Parsed test spec with 3 sessions

starting permutation: s1lock s2lock s1svpt s3lock s1lock2 s2c s1c s3c
step s1lock: SELECT * FROM justthis FOR SHARE;
value
-----
    1
(1 row)

step s2lock: SELECT * FROM justthis FOR SHARE;
value
-----
    1
(1 row)

step s1svpt: SAVEPOINT foo;
step s3lock: SELECT * FROM justthis FOR UPDATE; <waiting ...>
step s1lock2: SELECT * FROM justthis FOR SHARE;
value
-----
    1
(1 row)

step s2c: COMMIT;
step s1c: COMMIT;
step s3lock: <... completed>
value
-----
    1
(1 row)

step s3c: COMMIT;