From 781609b27a9d42f59f50c9850abc42bcda025cfc Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Fri, 11 Feb 2022 15:47:45 +0000
Subject: [PATCH] uses sendmmsg in streamer (backport #23062) (#23080)

* uses sendmmsg in streamer (#23062)

packet::send_to sends packets one by one:
https://github.com/solana-labs/solana/blob/9213fcb11/streamer/src/packet.rs#L63-L75

sendmmsg uses a single system call for multiple messages:
https://github.com/solana-labs/solana/blob/9213fcb11/streamer/src/sendmmsg.rs#L94

(cherry picked from commit c078ca3fb3e203dbd4f3a9556166695e8223cea7)

# Conflicts:
#	streamer/src/streamer.rs

* removes mergify merge conflicts

Co-authored-by: behzad nouri <behzadnouri@gmail.com>
---
 streamer/src/streamer.rs | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/streamer/src/streamer.rs b/streamer/src/streamer.rs
index 9f7db9c546..004c584642 100644
--- a/streamer/src/streamer.rs
+++ b/streamer/src/streamer.rs
@@ -3,8 +3,9 @@
 
 use {
     crate::{
-        packet::{self, send_to, PacketBatch, PacketBatchRecycler, PACKETS_PER_BATCH},
+        packet::{self, PacketBatch, PacketBatchRecycler, PACKETS_PER_BATCH},
         recvmmsg::NUM_RCVMMSGS,
+        sendmmsg::{batch_send, SendPktsError},
         socket::SocketAddrSpace,
     },
     solana_sdk::timing::timestamp,
@@ -34,6 +35,9 @@ pub enum StreamerError {
 
     #[error("send packets error")]
     Send(#[from] SendError<PacketBatch>),
+
+    #[error(transparent)]
+    SendPktsError(#[from] SendPktsError),
 }
 
 pub type Result<T> = std::result::Result<T, StreamerError>;
@@ -126,7 +130,13 @@ fn recv_send(
 ) -> Result<()> {
     let timer = Duration::new(1, 0);
     let packet_batch = r.recv_timeout(timer)?;
-    send_to(&packet_batch, sock, socket_addr_space)?;
+    let packets = packet_batch.packets.iter().filter_map(|pkt| {
+        let addr = pkt.meta.addr();
+        socket_addr_space
+            .check(&addr)
+            .then(|| (&pkt.data[..pkt.meta.size], addr))
+    });
+    batch_send(sock, &packets.collect::<Vec<_>>())?;
     Ok(())
 }