mirror of
				https://github.com/go-gitea/gitea.git
				synced 2025-10-31 05:11:41 +01:00 
			
		
		
		
	Fix races in the log module by using syncmap (#1421)
This commit is contained in:
		
							parent
							
								
									5d6b71fdbb
								
							
						
					
					
						commit
						93c25c9a35
					
				| @ -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
									
								
							
							
						
						
									
										27
									
								
								vendor/golang.org/x/sync/LICENSE
									
									
									
										generated
									
									
										vendored
									
									
										Normal 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
									
								
							
							
						
						
									
										22
									
								
								vendor/golang.org/x/sync/PATENTS
									
									
									
										generated
									
									
										vendored
									
									
										Normal 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
									
								
							
							
						
						
									
										372
									
								
								vendor/golang.org/x/sync/syncmap/map.go
									
									
									
										generated
									
									
										vendored
									
									
										Normal 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
									
									
								
							
							
						
						
									
										6
									
								
								vendor/vendor.json
									
									
									
									
										vendored
									
									
								
							| @ -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", | ||||
|  | ||||
		Loading…
	
	
			
			x
			
			
		
	
		Reference in New Issue
	
	Block a user