@ -30,6 +30,7 @@ type LockableState interface {
// BaseLockableStates are a minimum collection of variables for a basic implementation of a LockHolder
// Include in any state structs that should be lockable
type BaseLockableState struct {
_type string
name string
owner Lockable
requirements [ ] Lockable
@ -38,6 +39,7 @@ type BaseLockableState struct {
}
type BaseLockableStateJSON struct {
Type string ` json:"type" `
Name string ` json:"name" `
Owner * NodeID ` json:"owner" `
Dependencies [ ] NodeID ` json:"dependencies" `
@ -45,6 +47,10 @@ type BaseLockableStateJSON struct {
LocksHeld map [ NodeID ] * NodeID ` json:"locks_held" `
}
func ( state * BaseLockableState ) Type ( ) string {
return state . _type
}
func ( state * BaseLockableState ) MarshalJSON ( ) ( [ ] byte , error ) {
requirement_ids := make ( [ ] NodeID , len ( state . requirements ) )
for i , requirement := range ( state . requirements ) {
@ -73,6 +79,7 @@ func (state * BaseLockableState) MarshalJSON() ([]byte, error) {
}
return json . Marshal ( & BaseLockableStateJSON {
Type : state . _type ,
Name : state . name ,
Owner : owner_id ,
Dependencies : dependency_ids ,
@ -150,6 +157,10 @@ func LinkLockables(ctx * GraphContext, lockable Lockable, requirements []Lockabl
return fmt . Errorf ( "LOCKABLE_LINK_ERR: Will not link Lockables to nil as requirements" )
}
if len ( requirements ) == 0 {
return nil
}
for _ , requirement := range ( requirements ) {
if requirement == nil {
return fmt . Errorf ( "LOCKABLE_LINK_ERR: Will not link nil to a Lockable as a requirement" )
@ -165,48 +176,59 @@ func LinkLockables(ctx * GraphContext, lockable Lockable, requirements []Lockabl
for i , node := range ( requirements ) {
nodes [ i + 1 ] = node
}
err := UpdateStates ( ctx , nodes , func ( states [ ] NodeState ) ( [ ] NodeState , error ) {
err := UpdateStates ( ctx , nodes , func ( states NodeStateMap ) error {
// Check that all the requirements can be added
lockable_state := states [ 0 ] . ( LockableState )
lockable_state := states [ lockable . ID ( ) ] . ( LockableState )
// If the lockable is already locked, need to lock this resource as well before we can add it
for i , requirement := range ( requirements ) {
requirement_state := states [ i + 1 ] . ( LockableState )
if checkIfRequirement ( ctx , lockable . ID ( ) , requirement_state , requirement . ID ( ) ) == true {
return nil , fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is a dependency of %s so cannot link as requirement" , requirement . ID ( ) , lockable . ID ( ) )
for _ , requirement := range ( requirements ) {
requirement_state := states [ requirement . ID ( ) ] . ( LockableState )
for _ , req := range ( requirements ) {
if req . ID ( ) == requirement . ID ( ) {
continue
}
if checkIfRequirement ( ctx , req . ID ( ) , requirement_state , requirement . ID ( ) , states ) == true {
return fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is a dependenyc of %s so cannot add the same dependency" , req . ID ( ) , requirement . ID ( ) )
}
}
if checkIfRequirement ( ctx , lockable . ID ( ) , requirement_state , requirement . ID ( ) , states ) == true {
return fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is a dependency of %s so cannot link as requirement" , requirement . ID ( ) , lockable . ID ( ) )
}
if checkIfRequirement ( ctx , requirement . ID ( ) , lockable_state , lockable . ID ( ) ) == true {
return nil , fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is a dependency of %s so cannot link as dependency again" , lockable . ID ( ) , requirement . ID ( ) )
if checkIfRequirement ( ctx , requirement . ID ( ) , lockable_state , lockable . ID ( ) , states ) == true {
return fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is a dependency of %s so cannot link as dependency again" , lockable . ID ( ) , requirement . ID ( ) )
}
if lockable_state . Owner ( ) == nil {
// If the new owner isn't locked, we can add the requirement
} else if requirement_state . Owner ( ) == nil {
// if the new requirement isn't already locked but the owner is, the requirement needs to be locked first
return nil , fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is locked, %s must be locked to add" , lockable . ID ( ) , requirement . ID ( ) )
return fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is locked, %s must be locked to add" , lockable . ID ( ) , requirement . ID ( ) )
} else {
// If the new requirement is already locked and the owner is already locked, their owners need to match
if requirement_state . Owner ( ) . ID ( ) != lockable_state . Owner ( ) . ID ( ) {
return nil , fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is not locked by the same owner as %s, can't link as requirement" , requirement . ID ( ) , lockable . ID ( ) )
return fmt . Errorf ( "LOCKABLE_LINK_ERR: %s is not locked by the same owner as %s, can't link as requirement" , requirement . ID ( ) , lockable . ID ( ) )
}
}
}
// Update the states of the requirements
for i , requirement := range ( requirements ) {
requirement_state := states [ i+ 1 ] . ( LockableState )
for _ , requirement := range ( requirements ) {
requirement_state := states [ requirement. ID ( ) ] . ( LockableState )
requirement_state . AddDependency ( lockable )
lockable_state . AddRequirement ( requirement )
ctx . Log . Logf ( "lockable" , "LOCKABLE_LINK: linked %s to %s as a requirement" , requirement . ID ( ) , lockable . ID ( ) )
}
// Return no error
return states , nil
return nil
} )
return err
}
func NewBaseLockableState ( name string BaseLockableState {
func NewBaseLockableState ( name string , _type string ) BaseLockableState {
state := BaseLockableState {
locks_held : map [ NodeID ] Lockable { } ,
_type : _type ,
name : name ,
owner : nil ,
requirements : [ ] Lockable { } ,
@ -229,8 +251,8 @@ type Lockable interface {
}
func ( lockable * BaseLockable ) PropagateUpdate ( ctx * GraphContext , signal GraphSignal ) {
UseStates ( ctx , [ ] GraphNode { lockable } , func ( states [ ] NodeState ) ( error ) {
lockable_state := states [ 0 ] . ( LockableState )
UseStates ( ctx , [ ] GraphNode { lockable } , func ( states NodeStateMap ) error {
lockable_state := states [ lockable . ID ( ) ] . ( LockableState )
if signal . Direction ( ) == Up {
// Child->Parent, lockable updates dependency lockables
owner_sent := false
@ -259,15 +281,15 @@ func (lockable * BaseLockable) PropagateUpdate(ctx * GraphContext, signal GraphS
} )
}
func checkIfRequirement ( ctx * GraphContext , r_id NodeID , cur LockableState , cur_id NodeID bool {
func checkIfRequirement ( ctx * GraphContext , r_id NodeID , cur LockableState , cur_id NodeID , states NodeStateMap ) bool {
for _ , c := range ( cur . Requirements ( ) ) {
if c . ID ( ) == r_id {
return true
}
is_requirement := false
U s eStates( ctx , [ ] GraphNode { c } , func ( states [ ] NodeState ) ( error ) {
requirement_state := states [ 0 ] . ( LockableState )
is_requirement = checkIfRequirement ( ctx , cur_id , requirement_state , c . ID ( )
U pdateMor eStates( ctx , [ ] GraphNode { c } , states , func ( states NodeState Map ) ( error ) {
requirement_state := states [ c . ID ( ) ] . ( LockableState )
is_requirement = checkIfRequirement ( ctx , cur_id , requirement_state , c . ID ( ) , states )
return nil
} )
@ -279,7 +301,7 @@ func checkIfRequirement(ctx * GraphContext, r_id NodeID, cur LockableState, cur_
return false
}
func LockLockables ( ctx * GraphContext , to_lock [ ] Lockable , holder Lockable , holder_state LockableState , owner_ states map [ Node ID] Lockable State) error {
func LockLockables ( ctx * GraphContext , to_lock [ ] Lockable , holder Lockable , holder_state LockableState , Node StateMap ) error {
if to_lock == nil {
return fmt . Errorf ( "LOCKABLE_LOCK_ERR: no list provided" )
}
@ -311,20 +333,20 @@ func LockLockables(ctx * GraphContext, to_lock []Lockable, holder Lockable, hold
node_list [ i ] = l
}
err := Update States( ctx , node_list , func ( states [ ] NodeState ) ( [ ] NodeState , error ) {
err := Update More States( ctx , node_list , states , func ( states NodeStateMap ) error {
// First loop is to check that the states can be locked, and locks all requirements
for i, state := range ( states ) {
req := to_lock [ i ]
for _, req := range ( to_lock ) {
state := states [ req . ID ( ) ]
req_state , ok := state . ( LockableState )
ctx . Log . Logf ( "lockable" , "LOCKABLE_LOCKING: %s from %s" , req . ID ( ) , holder . ID ( ) )
if ok == false {
return nil , fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s(requirement of %s) does not have a LockableState" , req . ID ( ) , holder . ID ( ) )
return fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s(requirement of %s) does not have a LockableState" , req . ID ( ) , holder . ID ( ) )
}
// Check custom lock conditions
err := req . CanLock ( holder , req_state )
if err != nil {
return nil , err
return err
}
// If req is alreay locked, check that we can pass the lock
@ -338,22 +360,20 @@ func LockLockables(ctx * GraphContext, to_lock []Lockable, holder Lockable, hold
// So if the owner is the same node we don't need a new state, but if the owner is a different node then we need to grab it's state and add it to the list
if owner . ID ( ) == req . ID ( ) {
if req_state . AllowedToTakeLock ( holder . ID ( ) , req . ID ( ) ) == false {
return nil , fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s is not allowed to take %s's lock from %s" , holder . ID ( ) , req . ID ( ) , owner . ID ( ) )
return fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s is not allowed to take %s's lock from %s" , holder . ID ( ) , req . ID ( ) , owner . ID ( ) )
}
// RECURSE: At this point either:
// 1) req has no children and the next LockLockables will return instantly
// a) in this case, we're holding every state mutex up to the resource being locked
// and all the owners passing a lock, so we can start to change state
// 2) req has children, and we will recurse(checking that locking is allowed) until we reach a leaf and can release the locks as we change state. The call will either return nil if state has changed, on an error if no state has changed
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , owner_ states)
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , )
if err != nil {
return nil , err
return err
}
} else {
owner_state , exists := owner_states [ owner . ID ( ) ]
if exists == false {
err := UseStates ( ctx , [ ] GraphNode { req_state . Owner ( ) } , func ( states [ ] NodeState ) ( error ) {
owner_state , ok := states [ 0 ] . ( LockableState )
err := UpdateMoreStates ( ctx , [ ] GraphNode { owner } , states , func ( states NodeStateMap ) ( error ) {
owner_state , ok := states [ owner . ID ( ) ] . ( LockableState )
if ok == false {
return fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s does not have a LockableState" , owner . ID ( ) )
}
@ -361,35 +381,24 @@ func LockLockables(ctx * GraphContext, to_lock []Lockable, holder Lockable, hold
if owner_state . AllowedToTakeLock ( holder . ID ( ) , req . ID ( ) ) == false {
return fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s is not allowed to take %s's lock from %s" , holder . ID ( ) , req . ID ( ) , owner . ID ( ) )
}
owner_states [ owner . ID ( ) ] = owner_state
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , owner_states )
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , states )
return err
} )
if err != nil {
return nil , err
}
} else {
if owner_state . AllowedToTakeLock ( holder . ID ( ) , req . ID ( ) ) == false {
return nil , fmt . Errorf ( "LOCKABLE_LOCK_ERR: %s is not allowed to take %s's lock from %s" , holder . ID ( ) , req . ID ( ) , owner . ID ( ) )
}
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , owner_states )
if err != nil {
return nil , err
}
return err
}
}
} else {
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , owner_ states)
err := LockLockables ( ctx , req_state . Requirements ( ) , req , req_state , states )
if err != nil {
return nil , err
return err
}
}
}
// At this point state modification will be started, so no errors can be returned
for i , state := range ( states ) {
req := to_lock [ i ]
req_state := state . ( LockableState )
for _ , req := range ( to_lock ) {
req_state := states [ req . ID ( ) ] . ( LockableState )
old_owner := req_state . Owner ( )
req_state . SetOwner ( holder )
if req . ID ( ) == holder . ID ( ) {
@ -404,12 +413,12 @@ func LockLockables(ctx * GraphContext, to_lock []Lockable, holder Lockable, hold
ctx . Log . Logf ( "lockable" , "LOCKABLE_LOCK: %s took lock of %s from %s" , holder . ID ( ) , req . ID ( ) , old_owner . ID ( ) )
}
}
return states , nil
return nil
} )
return err
}
func UnlockLockables ( ctx * GraphContext , to_unlock [ ] Lockable , holder Lockable , holder_state LockableState , owner_ states map [ Node ID] Lockable State) error {
func UnlockLockables ( ctx * GraphContext , to_unlock [ ] Lockable , holder Lockable , holder_state LockableState , Node StateMap ) error {
if to_unlock == nil {
return fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: no list provided" )
}
@ -440,41 +449,39 @@ func UnlockLockables(ctx * GraphContext, to_unlock []Lockable, holder Lockable,
node_list [ i ] = l
}
err := Update States( ctx , node_list , func ( states [ ] NodeState ) ( [ ] NodeState , error ) {
err := Update More States( ctx , node_list , states , func ( states NodeStateMap ) error {
// First loop is to check that the states can be locked, and locks all requirements
for i , state := range ( states ) {
req := to_unlock [ i ]
req_state , ok := state . ( LockableState )
for _ , req := range ( to_unlock ) {
req_state , ok := states [ req . ID ( ) ] . ( LockableState )
ctx . Log . Logf ( "lockable" , "LOCKABLE_UNLOCKING: %s from %s" , req . ID ( ) , holder . ID ( ) )
if ok == false {
return nil , fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s(requirement of %s) does not have a LockableState" , req . ID ( ) , holder . ID ( ) )
return fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s(requirement of %s) does not have a LockableState" , req . ID ( ) , holder . ID ( ) )
}
// Check if the owner is correct
if req_state . Owner ( ) != nil {
if req_state . Owner ( ) . ID ( ) != holder . ID ( ) {
return nil , fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s is not locked by %s" , req . ID ( ) , holder . ID ( ) )
return fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s is not locked by %s" , req . ID ( ) , holder . ID ( ) )
}
} else {
return nil , fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s is not locked" , req . ID ( ) )
return fmt . Errorf ( "LOCKABLE_UNLOCK_ERR: %s is not locked" , req . ID ( ) )
}
// Check custom unlock conditions
err := req . CanUnlock ( holder , req_state )
if err != nil {
return nil , err
return err
}
err = UnlockLockables ( ctx , req_state . Requirements ( ) , req , req_state , owner_ states)
err = UnlockLockables ( ctx , req_state . Requirements ( ) , req , req_state , )
if err != nil {
return nil , err
return err
}
}
// At this point state modification will be started, so no errors can be returned
for i , state := range ( states ) {
req := to_unlock [ i ]
req_state := state . ( LockableState )
for _ , req := range ( to_unlock ) {
req_state := states [ req . ID ( ) ] . ( LockableState )
var new_owner Lockable = nil
if holder_state == nil {
new_owner = req_state . ReturnLock ( req . ID ( ) )
@ -489,7 +496,7 @@ func UnlockLockables(ctx * GraphContext, to_unlock []Lockable, holder Lockable,
ctx . Log . Logf ( "lockable" , "LOCKABLE_UNLOCK: %s passed lock of %s back to %s" , holder . ID ( ) , req . ID ( ) , new_owner . ID ( ) )
}
}
return states , nil
return nil
} )
return err
}
@ -530,8 +537,148 @@ func NewBaseLockable(ctx * GraphContext, state LockableState) (BaseLockable, err
return lockable , nil
}
func LoadBaseLockable ( ctx * GraphContext , id NodeID ) ( GraphNode , error ) {
// call LoadNodeRecurse on any connected nodes to ensure they're loaded and return the id
base_node := RestoreNode ( ctx , id )
lockable := BaseLockable {
BaseNode : base_node ,
}
return & lockable , nil
}
func LoadBaseLockableState ( ctx * GraphContext , id NodeID , data [ ] byte , loaded_nodes map [ NodeID ] GraphNode ) ( NodeState , error ) {
var j BaseLockableStateJSON
err := json . Unmarshal ( data , & j )
if err != nil {
return nil , err
}
var owner Lockable = nil
if j . Owner != nil {
o , err := LoadNodeRecurse ( ctx , * j . Owner , loaded_nodes )
if err != nil {
return nil , err
}
o_l , ok := o . ( Lockable )
if ok == false {
return nil , err
}
owner = o_l
}
state := BaseLockableState {
_type : "base_lockable" ,
name : j . Name ,
owner : owner ,
dependencies : make ( [ ] Lockable , len ( j . Dependencies ) ) ,
requirements : make ( [ ] Lockable , len ( j . Requirements ) ) ,
locks_held : map [ NodeID ] Lockable { } ,
}
for i , dep := range ( j . Dependencies ) {
dep_node , err := LoadNodeRecurse ( ctx , dep , loaded_nodes )
if err != nil {
return nil , err
}
dep_l , ok := dep_node . ( Lockable )
if ok == false {
return nil , fmt . Errorf ( "%+v is not a Lockable as expected" , dep_node )
}
state . dependencies [ i ] = dep_l
}
for i , req := range ( j . Requirements ) {
req_node , err := LoadNodeRecurse ( ctx , req , loaded_nodes )
if err != nil {
return nil , err
}
req_l , ok := req_node . ( Lockable )
if ok == false {
return nil , fmt . Errorf ( "%+v is not a Lockable as expected" , req_node )
}
state . requirements [ i ] = req_l
}
for l_id , h_id := range ( j . LocksHeld ) {
_ , err := LoadNodeRecurse ( ctx , l_id , loaded_nodes )
if err != nil {
return nil , err
}
var h_l Lockable = nil
if h_id != nil {
h_node , err := LoadNodeRecurse ( ctx , * h_id , loaded_nodes )
if err != nil {
return nil , err
}
h , ok := h_node . ( Lockable )
if ok == false {
return nil , err
}
h_l = h
}
state . locks_held [ l_id ] = h_l
}
return & state , nil
}
func LoadNode ( ctx * GraphContext , id NodeID ) ( GraphNode , error ) {
// Initialize an empty list of loaded nodes, then start loading them from id
loaded_nodes := map [ NodeID ] GraphNode { }
return LoadNodeRecurse ( ctx , id , loaded_nodes )
}
type DBJSONBase struct {
Type string ` json:"type" `
}
// Check if a node is already loaded, load it's state bytes from the DB and parse the type if it's not already loaded
// Call the node load function related to the type, which will call this parse function recusively as needed
func LoadNodeRecurse ( ctx * GraphContext , id NodeID , loaded_nodes map [ NodeID ] GraphNode ) ( GraphNode , error ) {
node , exists := loaded_nodes [ id ]
if exists == false {
state_bytes , err := ReadDBState ( ctx , id )
if err != nil {
return nil , err
}
var base DBJSONBase
err = json . Unmarshal ( state_bytes , & base )
if err != nil {
return nil , err
}
ctx . Log . Logf ( "graph" , "GRAPH_DB_LOAD: %s(%s)" , base . Type , id )
node_fn , exists := ctx . NodeLoadFuncs [ base . Type ]
if exists == false {
return nil , fmt . Errorf ( "%s is not a known node type" , base . Type )
}
node , err = node_fn ( ctx , id )
if err != nil {
return nil , err
}
loaded_nodes [ id ] = node
state_fn , exists := ctx . StateLoadFuncs [ base . Type ]
if exists == false {
return nil , fmt . Errorf ( "%s is not a known node state type" , base . Type )
}
state , err := state_fn ( ctx , id , state_bytes , loaded_nodes )
if err != nil {
return nil , err
}
node . SetState ( state )
}
return node , nil
}
func NewSimpleBaseLockable ( ctx * GraphContext , name string , requirements [ ] Lockable ) ( * BaseLockable , error ) {
state := NewBaseLockableState ( name )
state := NewBaseLockableState ( name , "base_lockable" )
lockable , err := NewBaseLockable ( ctx , & state )
if err != nil {
return nil , err
