From 62f6a78ccd0f8038e3f0896b7d033b01ee0b6406 Mon Sep 17 00:00:00 2001
From: Sagar Dhawan <sagar@solana.com>
Date: Tue, 3 Sep 2019 21:50:57 +0000
Subject: [PATCH] Make data plane shred filter parallel again (#5740)

---
 core/src/window_service.rs | 51 +++++++++++++++++++++++---------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/core/src/window_service.rs b/core/src/window_service.rs
index 6a9c68ae64..c32f94749d 100644
--- a/core/src/window_service.rs
+++ b/core/src/window_service.rs
@@ -4,11 +4,14 @@
 use crate::blocktree::Blocktree;
 use crate::cluster_info::ClusterInfo;
 use crate::leader_schedule_cache::LeaderScheduleCache;
+use crate::packet::Packets;
 use crate::repair_service::{RepairService, RepairStrategy};
 use crate::result::{Error, Result};
 use crate::service::Service;
 use crate::shred::Shred;
 use crate::streamer::{PacketReceiver, PacketSender};
+use rayon::iter::{ParallelBridge, ParallelIterator};
+use rayon::ThreadPool;
 use solana_metrics::{inc_new_counter_debug, inc_new_counter_error};
 use solana_runtime::bank::Bank;
 use solana_sdk::pubkey::Pubkey;
@@ -63,6 +66,7 @@ fn recv_window<F>(
     r: &PacketReceiver,
     retransmit: &PacketSender,
     shred_filter: F,
+    thread_pool: &ThreadPool,
 ) -> Result<()>
 where
     F: Fn(&Shred, &[u8]) -> bool,
@@ -77,26 +81,28 @@ where
     let now = Instant::now();
     inc_new_counter_debug!("streamer-recv_window-recv", packets.packets.len());
 
-    let mut shreds = vec![];
-    let mut discards = vec![];
-    for (i, packet) in packets.packets.iter_mut().enumerate() {
-        if let Ok(s) = bincode::deserialize(&packet.data) {
-            let shred: Shred = s;
-            if shred_filter(&shred, &packet.data) {
-                packet.meta.slot = shred.slot();
-                packet.meta.seed = shred.seed();
-                shreds.push(shred);
-            } else {
-                discards.push(i);
-            }
-        } else {
-            discards.push(i);
-        }
-    }
-
-    for i in discards.into_iter().rev() {
-        packets.packets.remove(i);
-    }
+    let (shreds, packets): (Vec<_>, Vec<_>) = thread_pool.install(|| {
+        packets
+            .packets
+            .drain(..)
+            .par_bridge()
+            .filter_map(|mut packet| {
+                if let Ok(s) = bincode::deserialize(&packet.data) {
+                    let shred: Shred = s;
+                    if shred_filter(&shred, &packet.data) {
+                        packet.meta.slot = shred.slot();
+                        packet.meta.seed = shred.seed();
+                        Some((shred, packet))
+                    } else {
+                        None
+                    }
+                } else {
+                    None
+                }
+            })
+            .unzip()
+    });
+    let packets = Packets::new(packets);
 
     trace!("{:?} shreds from packets", shreds.len());
 
@@ -187,6 +193,10 @@ impl WindowService {
                 let id = cluster_info.read().unwrap().id();
                 trace!("{}: RECV_WINDOW started", id);
                 let mut now = Instant::now();
+                let thread_pool = rayon::ThreadPoolBuilder::new()
+                    .num_threads(sys_info::cpu_num().unwrap_or(NUM_THREADS) as usize)
+                    .build()
+                    .unwrap();
                 loop {
                     if exit.load(Ordering::Relaxed) {
                         break;
@@ -207,6 +217,7 @@ impl WindowService {
                                     .map(|bank_forks| bank_forks.read().unwrap().working_bank()),
                             )
                         },
+                        &thread_pool,
                     ) {
                         match e {
                             Error::RecvTimeoutError(RecvTimeoutError::Disconnected) => break,