[PATCH v2 08/10] reftable/reader: keep readers alive during iteration
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Aug 23, 2024, 14:12 UTC
- Message-ID
- <8d08c3bc515db8a3d7fc0a617a2cf1025164f472.1724420744.git.ps@pks.im>
- In-Reply-To
- <cover.1724420744.git.ps@pks.im>
The lifetime of a table iterator may survive the lifetime of a reader when the stack gets reloaded. Keep the reader from being released by increasing its refcount while the iterator is still being used.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- reftable/reader.c | 2 ++ reftable/stack_test.c | 50 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+)
diff --git a/reftable/reader.c b/reftable/reader.c index 64a0953e687..f8770990876 100644 --- a/reftable/reader.c +++ b/reftable/reader.c @@ -175,6 +175,7 @@ static int table_iter_init(struct table_iter *ti, struct reftable_reader *r) { struct block_iter bi = BLOCK_ITER_INIT; memset(ti, 0, sizeof(*ti)); + reftable_reader_incref(r); ti->r = r; ti->bi = bi; return 0; @@ -262,6 +263,7 @@ static void table_iter_close(struct table_iter *ti) { table_iter_block_done(ti); block_iter_close(&ti->bi); + reftable_reader_decref(ti->r); } static int table_iter_next_block(struct table_iter *ti) diff --git a/reftable/stack_test.c b/reftable/stack_test.c index bc3bf772749..7fb5beb7c94 100644 --- a/reftable/stack_test.c +++ b/reftable/stack_test.c @@ -1076,6 +1076,55 @@ static void test_reftable_stack_compaction_concurrent_clean(void) clear_dir(dir); } +static void test_reftable_stack_read_across_reload(void) +{ + struct reftable_write_options opts = { 0 }; + struct reftable_stack *st1 = NULL, *st2 = NULL; + struct reftable_ref_record rec = { 0 }; + struct reftable_iterator it = { 0 }; + char *dir = get_tmp_dir(__LINE__); + int err; + + /* Create a first stack and set up an iterator for it. */ + err = reftable_new_stack(&st1, dir, &opts); + EXPECT_ERR(err); + write_n_ref_tables(st1, 2); + EXPECT(st1->merged->readers_len == 2); + reftable_stack_init_ref_iterator(st1, &it); + err = reftable_iterator_seek_ref(&it, ""); + EXPECT_ERR(err); + + /* Set up a second stack for the same directory and compact it. */ + err = reftable_new_stack(&st2, dir, &opts); + EXPECT_ERR(err); + EXPECT(st2->merged->readers_len == 2); + err = reftable_stack_compact_all(st2, NULL); + EXPECT_ERR(err); + EXPECT(st2->merged->readers_len == 1); + + /* + * Verify that we can continue to use the old iterator even after we + * have reloaded its stack. + */ + err = reftable_stack_reload(st1); + EXPECT_ERR(err); + EXPECT(st1->merged->readers_len == 1); + err = reftable_iterator_next_ref(&it, &rec); + EXPECT_ERR(err); + EXPECT(!strcmp(rec.refname, "refs/heads/branch-0000")); + err = reftable_iterator_next_ref(&it, &rec); + EXPECT_ERR(err); + EXPECT(!strcmp(rec.refname, "refs/heads/branch-0001")); + err = reftable_iterator_next_ref(&it, &rec); + EXPECT(err > 0); + + reftable_ref_record_release(&rec); + reftable_iterator_destroy(&it); + reftable_stack_destroy(st1); + reftable_stack_destroy(st2); + clear_dir(dir); +} + int stack_test_main(int argc, const char *argv[]) { RUN_TEST(test_empty_add); @@ -1098,6 +1147,7 @@ int stack_test_main(int argc, const char *argv[]) RUN_TEST(test_reftable_stack_auto_compaction_fails_gracefully); RUN_TEST(test_reftable_stack_update_index_check); RUN_TEST(test_reftable_stack_uptodate); + RUN_TEST(test_reftable_stack_read_across_reload); RUN_TEST(test_suggest_compaction_segment); RUN_TEST(test_suggest_compaction_segment_nothing); return 0;
-- 2.46.0.164.g477ce5ccd6.dirty