From 86a3ef27092e518d61a2540b37878da2423b4cd9 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 28 Nov 2021 09:03:15 +0100
Subject: [PATCH] LibIPC: Give MessageBuffer::fds some inline capacity (1)

This dodges a heap allocation when sending 0 or 1 fd across the IPC
boundary (which covers every message.)
---
 Userland/Libraries/LibIPC/Connection.cpp | 2 +-
 Userland/Libraries/LibIPC/Message.h      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Userland/Libraries/LibIPC/Connection.cpp b/Userland/Libraries/LibIPC/Connection.cpp
index b9600a8332..2571c8b456 100644
--- a/Userland/Libraries/LibIPC/Connection.cpp
+++ b/Userland/Libraries/LibIPC/Connection.cpp
@@ -41,7 +41,7 @@ void ConnectionBase::post_message(MessageBuffer buffer)
 
 #ifdef __serenity__
     for (auto& fd : buffer.fds) {
-        auto rc = sendfd(m_socket->fd(), fd->value());
+        auto rc = sendfd(m_socket->fd(), fd.value());
         if (rc < 0) {
             perror("sendfd");
             shutdown();
diff --git a/Userland/Libraries/LibIPC/Message.h b/Userland/Libraries/LibIPC/Message.h
index 86bf53c697..8590e28808 100644
--- a/Userland/Libraries/LibIPC/Message.h
+++ b/Userland/Libraries/LibIPC/Message.h
@@ -6,9 +6,9 @@
 
 #pragma once
 
+#include <AK/NonnullRefPtrVector.h>
 #include <AK/RefCounted.h>
 #include <AK/RefPtr.h>
-#include <AK/Vector.h>
 #include <unistd.h>
 
 namespace IPC {
@@ -34,7 +34,7 @@ private:
 
 struct MessageBuffer {
     Vector<u8, 1024> data;
-    Vector<RefPtr<AutoCloseFileDescriptor>> fds;
+    NonnullRefPtrVector<AutoCloseFileDescriptor, 1> fds;
 };
 
 enum class ErrorCode : u32 {