From ba4dfa7172a00f8b104a75a4655fe3de1e4a94c9 Mon Sep 17 00:00:00 2001 From: Jamie Liu Date: Wed, 24 Feb 2021 11:55:02 -0800 Subject: Move //pkg/gate.Gate to //pkg/sync. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - Use atomic add rather than CAS in every Gate method, which is slightly faster in most cases. - Implement Close wakeup using gopark/goready to avoid channel allocation. New benchmarks: name old time/op new time/op delta GateEnterLeave-12 16.7ns ± 1% 10.3ns ± 1% -38.44% (p=0.000 n=9+8) GateClose-12 50.2ns ± 8% 42.4ns ± 6% -15.44% (p=0.000 n=10+10) GateEnterLeaveAsyncClose-12 972ns ± 2% 640ns ± 7% -34.15% (p=0.000 n=9+10) PiperOrigin-RevId: 359336344 --- pkg/gate/gate_test.go | 192 -------------------------------------------------- 1 file changed, 192 deletions(-) delete mode 100644 pkg/gate/gate_test.go (limited to 'pkg/gate/gate_test.go') diff --git a/pkg/gate/gate_test.go b/pkg/gate/gate_test.go deleted file mode 100644 index 316015e06..000000000 --- a/pkg/gate/gate_test.go +++ /dev/null @@ -1,192 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package gate_test - -import ( - "runtime" - "testing" - "time" - - "gvisor.dev/gvisor/pkg/gate" - "gvisor.dev/gvisor/pkg/sync" -) - -func TestBasicEnter(t *testing.T) { - var g gate.Gate - - if !g.Enter() { - t.Fatalf("Failed to enter when it should be allowed") - } - - g.Leave() - - g.Close() - - if g.Enter() { - t.Fatalf("Allowed to enter when it should fail") - } -} - -func enterFunc(t *testing.T, g *gate.Gate, enter, leave, reenter chan struct{}, done1, done2, done3 *sync.WaitGroup) { - // Wait until instructed to enter. - <-enter - if !g.Enter() { - t.Errorf("Failed to enter when it should be allowed") - } - - done1.Done() - - // Wait until instructed to leave. - <-leave - g.Leave() - - done2.Done() - - // Wait until instructed to reenter. - <-reenter - if g.Enter() { - t.Errorf("Allowed to enter when it should fail") - } - done3.Done() -} - -func TestConcurrentEnter(t *testing.T) { - var g gate.Gate - var done1, done2, done3 sync.WaitGroup - - // Create 1000 worker goroutines. - enter := make(chan struct{}) - leave := make(chan struct{}) - reenter := make(chan struct{}) - done1.Add(1000) - done2.Add(1000) - done3.Add(1000) - for i := 0; i < 1000; i++ { - go enterFunc(t, &g, enter, leave, reenter, &done1, &done2, &done3) - } - - // Tell them all to enter, then leave. - close(enter) - done1.Wait() - - close(leave) - done2.Wait() - - // Close the gate, then have the workers try to enter again. - g.Close() - close(reenter) - done3.Wait() -} - -func closeFunc(g *gate.Gate, done chan struct{}) { - g.Close() - close(done) -} - -func TestCloseWaits(t *testing.T) { - var g gate.Gate - - // Enter 10 times. - for i := 0; i < 10; i++ { - if !g.Enter() { - t.Fatalf("Failed to enter when it should be allowed") - } - } - - // Launch closer. Check that it doesn't complete. - done := make(chan struct{}) - go closeFunc(&g, done) - - for i := 0; i < 10; i++ { - select { - case <-done: - t.Fatalf("Close function completed too soon") - case <-time.After(100 * time.Millisecond): - } - - g.Leave() - } - - // Now the closer must complete. - <-done -} - -func TestMultipleSerialCloses(t *testing.T) { - var g gate.Gate - - // Enter 10 times. - for i := 0; i < 10; i++ { - if !g.Enter() { - t.Fatalf("Failed to enter when it should be allowed") - } - } - - // Launch closer. Check that it doesn't complete. - done := make(chan struct{}) - go closeFunc(&g, done) - - for i := 0; i < 10; i++ { - select { - case <-done: - t.Fatalf("Close function completed too soon") - case <-time.After(100 * time.Millisecond): - } - - g.Leave() - } - - // Now the closer must complete. - <-done - - // Close again should not block. - done = make(chan struct{}) - go closeFunc(&g, done) - - select { - case <-done: - case <-time.After(2 * time.Second): - t.Fatalf("Second Close is blocking") - } -} - -func worker(g *gate.Gate, done *sync.WaitGroup) { - for { - if !g.Enter() { - break - } - // Golang before v1.14 doesn't preempt busyloops. - runtime.Gosched() - g.Leave() - } - done.Done() -} - -func TestConcurrentAll(t *testing.T) { - var g gate.Gate - var done sync.WaitGroup - - // Launch 1000 goroutines to concurrently enter/leave. - done.Add(1000) - for i := 0; i < 1000; i++ { - go worker(&g, &done) - } - - // Wait for the goroutines to do some work, then close the gate. - time.Sleep(2 * time.Second) - g.Close() - - // Wait for all of them to complete. - done.Wait() -} -- cgit v1.2.3