Fixed core dump bug when hot link list in key cache was empty. Bug #10167

mysql-test/r/drop.result:
  Fixed result

mysql-test/r/drop.result

@@ -30,13 +30,13 @@ table7, table8, table9, table10, table11, table12, table13,
 table14, table15, table16, table17, table18, table19, table20,
 table21, table22, table23, table24, table25, table26, table27,
 table28;
-ERROR 42S02: Unknown table 'table1,table2,table3,table4,table5,table6,table7,table8,table9,table10,table11,table12,table13,table14,table15,table16,table17,table18,table19,table20,table21,table22,table23,table'
+ERROR 42S02: Unknown table 'table1,table2,table3,table4,table5,table6,table7,table8,table9,table10,table11,table12,table13,table'
 drop table table1, table2, table3, table4, table5, table6,
 table7, table8, table9, table10, table11, table12, table13,
 table14, table15, table16, table17, table18, table19, table20,
 table21, table22, table23, table24, table25, table26, table27,
 table28, table29, table30;
-ERROR 42S02: Unknown table 'table1,table2,table3,table4,table5,table6,table7,table8,table9,table10,table11,table12,table13,table14,table15,table16,table17,table18,table19,table20,table21,table22,table23,table'
+ERROR 42S02: Unknown table 'table1,table2,table3,table4,table5,table6,table7,table8,table9,table10,table11,table12,table13,table'
 use test;
 drop database mysqltest;
 flush tables with read lock;

mysys/mf_keycache.c

@@ -1025,8 +1025,8 @@ static void reg_requests(KEY_CACHE *keycache, BLOCK_LINK *block, int count)
     for a too long time (this time is determined by parameter age_threshold).
 */
 
-static inline void unreg_request(KEY_CACHE *keycache,
-                                 BLOCK_LINK *block, int at_end)
+static void unreg_request(KEY_CACHE *keycache,
+                          BLOCK_LINK *block, int at_end)
 {
   if (! --block->requests)
   {
@@ -1045,10 +1045,13 @@ static inline void unreg_request(KEY_CACHE *keycache,
     }
     link_block(keycache, block, hot, (my_bool)at_end);
     block->last_hit_time= keycache->keycache_time;
-    if (++keycache->keycache_time - keycache->used_ins->last_hit_time >
+    keycache->keycache_time++;
+
+    block= keycache->used_ins;
+    /* Check if we should link a hot block to the warm block */
+    if (block && keycache->keycache_time - block->last_hit_time >
 	keycache->age_threshold)
     {
-      block= keycache->used_ins;
       unlink_block(keycache, block);
       link_block(keycache, block, 0, 0);
       if (block->temperature != BLOCK_WARM)

tests/index_corrupt.pl

+#!/usr/bin/perl -w
+#
+# This is a test for a key cache bug (bug #10167)
+# To expose the bug mysqld should be started with --key-buffer-size=64K
+#
+
+$opt_loop_count=100000; # Change this to make test harder/easier
+
+##################### Standard benchmark inits ##############################
+
+use DBI;
+use Getopt::Long;
+use Benchmark;
+
+package main;
+
+$opt_skip_create=$opt_skip_in=$opt_verbose=$opt_fast_insert=
+  $opt_lock_tables=$opt_debug=$opt_skip_delete=$opt_fast=$opt_force=0;
+$opt_host=$opt_user=$opt_password=""; $opt_db="test";
+
+GetOptions("host=s","db=s","loop-count=i","skip-create","skip-in",
+	   "skip-delete","verbose","fast-insert","lock-tables","debug","fast",
+	   "force","user=s","password=s") || die "Aborted";
+$opt_verbose=$opt_debug=$opt_lock_tables=$opt_fast_insert=$opt_fast=$opt_skip_in=$opt_force=undef;  # Ignore warnings from these
+
+$firsttable  = "bench_f1";
+$secondtable = "bench_f2";
+$kill_file= "/tmp/mysqltest_index_corrupt.$$";
+
+####
+####  Start timeing and start test
+####
+
+$start_time=new Benchmark;
+if (!$opt_skip_create)
+{
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+  $dbh->do("drop table if exists $firsttable, $secondtable");
+
+  print "Creating tables in $opt_db\n";
+  $dbh->do("create table $firsttable (
+c_pollid    INTEGER  NOT NULL,
+c_time      BIGINT   NOT NULL,
+c_data      DOUBLE   NOT NULL,
+c_error     INTEGER  NOT NULL,
+c_warning   INTEGER  NOT NULL,
+c_okay      INTEGER  NOT NULL,
+c_unknown   INTEGER  NOT NULL,
+c_rolled_up BIT      NOT NULL,
+INDEX t_mgmt_hist_r_i1 (c_pollid),
+INDEX t_mgmt_hist_r_i2 (c_time),
+INDEX t_mgmt_hist_r_i3 (c_rolled_up))") or die $DBI::errstr;
+
+  $dbh->do("create table $secondtable (
+c_pollid  INTEGER  NOT NULL,
+c_min_time  BIGINT   NOT NULL,
+c_max_time  BIGINT   NOT NULL,
+c_min_data  DOUBLE   NOT NULL,
+c_max_data  DOUBLE   NOT NULL,
+c_avg_data  DOUBLE   NOT NULL,
+c_error     INTEGER  NOT NULL,
+c_warning   INTEGER  NOT NULL,
+c_okay      INTEGER  NOT NULL,
+c_unknown   INTEGER  NOT NULL,
+c_rolled_up BIT      NOT NULL,
+INDEX t_mgmt_hist_d_i1 (c_pollid),
+INDEX t_mgmt_hist_d_i2 (c_min_time),
+INDEX t_mgmt_hist_d_i3 (c_max_time),
+INDEX t_mgmt_hist_d_i4 (c_rolled_up))") or die $DBI::errstr;
+
+
+  $dbh->disconnect; $dbh=0;	# Close handler
+}
+$|= 1;				# Autoflush
+
+####
+#### Start the tests
+####
+
+print "Running tests\n";
+insert_in_bench() if (($pid=fork()) == 0); $work{$pid}="insert";
+select_from_bench() if (($pid=fork()) == 0); $work{$pid}="insert-select;
+delete_from_bench() if (($pid=fork()) == 0); $work{$pid}="delete";
+
+$errors=0;
+while (($pid=wait()) != -1)
+{
+  $ret=$?/256;
+  print "thread '" . $work{$pid} . "' finished with exit code $ret\n";
+  $errors++ if ($ret != 0);
+}
+
+if (!$opt_skip_delete && !$errors)
+{
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+  $dbh->do("drop table $firsttable, $secondtable");
+}
+print ($errors ? "Test failed\n" :"Test ok\n");
+
+$end_time=new Benchmark;
+print "Total time: " .
+  timestr(timediff($end_time, $start_time),"noc") . "\n";
+
+unlink $kill_file;
+
+exit(0);
+
+#
+# Insert records in the two tables
+#
+
+sub insert_in_bench
+{
+  my ($dbh,$rows,$found,$i);
+
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+  for ($rows= 1; $rows <= $opt_loop_count ; $rows++)
+  {
+    $c_pollid = sprintf("%d",rand 1000);
+    $c_time = sprintf("%d",rand 100000);
+    $c_data = rand 1000000;
+    $test = rand 1;
+    $c_error=0;
+    $c_warning=0;
+    $c_okay=0;
+    $c_unknown=0;
+    if ($test < .8) {
+      $c_okay=1;
+    } elsif ($test <.9) {
+      $c_error=1;
+    } elsif ($test <.95) {
+      $c_warning=1;
+    } else {
+      $c_unknown=1;
+    }
+    $statement = "INSERT INTO $firsttable (c_pollid, c_time, c_data, c_error
+, c_warning, c_okay, c_unknown, c_rolled_up) ".
+  "VALUES ($c_pollid,$c_time,$c_data,$c_error,$c_warning,$c_okay,$c_unknown,0)";
+    $cursor = $dbh->prepare($statement);
+    $cursor->execute();
+    $cursor->finish();
+  }
+
+  $dbh->disconnect; $dbh=0;
+  print "insert_in_bench: Inserted $rows rows\n";
+
+  # Kill other threads
+  open(KILLFILE, "> $kill_file");
+  close(KILLFILE);
+
+  exit(0);
+}
+
+
+sub select_from_bench
+{
+  my ($dbh,$rows,$cursor);
+
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+  for ($rows= 1; $rows < $opt_loop_count ; $rows++)
+  {
+    $t_value = rand 100000;
+    $t_value2 = $t_value+10000;
+    $statement = "INSERT INTO $secondtable (c_pollid, c_min_time, c_max_time
+, c_min_data, c_max_data, c_avg_data, c_error, c_warning, c_okay, c_unknown, c_rolled_up) SELECT c_pollid, MIN(c_time), MAX(c_time), MIN(c_data), MAX(c_data), AVG(c_data), SUM(c_error), SUM(c_warning), SUM(c_okay), SUM(c_unknown), 0 FROM $firsttable WHERE (c_time>=$t_value) AND (c_time<$t_value2) AND (c_rolled_up=0) GROUP BY c_pollid";
+    $cursor = $dbh->prepare($statement);
+    $cursor->execute();
+    $cursor->finish();
+    sleep 1;
+    if (-e $kill_file)
+    {
+      last;
+    }
+  }
+  print "select_from_bench: insert-select executed $rows times\n";
+  exit(0);
+}
+
+
+sub delete_from_bench
+{
+  my ($dbh,$row, $t_value, $t2_value, $statement, $cursor);
+
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+
+  for ($rows= 1; $rows < $opt_loop_count ; $rows++)
+  {
+    $t_value = rand 50000;
+    $t2_value = $t_value + 50001;
+    $statement = "DELETE FROM $firsttable WHERE (c_time>$t_value) AND (c_time<$t2_value)";
+    $cursor = $dbh->prepare($statement);
+    $cursor->execute();
+    $cursor->finish();
+    sleep 10;
+    if (-e $kill_file)
+    {
+      last;
+    }
+  }
+  print "delete: delete executed $rows times\n";
+  exit(0);
+}