Fixed mutex problem in TRUNCATE TABLE

Docs/manual.texi

@@ -49343,6 +49343,9 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
 
 @itemize @bullet
 @item
+Added missing mutex in @code{TRUNCATE TABLE};  This fixes some core
+dump/hangup problems when using @code{TRUNCATE TABLE}.
+@item
 Fixed that @code{ALTER TABLE table_name RENAME new_table_name} is as fast
 as @code{RENAME TABLE}.
 @item

sql/mysqld.cc

@@ -3472,12 +3472,12 @@ static struct my_option my_long_options[] =
   {"query_cache_limit", OPT_QUERY_CACHE_LIMIT,
    "Don't cache results that are bigger than this.",
    (gptr*) &query_cache_limit, (gptr*) &query_cache_limit, 0, GET_ULONG,
-   REQUIRED_ARG, 1024*1024L, 0, ULONG_MAX, 0, 1, 0},
+   REQUIRED_ARG, 1024*1024L, 0, (longlong) ULONG_MAX, 0, 1, 0},
 #endif /*HAVE_QUERY_CACHE*/
   {"query_cache_size", OPT_QUERY_CACHE_SIZE,
    "The memory allocated to store results from old queries.",
    (gptr*) &query_cache_size, (gptr*) &query_cache_size, 0, GET_ULONG,
-   REQUIRED_ARG, 0, 0, ULONG_MAX, 0, 1, 0},
+   REQUIRED_ARG, 0, 0, (longlong) ULONG_MAX, 0, 1, 0},
 #ifdef HAVE_QUERY_CACHE
   {"query_cache_startup_type", OPT_QUERY_CACHE_STARTUP_TYPE,
    "0 = OFF = Don't cache or retrieve results. 1 = ON = Cache all results except SELECT SQL_NO_CACHE ... queries. 2 = DEMAND = Cache only SELECT SQL_CACHE ... queries.",
@@ -3497,7 +3497,7 @@ static struct my_option my_long_options[] =
   {"relay_log_space_limit", OPT_RELAY_LOG_SPACE_LIMIT,
    "Undocumented", (gptr*) &relay_log_space_limit,
    (gptr*) &relay_log_space_limit, 0, GET_ULONG, REQUIRED_ARG, 0L, 0L,
-   ULONG_MAX, 0, 1, 0},
+   (longlong) ULONG_MAX, 0, 1, 0},
   {"slave_net_timeout", OPT_SLAVE_NET_TIMEOUT,
    "Number of seconds to wait for more data from a master/slave connection before aborting the read.",
    (gptr*) &slave_net_timeout, (gptr*) &slave_net_timeout, 0,

sql/sql_delete.cc

@@ -573,9 +573,15 @@ int mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
       }
       send_ok(&thd->net);		// This should return record count
     }
+    VOID(pthread_mutex_lock(&LOCK_open));
     unlock_table_name(thd, table_list);
+    VOID(pthread_mutex_unlock(&LOCK_open));
   }
   else if (error)
+  {
+    VOID(pthread_mutex_lock(&LOCK_open));
     unlock_table_name(thd, table_list);
+    VOID(pthread_mutex_unlock(&LOCK_open));
+  }
   DBUG_RETURN(error ? -1 : 0);
 }

tests/truncate.pl

+#!/usr/bin/perl -w
+#
+# This is a test with uses many processes to test a MySQL server.
+#
+
+$opt_loop_count=10000; # Change this to make test harder/easier
+
+##################### Standard benchmark inits ##############################
+
+use DBI;
+use Getopt::Long;
+use Benchmark;
+
+package main;
+
+$opt_skip_create=$opt_skip_in=$opt_verbose=$opt_fast_insert=
+$opt_lock_tables=$opt_debug=$opt_skip_delete=$opt_fast=$opt_force=0;
+$opt_threads=2;
+$opt_host=$opt_user=$opt_password=""; $opt_db="test";
+
+GetOptions("host=s","db=s","user=s","password=s","loop-count=i","skip-create","skip-in","skip-delete","verbose","fast-insert","lock-tables","debug","fast","force","threads=i") || die "Aborted";
+$opt_verbose=$opt_debug=$opt_lock_tables=$opt_fast_insert=$opt_fast=$opt_skip_in=$opt_force=undef;  # Ignore warnings from these
+
+print "Testing truncate from $opt_threads multiple connections $opt_loop_count times\n";
+
+@testtables = ( ["bench_f31", "type=heap"]);
+
+####
+####  Start timeing and start test
+####
+
+$start_time=new Benchmark;
+$dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		    $opt_user, $opt_password,
+		  { PrintError => 0}) || die $DBI::errstr;
+if (!$opt_skip_create)
+{
+  my $table_def;
+  foreach $table_def (@testtables)
+  {
+    my ($table,$extra)= ($table_def->[0], $table_def->[1]);
+    print "Creating table $table in database $opt_db\n";
+    $dbh->do("drop table if exists $table");
+    $dbh->do("create table $table".
+	     " (id int(6) not null,".
+	     " info varchar(32)," .
+	     " marker timestamp," .
+	     " flag int not null," .
+	     " primary key(id)) $extra")
+
+      or die $DBI::errstr;
+  }
+}
+
+$dbh->disconnect; $dbh=0;	# Close handler
+$|= 1;				# Autoflush
+
+####
+#### Start the tests
+####
+
+for ($i=0 ; $i < $opt_threads ; $i ++)
+{
+  test_truncate() if (($pid=fork()) == 0); $work{$pid}="truncate";
+}
+
+print "Started $opt_threads threads\n";
+
+$errors=0;
+$running_insert_threads=$opt_threads;
+while (($pid=wait()) != -1)
+{
+  $ret=$?/256;
+  print "thread '" . $work{$pid} . "' finished with exit code $ret\n";
+  --$running_insert_threads;
+  $errors++ if ($ret != 0);
+}
+
+#
+# Cleanup
+#
+
+if (!$opt_skip_delete && !$errors)
+{
+  my $table_def;
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+
+  foreach $table_def (@testtables)
+  {
+    $dbh->do("drop table " . $table_def->[0]);
+  }
+  $dbh->disconnect; $dbh=0;	# Close handler
+}
+
+print ($errors ? "Test failed\n" :"Test ok\n");
+$end_time=new Benchmark;
+print "Total time: " .
+  timestr(timediff($end_time, $start_time),"noc") . "\n";
+
+exit(0);
+
+
+#
+# Insert records in the table
+#
+
+sub test_truncate
+{
+  my ($dbh,$i,$j,$count,$table_def,$table);
+
+  $dbh = DBI->connect("DBI:mysql:$opt_db:$opt_host",
+		      $opt_user, $opt_password,
+		    { PrintError => 0}) || die $DBI::errstr;
+
+  for ($count=0; $count < $opt_loop_count ; $count++)
+  {
+    my ($table)= ($testtables[0]->[0]);
+    $dbh->do("truncate table $table") || die "Got error on truncate: $DBI::errstr\n";
+  }
+  $dbh->disconnect; $dbh=0;
+  print "Test_truncate: Run $count times\n";
+  exit(0);
+}