From 93c25c9a35141a1bb52966c5256ad7020e82ab79 Mon Sep 17 00:00:00 2001 From: Mura Li Date: Mon, 3 Apr 2017 10:22:26 +0800 Subject: [PATCH] Fix races in the log module by using syncmap (#1421) --- modules/log/log.go | 54 ++-- vendor/golang.org/x/sync/LICENSE | 27 ++ vendor/golang.org/x/sync/PATENTS | 22 ++ vendor/golang.org/x/sync/syncmap/map.go | 372 ++++++++++++++++++++++++ vendor/vendor.json | 6 + 5 files changed, 455 insertions(+), 26 deletions(-) create mode 100644 vendor/golang.org/x/sync/LICENSE create mode 100644 vendor/golang.org/x/sync/PATENTS create mode 100644 vendor/golang.org/x/sync/syncmap/map.go diff --git a/modules/log/log.go b/modules/log/log.go index 0b76002230..24ac3f652f 100644 --- a/modules/log/log.go +++ b/modules/log/log.go @@ -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 diff --git a/vendor/golang.org/x/sync/LICENSE b/vendor/golang.org/x/sync/LICENSE new file mode 100644 index 0000000000..6a66aea5ea --- /dev/null +++ b/vendor/golang.org/x/sync/LICENSE @@ -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. diff --git a/vendor/golang.org/x/sync/PATENTS b/vendor/golang.org/x/sync/PATENTS new file mode 100644 index 0000000000..733099041f --- /dev/null +++ b/vendor/golang.org/x/sync/PATENTS @@ -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. diff --git a/vendor/golang.org/x/sync/syncmap/map.go b/vendor/golang.org/x/sync/syncmap/map.go new file mode 100644 index 0000000000..80e15847ef --- /dev/null +++ b/vendor/golang.org/x/sync/syncmap/map.go @@ -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 +} diff --git a/vendor/vendor.json b/vendor/vendor.json index 4b24848ea7..d5ad949feb 100644 --- a/vendor/vendor.json +++ b/vendor/vendor.json @@ -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",