tyiu/damus
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

txn: fix subtle transaction inheritence bugs

Browse Source 
This fixes subtle bugs with transaction inheritence. Since we were not
passing the inherited state to moved value, we were sometimes committing
transactions more than once.

Changelog-Fixed: Fix many nostrdb transaction related crashes
This commit is contained in:
William Casarin
2024-01-26 14:03:49 -08:00
parent f190b6414c
commit e3642b92d1
8 changed files with 53 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
nostrdb/Ndb.swift
View File

@@ -76,7 +76,8 @@ class Ndb {
static private var db_files: [String] = ["data.mdb", "lock.mdb"]
static var empty: Ndb {
Ndb(ndb: ndb_t(ndb: nil))
print("txn: NOSTRDB EMPTY")
return Ndb(ndb: ndb_t(ndb: nil))
}
static func open(path: String? = nil, owns_db_file: Bool = true) -> ndb_t? {
@@ -187,6 +188,7 @@ class Ndb {
self.closed = true
print("txn: CLOSING NOSTRDB")
ndb_destroy(self.ndb.ndb)
self.generation += 1
print("txn: NOSTRDB CLOSED")
}
@@ -195,8 +197,9 @@ class Ndb {
let db = Self.open(path: self.path, owns_db_file: self.owns_db) else {
return false
}
print("txn: NOSTRDB REOPENED (gen \(generation))")
self.generation += 1
self.closed = false
self.ndb = db
return true
@@ -368,14 +371,14 @@ class Ndb {
return txn.value
}
func lookup_note(_ id: NoteId) -> NdbTxn<NdbNote?>? {
NdbTxn(ndb: self) { txn in
func lookup_note(_ id: NoteId, txn_name: String? = nil) -> NdbTxn<NdbNote?>? {
NdbTxn(ndb: self, name: txn_name) { txn in
lookup_note_with_txn_inner(id: id, txn: txn)
}
}
func lookup_profile(_ pubkey: Pubkey) -> NdbTxn<ProfileRecord?>? {
NdbTxn(ndb: self) { txn in
func lookup_profile(_ pubkey: Pubkey, txn_name: String? = nil) -> NdbTxn<ProfileRecord?>? {
NdbTxn(ndb: self, name: txn_name) { txn in
lookup_profile_with_txn_inner(pubkey: pubkey, txn: txn)
}
}
@@ -456,17 +459,8 @@ class Ndb {
}
deinit {
//print("txn: Ndb de-init close")
//
// DO NOT CLOSE IN DESTRUCTOR! Destructor deinit is clearly
// not reliable, since it seems to be getting called more than
// once when we have a few references to the database.
//
// Not sure if this is indicitable of a larger problem but I've
// experienced nothing but hell when relying on de-init for
// global resources. Free them manually.
//
// EVIL --> self.close() <-- EVIL
print("txn: Ndb de-init")
self.close()
}
}

46
nostrdb/NdbTxn.swift
View File

@@ -19,17 +19,16 @@ class NdbTxn<T> {
var inherited: Bool
var ndb: Ndb
var generation: Int
var name: String
init?(ndb: Ndb, with: (NdbTxn<T>) -> T = { _ in () }) {
guard !ndb.closed else { return nil }
init?(ndb: Ndb, with: (NdbTxn<T>) -> T = { _ in () }, name: String? = nil) {
guard !ndb.is_closed else { return nil }
self.name = name ?? "txn"
self.ndb = ndb
self.generation = ndb.generation
#if TXNDEBUG
txn_count += 1
print("opening transaction \(txn_count)")
#endif
if let active_txn = Thread.current.threadDictionary["ndb_txn"] as? ndb_txn {
// some parent thread is active, use that instead
print("txn: inherited txn")
self.txn = active_txn
self.inherited = true
self.generation = Thread.current.threadDictionary["txn_generation"] as! Int
@@ -37,6 +36,9 @@ class NdbTxn<T> {
self.txn = ndb_txn()
guard !ndb.is_closed else { return nil }
self.generation = ndb.generation
#if TXNDEBUG
txn_count += 1
#endif
let ok = ndb_begin_query(ndb.ndb.ndb, &self.txn) != 0
if !ok {
return nil
@@ -46,17 +48,21 @@ class NdbTxn<T> {
Thread.current.threadDictionary["txn_generation"] = ndb.generation
self.inherited = false
}
#if TXNDEBUG
print("txn: open gen\(self.generation) '\(self.name)' \(txn_count)")
#endif
self.moved = false
self.val = with(self)
}
private init(ndb: Ndb, txn: ndb_txn, val: T) {
private init(ndb: Ndb, txn: ndb_txn, val: T, generation: Int, inherited: Bool, name: String) {
self.txn = txn
self.val = val
self.moved = false
self.inherited = false
self.inherited = inherited
self.ndb = ndb
self.generation = 0
self.generation = generation
self.name = name
}
/// Only access temporarily! Do not store database references for longterm use. If it's a primitive type you
@@ -68,32 +74,42 @@ class NdbTxn<T> {
deinit {
if self.generation != ndb.generation {
//print("txn: OLD GENERATION (\(self.generation) != \(ndb.generation)), IGNORING")
print("txn: OLD GENERATION (\(self.generation) != \(ndb.generation)), IGNORING")
return
}
if moved || inherited || ndb.closed {
if inherited {
print("txn: not closing. inherited ")
return
}
if moved {
//print("txn: not closing. moved")
return
}
if ndb.is_closed {
print("txn: not closing. db closed")
return
}
#if TXNDEBUG
txn_count -= 1;
print("txn: closing transaction \(txn_count)")
print("txn: close gen\(generation) '\(name)' \(txn_count)")
#endif
ndb_end_query(&self.txn)
//self.skip_close = true
Thread.current.threadDictionary.removeObject(forKey: "ndb_txn")
}
// functor
func map<Y>(_ transform: (T) -> Y) -> NdbTxn<Y> {
self.moved = true
return .init(ndb: self.ndb, txn: self.txn, val: transform(val))
return .init(ndb: self.ndb, txn: self.txn, val: transform(val), generation: generation, inherited: inherited, name: self.name)
}
// comonad!?
// useful for moving ownership of a transaction to another value
func extend<Y>(_ with: (NdbTxn<T>) -> Y) -> NdbTxn<Y> {
self.moved = true
return .init(ndb: self.ndb, txn: self.txn, val: with(self))
return .init(ndb: self.ndb, txn: self.txn, val: with(self), generation: generation, inherited: inherited, name: self.name)
}
}
@@ -116,7 +132,7 @@ extension NdbTxn where T: OptionalType {
return nil
}
self.moved = true
return NdbTxn<T.Wrapped>(ndb: self.ndb, txn: self.txn, val: unwrappedVal)
return NdbTxn<T.Wrapped>(ndb: self.ndb, txn: self.txn, val: unwrappedVal, generation: generation, inherited: inherited, name: name)
}
}