62 lines
1.2 KiB
Go
62 lines
1.2 KiB
Go
// Copyright (C) 2014 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at http://mozilla.org/MPL/2.0/.
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package model
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import (
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"fmt"
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"sync"
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"time"
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)
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type Holdable interface {
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Holders() string
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}
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func newDeadlockDetector(timeout time.Duration) *deadlockDetector {
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return &deadlockDetector{
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timeout: timeout,
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lockers: make(map[string]sync.Locker),
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}
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}
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type deadlockDetector struct {
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timeout time.Duration
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lockers map[string]sync.Locker
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}
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func (d *deadlockDetector) Watch(name string, mut sync.Locker) {
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d.lockers[name] = mut
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go func() {
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for {
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time.Sleep(d.timeout / 4)
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ok := make(chan bool, 2)
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go func() {
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mut.Lock()
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_ = 1 // empty critical section
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mut.Unlock()
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ok <- true
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}()
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go func() {
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time.Sleep(d.timeout)
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ok <- false
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}()
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if r := <-ok; !r {
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msg := fmt.Sprintf("deadlock detected at %s", name)
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for otherName, otherMut := range d.lockers {
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if otherHolder, ok := otherMut.(Holdable); ok {
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msg += "\n===" + otherName + "===\n" + otherHolder.Holders()
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}
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}
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panic(msg)
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}
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}
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}()
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}
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