lock: Do not limit backend concurrency for lock files

restic must be able to refresh lock files in time. However, large
uploads over slow connections can cause the lock refresh to be stuck
behind the large uploads and thus time out.
This commit is contained in:
Michael Eischer 2023-04-23 12:16:54 +02:00
parent 41cc320145
commit d05f6211d1
3 changed files with 46 additions and 15 deletions

View file

@ -88,7 +88,7 @@ func countingBlocker() (func(), func(int) int) {
unblock := func(expected int) int {
// give goroutines enough time to block
var blocked int64
for i := 0; i < 100 && blocked != int64(expected); i++ {
for i := 0; i < 100 && blocked < int64(expected); i++ {
time.Sleep(100 * time.Microsecond)
blocked = atomic.LoadInt64(&ctr)
}
@ -99,8 +99,9 @@ func countingBlocker() (func(), func(int) int) {
return wait, unblock
}
func concurrencyTester(t *testing.T, setup func(m *mock.Backend), handler func(be restic.Backend) func() error, unblock func(int) int) {
func concurrencyTester(t *testing.T, setup func(m *mock.Backend), handler func(be restic.Backend) func() error, unblock func(int) int, isUnlimited bool) {
expectBlocked := int(2)
workerCount := expectBlocked + 1
m := mock.NewBackend()
setup(m)
@ -108,10 +109,13 @@ func concurrencyTester(t *testing.T, setup func(m *mock.Backend), handler func(b
be := sema.NewBackend(m)
var wg errgroup.Group
for i := 0; i < int(expectBlocked+1); i++ {
for i := 0; i < workerCount; i++ {
wg.Go(handler(be))
}
if isUnlimited {
expectBlocked = workerCount
}
blocked := unblock(expectBlocked)
test.Assert(t, blocked == expectBlocked, "Unexpected number of goroutines blocked: %v", blocked)
test.OK(t, wg.Wait())
@ -129,7 +133,7 @@ func TestConcurrencyLimitSave(t *testing.T) {
h := restic.Handle{Type: restic.PackFile, Name: "foobar"}
return be.Save(context.TODO(), h, nil)
}
}, unblock)
}, unblock, false)
}
func TestConcurrencyLimitLoad(t *testing.T) {
@ -145,7 +149,7 @@ func TestConcurrencyLimitLoad(t *testing.T) {
nilCb := func(rd io.Reader) error { return nil }
return be.Load(context.TODO(), h, 10, 0, nilCb)
}
}, unblock)
}, unblock, false)
}
func TestConcurrencyLimitStat(t *testing.T) {
@ -161,7 +165,7 @@ func TestConcurrencyLimitStat(t *testing.T) {
_, err := be.Stat(context.TODO(), h)
return err
}
}, unblock)
}, unblock, false)
}
func TestConcurrencyLimitDelete(t *testing.T) {
@ -176,5 +180,20 @@ func TestConcurrencyLimitDelete(t *testing.T) {
h := restic.Handle{Type: restic.PackFile, Name: "foobar"}
return be.Remove(context.TODO(), h)
}
}, unblock)
}, unblock, false)
}
func TestConcurrencyUnlimitedLockSave(t *testing.T) {
wait, unblock := countingBlocker()
concurrencyTester(t, func(m *mock.Backend) {
m.SaveFn = func(ctx context.Context, h restic.Handle, rd restic.RewindReader) error {
wait()
return nil
}
}, func(be restic.Backend) func() error {
return func() error {
h := restic.Handle{Type: restic.LockFile, Name: "foobar"}
return be.Save(context.TODO(), h, nil)
}
}, unblock, true)
}