MWL#116: Efficient group commit: PBXT part

Implement the commit_ordered() API in PBXT, getting consistent commit ordering
with other engines and binlog.

Make pbxt_support_xa default in MariaDB debug build (as the bug that causes
assert in MySQL is fixed in MariaDB).

1 files changed, 107 insertions, 0 deletions

diff --git a/tests/consistent_snapshot.pl b/tests/consistent_snapshot.pl
new file mode 100755
index 00000000000..9e53eaea6a1
--- /dev/null
+++ b/tests/consistent_snapshot.pl
@@ -0,0 +1,107 @@
+#! /usr/bin/perl
+
+# Test START TRANSACTION WITH CONSISTENT SNAPSHOT.
+# With MWL#116, this is implemented so it is actually consistent.
+
+use strict;
+use warnings;
+
+use DBI;
+
+my $UPDATERS= 10;
+my $READERS= 5;
+
+my $ROWS= 50;
+my $DURATION= 20;
+
+my $stop_time= time() + $DURATION;
+
+sub my_connect {
+  my $dbh= DBI->connect("dbi:mysql:mysql_socket=/tmp/mysql.sock;database=test",
+                        "root", undef, { RaiseError=>1, PrintError=>0, AutoCommit=>0});
+  $dbh->do("SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ");
+  $dbh->do("SET SESSION autocommit = 0");
+  return $dbh;
+}
+
+sub my_setup {
+  my $dbh= my_connect();
+
+  $dbh->do("DROP TABLE IF EXISTS test_consistent_snapshot1, test_consistent_snapshot2");
+  $dbh->do(<<TABLE);
+CREATE TABLE test_consistent_snapshot1 (
+  a INT PRIMARY KEY,
+  b INT NOT NULL
+) ENGINE=InnoDB
+TABLE
+  $dbh->do(<<TABLE);
+CREATE TABLE test_consistent_snapshot2(
+  a INT PRIMARY KEY,
+  b INT NOT NULL
+) ENGINE=PBXT
+TABLE
+
+  for (my $i= 0; $i < $ROWS; $i++) {
+    my $value= int(rand()*1000);
+    $dbh->do("INSERT INTO test_consistent_snapshot1 VALUES (?, ?)", undef,
+             $i, $value);
+    $dbh->do("INSERT INTO test_consistent_snapshot2 VALUES (?, ?)", undef,
+             $i, -$value);
+  }
+  $dbh->commit();
+  $dbh->disconnect();
+}
+
+sub my_updater {
+  my $dbh= my_connect();
+
+  while (time() < $stop_time) {
+    my $i1= int(rand()*$ROWS);
+    my $i2= int(rand()*$ROWS);
+    my $v= int(rand()*99)-49;
+    $dbh->do("UPDATE test_consistent_snapshot1 SET b = b + ? WHERE a = ?",
+             undef, $v, $i1);
+    $dbh->do("UPDATE test_consistent_snapshot2 SET b = b - ? WHERE a = ?",
+             undef, $v, $i2);
+    $dbh->commit();
+  }
+
+  $dbh->disconnect();
+  exit(0);
+}
+
+sub my_reader {
+  my $dbh= my_connect();
+
+  my $iteration= 0;
+  while (time() < $stop_time) {
+    $dbh->do("START TRANSACTION WITH CONSISTENT SNAPSHOT");
+    my $s1= $dbh->selectrow_arrayref("SELECT SUM(b) FROM test_consistent_snapshot1");
+    $s1= $s1->[0];
+    my $s2= $dbh->selectrow_arrayref("SELECT SUM(b) FROM test_consistent_snapshot2");
+    $s2= $s2->[0];
+    $dbh->commit();
+    if ($s1 + $s2 != 0) {
+      print STDERR "Found inconsistency, s1=$s1 s2=$s2 iteration=$iteration\n";
+      last;
+    }
+    ++$iteration;
+  }
+
+  $dbh->disconnect();
+  exit(0);
+}
+
+my_setup();
+
+for (1 .. $UPDATERS) {
+  fork() || my_updater();
+}
+
+for (1 .. $READERS) {
+  fork() || my_reader();
+}
+
+waitpid(-1, 0) for (1 .. ($UPDATERS + $READERS));
+
+print "All checks done\n";