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@xxxxxx>
---
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
