#ifndef PEDANTIC_SAFEMALLOC
+static int sf_malloc_tampered = 0; /* set to 1 after TERMINATE() if we had
+				    to fiddle with cNewCount and the linked
+				    list of blocks so that _sanity() will
+				    not fuss when it is not supposed to
+				 */
+#endif
+				   
+
 	/* Static functions prototypes */

 static int check_ptr(const char *where, byte *ptr, const char *sFile,
@ -174,6 +185,7 @@ gptr _mymalloc (uint uSize, const char *sFile, uint uLine, myf MyFlags)
    pTmp -> sFileName = (my_string) sFile;
    pTmp -> uLineNum = uLine;
    pTmp -> uDataSize = uSize;
+    pTmp->thread_id = pthread_self();
    pTmp -> pPrev = NULL;

    /* Add this remember structure to the linked list */
@ -359,6 +371,12 @@ static int check_ptr(const char *where, byte *ptr, const char *sFile,
  return 0;
 }

+static int legal_leak(struct remember* pPtr)
+{
+ return pthread_self() == pPtr->thread_id || main_th == pPtr->thread_id
+	    || shutdown_th == pPtr->thread_id
+   || signal_th == pPtr->thread_id;
+}

 /*
 * TERMINATE(FILE *file)
@ -376,6 +394,47 @@ void TERMINATE (FILE *file)
  /* NEW and the number of calls to FREE.  >0 means more	 */
  /* NEWs than FREEs.  <0, etc.				 */

+#ifndef PEDANTIC_SAFEMALLOC
+  /* Avoid false alarms for blocks that we cannot free before my_end()
+     This does miss some positives, but that is ok. This will only miss
+     failures to free things allocated in the main thread which 
+     performs only one-time allocations. If you really need to
+     debug memory allocations in the main thread,
+     #define PEDANTIC_SAFEMALLOC
+  */
+  if ((pPtr=pRememberRoot))
+  {
+    while (pPtr)
+    {
+      if (legal_leak(pPtr))
+      {
+	sf_malloc_tampered=1;
+	cNewCount--;
+	lCurMemory -= pPtr->uDataSize;
+	if (pPtr->pPrev)
+	{
+	  struct remember* tmp;
+	  tmp = pPtr->pPrev->pNext = pPtr->pNext;
+	  if (tmp)
+	   tmp->pPrev = pPtr->pPrev; 
+	  pPtr->pNext = pPtr->pPrev = 0;
+	  pPtr = tmp;
+	}
+	else
+	{
+	  pRememberRoot = pPtr->pNext;
+	  pPtr->pNext = pPtr->pPrev = 0;
+	  pPtr = pRememberRoot;
+	  if (pPtr)
+	    pPtr->pPrev=0;
+	}
+      }
+      else
+	pPtr = pPtr->pNext;
+    }
+  }
+#endif  
+  
  if (cNewCount)
  {
    if (file)
@ -402,10 +461,14 @@ void TERMINATE (FILE *file)
      if (file)
      {
 	fprintf (file,
-		 "\t%6u bytes at 0x%09lx, allocated at line %4u in '%s'\n",
+		 "\t%6u bytes at 0x%09lx, allocated at line %4u in '%s'",
 		 pPtr -> uDataSize,
 		 (ulong) &(pPtr -> aData[sf_malloc_prehunc]),
 		 pPtr -> uLineNum, pPtr -> sFileName);
+#ifdef THREAD
+	fprintf(file, " in thread %ld", pPtr->thread_id);
+#endif
+	fprintf(file, "\n");
 	(void) fflush(file);
      }
      DBUG_PRINT("safe",
@ -484,6 +547,10 @@ int _sanity (const char *sFile, uint uLine)
  uint count=0;

  pthread_mutex_lock(&THR_LOCK_malloc);
+#ifndef PEDANTIC_SAFEMALLOC  
+  if (sf_malloc_tampered && cNewCount < 0)
+    cNewCount=0;
+#endif  
  count=cNewCount;
  for (pTmp = pRememberRoot; pTmp != NULL && count-- ; pTmp = pTmp -> pNext)
    flag+=_checkchunk (pTmp, sFile, uLine);
@ -492,6 +559,7 @@ int _sanity (const char *sFile, uint uLine)
  {
    const char *format="Safemalloc link list destroyed, discovered at '%s:%d'";
    fprintf (stderr, format, sFile, uLine); fputc('\n',stderr);
+    fprintf (stderr, "root=%p,count=%d,pTmp=%p\n", pRememberRoot,count,pTmp);
    (void) fflush(stderr);
    DBUG_PRINT("safe",(format, sFile, uLine));
    flag=1;
--- a/sql/lex.h
+++ b/sql/lex.h
@ -280,6 +280,8 @@ static SYMBOL symbols[] = {
  { "READ",		SYM(READ_SYM),0,0},
  { "REAL",		SYM(REAL),0,0},
  { "REFERENCES",	SYM(REFERENCES),0,0},
+  { "RELAY_LOG_FILE",   SYM(RELAY_LOG_FILE_SYM),0,0},
+  { "RELAY_LOG_POS",    SYM(RELAY_LOG_POS_SYM),0,0},
  { "RELOAD",		SYM(RELOAD),0,0},
  { "REGEXP",		SYM(REGEXP),0,0},
  { "RENAME",		SYM(RENAME),0,0},
--- a/sql/log.cc
+++ b/sql/log.cc
@ -479,6 +479,7 @@ err:
    rli->relay_log_pos = 4;
    strnmov(rli->relay_log_name,rli->linfo.log_file_name,
 	    sizeof(rli->relay_log_name));
+    flush_relay_log_info(rli);
  }
  /*
    No need to free io_buf because we allocated both fname and io_buf in
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@ -1607,7 +1607,8 @@ int Query_log_event::exec_event(struct st_relay_log_info* rli)
    {
      mysql_parse(thd, thd->query, q_len);
      if (expected_error !=
-	  (actual_error = thd->net.last_errno) && expected_error)
+	  (actual_error = thd->net.last_errno) && expected_error &&
+	  !ignored_error_code(actual_error))
      {
 	const char* errmsg = "Slave: did not get the expected error\
 running query from master - expected: '%s' (%d), got '%s' (%d)"; 
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@ -38,7 +38,17 @@
 #define ONE_THREAD
 #endif

-/* do stack traces are only supported on linux intel */
+#ifdef SAFEMALLOC
+#define SHUTDOWN_THD shutdown_th=pthread_self();
+#define MAIN_THD main_th=pthread_self();
+#define SIGNAL_THD signal_th=pthread_self();
+#else
+#define SHUTDOWN_THD
+#define MAIN_THD
+#define SIGNAL_THD
+#endif
+
+/* stack traces are only supported on linux intel */
 #if defined(__linux__)  && defined(__i386__) && defined(USE_PSTACK)
 #define	HAVE_STACK_TRACE_ON_SEGV
 #include "../pstack/pstack.h"
@ -701,6 +711,7 @@ static void __cdecl kill_server(int sig_ptr)
    sql_print_error(ER(ER_GOT_SIGNAL),my_progname,sig); /* purecov: inspected */

 #if defined(USE_ONE_SIGNAL_HAND) && !defined(__WIN__) && !defined(OS2)
+  SHUTDOWN_THD;
  my_thread_init();				// If this is a new thread
 #endif
  close_connections();
@ -716,6 +727,7 @@ static void __cdecl kill_server(int sig_ptr)
 #ifdef USE_ONE_SIGNAL_HAND
 static pthread_handler_decl(kill_server_thread,arg __attribute__((unused)))
 {
+  SHUTDOWN_THD;
  my_thread_init();				// Initialize new thread
  kill_server(0);
  my_thread_end();				// Normally never reached
@ -1262,6 +1274,7 @@ static void init_signals(void)
  signal(SIGALRM, SIG_IGN);
  signal(SIGBREAK,SIG_IGN);
  signal_thread = pthread_self();
+  SIGNAL_THD;
 }

 static void start_signal_handler(void)
@ -1387,6 +1400,7 @@ static void init_signals(void)
    sigaction(SIGBUS, &sa, NULL);
 #endif
    sigaction(SIGILL, &sa, NULL);
+    sigaction(SIGFPE, &sa, NULL);
  }
  (void) sigemptyset(&set);
 #ifdef THREAD_SPECIFIC_SIGPIPE
@ -1454,7 +1468,7 @@ static void *signal_hand(void *arg __attribute__((unused)))
  int sig;
  my_thread_init();				// Init new thread
  DBUG_ENTER("signal_hand");
-
+  SIGNAL_THD;
  /* Setup alarm handler */
  init_thr_alarm(max_connections+max_insert_delayed_threads);
 #if SIGINT != THR_KILL_SIGNAL
@ -1509,7 +1523,10 @@ static void *signal_hand(void *arg __attribute__((unused)))
    else
      while ((error=my_sigwait(&set,&sig)) == EINTR) ;
    if (cleanup_done)
+    {
+      my_thread_end();
      pthread_exit(0);				// Safety
+    }
    switch (sig) {
    case SIGTERM:
    case SIGQUIT:
@ -1603,6 +1620,7 @@ int uname(struct utsname *a)
 pthread_handler_decl(handle_shutdown,arg)
 {
  MSG msg;
+  SHUTDOWN_THD;
  my_thread_init();

  /* this call should create the message queue for this thread */
@ -1629,6 +1647,7 @@ int __stdcall handle_kill(ulong ctrl_type)
 #ifdef OS2
 pthread_handler_decl(handle_shutdown,arg)
 {
+  SHUTDOWN_THD;
  my_thread_init();

  // wait semaphore
@ -1700,6 +1719,7 @@ int main(int argc, char **argv)

  my_umask=0660;		// Default umask for new files
  my_umask_dir=0700;		// Default umask for new directories
+  MAIN_THD;
  MY_INIT(argv[0]);		// init my_sys library & pthreads
  tzset();			// Set tzname

--- a/sql/slave.cc
+++ b/sql/slave.cc
@ -345,7 +345,13 @@ int terminate_slave_thread(THD* thd, pthread_mutex_t* term_lock,
    }
  }
  DBUG_ASSERT(thd != 0);
-  KICK_SLAVE(thd);
+  /* is is criticate to test if the slave is running. Otherwise, we might
+     be referening freed memory trying to kick it
+  */
+  if (*slave_running)
+  {
+    KICK_SLAVE(thd);
+  }
  while (*slave_running)
  {
    /* there is a small chance that slave thread might miss the first
@ -367,7 +373,9 @@ int terminate_slave_thread(THD* thd, pthread_mutex_t* term_lock,
    DBUG_ASSERT_LOCK(cond_lock);
    pthread_cond_timedwait(term_cond, cond_lock, &abstime);
    if (*slave_running)
+    {
      KICK_SLAVE(thd);
+    }
  }
  if (term_lock)
    pthread_mutex_unlock(term_lock);
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@ -151,6 +151,7 @@ LEX *lex_start(THD *thd, uchar *buf,uint length)
  lex->yacc_yyss=lex->yacc_yyvs=0;
  lex->ignore_space=test(thd->sql_mode & MODE_IGNORE_SPACE);
  lex->slave_thd_opt=0;
+  bzero(&lex->mi,sizeof(lex->mi));
  return lex;
 }

--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@ -98,6 +98,8 @@ typedef struct st_lex_master_info
  uint port, connect_retry;
  ulonglong pos;
  ulong server_id;
+  char* relay_log_name;
+  ulong relay_log_pos;
 } LEX_MASTER_INFO;


--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@ -690,6 +690,7 @@ int change_master(THD* thd, MASTER_INFO* mi)
 {
  int error=0,restart_thread_mask;
  const char* errmsg=0;
+  bool need_relay_log_purge=1;
  
  // kill slave thread
  lock_slave_threads(mi);
@ -742,17 +743,47 @@ int change_master(THD* thd, MASTER_INFO* mi)
  if (lex_mi->connect_retry)
    mi->connect_retry = lex_mi->connect_retry;

-  flush_master_info(mi);
-  pthread_mutex_unlock(&mi->data_lock);
-  thd->proc_info="purging old relay logs";
-  if (purge_relay_logs(&mi->rli,0 /* not only reset, but also reinit*/,
-		       &errmsg))
+  if (lex_mi->relay_log_name)
  {
-    send_error(&thd->net, 0, "Failed purging old relay logs");
-    unlock_slave_threads(mi);
-    return 1;
+    need_relay_log_purge = 0;
+    strnmov(mi->rli.relay_log_name,lex_mi->relay_log_name,
+	    sizeof(mi->rli.relay_log_name));
+  }
+
+  if (lex_mi->relay_log_pos)
+  {
+    need_relay_log_purge=0;
+    mi->rli.relay_log_pos=lex_mi->relay_log_pos;
+  }
+
+  flush_master_info(mi);
+  if (need_relay_log_purge)
+  {
+    pthread_mutex_unlock(&mi->data_lock);
+    thd->proc_info="purging old relay logs";
+    if (purge_relay_logs(&mi->rli,0 /* not only reset, but also reinit*/,
+			 &errmsg))
+    {
+      send_error(&thd->net, 0, "Failed purging old relay logs");
+      unlock_slave_threads(mi);
+      return 1;
+    }
+    pthread_mutex_lock(&mi->rli.data_lock);
+  }
+  else
+  {
+    const char* msg;
+    if (init_relay_log_pos(&mi->rli,0/*log already inited*/,
+			   0 /*pos already inited*/,
+			   0 /*no data lock*/,
+			   &msg))
+    {
+      net_printf(&thd->net,0,"Failed initializing relay log position: %s",msg);
+      unlock_slave_threads(mi);
+      return 1;
+    }
+      
  }
-  pthread_mutex_lock(&mi->rli.data_lock);
  mi->rli.master_log_pos = mi->master_log_pos;
  strnmov(mi->rli.master_log_name,mi->master_log_name,
 	  sizeof(mi->rli.master_log_name));
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@ -241,6 +241,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token  MASTER_PORT_SYM
 %token  MASTER_CONNECT_RETRY_SYM
 %token  MASTER_SERVER_ID_SYM
+%token  RELAY_LOG_FILE_SYM
+%token  RELAY_LOG_POS_SYM
 %token	MATCH
 %token	MAX_ROWS
 %token  MAX_QUERIES_PER_HOUR
@ -701,6 +703,16 @@ master_def:
       {
 	 Lex->mi.connect_retry = $3;
       }
+       |
+       RELAY_LOG_FILE_SYM EQ TEXT_STRING
+       {
+	 Lex->mi.relay_log_name = $3.str;
+       }
+       |
+       RELAY_LOG_POS_SYM EQ ULONG_NUM
+       {
+	 Lex->mi.relay_log_pos = $3;
+       }


 /* create a table */
@ -3013,6 +3025,7 @@ keyword:
 	| ISSUER_SYM		{}
 	| INNOBASE_SYM		{}
 	| INSERT_METHOD		{}
+        | IO_THREAD {}
 	| LAST_SYM		{}
 	| LEVEL_SYM		{}
 	| LOCAL_SYM		{}
@ -3055,6 +3068,8 @@ keyword:
 	| RAID_CHUNKSIZE	{}
 	| RAID_STRIPED_SYM      {}
 	| RAID_TYPE		{}
+        | RELAY_LOG_FILE_SYM {}
+        | RELAY_LOG_POS_SYM {}
 	| RELOAD		{}
 	| REPAIR		{}
 	| REPEATABLE_SYM	{}
@ -3074,6 +3089,7 @@ keyword:
 	| SQL_CACHE_SYM		{}
 	| SQL_NO_CACHE_SYM	{}
 	| SQL_QUERY_CACHE_TYPE_SYM {}
+        | SQL_THREAD {}
 	| START_SYM		{}
 	| STATUS_SYM		{}
 	| STOP_SYM		{}