snapshot: sagernet/gvisor v0.0.0-20250811.0-sing-box-mod.1
Содержимое пина, зафиксированного в go.mod sing-box-lx, одним коммитом без истории. Полная история SagerNet/gvisor — 1.45 ГБ и клонируется в каждой CI-джобе; наша дельта — одна вставка в одну функцию, история для неё не нужна. Module path github.com/sagernet/gvisor сохранён намеренно: на него опирается replace-директива суперпроекта. Патч поверх — отдельным коммитом, чтобы дельта читалась одним git show и переносилась на новый пин копированием. SPECS/TASKS/048-GVISOR_HANDSHAKE_NIL_CRASH
This commit is contained in:
Leadaxe
commit
2c4ae3b0a4
712 changed files with 185689 additions and 0 deletions
439
pkg/sync/locking/atomicptrmap_ancestors_unsafe.go
Normal file
439
pkg/sync/locking/atomicptrmap_ancestors_unsafe.go
Normal file
|
|
@ -0,0 +1,439 @@
|
|||
package locking
|
||||
|
||||
import (
|
||||
"sync/atomic"
|
||||
"unsafe"
|
||||
|
||||
"github.com/sagernet/gvisor/pkg/gohacks"
|
||||
"github.com/sagernet/gvisor/pkg/sync"
|
||||
)
|
||||
|
||||
const (
|
||||
// ShardOrder is an optional parameter specifying the base-2 log of the
|
||||
// number of shards per AtomicPtrMap. Higher values of ShardOrder reduce
|
||||
// unnecessary synchronization between unrelated concurrent operations,
|
||||
// improving performance for write-heavy workloads, but increase memory
|
||||
// usage for small maps.
|
||||
ancestorsShardOrder = 0
|
||||
)
|
||||
|
||||
// Hasher is an optional type parameter. If Hasher is provided, it must define
|
||||
// the Init and Hash methods. One Hasher will be shared by all AtomicPtrMaps.
|
||||
type ancestorsHasher struct {
|
||||
ancestorsdefaultHasher
|
||||
}
|
||||
|
||||
// defaultHasher is the default Hasher. This indirection exists because
|
||||
// defaultHasher must exist even if a custom Hasher is provided, to prevent the
|
||||
// Go compiler from complaining about defaultHasher's unused imports.
|
||||
type ancestorsdefaultHasher struct {
|
||||
fn func(unsafe.Pointer, uintptr) uintptr
|
||||
seed uintptr
|
||||
}
|
||||
|
||||
// Init initializes the Hasher.
|
||||
func (h *ancestorsdefaultHasher) Init() {
|
||||
h.fn = sync.MapKeyHasher(map[*MutexClass]*string(nil))
|
||||
h.seed = sync.RandUintptr()
|
||||
}
|
||||
|
||||
// Hash returns the hash value for the given Key.
|
||||
func (h *ancestorsdefaultHasher) Hash(key *MutexClass) uintptr {
|
||||
return h.fn(gohacks.Noescape(unsafe.Pointer(&key)), h.seed)
|
||||
}
|
||||
|
||||
var ancestorshasher ancestorsHasher
|
||||
|
||||
func init() {
|
||||
ancestorshasher.Init()
|
||||
}
|
||||
|
||||
// An AtomicPtrMap maps Keys to non-nil pointers to Values. AtomicPtrMap are
|
||||
// safe for concurrent use from multiple goroutines without additional
|
||||
// synchronization.
|
||||
//
|
||||
// The zero value of AtomicPtrMap is empty (maps all Keys to nil) and ready for
|
||||
// use. AtomicPtrMaps must not be copied after first use.
|
||||
//
|
||||
// sync.Map may be faster than AtomicPtrMap if most operations on the map are
|
||||
// concurrent writes to a fixed set of keys. AtomicPtrMap is usually faster in
|
||||
// other circumstances.
|
||||
type ancestorsAtomicPtrMap struct {
|
||||
shards [1 << ancestorsShardOrder]ancestorsapmShard
|
||||
}
|
||||
|
||||
func (m *ancestorsAtomicPtrMap) shard(hash uintptr) *ancestorsapmShard {
|
||||
// Go defines right shifts >= width of shifted unsigned operand as 0, so
|
||||
// this is correct even if ShardOrder is 0 (although nogo complains because
|
||||
// nogo is dumb).
|
||||
const indexLSB = unsafe.Sizeof(uintptr(0))*8 - ancestorsShardOrder
|
||||
index := hash >> indexLSB
|
||||
return (*ancestorsapmShard)(unsafe.Pointer(uintptr(unsafe.Pointer(&m.shards)) + (index * unsafe.Sizeof(ancestorsapmShard{}))))
|
||||
}
|
||||
|
||||
type ancestorsapmShard struct {
|
||||
ancestorsapmShardMutationData
|
||||
_ [ancestorsapmShardMutationDataPadding]byte
|
||||
ancestorsapmShardLookupData
|
||||
_ [ancestorsapmShardLookupDataPadding]byte
|
||||
}
|
||||
|
||||
type ancestorsapmShardMutationData struct {
|
||||
dirtyMu sync.Mutex // serializes slot transitions out of empty
|
||||
dirty uintptr // # slots with val != nil
|
||||
count uintptr // # slots with val != nil and val != tombstone()
|
||||
rehashMu sync.Mutex // serializes rehashing
|
||||
}
|
||||
|
||||
type ancestorsapmShardLookupData struct {
|
||||
seq sync.SeqCount // allows atomic reads of slots+mask
|
||||
slots unsafe.Pointer // [mask+1]slot or nil; protected by rehashMu/seq
|
||||
mask uintptr // always (a power of 2) - 1; protected by rehashMu/seq
|
||||
}
|
||||
|
||||
const (
|
||||
ancestorscacheLineBytes = 64
|
||||
// Cache line padding is enabled if sharding is.
|
||||
ancestorsapmEnablePadding = (ancestorsShardOrder + 63) >> 6 // 0 if ShardOrder == 0, 1 otherwise
|
||||
// The -1 and +1 below are required to ensure that if unsafe.Sizeof(T) %
|
||||
// cacheLineBytes == 0, then padding is 0 (rather than cacheLineBytes).
|
||||
ancestorsapmShardMutationDataRequiredPadding = ancestorscacheLineBytes - (((unsafe.Sizeof(ancestorsapmShardMutationData{}) - 1) % ancestorscacheLineBytes) + 1)
|
||||
ancestorsapmShardMutationDataPadding = ancestorsapmEnablePadding * ancestorsapmShardMutationDataRequiredPadding
|
||||
ancestorsapmShardLookupDataRequiredPadding = ancestorscacheLineBytes - (((unsafe.Sizeof(ancestorsapmShardLookupData{}) - 1) % ancestorscacheLineBytes) + 1)
|
||||
ancestorsapmShardLookupDataPadding = ancestorsapmEnablePadding * ancestorsapmShardLookupDataRequiredPadding
|
||||
|
||||
// These define fractional thresholds for when apmShard.rehash() is called
|
||||
// (i.e. the load factor) and when it rehases to a larger table
|
||||
// respectively. They are chosen such that the rehash threshold = the
|
||||
// expansion threshold + 1/2, so that when reuse of deleted slots is rare
|
||||
// or non-existent, rehashing occurs after the insertion of at least 1/2
|
||||
// the table's size in new entries, which is acceptably infrequent.
|
||||
ancestorsapmRehashThresholdNum = 2
|
||||
ancestorsapmRehashThresholdDen = 3
|
||||
ancestorsapmExpansionThresholdNum = 1
|
||||
ancestorsapmExpansionThresholdDen = 6
|
||||
)
|
||||
|
||||
type ancestorsapmSlot struct {
|
||||
// slot states are indicated by val:
|
||||
//
|
||||
// * Empty: val == nil; key is meaningless. May transition to full or
|
||||
// evacuated with dirtyMu locked.
|
||||
//
|
||||
// * Full: val != nil, tombstone(), or evacuated(); key is immutable. val
|
||||
// is the Value mapped to key. May transition to deleted or evacuated.
|
||||
//
|
||||
// * Deleted: val == tombstone(); key is still immutable. key is mapped to
|
||||
// no Value. May transition to full or evacuated.
|
||||
//
|
||||
// * Evacuated: val == evacuated(); key is immutable. Set by rehashing on
|
||||
// slots that have already been moved, requiring readers to wait for
|
||||
// rehashing to complete and use the new table. Terminal state.
|
||||
//
|
||||
// Note that once val is non-nil, it cannot become nil again. That is, the
|
||||
// transition from empty to non-empty is irreversible for a given slot;
|
||||
// the only way to create more empty slots is by rehashing.
|
||||
val unsafe.Pointer
|
||||
key *MutexClass
|
||||
}
|
||||
|
||||
func ancestorsapmSlotAt(slots unsafe.Pointer, pos uintptr) *ancestorsapmSlot {
|
||||
return (*ancestorsapmSlot)(unsafe.Pointer(uintptr(slots) + pos*unsafe.Sizeof(ancestorsapmSlot{})))
|
||||
}
|
||||
|
||||
var ancestorstombstoneObj byte
|
||||
|
||||
func ancestorstombstone() unsafe.Pointer {
|
||||
return unsafe.Pointer(&ancestorstombstoneObj)
|
||||
}
|
||||
|
||||
var ancestorsevacuatedObj byte
|
||||
|
||||
func ancestorsevacuated() unsafe.Pointer {
|
||||
return unsafe.Pointer(&ancestorsevacuatedObj)
|
||||
}
|
||||
|
||||
// Load returns the Value stored in m for key.
|
||||
func (m *ancestorsAtomicPtrMap) Load(key *MutexClass) *string {
|
||||
hash := ancestorshasher.Hash(key)
|
||||
shard := m.shard(hash)
|
||||
|
||||
retry:
|
||||
epoch := shard.seq.BeginRead()
|
||||
slots := atomic.LoadPointer(&shard.slots)
|
||||
mask := atomic.LoadUintptr(&shard.mask)
|
||||
if !shard.seq.ReadOk(epoch) {
|
||||
goto retry
|
||||
}
|
||||
if slots == nil {
|
||||
return nil
|
||||
}
|
||||
|
||||
i := hash & mask
|
||||
inc := uintptr(1)
|
||||
for {
|
||||
slot := ancestorsapmSlotAt(slots, i)
|
||||
slotVal := atomic.LoadPointer(&slot.val)
|
||||
if slotVal == nil {
|
||||
return nil
|
||||
}
|
||||
if slotVal == ancestorsevacuated() {
|
||||
goto retry
|
||||
}
|
||||
if slot.key == key {
|
||||
if slotVal == ancestorstombstone() {
|
||||
return nil
|
||||
}
|
||||
return (*string)(slotVal)
|
||||
}
|
||||
i = (i + inc) & mask
|
||||
inc++
|
||||
}
|
||||
}
|
||||
|
||||
// Store stores the Value val for key.
|
||||
func (m *ancestorsAtomicPtrMap) Store(key *MutexClass, val *string) {
|
||||
m.maybeCompareAndSwap(key, false, nil, val)
|
||||
}
|
||||
|
||||
// Swap stores the Value val for key and returns the previously-mapped Value.
|
||||
func (m *ancestorsAtomicPtrMap) Swap(key *MutexClass, val *string) *string {
|
||||
return m.maybeCompareAndSwap(key, false, nil, val)
|
||||
}
|
||||
|
||||
// CompareAndSwap checks that the Value stored for key is oldVal; if it is, it
|
||||
// stores the Value newVal for key. CompareAndSwap returns the previous Value
|
||||
// stored for key, whether or not it stores newVal.
|
||||
func (m *ancestorsAtomicPtrMap) CompareAndSwap(key *MutexClass, oldVal, newVal *string) *string {
|
||||
return m.maybeCompareAndSwap(key, true, oldVal, newVal)
|
||||
}
|
||||
|
||||
func (m *ancestorsAtomicPtrMap) maybeCompareAndSwap(key *MutexClass, compare bool, typedOldVal, typedNewVal *string) *string {
|
||||
hash := ancestorshasher.Hash(key)
|
||||
shard := m.shard(hash)
|
||||
oldVal := ancestorstombstone()
|
||||
if typedOldVal != nil {
|
||||
oldVal = unsafe.Pointer(typedOldVal)
|
||||
}
|
||||
newVal := ancestorstombstone()
|
||||
if typedNewVal != nil {
|
||||
newVal = unsafe.Pointer(typedNewVal)
|
||||
}
|
||||
|
||||
retry:
|
||||
epoch := shard.seq.BeginRead()
|
||||
slots := atomic.LoadPointer(&shard.slots)
|
||||
mask := atomic.LoadUintptr(&shard.mask)
|
||||
if !shard.seq.ReadOk(epoch) {
|
||||
goto retry
|
||||
}
|
||||
if slots == nil {
|
||||
if (compare && oldVal != ancestorstombstone()) || newVal == ancestorstombstone() {
|
||||
return nil
|
||||
}
|
||||
|
||||
shard.rehash(nil)
|
||||
goto retry
|
||||
}
|
||||
|
||||
i := hash & mask
|
||||
inc := uintptr(1)
|
||||
for {
|
||||
slot := ancestorsapmSlotAt(slots, i)
|
||||
slotVal := atomic.LoadPointer(&slot.val)
|
||||
if slotVal == nil {
|
||||
if (compare && oldVal != ancestorstombstone()) || newVal == ancestorstombstone() {
|
||||
return nil
|
||||
}
|
||||
|
||||
shard.dirtyMu.Lock()
|
||||
slotVal = atomic.LoadPointer(&slot.val)
|
||||
if slotVal == nil {
|
||||
|
||||
if dirty, capacity := shard.dirty+1, mask+1; dirty*ancestorsapmRehashThresholdDen >= capacity*ancestorsapmRehashThresholdNum {
|
||||
shard.dirtyMu.Unlock()
|
||||
shard.rehash(slots)
|
||||
goto retry
|
||||
}
|
||||
slot.key = key
|
||||
atomic.StorePointer(&slot.val, newVal)
|
||||
shard.dirty++
|
||||
atomic.AddUintptr(&shard.count, 1)
|
||||
shard.dirtyMu.Unlock()
|
||||
return nil
|
||||
}
|
||||
|
||||
shard.dirtyMu.Unlock()
|
||||
}
|
||||
if slotVal == ancestorsevacuated() {
|
||||
goto retry
|
||||
}
|
||||
if slot.key == key {
|
||||
for {
|
||||
if (compare && oldVal != slotVal) || newVal == slotVal {
|
||||
if slotVal == ancestorstombstone() {
|
||||
return nil
|
||||
}
|
||||
return (*string)(slotVal)
|
||||
}
|
||||
if atomic.CompareAndSwapPointer(&slot.val, slotVal, newVal) {
|
||||
if slotVal == ancestorstombstone() {
|
||||
atomic.AddUintptr(&shard.count, 1)
|
||||
return nil
|
||||
}
|
||||
if newVal == ancestorstombstone() {
|
||||
atomic.AddUintptr(&shard.count, ^uintptr(0))
|
||||
}
|
||||
return (*string)(slotVal)
|
||||
}
|
||||
slotVal = atomic.LoadPointer(&slot.val)
|
||||
if slotVal == ancestorsevacuated() {
|
||||
goto retry
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
i = (i + inc) & mask
|
||||
inc++
|
||||
}
|
||||
}
|
||||
|
||||
// rehash is marked nosplit to avoid preemption during table copying.
|
||||
//
|
||||
//go:nosplit
|
||||
func (shard *ancestorsapmShard) rehash(oldSlots unsafe.Pointer) {
|
||||
shard.rehashMu.Lock()
|
||||
defer shard.rehashMu.Unlock()
|
||||
|
||||
if shard.slots != oldSlots {
|
||||
return
|
||||
}
|
||||
|
||||
newSize := uintptr(8)
|
||||
if oldSlots != nil {
|
||||
oldSize := shard.mask + 1
|
||||
newSize = oldSize
|
||||
if count := atomic.LoadUintptr(&shard.count) + 1; count*ancestorsapmExpansionThresholdDen > oldSize*ancestorsapmExpansionThresholdNum {
|
||||
newSize *= 2
|
||||
}
|
||||
}
|
||||
|
||||
newSlotsSlice := make([]ancestorsapmSlot, newSize)
|
||||
newSlots := unsafe.Pointer(&newSlotsSlice[0])
|
||||
newMask := newSize - 1
|
||||
|
||||
shard.dirtyMu.Lock()
|
||||
shard.seq.BeginWrite()
|
||||
|
||||
if oldSlots != nil {
|
||||
realCount := uintptr(0)
|
||||
|
||||
oldMask := shard.mask
|
||||
for i := uintptr(0); i <= oldMask; i++ {
|
||||
oldSlot := ancestorsapmSlotAt(oldSlots, i)
|
||||
val := atomic.SwapPointer(&oldSlot.val, ancestorsevacuated())
|
||||
if val == nil || val == ancestorstombstone() {
|
||||
continue
|
||||
}
|
||||
hash := ancestorshasher.Hash(oldSlot.key)
|
||||
j := hash & newMask
|
||||
inc := uintptr(1)
|
||||
for {
|
||||
newSlot := ancestorsapmSlotAt(newSlots, j)
|
||||
if newSlot.val == nil {
|
||||
newSlot.val = val
|
||||
newSlot.key = oldSlot.key
|
||||
break
|
||||
}
|
||||
j = (j + inc) & newMask
|
||||
inc++
|
||||
}
|
||||
realCount++
|
||||
}
|
||||
|
||||
shard.dirty = realCount
|
||||
}
|
||||
|
||||
atomic.StorePointer(&shard.slots, newSlots)
|
||||
atomic.StoreUintptr(&shard.mask, newMask)
|
||||
|
||||
shard.seq.EndWrite()
|
||||
shard.dirtyMu.Unlock()
|
||||
}
|
||||
|
||||
// Range invokes f on each Key-Value pair stored in m. If any call to f returns
|
||||
// false, Range stops iteration and returns.
|
||||
//
|
||||
// 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.
|
||||
//
|
||||
// f must not call other methods on m.
|
||||
func (m *ancestorsAtomicPtrMap) Range(f func(key *MutexClass, val *string) bool) {
|
||||
for si := 0; si < len(m.shards); si++ {
|
||||
shard := &m.shards[si]
|
||||
if !shard.doRange(f) {
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (shard *ancestorsapmShard) doRange(f func(key *MutexClass, val *string) bool) bool {
|
||||
shard.rehashMu.Lock()
|
||||
defer shard.rehashMu.Unlock()
|
||||
slots := shard.slots
|
||||
if slots == nil {
|
||||
return true
|
||||
}
|
||||
mask := shard.mask
|
||||
for i := uintptr(0); i <= mask; i++ {
|
||||
slot := ancestorsapmSlotAt(slots, i)
|
||||
slotVal := atomic.LoadPointer(&slot.val)
|
||||
if slotVal == nil || slotVal == ancestorstombstone() {
|
||||
continue
|
||||
}
|
||||
if !f(slot.key, (*string)(slotVal)) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// RangeRepeatable is like Range, but:
|
||||
//
|
||||
// - RangeRepeatable may visit the same Key multiple times in the presence of
|
||||
// concurrent mutators, possibly passing different Values to f in different
|
||||
// calls.
|
||||
//
|
||||
// - It is safe for f to call other methods on m.
|
||||
func (m *ancestorsAtomicPtrMap) RangeRepeatable(f func(key *MutexClass, val *string) bool) {
|
||||
for si := 0; si < len(m.shards); si++ {
|
||||
shard := &m.shards[si]
|
||||
|
||||
retry:
|
||||
epoch := shard.seq.BeginRead()
|
||||
slots := atomic.LoadPointer(&shard.slots)
|
||||
mask := atomic.LoadUintptr(&shard.mask)
|
||||
if !shard.seq.ReadOk(epoch) {
|
||||
goto retry
|
||||
}
|
||||
if slots == nil {
|
||||
continue
|
||||
}
|
||||
|
||||
for i := uintptr(0); i <= mask; i++ {
|
||||
slot := ancestorsapmSlotAt(slots, i)
|
||||
slotVal := atomic.LoadPointer(&slot.val)
|
||||
if slotVal == ancestorsevacuated() {
|
||||
goto retry
|
||||
}
|
||||
if slotVal == nil || slotVal == ancestorstombstone() {
|
||||
continue
|
||||
}
|
||||
if !f(slot.key, (*string)(slotVal)) {
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue