315 lines
10 KiB
Go
315 lines
10 KiB
Go
package graphvent
|
|
|
|
import (
|
|
"github.com/google/uuid"
|
|
)
|
|
|
|
type ReqState byte
|
|
const (
|
|
Unlocked = ReqState(0)
|
|
Unlocking = ReqState(1)
|
|
Locked = ReqState(2)
|
|
Locking = ReqState(3)
|
|
AbortingLock = ReqState(4)
|
|
)
|
|
|
|
type ReqInfo struct {
|
|
State ReqState `gv:"state"`
|
|
MsgID uuid.UUID `gv:"msg_id"`
|
|
}
|
|
|
|
type LockableExt struct{
|
|
State ReqState `gv:"state"`
|
|
ReqID *uuid.UUID `gv:"req_id"`
|
|
Owner *NodeID `gv:"owner"`
|
|
PendingOwner *NodeID `gv:"pending_owner"`
|
|
PendingID uuid.UUID `gv:"pending_id"`
|
|
Requirements map[NodeID]ReqInfo `gv:"requirements"`
|
|
}
|
|
|
|
func (ext *LockableExt) Type() ExtType {
|
|
return LockableExtType
|
|
}
|
|
|
|
func NewLockableExt(requirements []NodeID) *LockableExt {
|
|
var reqs map[NodeID]ReqInfo = nil
|
|
if requirements != nil {
|
|
reqs = map[NodeID]ReqInfo{}
|
|
for _, id := range(requirements) {
|
|
reqs[id] = ReqInfo{
|
|
Unlocked,
|
|
uuid.UUID{},
|
|
}
|
|
}
|
|
}
|
|
return &LockableExt{
|
|
State: Unlocked,
|
|
Owner: nil,
|
|
PendingOwner: nil,
|
|
Requirements: reqs,
|
|
}
|
|
}
|
|
|
|
func UnlockLockable(ctx *Context, node *Node) (uuid.UUID, error) {
|
|
msgs := Messages{}
|
|
signal := NewLockSignal("unlock")
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, signal, node.ID)
|
|
return signal.ID(), ctx.Send(msgs)
|
|
}
|
|
|
|
func LockLockable(ctx *Context, node *Node) (uuid.UUID, error) {
|
|
msgs := Messages{}
|
|
signal := NewLockSignal("lock")
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, signal, node.ID)
|
|
return signal.ID(), ctx.Send(msgs)
|
|
}
|
|
|
|
func (ext *LockableExt) HandleErrorSignal(ctx *Context, node *Node, source NodeID, signal *ErrorSignal) Messages {
|
|
str := signal.Error
|
|
ctx.Log.Logf("lockable", "ERROR_SIGNAL: %s->%s %+v", source, node.ID, str)
|
|
|
|
msgs := Messages {}
|
|
switch str {
|
|
case "not_unlocked":
|
|
if ext.State == Locking {
|
|
ext.State = AbortingLock
|
|
req_info := ext.Requirements[source]
|
|
req_info.State = Unlocked
|
|
ext.Requirements[source] = req_info
|
|
for id, info := range(ext.Requirements) {
|
|
if info.State == Locked {
|
|
lock_signal := NewLockSignal("unlock")
|
|
|
|
req_info := ext.Requirements[id]
|
|
req_info.State = Unlocking
|
|
req_info.MsgID = lock_signal.ID()
|
|
ext.Requirements[id] = req_info
|
|
ctx.Log.Logf("lockable", "SENT_ABORT_UNLOCK: %s to %s", lock_signal.ID(), id)
|
|
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, lock_signal, id)
|
|
}
|
|
}
|
|
}
|
|
case "not_locked":
|
|
panic("RECEIVED not_locked, meaning a node thought it held a lock it didn't")
|
|
case "not_requirement":
|
|
}
|
|
|
|
return msgs
|
|
}
|
|
|
|
func (ext *LockableExt) HandleLinkSignal(ctx *Context, node *Node, source NodeID, signal *LinkSignal) Messages {
|
|
msgs := Messages {}
|
|
if ext.State == Unlocked {
|
|
switch signal.Action {
|
|
case "add":
|
|
_, exists := ext.Requirements[signal.NodeID]
|
|
if exists == true {
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "already_requirement"), source)
|
|
} else {
|
|
if ext.Requirements == nil {
|
|
ext.Requirements = map[NodeID]ReqInfo{}
|
|
}
|
|
ext.Requirements[signal.NodeID] = ReqInfo{
|
|
Unlocked,
|
|
uuid.UUID{},
|
|
}
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "req_added"), source)
|
|
}
|
|
case "remove":
|
|
_, exists := ext.Requirements[signal.NodeID]
|
|
if exists == false {
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "can't link: not_requirement"), source)
|
|
} else {
|
|
delete(ext.Requirements, signal.NodeID)
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "req_removed"), source)
|
|
}
|
|
default:
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "unknown_action"), source)
|
|
}
|
|
} else {
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "not_unlocked"), source)
|
|
}
|
|
return msgs
|
|
}
|
|
|
|
func (ext *LockableExt) HandleSuccessSignal(ctx *Context, node *Node, source NodeID, signal *SuccessSignal) Messages {
|
|
ctx.Log.Logf("lockable", "SUCCESS_SIGNAL: %+v", signal)
|
|
|
|
msgs := Messages{}
|
|
|
|
info, found := ext.Requirements[source]
|
|
ctx.Log.Logf("lockable", "State: %+v", ext.State)
|
|
if found == false {
|
|
ctx.Log.Logf("lockable", "Got success from non-requirement %s", source)
|
|
} else if source == node.ID {
|
|
// Do nothing with it
|
|
} else if info.MsgID != signal.ReqID {
|
|
ctx.Log.Logf("lockable", "Got success for wrong signal for %s: %s, expecting %s", source, signal.ReqID, info.MsgID)
|
|
} else {
|
|
if info.State == Locking {
|
|
if ext.State == Locking {
|
|
info.State = Locked
|
|
info.MsgID = uuid.UUID{}
|
|
ext.Requirements[source] = info
|
|
reqs := 0
|
|
locked := 0
|
|
for _, s := range(ext.Requirements) {
|
|
reqs += 1
|
|
if s.State == Locked {
|
|
locked += 1
|
|
}
|
|
}
|
|
|
|
if locked == reqs {
|
|
ctx.Log.Logf("lockable", "WHOLE LOCK: %s - %s - %+v", node.ID, ext.PendingID, ext.PendingOwner)
|
|
ext.State = Locked
|
|
ext.Owner = ext.PendingOwner
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewSuccessSignal(ext.PendingID), *ext.Owner)
|
|
} else {
|
|
ctx.Log.Logf("lockable", "PARTIAL LOCK: %s - %d/%d", node.ID, locked, reqs)
|
|
}
|
|
} else if ext.State == AbortingLock {
|
|
lock_signal := NewLockSignal("unlock")
|
|
info.State = Unlocking
|
|
info.MsgID = lock_signal.ID()
|
|
ext.Requirements[source] = info
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, lock_signal, source)
|
|
}
|
|
} else if info.State == Unlocking {
|
|
info.State = Unlocked
|
|
info.MsgID = uuid.UUID{}
|
|
ext.Requirements[source] = info
|
|
reqs := 0
|
|
unlocked := 0
|
|
for _, s := range(ext.Requirements) {
|
|
reqs += 1
|
|
if s.State == Unlocked {
|
|
unlocked += 1
|
|
}
|
|
}
|
|
|
|
if unlocked == reqs {
|
|
old_state := ext.State
|
|
ext.State = Unlocked
|
|
ctx.Log.Logf("lockable", "WHOLE UNLOCK: %s - %s - %+v", node.ID, ext.PendingID, ext.PendingOwner)
|
|
if old_state == Unlocking {
|
|
previous_owner := *ext.Owner
|
|
ext.Owner = ext.PendingOwner
|
|
ext.ReqID = nil
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewSuccessSignal(ext.PendingID), previous_owner)
|
|
} else if old_state == AbortingLock {
|
|
msgs = msgs.Add(ctx ,node.ID, node.Key, NewErrorSignal(*ext.ReqID, "not_unlocked"), *ext.PendingOwner)
|
|
ext.PendingOwner = ext.Owner
|
|
}
|
|
} else {
|
|
ctx.Log.Logf("lockable", "PARTIAL UNLOCK: %s - %d/%d", node.ID, unlocked, reqs)
|
|
}
|
|
}
|
|
}
|
|
|
|
return msgs
|
|
}
|
|
|
|
// Handle a LockSignal and update the extensions owner/requirement states
|
|
func (ext *LockableExt) HandleLockSignal(ctx *Context, node *Node, source NodeID, signal *LockSignal) Messages {
|
|
ctx.Log.Logf("lockable", "LOCK_SIGNAL: %s->%s %+v", source, node.ID, signal.State)
|
|
|
|
msgs := Messages{}
|
|
switch signal.State {
|
|
case "lock":
|
|
if ext.State == Unlocked {
|
|
if len(ext.Requirements) == 0 {
|
|
ext.State = Locked
|
|
new_owner := source
|
|
ext.PendingOwner = &new_owner
|
|
ext.Owner = &new_owner
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewSuccessSignal(signal.ID()), new_owner)
|
|
} else {
|
|
ext.State = Locking
|
|
id := signal.ID()
|
|
ext.ReqID = &id
|
|
new_owner := source
|
|
ext.PendingOwner = &new_owner
|
|
ext.PendingID = signal.ID()
|
|
for id, info := range(ext.Requirements) {
|
|
if info.State != Unlocked {
|
|
ctx.Log.Logf("lockable", "REQ_NOT_UNLOCKED_WHEN_LOCKING")
|
|
}
|
|
lock_signal := NewLockSignal("lock")
|
|
info.State = Locking
|
|
info.MsgID = lock_signal.ID()
|
|
ext.Requirements[id] = info
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, lock_signal, id)
|
|
}
|
|
}
|
|
} else {
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "not_unlocked"), source)
|
|
}
|
|
case "unlock":
|
|
if ext.State == Locked {
|
|
if len(ext.Requirements) == 0 {
|
|
ext.State = Unlocked
|
|
new_owner := source
|
|
ext.PendingOwner = nil
|
|
ext.Owner = nil
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewSuccessSignal(signal.ID()), new_owner)
|
|
} else if source == *ext.Owner {
|
|
ext.State = Unlocking
|
|
id := signal.ID()
|
|
ext.ReqID = &id
|
|
ext.PendingOwner = nil
|
|
ext.PendingID = signal.ID()
|
|
for id, info := range(ext.Requirements) {
|
|
if info.State != Locked {
|
|
ctx.Log.Logf("lockable", "REQ_NOT_LOCKED_WHEN_UNLOCKING")
|
|
}
|
|
lock_signal := NewLockSignal("unlock")
|
|
info.State = Unlocking
|
|
info.MsgID = lock_signal.ID()
|
|
ext.Requirements[id] = info
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, lock_signal, id)
|
|
}
|
|
}
|
|
} else {
|
|
msgs = msgs.Add(ctx, node.ID, node.Key, NewErrorSignal(signal.ID(), "not_locked"), source)
|
|
}
|
|
default:
|
|
ctx.Log.Logf("lockable", "LOCK_ERR: unkown state %s", signal.State)
|
|
}
|
|
return msgs
|
|
}
|
|
|
|
// LockableExts process Up/Down signals by forwarding them to owner, dependency, and requirement nodes
|
|
// LockSignal and LinkSignal Direct signals are processed to update the requirement/dependency/lock state
|
|
func (ext *LockableExt) Process(ctx *Context, node *Node, source NodeID, signal Signal) Messages {
|
|
messages := Messages{}
|
|
switch signal.Direction() {
|
|
case Up:
|
|
if ext.Owner != nil {
|
|
if *ext.Owner != node.ID {
|
|
messages = messages.Add(ctx, node.ID, node.Key, signal, *ext.Owner)
|
|
}
|
|
}
|
|
case Down:
|
|
for requirement, _ := range(ext.Requirements) {
|
|
messages = messages.Add(ctx, node.ID, node.Key, signal, requirement)
|
|
}
|
|
case Direct:
|
|
switch sig := signal.(type) {
|
|
case *LinkSignal:
|
|
messages = ext.HandleLinkSignal(ctx, node, source, sig)
|
|
case *LockSignal:
|
|
messages = ext.HandleLockSignal(ctx, node, source, sig)
|
|
case *ErrorSignal:
|
|
messages = ext.HandleErrorSignal(ctx, node, source, sig)
|
|
case *SuccessSignal:
|
|
messages = ext.HandleSuccessSignal(ctx, node, source, sig)
|
|
default:
|
|
}
|
|
default:
|
|
}
|
|
return messages
|
|
}
|
|
|