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bf24d54143
This allows us to check lock invariants. It was proposed upstream and rejected in: https://github.com/golang/go/issues/1366 Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
124 lines
2.8 KiB
Go
124 lines
2.8 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build go1.13,!go1.16
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//lint:file-ignore SA2001 the empty critical sections are part of triggering different internal mutex states
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package syncs
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import (
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"sync"
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"testing"
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"time"
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)
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func wantPanic(t *testing.T, fn func()) {
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t.Helper()
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defer func() {
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recover()
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}()
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fn()
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t.Fatal("failed to panic")
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}
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func TestAssertLocked(t *testing.T) {
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m := new(sync.Mutex)
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wantPanic(t, func() { AssertLocked(m) })
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m.Lock()
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AssertLocked(m)
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m.Unlock()
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wantPanic(t, func() { AssertLocked(m) })
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// Test correct handling of mutex with waiter.
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m.Lock()
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AssertLocked(m)
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go func() {
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m.Lock()
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m.Unlock()
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}()
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// Give the goroutine above a few moments to get started.
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// The test will pass whether or not we win the race,
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// but we want to run sometimes, to get the test coverage.
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time.Sleep(10 * time.Millisecond)
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AssertLocked(m)
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}
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func TestAssertWLocked(t *testing.T) {
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m := new(sync.RWMutex)
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wantPanic(t, func() { AssertWLocked(m) })
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m.Lock()
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AssertWLocked(m)
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m.Unlock()
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wantPanic(t, func() { AssertWLocked(m) })
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// Test correct handling of mutex with waiter.
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m.Lock()
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AssertWLocked(m)
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go func() {
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m.Lock()
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m.Unlock()
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}()
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// Give the goroutine above a few moments to get started.
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// The test will pass whether or not we win the race,
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// but we want to run sometimes, to get the test coverage.
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time.Sleep(10 * time.Millisecond)
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AssertWLocked(m)
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}
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func TestAssertRLocked(t *testing.T) {
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m := new(sync.RWMutex)
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wantPanic(t, func() { AssertRLocked(m) })
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m.Lock()
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AssertRLocked(m)
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m.Unlock()
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m.RLock()
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AssertRLocked(m)
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m.RUnlock()
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wantPanic(t, func() { AssertRLocked(m) })
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// Test correct handling of mutex with waiter.
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m.RLock()
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AssertRLocked(m)
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go func() {
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m.RLock()
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m.RUnlock()
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}()
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// Give the goroutine above a few moments to get started.
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// The test will pass whether or not we win the race,
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// but we want to run sometimes, to get the test coverage.
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time.Sleep(10 * time.Millisecond)
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AssertRLocked(m)
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m.RUnlock()
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// Test correct handling of rlock with write waiter.
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m.RLock()
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AssertRLocked(m)
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go func() {
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m.Lock()
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m.Unlock()
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}()
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// Give the goroutine above a few moments to get started.
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// The test will pass whether or not we win the race,
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// but we want to run sometimes, to get the test coverage.
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time.Sleep(10 * time.Millisecond)
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AssertRLocked(m)
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m.RUnlock()
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// Test correct handling of rlock with other rlocks.
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// This is a bit racy, but losing the race hurts nothing,
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// and winning the race means correct test coverage.
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m.RLock()
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AssertRLocked(m)
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go func() {
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m.RLock()
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time.Sleep(10 * time.Millisecond)
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m.RUnlock()
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}()
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time.Sleep(5 * time.Millisecond)
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AssertRLocked(m)
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m.RUnlock()
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}
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