#include "catalog/pg_type.h"
#include "commands/extension.h"
#include "miscadmin.h"
+#include "storage/lmgr.h"
+#include "storage/lock.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
+#include "utils/snapmgr.h"
#include "utils/syscache.h"
static bool isObjectPinned(const ObjectAddress *object);
+static void dependencyLockAndCheckObject(Oid classId, Oid objectId);
/*
if (isObjectPinned(referenced))
continue;
+ /*
+ * Make sure the new referenced object doesn't go away while we record
+ * the dependency. DROP routines should lock the object exclusively
+ * before they check dependencies.
+ */
+ dependencyLockAndCheckObject(referenced->classId, referenced->objectId);
+
if (slot_init_count < max_slots)
{
slot[slot_stored_count] = MakeSingleTupleTableSlot(RelationGetDescr(dependDesc),
return 1;
}
+ /*
+ * Make sure the new referenced object doesn't go away while we record the
+ * dependency.
+ */
+ if (!newIsPinned)
+ dependencyLockAndCheckObject(refClassId, newRefObjectId);
+
depRel = table_open(DependRelationId, RowExclusiveLock);
/* There should be existing dependency record(s), so search. */
}
+/*
+ * dependencyLockAndCheckObject
+ *
+ * Lock the object that we are about to record a dependency on. After it's
+ * locked, verify that it hasn't been dropped while we weren't looking. If it
+ * has been dropped, throw an an error.
+ *
+ * If the caller already holds a lock that conflicts with DROP
+ * (AccessShareLock or stronger), this does nothing. Callers should acquire
+ * locks already when they look up the dependent objects, but many callers
+ * currently do not. This is a backstop to make sure that we don't record a
+ * bogus reference permanently in the catalogs in that case. In the future,
+ * after we have tightened up all the callers to acquire locks earlier, this
+ * could just verify that the object is already locked and throw an error if
+ * not.
+ */
+static void
+dependencyLockAndCheckObject(Oid classId, Oid objectId)
+{
+ /*
+ * Pinned objects cannot be dropped concurrently, and callers checked this
+ * already.
+ */
+ Assert(!IsPinnedObject(classId, objectId));
+
+ if (classId != RelationRelationId)
+ {
+ LOCKTAG tag;
+ int cache;
+ Relation rel;
+ SysScanDesc scan;
+ ScanKeyData skey;
+ HeapTuple tuple;
+
+ SET_LOCKTAG_OBJECT(tag,
+ MyDatabaseId,
+ classId,
+ objectId,
+ 0);
+
+ if (LockOrStrongerHeldByMe(&tag, AccessShareLock))
+ return;
+
+ /* Assume we should lock the whole object not a sub-object */
+ LockDatabaseObject(classId, objectId, 0, AccessShareLock);
+
+ /*
+ * Check that the object still exists. If the catalog has a suitable
+ * syscache, check that first.
+ */
+ cache = get_object_catcache_oid(classId);
+ if (cache != -1)
+ {
+ if (SearchSysCacheExists1(cache, ObjectIdGetDatum(objectId)))
+ return;
+ }
+
+ /*
+ * If it's not found in the syscache, or there's no suitable syscache
+ * we can use, scan the catalog table using SnapshotSelf. This
+ * handles the case that it's an object we just created (for example,
+ * if it's a composite type created as part of creating a table).
+ */
+ rel = table_open(classId, AccessShareLock);
+
+ ScanKeyInit(&skey,
+ get_object_attnum_oid(classId),
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(objectId));
+
+ scan = systable_beginscan(rel, get_object_oid_index(classId),
+ true, SnapshotSelf, 1, &skey);
+
+ tuple = systable_getnext(scan);
+ if (!HeapTupleIsValid(tuple))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("dependent %s was concurrently dropped",
+ get_object_class_descr(classId))));
+
+ systable_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ else
+ {
+ /*
+ * Same logic for pg_class entries, but locking relations is handled
+ * by different functions.
+ *
+ * Callers are more careful with locking relations than other objects,
+ * so we should already have a lock on the relation, or on another
+ * object that indirectly prevents the relation from being dropped.
+ * For example, we might have a strong lock on a table while adding
+ * dependency to its index. However, we cannot detect the indirectly
+ * protected case here easily. To err on the safe side, acquire a
+ * lock directly on the relation if we're not holding one already.
+ */
+
+ /* all shared relations are pinned */
+ Assert(!IsSharedRelation(objectId));
+
+ if (CheckRelationOidLockedByMe(objectId, AccessShareLock, true))
+ return;
+ LockRelationOid(objectId, AccessShareLock);
+
+ if (SearchSysCacheExists1(RELOID, ObjectIdGetDatum(objectId)))
+ return;
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("dependent relation was concurrently dropped")));
+ }
+}
+
/*
* Various special-purpose lookups and manipulations of pg_depend.
*/
--- /dev/null
+Parsed test spec with 2 sessions
+
+starting permutation: s1_begin s1_create_function_in_schema s2_drop_schema s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_schema: DROP SCHEMA testschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_schema: <... completed>
+ERROR: cannot drop schema testschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_schema s1_create_function_in_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_schema: DROP SCHEMA testschema;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_in_schema: <... completed>
+ERROR: dependent schema was concurrently dropped
+
+starting permutation: s1_begin s1_alter_function_schema s2_drop_alterschema s1_commit
+step s1_begin: BEGIN;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema;
+step s2_drop_alterschema: DROP SCHEMA alterschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_alterschema: <... completed>
+ERROR: cannot drop schema alterschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_alterschema s1_alter_function_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_alterschema: DROP SCHEMA alterschema;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema; <waiting ...>
+step s2_commit: COMMIT;
+step s1_alter_function_schema: <... completed>
+ERROR: dependent schema was concurrently dropped
+
+starting permutation: s1_begin s1_create_function_with_argtype s2_drop_foo_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_foo_type: DROP TYPE public.foo; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_type: <... completed>
+ERROR: cannot drop type foo because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_type s1_create_function_with_argtype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_type: DROP TYPE public.foo;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_argtype: <... completed>
+ERROR: dependent type was concurrently dropped
+
+starting permutation: s1_begin s1_create_function_with_rettype s2_drop_foo_rettype s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1;
+step s2_drop_foo_rettype: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_rettype: <... completed>
+ERROR: cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_rettype s1_create_function_with_rettype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_rettype: DROP DOMAIN id;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_rettype: <... completed>
+ERROR: dependent type was concurrently dropped
+
+starting permutation: s1_begin s1_create_function_with_function s2_drop_function_f s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1;
+step s2_drop_function_f: DROP FUNCTION f(); <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_function_f: <... completed>
+ERROR: cannot drop function f() because other objects depend on it
+
+starting permutation: s2_begin s2_drop_function_f s1_create_function_with_function s2_commit
+step s2_begin: BEGIN;
+step s2_drop_function_f: DROP FUNCTION f();
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_function: <... completed>
+ERROR: dependent function was concurrently dropped
+
+starting permutation: s1_begin s1_create_domain_with_domain s2_drop_domain_id s1_commit
+step s1_begin: BEGIN;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id;
+step s2_drop_domain_id: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_domain_id: <... completed>
+ERROR: cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_domain_id s1_create_domain_with_domain s2_commit
+step s2_begin: BEGIN;
+step s2_drop_domain_id: DROP DOMAIN id;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_domain_with_domain: <... completed>
+ERROR: dependent type was concurrently dropped
+
+starting permutation: s1_begin s1_create_table_with_type s2_drop_footab_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab);
+step s2_drop_footab_type: DROP TYPE public.footab; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_footab_type: <... completed>
+ERROR: cannot drop type footab because other objects depend on it
+
+starting permutation: s2_begin s2_drop_footab_type s1_create_table_with_type s2_commit
+step s2_begin: BEGIN;
+step s2_drop_footab_type: DROP TYPE public.footab;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab); <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_table_with_type: <... completed>
+ERROR: dependent type was concurrently dropped
+
+starting permutation: s1_begin s1_create_server_with_fdw_wrapper s2_drop_fdw_wrapper s1_commit
+step s1_begin: BEGIN;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_fdw_wrapper: <... completed>
+ERROR: cannot drop foreign-data wrapper fdw_wrapper because other objects depend on it
+
+starting permutation: s2_begin s2_drop_fdw_wrapper s1_create_server_with_fdw_wrapper s2_commit
+step s2_begin: BEGIN;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_server_with_fdw_wrapper: <... completed>
+ERROR: dependent foreign-data wrapper was concurrently dropped
+
+starting permutation: s1_begin s1_alter_function_owner s2_drop_role s1_commit
+step s1_begin: BEGIN;
+step s1_alter_function_owner: ALTER FUNCTION public.falter() OWNER TO regress_dependency;
+step s2_drop_role: DROP ROLE regress_dependency; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_role: <... completed>
+ERROR: role "regress_dependency" cannot be dropped because some objects depend on it
test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
+test: ddl-dependency-locking
--- /dev/null
+# Test that concurrent DROP and CREATE commands do not leave behind
+# references to non-existent objects.
+
+setup
+{
+ CREATE SCHEMA testschema;
+ CREATE SCHEMA alterschema;
+ CREATE TYPE public.foo as enum ('one', 'two');
+ CREATE TYPE public.footab as enum ('three', 'four');
+ CREATE DOMAIN id AS int;
+ CREATE FUNCTION f() RETURNS int LANGUAGE SQL RETURN 1;
+ CREATE FUNCTION public.falter() RETURNS int LANGUAGE SQL RETURN 1;
+ CREATE FOREIGN DATA WRAPPER fdw_wrapper;
+ CREATE ROLE regress_dependency;
+}
+
+teardown
+{
+ DROP FUNCTION IF EXISTS testschema.foo();
+ DROP FUNCTION IF EXISTS fooargtype(num foo);
+ DROP FUNCTION IF EXISTS footrettype();
+ DROP FUNCTION IF EXISTS foofunc();
+ DROP FUNCTION IF EXISTS public.falter();
+ DROP FUNCTION IF EXISTS alterschema.falter();
+ DROP DOMAIN IF EXISTS idid;
+ DROP SERVER IF EXISTS srv_fdw_wrapper;
+ DROP TABLE IF EXISTS tabtype;
+ DROP SCHEMA IF EXISTS testschema;
+ DROP SCHEMA IF EXISTS alterschema;
+ DROP TYPE IF EXISTS public.foo;
+ DROP TYPE IF EXISTS public.footab;
+ DROP DOMAIN IF EXISTS id;
+ DROP FUNCTION IF EXISTS f();
+ DROP FOREIGN DATA WRAPPER IF EXISTS fdw_wrapper;
+ DROP ROLE regress_dependency;
+}
+
+session "s1"
+
+step "s1_begin" { BEGIN; }
+step "s1_create_function_in_schema" { CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_argtype" { CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_rettype" { CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; }
+step "s1_create_function_with_function" { CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; }
+step "s1_alter_function_owner" { ALTER FUNCTION public.falter() OWNER TO regress_dependency; }
+step "s1_alter_function_schema" { ALTER FUNCTION public.falter() SET SCHEMA alterschema; }
+step "s1_create_domain_with_domain" { CREATE DOMAIN idid as id; }
+step "s1_create_table_with_type" { CREATE TABLE tabtype(a footab); }
+step "s1_create_server_with_fdw_wrapper" { CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; }
+step "s1_commit" { COMMIT; }
+
+session "s2"
+
+step "s2_begin" { BEGIN; }
+step "s2_drop_schema" { DROP SCHEMA testschema; }
+step "s2_drop_alterschema" { DROP SCHEMA alterschema; }
+step "s2_drop_foo_type" { DROP TYPE public.foo; }
+step "s2_drop_foo_rettype" { DROP DOMAIN id; }
+step "s2_drop_footab_type" { DROP TYPE public.footab; }
+step "s2_drop_function_f" { DROP FUNCTION f(); }
+step "s2_drop_domain_id" { DROP DOMAIN id; }
+step "s2_drop_fdw_wrapper" { DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; }
+step "s2_drop_role" { DROP ROLE regress_dependency; }
+step "s2_commit" { COMMIT; }
+
+# create function - drop schema
+permutation "s1_begin" "s1_create_function_in_schema" "s2_drop_schema" "s1_commit"
+permutation "s2_begin" "s2_drop_schema" "s1_create_function_in_schema" "s2_commit"
+
+# alter function - drop schema
+permutation "s1_begin" "s1_alter_function_schema" "s2_drop_alterschema" "s1_commit"
+permutation "s2_begin" "s2_drop_alterschema" "s1_alter_function_schema" "s2_commit"
+
+# create function - drop argtype
+permutation "s1_begin" "s1_create_function_with_argtype" "s2_drop_foo_type" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_type" "s1_create_function_with_argtype" "s2_commit"
+
+# create function - drop rettype
+permutation "s1_begin" "s1_create_function_with_rettype" "s2_drop_foo_rettype" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_rettype" "s1_create_function_with_rettype" "s2_commit"
+
+# create function - drop function used in its body
+permutation "s1_begin" "s1_create_function_with_function" "s2_drop_function_f" "s1_commit"
+permutation "s2_begin" "s2_drop_function_f" "s1_create_function_with_function" "s2_commit"
+
+# create domain over domain - drop the base domain
+permutation "s1_begin" "s1_create_domain_with_domain" "s2_drop_domain_id" "s1_commit"
+permutation "s2_begin" "s2_drop_domain_id" "s1_create_domain_with_domain" "s2_commit"
+
+# create table - drop type used in column
+permutation "s1_begin" "s1_create_table_with_type" "s2_drop_footab_type" "s1_commit"
+permutation "s2_begin" "s2_drop_footab_type" "s1_create_table_with_type" "s2_commit"
+
+# create server - drop foreign data wrapper
+permutation "s1_begin" "s1_create_server_with_fdw_wrapper" "s2_drop_fdw_wrapper" "s1_commit"
+permutation "s2_begin" "s2_drop_fdw_wrapper" "s1_create_server_with_fdw_wrapper" "s2_commit"
+
+# create function - drop owner role
+permutation "s1_begin" "s1_alter_function_owner" "s2_drop_role" "s1_commit"
+
+# XXX: This permutation is disabled because the error message, "role
+# <OID> was concurrently dropped", contains an OID that is not stable.
+#
+# permutation "s2_begin" "s2_drop_role" "s1_alter_function_owner" "s2_commit"
alter table alterlock2
add constraint alterlock2nv foreign key (f1) references alterlock (f1) NOT VALID;
select * from my_locks order by 1;
- relname | max_lockmode
-------------+-----------------------
- alterlock | ShareRowExclusiveLock
- alterlock2 | ShareRowExclusiveLock
-(2 rows)
+ relname | max_lockmode
+----------------+-----------------------
+ alterlock | ShareRowExclusiveLock
+ alterlock2 | ShareRowExclusiveLock
+ alterlock_pkey | AccessShareLock
+(3 rows)
commit;
begin;
projects / thirdparty / postgresql.git / commitdiff
