make CHECK killable

myisam/mi_check.c

@@ -142,6 +142,8 @@ int chk_del(MI_CHECK *param, register MI_INFO *info, uint test_flag)
     empty=0;
     for (i= info->state->del ; i > 0L && next_link != HA_OFFSET_ERROR ; i--)
     {
+      if (*killed_ptr(param))
+        DBUG_RETURN(1);
       if (test_flag & T_VERBOSE)
 	printf(" %9s",llstr(next_link,buff));
       if (next_link >= info->state->data_file_length)
@@ -233,6 +235,8 @@ static int check_k_link(MI_CHECK *param, register MI_INFO *info, uint nr)
   records= (ha_rows) (info->state->key_file_length / block_size);
   while (next_link != HA_OFFSET_ERROR && records > 0)
   {
+    if (*killed_ptr(param))
+      DBUG_RETURN(1);
     if (param->testflag & T_VERBOSE)
       printf("%16s",llstr(next_link,llbuff));
     if (next_link > info->state->key_file_length ||
@@ -372,6 +376,8 @@ int chk_key(MI_CHECK *param, register MI_INFO *info)
   for (key= 0,keyinfo= &share->keyinfo[0]; key < share->base.keys ;
        rec_per_key_part+=keyinfo->keysegs, key++, keyinfo++)
   {
+    if (*killed_ptr(param))
+      DBUG_RETURN(-1);
     param->key_crc[key]=0;
     if (!(((ulonglong) 1 << key) & share->state.key_map))
     {
@@ -592,6 +598,8 @@ static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
   }
   for ( ;; )
   {
+    if (*killed_ptr(param))
+      goto err;
     memcpy((char*) info->lastkey,(char*) key,key_length);
     info->lastkey_length=key_length;
     if (nod_flag)
@@ -782,6 +790,8 @@ int chk_data_link(MI_CHECK *param, MI_INFO *info,int extend)
   bzero((char*) key_checksum, info->s->base.keys * sizeof(key_checksum[0]));
   while (pos < info->state->data_file_length)
   {
+    if (*killed_ptr(param))
+      goto err2;
     switch (info->s->data_file_type) {
     case STATIC_RECORD:
       if (my_b_read(&param->read_cache,(byte*) record,