1 files changed, 81 insertions, 8 deletions

diff --git a/t/t0610-reftable-basics.sh b/t/t0610-reftable-basics.sh
index b06c46999d..4618ffc108 100755
--- a/t/t0610-reftable-basics.sh
+++ b/t/t0610-reftable-basics.sh
@@ -10,7 +10,6 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 GIT_TEST_DEFAULT_REF_FORMAT=reftable
 export GIT_TEST_DEFAULT_REF_FORMAT
 
-TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 INVALID_OID=$(test_oid 001)
@@ -423,6 +422,73 @@ test_expect_success 'ref transaction: fails gracefully when auto compaction fail
 	)
 '
 
+test_expect_success 'ref transaction: timeout acquiring tables.list lock' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit initial &&
+		>.git/reftable/tables.list.lock &&
+		test_must_fail git update-ref refs/heads/branch HEAD 2>err &&
+		test_grep "cannot lock references" err
+	)
+'
+
+test_expect_success 'ref transaction: retry acquiring tables.list lock' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit initial &&
+		LOCK=.git/reftable/tables.list.lock &&
+		>$LOCK &&
+		{
+			( sleep 1 && rm -f $LOCK ) &
+		} &&
+		git -c reftable.lockTimeout=5000 update-ref refs/heads/branch HEAD
+	)
+'
+
+# This test fails most of the time on Cygwin systems. The root cause is
+# that Windows does not allow us to rename the "tables.list.lock" file into
+# place when "tables.list" is open for reading by a concurrent process. We have
+# worked around that in our MinGW-based rename emulation, but the Cygwin
+# emulation seems to be insufficient.
+test_expect_success !CYGWIN 'ref transaction: many concurrent writers' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		# Set a high timeout. While a couple of seconds should be
+		# plenty, using the address sanitizer will significantly slow
+		# us down here. So we are aiming way higher than you would ever
+		# think is necessary just to keep us from flaking. We could
+		# also lock indefinitely by passing -1, but that could
+		# potentially block CI jobs indefinitely if there was a bug
+		# here.
+		git config set reftable.lockTimeout 300000 &&
+		test_commit --no-tag initial &&
+
+		head=$(git rev-parse HEAD) &&
+		for i in $(test_seq 100)
+		do
+			printf "%s commit\trefs/heads/branch-%s\n" "$head" "$i" ||
+			return 1
+		done >expect &&
+		printf "%s commit\trefs/heads/main\n" "$head" >>expect &&
+
+		for i in $(test_seq 100)
+		do
+			{ git update-ref refs/heads/branch-$i HEAD& } ||
+			return 1
+		done &&
+
+		wait &&
+		git for-each-ref --sort=v:refname >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_expect_success 'pack-refs: compacts tables' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
@@ -478,19 +544,26 @@ test_expect_success "$command: auto compaction" '
 
 		test_oid blob17_2 | git hash-object -w --stdin &&
 
-		# Lock all tables write some refs. Auto-compaction will be
-		# unable to compact tables and thus fails gracefully, leaving
-		# the stack in a sub-optimal state.
-		ls .git/reftable/*.ref |
+		# Lock all tables, write some refs. Auto-compaction will be
+		# unable to compact tables and thus fails gracefully,
+		# compacting only those tables which are not locked.
+		ls .git/reftable/*.ref | sort |
 		while read table
 		do
-			touch "$table.lock" || exit 1
+			touch "$table.lock" &&
+			basename "$table" >>tables.expect || exit 1
 		done &&
+		test_line_count = 2 .git/reftable/tables.list &&
 		git branch B &&
 		git branch C &&
-		rm .git/reftable/*.lock &&
-		test_line_count = 4 .git/reftable/tables.list &&
 
+		# The new tables are auto-compacted, but the locked tables are
+		# left intact.
+		test_line_count = 3 .git/reftable/tables.list &&
+		head -n 2 .git/reftable/tables.list >tables.head &&
+		test_cmp tables.expect tables.head &&
+
+		rm .git/reftable/*.lock &&
 		git $command --auto &&
 		test_line_count = 1 .git/reftable/tables.list
 	)