add test

Author: alvherre

src/test/isolation/expected/multixact-no-deadlock.out

@@ -0,0 +1,24 @@
+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              
+step s2lock: SELECT * FROM justthis FOR SHARE;
+value          
+
+1              
+step s1svpt: SAVEPOINT foo;
+step s3lock: SELECT * FROM justthis FOR UPDATE; <waiting ...>
+step s1lock2: SELECT * FROM justthis FOR SHARE;
+value          
+
+1              
+step s2c: COMMIT;
+step s1c: COMMIT;
+step s3lock: <... completed>
+value          
+
+1              
+step s3c: COMMIT;

src/test/isolation/specs/multixact-no-deadlock.spec

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+# If we already hold a lock of a given strength, do not deadlock when
+# some other transaction is waiting for a conflicting lock and we try
+# to acquire the same lock we already held.
+setup
+{
+  CREATE TABLE justthis (
+	value	int
+  );
+
+  INSERT INTO justthis VALUES (1);
+}
+
+teardown
+{
+  DROP TABLE justthis;
+}
+
+session "s1"
+setup			{ BEGIN; }
+step "s1lock"	{ SELECT * FROM justthis FOR SHARE; }
+step "s1svpt"	{ SAVEPOINT foo; }
+step "s1lock2"	{ SELECT * FROM justthis FOR SHARE; }
+step "s1c"		{ COMMIT; }
+
+session "s2"
+setup			{ BEGIN; }
+step "s2lock"	{ SELECT * FROM justthis FOR SHARE; }	# ensure it's a multi
+step "s2c"		{ COMMIT; }
+
+session "s3"
+setup			{ BEGIN; }
+step "s3lock"	{ SELECT * FROM justthis FOR UPDATE; }
+step "s3c"		{ COMMIT; }
+
+permutation "s1lock" "s2lock" "s1svpt" "s3lock" "s1lock2" "s2c" "s1c" "s3c"