Skip to content

Fix #49: synchronize Connection.flushQueue against concurrent region threads #75

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
mliem2k wants to merge 1 commit into
base: ver/26.2
Choose a base branch
from
Open

Fix #49: synchronize Connection.flushQueue against concurrent region threads #75

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 19 additions & 1 deletion shreddedpaper-server/minecraft-patches/sources/net/minecraft/network/Connection.java.patch
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,7 @@
this.channel.eventLoop().execute(() -> this.doSendPacket(packet, listener, flush));
}
}
@@ -499,7 +_,7 @@
@@ -499,19 +_,18 @@
}

// Paper start - Optimize network: Rewrite this to be safer if ran off main thread
Expand All @@ -71,6 +71,24 @@
if (!this.isConnected()) {
return true;
}
- if (io.papermc.paper.util.MCUtil.isMainThread()) {
+ // ShreddedPaper start - Fix packet order: every ShreddedPaperTickThread satisfies isMainThread(), so unlike
+ // vanilla's single main thread, multiple region-tick-pool threads can reach flushQueue() for the same
+ // connection at once (tick(), send() from an async plugin call, and flushQueueInParallel's own sweep all
+ // race). Always synchronize so pendingActions is only ever drained by one thread at a time.
+ synchronized (this.pendingActions) {
return this.processQueue();
- } else if (this.isPending) {
- // Should only happen during login/status stages
- synchronized (this.pendingActions) {
- return this.processQueue();
- }
}
- return false;
+ // ShreddedPaper end - Fix packet order
}

private boolean processQueue() {
@@ -555,7 +_,8 @@
private static int currTick; // Paper - Buffer joins to world
private static int tickSecond; // Purpur - Max joins per second
Expand Down