fix(gameserver): stamp save blobs to prevent a periodic write rolling back a disconnect save #96

Merged

marco merged 1 commit from fix/persistence-lost-update into main

2026-07-19 13:37:37 +02:00

marco commented

2026-07-19 13:34:17 +02:00

Owner

Code-review finding bug-1 (integrity).

The periodic snapshot captures every online player's blob (SerializeOnlinePlayers) then writes them to the store in a later step; a disconnect that lands in between writes a fresher blob that the stale periodic write could then overwrite — silently rolling the session back on next login (PlayerStore was last-writer-wins with no recency ordering).

Stamp each blob with its capture tick (World.CurrentTick, read on the sim thread in the same InvokeAsync as the serialize). PlayerStore.SaveAsync now drops a save whose stamp is older than the one already stored, so the later-captured blob wins regardless of the off-thread write order.

Test: PlayerStore_DropsAnOlderStampedSave — a fresh (stamp 10) save survives a subsequent stale (stamp 5) write.

Definition of Done

A disconnect save is never overwritten by a concurrently-running periodic snapshot captured earlier.
Suite green (158 GameServer), zero warnings.

Code-review finding **bug-1** (integrity). The periodic snapshot captures every online player's blob (`SerializeOnlinePlayers`) then writes them to the store in a **later** step; a disconnect that lands in between writes a **fresher** blob that the stale periodic write could then overwrite — silently rolling the session back on next login (`PlayerStore` was last-writer-wins with no recency ordering). Stamp each blob with its **capture tick** (`World.CurrentTick`, read on the sim thread in the same `InvokeAsync` as the serialize). `PlayerStore.SaveAsync` now **drops a save whose stamp is older** than the one already stored, so the later-captured blob wins regardless of the off-thread write order. Test: `PlayerStore_DropsAnOlderStampedSave` — a fresh (stamp 10) save survives a subsequent stale (stamp 5) write. ## Definition of Done - [ ] A disconnect save is never overwritten by a concurrently-running periodic snapshot captured earlier. - [ ] Suite green (158 GameServer), zero warnings.

marco added 1 commit

2026-07-19 13:34:17 +02:00

fix(gameserver): stamp save blobs so a stale periodic write can't roll back a disconnect save

ci / Lint & Test (pull_request) Successful in 2m57s

Details

6eb9d1167e

The periodic snapshot captures every online player's blob, then writes them to the
store in a later step; a disconnect that lands in between writes a fresher blob that
the stale periodic write could then overwrite, silently rolling the session back on
next login. Stamp each blob with its capture tick (World.CurrentTick); PlayerStore
drops a save whose stamp is older than the one already stored, so the later-captured
blob always wins regardless of write order.

Review finding bug-1. Test: an older-stamped save does not overwrite a newer one.

marco merged commit eb57163fb1 into main

2026-07-19 13:37:37 +02:00

marco deleted branch fix/persistence-lost-update

2026-07-19 13:37:38 +02:00

marco referenced this pull request from a commit

2026-07-19 13:37:38 +02:00

fix(gameserver): stamp save blobs to prevent a periodic write rolling back a disconnect save (#96)