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Fix races in the log module by using syncmap (#1421)

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This commit is contained in:
Mura Li 2017-04-03 10:22:26 +08:00 committed by Bo-Yi Wu
parent 5d6b71fdbb
commit 93c25c9a35
5 changed files with 455 additions and 26 deletions
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54
modules/log/log.go
View file

@ -12,6 +12,8 @@ import (
"runtime"
"strings"
"sync"
"golang.org/x/sync/syncmap"
)
var (
@ -42,10 +44,11 @@ func NewLogger(bufLen int64, mode, config string) {
// DelLogger removes loggers that are for the given mode
func DelLogger(mode string) error {
for _, l := range loggers {
if _, ok := l.outputs[mode]; ok {
if _, ok := l.outputs.Load(mode); ok {
return l.DelLogger(mode)
}
}
Trace("Log adapter %s not found, no need to delete", mode)
return nil
}
@ -177,16 +180,15 @@ type Logger struct {
lock sync.Mutex
level int
msg chan *logMsg
outputs map[string]LoggerInterface
outputs syncmap.Map
quit chan bool
}
// newLogger initializes and returns a new logger.
func newLogger(buffer int64) *Logger {
l := &Logger{
msg: make(chan *logMsg, buffer),
outputs: make(map[string]LoggerInterface),
quit: make(chan bool),
msg: make(chan *logMsg, buffer),
quit: make(chan bool),
}
go l.StartLogger()
return l
@ -194,14 +196,12 @@ func newLogger(buffer int64) *Logger {
// SetLogger sets new logger instance with given logger adapter and config.
func (l *Logger) SetLogger(adapter string, config string) error {
l.lock.Lock()
defer l.lock.Unlock()
if log, ok := adapters[adapter]; ok {
lg := log()
if err := lg.Init(config); err != nil {
return err
}
l.outputs[adapter] = lg
l.outputs.Store(adapter, lg)
l.adapter = adapter
} else {
panic("log: unknown adapter \"" + adapter + "\" (forgotten register?)")
@ -211,11 +211,9 @@ func (l *Logger) SetLogger(adapter string, config string) error {
// DelLogger removes a logger adapter instance.
func (l *Logger) DelLogger(adapter string) error {
l.lock.Lock()
defer l.lock.Unlock()
if lg, ok := l.outputs[adapter]; ok {
lg.Destroy()
delete(l.outputs, adapter)
if lg, ok := l.outputs.Load(adapter); ok {
lg.(LoggerInterface).Destroy()
l.outputs.Delete(adapter)
} else {
panic("log: unknown adapter \"" + adapter + "\" (forgotten register?)")
}
@ -264,11 +262,12 @@ func (l *Logger) StartLogger() {
for {
select {
case bm := <-l.msg:
for _, l := range l.outputs {
if err := l.WriteMsg(bm.msg, bm.skip, bm.level); err != nil {
l.outputs.Range(func(k, v interface{}) bool {
if err := v.(LoggerInterface).WriteMsg(bm.msg, bm.skip, bm.level); err != nil {
fmt.Println("ERROR, unable to WriteMsg:", err)
}
}
return true
})
case <-l.quit:
return
}
@ -277,9 +276,10 @@ func (l *Logger) StartLogger() {
// Flush flushes all chan data.
func (l *Logger) Flush() {
for _, l := range l.outputs {
l.Flush()
}
l.outputs.Range(func(k, v interface{}) bool {
v.(LoggerInterface).Flush()
return true
})
}
// Close closes logger, flush all chan data and destroy all adapter instances.
@ -288,19 +288,21 @@ func (l *Logger) Close() {
for {
if len(l.msg) > 0 {
bm := <-l.msg
for _, l := range l.outputs {
if err := l.WriteMsg(bm.msg, bm.skip, bm.level); err != nil {
l.outputs.Range(func(k, v interface{}) bool {
if err := v.(LoggerInterface).WriteMsg(bm.msg, bm.skip, bm.level); err != nil {
fmt.Println("ERROR, unable to WriteMsg:", err)
}
}
return true
})
} else {
break
}
}
for _, l := range l.outputs {
l.Flush()
l.Destroy()
}
l.outputs.Range(func(k, v interface{}) bool {
v.(LoggerInterface).Flush()
v.(LoggerInterface).Destroy()
return true
})
}
// Trace records trace log

27
vendor/golang.org/x/sync/LICENSE generated vendored Normal file
View file

@ -0,0 +1,27 @@
Copyright (c) 2009 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

22
vendor/golang.org/x/sync/PATENTS generated vendored Normal file
View file

@ -0,0 +1,22 @@
Additional IP Rights Grant (Patents)
"This implementation" means the copyrightable works distributed by
Google as part of the Go project.
Google hereby grants to You a perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as stated in this section)
patent license to make, have made, use, offer to sell, sell, import,
transfer and otherwise run, modify and propagate the contents of this
implementation of Go, where such license applies only to those patent
claims, both currently owned or controlled by Google and acquired in
the future, licensable by Google that are necessarily infringed by this
implementation of Go. This grant does not include claims that would be
infringed only as a consequence of further modification of this
implementation. If you or your agent or exclusive licensee institute or
order or agree to the institution of patent litigation against any
entity (including a cross-claim or counterclaim in a lawsuit) alleging
that this implementation of Go or any code incorporated within this
implementation of Go constitutes direct or contributory patent
infringement, or inducement of patent infringement, then any patent
rights granted to you under this License for this implementation of Go
shall terminate as of the date such litigation is filed.

372
vendor/golang.org/x/sync/syncmap/map.go generated vendored Normal file
View file

@ -0,0 +1,372 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package syncmap provides a concurrent map implementation.
// It is a prototype for a proposed addition to the sync package
// in the standard library.
// (https://golang.org/issue/18177)
package syncmap
import (
"sync"
"sync/atomic"
"unsafe"
)
// Map is a concurrent map with amortized-constant-time loads, stores, and deletes.
// It is safe for multiple goroutines to call a Map's methods concurrently.
//
// The zero Map is valid and empty.
//
// A Map must not be copied after first use.
type Map struct {
mu sync.Mutex
// read contains the portion of the map's contents that are safe for
// concurrent access (with or without mu held).
//
// The read field itself is always safe to load, but must only be stored with
// mu held.
//
// Entries stored in read may be updated concurrently without mu, but updating
// a previously-expunged entry requires that the entry be copied to the dirty
// map and unexpunged with mu held.
read atomic.Value // readOnly
// dirty contains the portion of the map's contents that require mu to be
// held. To ensure that the dirty map can be promoted to the read map quickly,
// it also includes all of the non-expunged entries in the read map.
//
// Expunged entries are not stored in the dirty map. An expunged entry in the
// clean map must be unexpunged and added to the dirty map before a new value
// can be stored to it.
//
// If the dirty map is nil, the next write to the map will initialize it by
// making a shallow copy of the clean map, omitting stale entries.
dirty map[interface{}]*entry
// misses counts the number of loads since the read map was last updated that
// needed to lock mu to determine whether the key was present.
//
// Once enough misses have occurred to cover the cost of copying the dirty
// map, the dirty map will be promoted to the read map (in the unamended
// state) and the next store to the map will make a new dirty copy.
misses int
}
// readOnly is an immutable struct stored atomically in the Map.read field.
type readOnly struct {
m map[interface{}]*entry
amended bool // true if the dirty map contains some key not in m.
}
// expunged is an arbitrary pointer that marks entries which have been deleted
// from the dirty map.
var expunged = unsafe.Pointer(new(interface{}))
// An entry is a slot in the map corresponding to a particular key.
type entry struct {
// p points to the interface{} value stored for the entry.
//
// If p == nil, the entry has been deleted and m.dirty == nil.
//
// If p == expunged, the entry has been deleted, m.dirty != nil, and the entry
// is missing from m.dirty.
//
// Otherwise, the entry is valid and recorded in m.read.m[key] and, if m.dirty
// != nil, in m.dirty[key].
//
// An entry can be deleted by atomic replacement with nil: when m.dirty is
// next created, it will atomically replace nil with expunged and leave
// m.dirty[key] unset.
//
// An entry's associated value can be updated by atomic replacement, provided
// p != expunged. If p == expunged, an entry's associated value can be updated
// only after first setting m.dirty[key] = e so that lookups using the dirty
// map find the entry.
p unsafe.Pointer // *interface{}
}
func newEntry(i interface{}) *entry {
return &entry{p: unsafe.Pointer(&i)}
}
// Load returns the value stored in the map for a key, or nil if no
// value is present.
// The ok result indicates whether value was found in the map.
func (m *Map) Load(key interface{}) (value interface{}, ok bool) {
read, _ := m.read.Load().(readOnly)
e, ok := read.m[key]
if !ok && read.amended {
m.mu.Lock()
// Avoid reporting a spurious miss if m.dirty got promoted while we were
// blocked on m.mu. (If further loads of the same key will not miss, it's
// not worth copying the dirty map for this key.)
read, _ = m.read.Load().(readOnly)
e, ok = read.m[key]
if !ok && read.amended {
e, ok = m.dirty[key]
// Regardless of whether the entry was present, record a miss: this key
// will take the slow path until the dirty map is promoted to the read
// map.
m.missLocked()
}
m.mu.Unlock()
}
if !ok {
return nil, false
}
return e.load()
}
func (e *entry) load() (value interface{}, ok bool) {
p := atomic.LoadPointer(&e.p)
if p == nil || p == expunged {
return nil, false
}
return *(*interface{})(p), true
}
// Store sets the value for a key.
func (m *Map) Store(key, value interface{}) {
read, _ := m.read.Load().(readOnly)
if e, ok := read.m[key]; ok && e.tryStore(&value) {
return
}
m.mu.Lock()
read, _ = m.read.Load().(readOnly)
if e, ok := read.m[key]; ok {
if e.unexpungeLocked() {
// The entry was previously expunged, which implies that there is a
// non-nil dirty map and this entry is not in it.
m.dirty[key] = e
}
e.storeLocked(&value)
} else if e, ok := m.dirty[key]; ok {
e.storeLocked(&value)
} else {
if !read.amended {
// We're adding the first new key to the dirty map.
// Make sure it is allocated and mark the read-only map as incomplete.
m.dirtyLocked()
m.read.Store(readOnly{m: read.m, amended: true})
}
m.dirty[key] = newEntry(value)
}
m.mu.Unlock()
}
// tryStore stores a value if the entry has not been expunged.
//
// If the entry is expunged, tryStore returns false and leaves the entry
// unchanged.
func (e *entry) tryStore(i *interface{}) bool {
p := atomic.LoadPointer(&e.p)
if p == expunged {
return false
}
for {
if atomic.CompareAndSwapPointer(&e.p, p, unsafe.Pointer(i)) {
return true
}
p = atomic.LoadPointer(&e.p)
if p == expunged {
return false
}
}
}
// unexpungeLocked ensures that the entry is not marked as expunged.
//
// If the entry was previously expunged, it must be added to the dirty map
// before m.mu is unlocked.
func (e *entry) unexpungeLocked() (wasExpunged bool) {
return atomic.CompareAndSwapPointer(&e.p, expunged, nil)
}
// storeLocked unconditionally stores a value to the entry.
//
// The entry must be known not to be expunged.
func (e *entry) storeLocked(i *interface{}) {
atomic.StorePointer(&e.p, unsafe.Pointer(i))
}
// LoadOrStore returns the existing value for the key if present.
// Otherwise, it stores and returns the given value.
// The loaded result is true if the value was loaded, false if stored.
func (m *Map) LoadOrStore(key, value interface{}) (actual interface{}, loaded bool) {
// Avoid locking if it's a clean hit.
read, _ := m.read.Load().(readOnly)
if e, ok := read.m[key]; ok {
actual, loaded, ok := e.tryLoadOrStore(value)
if ok {
return actual, loaded
}
}
m.mu.Lock()
read, _ = m.read.Load().(readOnly)
if e, ok := read.m[key]; ok {
if e.unexpungeLocked() {
m.dirty[key] = e
}
actual, loaded, _ = e.tryLoadOrStore(value)
} else if e, ok := m.dirty[key]; ok {
actual, loaded, _ = e.tryLoadOrStore(value)
m.missLocked()
} else {
if !read.amended {
// We're adding the first new key to the dirty map.
// Make sure it is allocated and mark the read-only map as incomplete.
m.dirtyLocked()
m.read.Store(readOnly{m: read.m, amended: true})
}
m.dirty[key] = newEntry(value)
actual, loaded = value, false
}
m.mu.Unlock()
return actual, loaded
}
// tryLoadOrStore atomically loads or stores a value if the entry is not
// expunged.
//
// If the entry is expunged, tryLoadOrStore leaves the entry unchanged and
// returns with ok==false.
func (e *entry) tryLoadOrStore(i interface{}) (actual interface{}, loaded, ok bool) {
p := atomic.LoadPointer(&e.p)
if p == expunged {
return nil, false, false
}
if p != nil {
return *(*interface{})(p), true, true
}
// Copy the interface after the first load to make this method more amenable
// to escape analysis: if we hit the "load" path or the entry is expunged, we
// shouldn't bother heap-allocating.
ic := i
for {
if atomic.CompareAndSwapPointer(&e.p, nil, unsafe.Pointer(&ic)) {
return i, false, true
}
p = atomic.LoadPointer(&e.p)
if p == expunged {
return nil, false, false
}
if p != nil {
return *(*interface{})(p), true, true
}
}
}
// Delete deletes the value for a key.
func (m *Map) Delete(key interface{}) {
read, _ := m.read.Load().(readOnly)
e, ok := read.m[key]
if !ok && read.amended {
m.mu.Lock()
read, _ = m.read.Load().(readOnly)
e, ok = read.m[key]
if !ok && read.amended {
delete(m.dirty, key)
}
m.mu.Unlock()
}
if ok {
e.delete()
}
}
func (e *entry) delete() (hadValue bool) {
for {
p := atomic.LoadPointer(&e.p)
if p == nil || p == expunged {
return false
}
if atomic.CompareAndSwapPointer(&e.p, p, nil) {
return true
}
}
}
// Range calls f sequentially for each key and value present in the map.
// If f returns false, range stops the iteration.
//
// Range does not necessarily correspond to any consistent snapshot of the Map's
// contents: no key will be visited more than once, but if the value for any key
// is stored or deleted concurrently, Range may reflect any mapping for that key
// from any point during the Range call.
//
// Range may be O(N) with the number of elements in the map even if f returns
// false after a constant number of calls.
func (m *Map) Range(f func(key, value interface{}) bool) {
// We need to be able to iterate over all of the keys that were already
// present at the start of the call to Range.
// If read.amended is false, then read.m satisfies that property without
// requiring us to hold m.mu for a long time.
read, _ := m.read.Load().(readOnly)
if read.amended {
// m.dirty contains keys not in read.m. Fortunately, Range is already O(N)
// (assuming the caller does not break out early), so a call to Range
// amortizes an entire copy of the map: we can promote the dirty copy
// immediately!
m.mu.Lock()
read, _ = m.read.Load().(readOnly)
if read.amended {
read = readOnly{m: m.dirty}
m.read.Store(read)
m.dirty = nil
m.misses = 0
}
m.mu.Unlock()
}
for k, e := range read.m {
v, ok := e.load()
if !ok {
continue
}
if !f(k, v) {
break
}
}
}
func (m *Map) missLocked() {
m.misses++
if m.misses < len(m.dirty) {
return
}
m.read.Store(readOnly{m: m.dirty})
m.dirty = nil
m.misses = 0
}
func (m *Map) dirtyLocked() {
if m.dirty != nil {
return
}
read, _ := m.read.Load().(readOnly)
m.dirty = make(map[interface{}]*entry, len(read.m))
for k, e := range read.m {
if !e.tryExpungeLocked() {
m.dirty[k] = e
}
}
}
func (e *entry) tryExpungeLocked() (isExpunged bool) {
p := atomic.LoadPointer(&e.p)
for p == nil {
if atomic.CompareAndSwapPointer(&e.p, nil, expunged) {
return true
}
p = atomic.LoadPointer(&e.p)
}
return p == expunged
}

6
vendor/vendor.json vendored
View file

@ -1266,6 +1266,12 @@
"revision": "569280fa63be4e201b975e5411e30a92178f0118",
"revisionTime": "2016-11-03T00:14:07Z"
},
{
"checksumSHA1": "4TEYFKrAUuwBMqExjQBsnf/CgjQ=",
"path": "golang.org/x/sync/syncmap",
"revision": "5a06fca2c336a4b2b2fcb45702e8c47621b2aa2c",
"revisionTime": "2017-03-17T17:13:11Z"
},
{
"checksumSHA1": "8fD/im5Kwvy3JgmxulDTambmE8w=",
"path": "golang.org/x/sys/unix",