postgresql/src/test/isolation/specs/tuplelock-update.spec

setup {
   DROP TABLE IF EXISTS pktab;
   CREATE TABLE pktab (id int PRIMARY KEY, data SERIAL NOT NULL);
   INSERT INTO pktab VALUES (1, DEFAULT);
}

teardown {
   DROP TABLE pktab;
}

session s1
step s1_advlock {
    SELECT pg_advisory_lock(142857),
        pg_advisory_lock(285714),
        pg_advisory_lock(571428);
 }
step s1_chain { UPDATE pktab SET data = DEFAULT; }
step s1_begin { BEGIN; }
step s1_grablock { SELECT * FROM pktab FOR KEY SHARE; }
step s1_advunlock1 { SELECT pg_advisory_unlock(142857); }
step s1_advunlock2 { SELECT pg_advisory_unlock(285714); }
step s1_advunlock3 { SELECT pg_advisory_unlock(571428); }
step s1_commit { COMMIT; }

session s2
step s2_update { UPDATE pktab SET data = DEFAULT WHERE pg_advisory_lock_shared(142857) IS NOT NULL; }

session s3
step s3_update { UPDATE pktab SET data = DEFAULT WHERE pg_advisory_lock_shared(285714) IS NOT NULL; }

session s4
step s4_update { UPDATE pktab SET data = DEFAULT WHERE pg_advisory_lock_shared(571428) IS NOT NULL; }

# We use blocker annotations on the s1_advunlockN steps so that we will not
# move on to the next step until the other session's released step finishes.
# This ensures stable ordering of the test output.
permutation s1_advlock s2_update s3_update s4_update s1_chain s1_begin s1_grablock s1_advunlock1(s2_update) s1_advunlock2(s3_update) s1_advunlock3(s4_update) s1_commit