Fix for lp:711565 "Index Condition Pushdown can make a thread hold MyISAM locks as well as be unKILLable for long time"

- In Maria/MyISAM: Release/re-acquire locks to give queries that wait on them a chance to make progress
- In Maria/MyISAM: Change from numeric constants to ICP_RES values.
- In Maria: Do check index condition in maria_rprev() (was lost in the merge/backport?)
- In Maria/MyISAM/XtraDB: Check if the query was killed, and return immediately if it was.

Added new storage engine error: HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted

Authors: Sergey Petrunia & Monty

include/my_base.h:
  Added HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted
include/my_handler.h:
  Added comment
mysql-test/r/myisam_icp.result:
  Updated test
mysql-test/t/myisam_icp.test:
  Drop used tables at start of test
  Added test case that can help with manual testing of killing index condition pushdown query.
mysys/my_handler_errors.h:
  Text for new storage engine error
sql/handler.cc:
  If engine got HA_ERR_ABORTED_BY_USER, send kill message.
sql/multi_range_read.cc:
  Return error code
storage/maria/ha_maria.cc:
  Added ma_killed_in_mariadb() to detect kill.
  Ensure that file->external_ref points to TABLE object.
storage/maria/ma_extra.c:
  Dummy test-if-killed for standalone
storage/maria/ma_key.c:
  If ma_check_index_cond() fails, set my_errno and info->cur_row.lastpos
storage/maria/ma_rkey.c:
  Release/re-acquire locks to give queries that wait on them a chance to make progress
  Check if the query was killed, and return immediately if it was
storage/maria/ma_rnext.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info)
storage/maria/ma_rnext_same.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info)
storage/maria/ma_rprev.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info) and ma_check_index_cond()
storage/maria/ma_search.c:
  Give error message if we find a wrong key
storage/maria/ma_static.c:
  Added pointer to test-if-killed function
storage/maria/maria_def.h:
  New prototypes
storage/myisam/ha_myisam.cc:
  Added mi_killed_in_mariadb()
  Ensure that file->external_ref points to TABLE object.
storage/myisam/mi_extra.c:
  Dummy test-if-killed for standalone
storage/myisam/mi_key.c:
  If ma_check_index_cond() fails, set my_errno and info->lastpos
storage/myisam/mi_rkey.c:
  Ensure that info->lastpos= HA_OFFSET_ERROR in case of error
  Release/re-acquire locks to give queries that wait on them a chance to make progress
  Check if the query was killed, and return immediately if it was
  Reorder code to do less things in case of error.
  Added missing fast_mi_writeinfo()
storage/myisam/mi_rnext.c:
  Check if the query was killed, and return immediately if it was
  Simplify old ICP code
  Added missing fast_ma_writeinfo(info)
storage/myisam/mi_rnext_same.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_mi_writeinfo(info)
storage/myisam/mi_rprev.c:
  Check if the query was killed, and return immediately if it was
  Simplify error handling of ICP
  Added missing fast_mi_writeinfo(info)
storage/myisam/mi_search.c:
  Give error message if we find a wrong key
storage/myisam/mi_static.c:
  Added pointer to test-if-killed function
storage/myisam/myisamdef.h:
  New prototypes
storage/xtradb/handler/ha_innodb.cc:
  Added DB_SEARCH_ABORTED_BY_USER and ha_innobase::is_thd_killed()
  Check if the query was killed, and return immediately if it was
storage/xtradb/handler/ha_innodb.h:
  Added prototype
storage/xtradb/include/db0err.h:
  Added DB_SEARCH_ABORTED_BY_USER
storage/xtradb/include/row0mysql.h:
  Added possible ICP errors
storage/xtradb/row/row0sel.c:
  Use ICP errors instead of constants.
  Detect if killed and return B_SEARCH_ABORTED_BY_USER

10 files changed, 164 insertions, 35 deletions

diff --git a/storage/maria/ha_maria.cc b/storage/maria/ha_maria.cc
index 9acabf29774..406def92808 100644
--- a/storage/maria/ha_maria.cc
+++ b/storage/maria/ha_maria.cc
@@ -758,7 +758,7 @@ void _ma_check_print_warning(HA_CHECK *param, const char *fmt, ...)
 
 static int maria_create_trn_for_mysql(MARIA_HA *info)
 {
-  THD *thd= (THD*) info->external_ptr;
+  THD *thd= ((TABLE*) info->external_ref)->in_use;
   TRN *trn= THD_TRN;
   DBUG_ENTER("maria_create_trn_for_mysql");
 
@@ -797,6 +797,11 @@ static int maria_create_trn_for_mysql(MARIA_HA *info)
   DBUG_RETURN(0);
 }
 
+my_bool ma_killed_in_mariadb(MARIA_HA *info)
+{
+  return (((TABLE*) (info->external_ref))->in_use->killed != 0);
+}
+
 } /* extern "C" */
 
 /**
@@ -1013,6 +1018,8 @@ int ha_maria::open(const char *name, int mode, uint test_if_locked)
     return (my_errno ? my_errno : -1);
 
   file->s->chst_invalidator= query_cache_invalidate_by_MyISAM_filename_ref;
+  /* Set external_ref, mainly for temporary tables */
+  file->external_ref= (void*) table;            // For ma_killed()
 
   if (test_if_locked & (HA_OPEN_IGNORE_IF_LOCKED | HA_OPEN_TMP_TABLE))
     VOID(maria_extra(file, HA_EXTRA_NO_WAIT_LOCK, 0));
@@ -2525,6 +2532,7 @@ void ha_maria::drop_table(const char *name)
 int ha_maria::external_lock(THD *thd, int lock_type)
 {
   DBUG_ENTER("ha_maria::external_lock");
+  file->external_ref= (void*) table;            // For ma_killed()
   /*
     We don't test now_transactional because it may vary between lock/unlock
     and thus confuse our reference counting.
@@ -2543,8 +2551,6 @@ int ha_maria::external_lock(THD *thd, int lock_type)
     /* Transactional table */
     if (lock_type != F_UNLCK)
     {
-      file->external_ptr= thd;                  // For maria_register_trn()
-
       if (!file->s->lock_key_trees)             // If we don't use versioning
       {
         /*
@@ -3392,6 +3398,9 @@ static int ha_maria_init(void *p)
 #endif
   if (res)
     maria_hton= 0;
+
+  ma_killed= ma_killed_in_mariadb;
+
   return res ? HA_ERR_INITIALIZATION : 0;
 }
 
diff --git a/storage/maria/ma_extra.c b/storage/maria/ma_extra.c
index 7a30b613ea5..a2d40b1c828 100644
--- a/storage/maria/ma_extra.c
+++ b/storage/maria/ma_extra.c
@@ -635,3 +635,9 @@ int _ma_flush_table_files(MARIA_HA *info, uint flush_data_or_index,
   return 1;
 }
 
+
+my_bool ma_killed_standalone(MARIA_HA *info __attribute__((unused)))
+{
+  return 0;
+}
+
diff --git a/storage/maria/ma_key.c b/storage/maria/ma_key.c
index ac23bf5fef6..df15d029ce6 100644
--- a/storage/maria/ma_key.c
+++ b/storage/maria/ma_key.c
@@ -669,25 +669,39 @@ int _ma_read_key_record(MARIA_HA *info, uchar *buf, MARIA_RECORD_POS filepos)
               will look for column values there)
 
   RETURN
-    ICP_ERROR         Error 
+    ICP_ERROR         Error ; my_errno set to HA_ERR_CRASHED
     ICP_NO_MATCH      Index condition is not satisfied, continue scanning
     ICP_MATCH         Index condition is satisfied
-    ICP_OUT_OF_RANGE  Index condition is not satisfied, end the scan. 
+    ICP_OUT_OF_RANGE  Index condition is not satisfied, end the scan.
+                      my_errno set to HA_ERR_END_OF_FILE
+
+    info->cur_row.lastpos is set to HA_OFFSET_ERROR in case of ICP_ERROR or
+    ICP_OUT_OF_RANGE to indicate that we don't have any active row.
 */
 
-int ma_check_index_cond(register MARIA_HA *info, uint keynr, uchar *record)
+ICP_RESULT ma_check_index_cond(register MARIA_HA *info, uint keynr,
+                               uchar *record)
 {
+  ICP_RESULT res= ICP_MATCH;
   if (info->index_cond_func)
   {
     if (_ma_put_key_in_record(info, keynr, FALSE, record))
     {
+      /* Impossible case; Can only happen if bug in code */
       maria_print_error(info->s, HA_ERR_CRASHED);
-      my_errno=HA_ERR_CRASHED;
-      return -1;
+      info->cur_row.lastpos= HA_OFFSET_ERROR;   /* No active record */
+      my_errno= HA_ERR_CRASHED;
+      res= ICP_ERROR;
+    }
+    else if ((res= info->index_cond_func(info->index_cond_func_arg)) ==
+             ICP_OUT_OF_RANGE)
+    {
+      /* We got beyond the end of scanned range */
+      info->cur_row.lastpos= HA_OFFSET_ERROR;   /* No active record */
+      my_errno= HA_ERR_END_OF_FILE;
     }
-    return info->index_cond_func(info->index_cond_func_arg);
   }
-  return 1;
+  return res;
 }
 
 
diff --git a/storage/maria/ma_rkey.c b/storage/maria/ma_rkey.c
index 5da541005f8..01a7f64e431 100644
--- a/storage/maria/ma_rkey.c
+++ b/storage/maria/ma_rkey.c
@@ -34,7 +34,7 @@ int maria_rkey(MARIA_HA *info, uchar *buf, int inx, const uchar *key_data,
   HA_KEYSEG *last_used_keyseg;
   uint32 nextflag;
   MARIA_KEY key;
-  int icp_res= 1;
+  ICP_RESULT icp_res= ICP_MATCH;
   DBUG_ENTER("maria_rkey");
   DBUG_PRINT("enter", ("base: 0x%lx  buf: 0x%lx  inx: %d  search_flag: %d",
                        (long) info, (long) buf, inx, search_flag));
@@ -115,7 +115,7 @@ int maria_rkey(MARIA_HA *info, uchar *buf, int inx, const uchar *key_data,
         not satisfied with an out-of-range condition.
       */
       if ((*share->row_is_visible)(info) && 
-          ((icp_res= ma_check_index_cond(info, inx, buf)) != 0))
+          ((icp_res= ma_check_index_cond(info, inx, buf)) != ICP_NO_MATCH))
         break;
 
       /* The key references a concurrently inserted record. */
@@ -145,6 +145,18 @@ int maria_rkey(MARIA_HA *info, uchar *buf, int inx, const uchar *key_data,
         if  (_ma_search_next(info, &lastkey, maria_readnext_vec[search_flag],
                              info->s->state.key_root[inx]))
           break;                          /* purecov: inspected */
+
+        /*
+          If we are at the last key on the key page, allow writers to
+          access the index.
+        */
+        if (info->int_keypos >= info->int_maxpos &&
+            ma_yield_and_check_if_killed(info, inx))
+        {
+          DBUG_ASSERT(info->cur_row.lastpos == HA_OFFSET_ERROR);
+          break;
+        }
+
         /*
           Check that the found key does still match the search.
           _ma_search_next() delivers the next key regardless of its
@@ -164,15 +176,19 @@ int maria_rkey(MARIA_HA *info, uchar *buf, int inx, const uchar *key_data,
       } while (!(*share->row_is_visible)(info) || 
                ((icp_res= ma_check_index_cond(info, inx, buf)) == 0));
     }
+    else
+    {
+      DBUG_ASSERT(info->cur_row.lastpos);
+    }
   }
   if (share->lock_key_trees)
     rw_unlock(&keyinfo->root_lock);
 
-  if (info->cur_row.lastpos == HA_OFFSET_ERROR || (icp_res != 1))
+  if (info->cur_row.lastpos == HA_OFFSET_ERROR)
   {
-    if (icp_res == 2)
+    if (icp_res == ICP_OUT_OF_RANGE)
     {
-      info->cur_row.lastpos= HA_OFFSET_ERROR;
+      /* We don't want HA_ERR_END_OF_FILE in this particular case */
       my_errno= HA_ERR_KEY_NOT_FOUND;
     }
     fast_ma_writeinfo(info);
@@ -214,3 +230,35 @@ err:
     info->update|=HA_STATE_NEXT_FOUND;		/* Previous gives last row */
   DBUG_RETURN(my_errno);
 } /* _ma_rkey */
+
+
+/*
+  Yield to possible other writers during a index scan.
+  Check also if we got killed by the user and if yes, return
+  HA_ERR_LOCK_WAIT_TIMEOUT
+
+  return  0  ok
+  return  1  Query has been requested to be killed
+*/
+
+my_bool ma_yield_and_check_if_killed(MARIA_HA *info, int inx)
+{
+  MARIA_SHARE *share;
+  if (ma_killed(info))
+  {
+    /* Mark that we don't have an active row */
+    info->cur_row.lastpos= HA_OFFSET_ERROR;
+    /* Set error that we where aborted by kill from application */
+    my_errno= HA_ERR_ABORTED_BY_USER;
+    return 1;
+  }
+
+  if ((share= info->s)->lock_key_trees)
+  {
+    /* Give writers a chance to access index */
+    rw_unlock(&share->keyinfo[inx].root_lock);
+    rw_rdlock(&share->keyinfo[inx].root_lock);
+  }
+  return 0;
+}
+
diff --git a/storage/maria/ma_rnext.c b/storage/maria/ma_rnext.c
index bdba5ff3a17..2fd8bf4e603 100644
--- a/storage/maria/ma_rnext.c
+++ b/storage/maria/ma_rnext.c
@@ -30,7 +30,7 @@ int maria_rnext(MARIA_HA *info, uchar *buf, int inx)
   uint flag;
   MARIA_SHARE *share= info->s;
   MARIA_KEYDEF *keyinfo;
-  int icp_res= 1;
+  ICP_RESULT icp_res= ICP_MATCH;
   DBUG_ENTER("maria_rnext");
 
   if ((inx = _ma_check_index(info,inx)) < 0)
@@ -92,8 +92,20 @@ int maria_rnext(MARIA_HA *info, uchar *buf, int inx)
   if (!error)
   {
     while (!(*share->row_is_visible)(info) ||
-           ((icp_res= ma_check_index_cond(info, inx, buf)) == 0))
+           ((icp_res= ma_check_index_cond(info, inx, buf)) == ICP_NO_MATCH))
     {
+      /*
+        If we are at the last key on the key page, allow writers to
+        access the index.
+      */
+      if (info->int_keypos >= info->int_maxpos &&
+          ma_yield_and_check_if_killed(info, inx))
+      {
+        /* my_errno is set by ma_yield_and_check_if_killed() */
+        error= 1;
+        break;
+      }
+
       /* Skip rows inserted by other threads since we got a lock */
       if  ((error= _ma_search_next(info, &info->last_key,
                                    SEARCH_BIGGER,
@@ -108,16 +120,15 @@ int maria_rnext(MARIA_HA *info, uchar *buf, int inx)
   info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
   info->update|= HA_STATE_NEXT_FOUND;
   
-  if (icp_res == 2)
-    my_errno=HA_ERR_END_OF_FILE; /* got beyond the end of scanned range */
-
-  if (error || icp_res != 1)
+  if (error || icp_res != ICP_MATCH)
   {
+    fast_ma_writeinfo(info);
     if (my_errno == HA_ERR_KEY_NOT_FOUND)
-      my_errno=HA_ERR_END_OF_FILE;
+      my_errno= HA_ERR_END_OF_FILE;
   }
   else if (!buf)
   {
+    fast_ma_writeinfo(info);
     DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
   }
   else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
diff --git a/storage/maria/ma_rnext_same.c b/storage/maria/ma_rnext_same.c
index f67a76a366f..c35d8ae0222 100644
--- a/storage/maria/ma_rnext_same.c
+++ b/storage/maria/ma_rnext_same.c
@@ -30,7 +30,7 @@ int maria_rnext_same(MARIA_HA *info, uchar *buf)
   int error;
   uint inx,not_used[2];
   MARIA_KEYDEF *keyinfo;
-  int icp_res= 1;
+  ICP_RESULT icp_res= ICP_MATCH;
   DBUG_ENTER("maria_rnext_same");
 
   if ((int) (inx= info->lastinx) < 0 ||
@@ -80,9 +80,19 @@ int maria_rnext_same(MARIA_HA *info, uchar *buf)
           info->cur_row.lastpos= HA_OFFSET_ERROR;
           break;
         }
+        /*
+          If we are at the last key on the key page, allow writers to
+          access the index.
+        */
+        if (info->int_keypos >= info->int_maxpos &&
+            ma_yield_and_check_if_killed(info, inx))
+        {
+          error= 1;
+          break;
+        }
         /* Skip rows that are inserted by other threads since we got a lock */
         if ((info->s->row_is_visible)(info) &&
-            ((icp_res= ma_check_index_cond(info, inx, buf)) != 0))
+            ((icp_res= ma_check_index_cond(info, inx, buf)) != ICP_NO_MATCH))
           break;
       }
   }
@@ -92,16 +102,15 @@ int maria_rnext_same(MARIA_HA *info, uchar *buf)
   info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
   info->update|= HA_STATE_NEXT_FOUND | HA_STATE_RNEXT_SAME;
 
-  if (icp_res == 2)
-    my_errno=HA_ERR_END_OF_FILE; /* got beyond the end of scanned range */
-
-  if (error || icp_res != 1)
+  if (error || icp_res != ICP_MATCH)
   {
+    fast_ma_writeinfo(info);
     if (my_errno == HA_ERR_KEY_NOT_FOUND)
-      my_errno=HA_ERR_END_OF_FILE;
+      my_errno= HA_ERR_END_OF_FILE;
   }
   else if (!buf)
   {
+    fast_ma_writeinfo(info);
     DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
   }
   else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
diff --git a/storage/maria/ma_rprev.c b/storage/maria/ma_rprev.c
index b9f46d7c405..c4bcb9de967 100644
--- a/storage/maria/ma_rprev.c
+++ b/storage/maria/ma_rprev.c
@@ -28,6 +28,7 @@ int maria_rprev(MARIA_HA *info, uchar *buf, int inx)
   register uint flag;
   MARIA_SHARE *share= info->s;
   MARIA_KEYDEF *keyinfo;
+  ICP_RESULT   icp_res= ICP_MATCH;
   DBUG_ENTER("maria_rprev");
 
   if ((inx = _ma_check_index(info,inx)) < 0)
@@ -55,8 +56,24 @@ int maria_rprev(MARIA_HA *info, uchar *buf, int inx)
 
   if (!error)
   {
-    while (!(*share->row_is_visible)(info))
+    my_off_t cur_keypage= info->last_keypage;
+    while (!(*share->row_is_visible)(info) ||
+           ((icp_res= ma_check_index_cond(info, inx, buf)) == ICP_NO_MATCH))
     {
+      /*
+        If we are at the last (i.e. first?) key on the key page, 
+        allow writers to access the index.
+      */
+      if (info->last_keypage != cur_keypage)
+      {
+        cur_keypage= info->last_keypage;
+        if (ma_yield_and_check_if_killed(info, inx))
+        {
+          error= 1;
+          break;
+        }
+      }
+
       /* Skip rows that are inserted by other threads since we got a lock */
       if  ((error= _ma_search_next(info, &info->last_key,
                                    SEARCH_SMALLER,
@@ -68,13 +85,16 @@ int maria_rprev(MARIA_HA *info, uchar *buf, int inx)
     rw_unlock(&keyinfo->root_lock);
   info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
   info->update|= HA_STATE_PREV_FOUND;
-  if (error)
+
+  if (error || icp_res != ICP_MATCH)
   {
+    fast_ma_writeinfo(info);
     if (my_errno == HA_ERR_KEY_NOT_FOUND)
-      my_errno=HA_ERR_END_OF_FILE;
+      my_errno= HA_ERR_END_OF_FILE;
   }
   else if (!buf)
   {
+    fast_ma_writeinfo(info);
     DBUG_RETURN(info->cur_row.lastpos == HA_OFFSET_ERROR ? my_errno : 0);
   }
   else if (!(*info->read_record)(info, buf, info->cur_row.lastpos))
diff --git a/storage/maria/ma_search.c b/storage/maria/ma_search.c
index 8d3b5721336..4ac6dfeb15f 100644
--- a/storage/maria/ma_search.c
+++ b/storage/maria/ma_search.c
@@ -141,7 +141,11 @@ static int _ma_search_no_save(register MARIA_HA *info, MARIA_KEY *key,
   flag= (*keyinfo->bin_search)(key, &page, nextflag, &keypos, lastkey,
                                &last_key_not_used);
   if (flag == MARIA_FOUND_WRONG_KEY)
-    DBUG_RETURN(-1);
+  {
+    maria_print_error(info->s, HA_ERR_CRASHED);
+    my_errno= HA_ERR_CRASHED;
+    goto err;
+  }
   page_flag=   page.flag;
   used_length= page.size;
   nod_flag=    page.node;
diff --git a/storage/maria/ma_static.c b/storage/maria/ma_static.c
index 917385f9568..37814b42dc2 100644
--- a/storage/maria/ma_static.c
+++ b/storage/maria/ma_static.c
@@ -107,3 +107,6 @@ static int always_valid(const char *filename __attribute__((unused)))
 }
 
 int (*maria_test_invalid_symlink)(const char *filename)= always_valid;
+
+my_bool (*ma_killed)(MARIA_HA *)= ma_killed_standalone;
+
diff --git a/storage/maria/maria_def.h b/storage/maria/maria_def.h
index 65898666686..beb286c7d4b 100644
--- a/storage/maria/maria_def.h
+++ b/storage/maria/maria_def.h
@@ -492,7 +492,6 @@ struct st_maria_handler
 {
   MARIA_SHARE *s;			/* Shared between open:s */
   struct st_ma_transaction *trn;        /* Pointer to active transaction */
-  void *external_ptr;           	/* Pointer to THD in mysql */
   MARIA_STATUS_INFO *state, state_save;
   MARIA_STATUS_INFO *state_start;       /* State at start of transaction */
   MARIA_ROW cur_row;                    /* The active row that we just read */
@@ -509,6 +508,7 @@ struct st_maria_handler
   DYNAMIC_ARRAY *ft1_to_ft2;		/* used only in ft1->ft2 conversion */
   MEM_ROOT      ft_memroot;             /* used by the parser               */
   MYSQL_FTPARSER_PARAM *ftparser_param;	/* share info between init/deinit */
+  void *external_ref;			/* For MariaDB TABLE */
   uchar *buff;				/* page buffer */
   uchar *keyread_buff;                   /* Buffer for last key read */
   uchar *lastkey_buff;			/* Last used search key */
@@ -813,6 +813,7 @@ extern my_bool maria_inited, maria_in_ha_maria, maria_recovery_changed_data;
 extern my_bool maria_recovery_verbose;
 extern HASH maria_stored_state;
 extern int (*maria_create_trn_hook)(MARIA_HA *);
+extern my_bool (*ma_killed)(MARIA_HA *);
 
 /* This is used by _ma_calc_xxx_key_length och _ma_store_key */
 typedef struct st_maria_s_param
@@ -1281,4 +1282,8 @@ extern my_bool maria_flush_log_for_page_none(uchar *page,
 extern PAGECACHE *maria_log_pagecache;
 extern void ma_set_index_cond_func(MARIA_HA *info, index_cond_func_t func,
                                    void *func_arg);
-int ma_check_index_cond(register MARIA_HA *info, uint keynr, uchar *record);
+ICP_RESULT ma_check_index_cond(register MARIA_HA *info, uint keynr, uchar *record);
+
+extern my_bool ma_yield_and_check_if_killed(MARIA_HA *info, int inx);
+extern my_bool ma_killed_standalone(MARIA_HA *);
+