From e3a4b98432c9962fa06974d7d08ad4f429d15a70 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Sat, 18 Dec 2021 19:37:07 +0000
Subject: [PATCH] removes Select in favor of recv_timeout/try_iter (#21981)
 (#22001)

crossbeam_channel::Select::ready_timeout might return with success spuriously.

(cherry picked from commit 7476dfeec07a6874878427ecd62287cec544f158)

Co-authored-by: behzad nouri <behzadnouri@gmail.com>
---
 core/src/commitment_service.rs     |  7 ++-----
 core/src/ledger_cleanup_service.rs |  7 ++-----
 core/src/verified_vote_packets.rs  | 11 +++++------
 core/src/window_service.rs         | 12 ++++--------
 4 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/core/src/commitment_service.rs b/core/src/commitment_service.rs
index f918065d02..fe425fa2cf 100644
--- a/core/src/commitment_service.rs
+++ b/core/src/commitment_service.rs
@@ -97,11 +97,8 @@ impl AggregateCommitmentService {
                 return Ok(());
             }
 
-            let mut aggregation_data = receiver.recv_timeout(Duration::from_secs(1))?;
-
-            while let Ok(new_data) = receiver.try_recv() {
-                aggregation_data = new_data;
-            }
+            let aggregation_data = receiver.recv_timeout(Duration::from_secs(1))?;
+            let aggregation_data = receiver.try_iter().last().unwrap_or(aggregation_data);
 
             let ancestors = aggregation_data.bank.status_cache_ancestors();
             if ancestors.is_empty() {
diff --git a/core/src/ledger_cleanup_service.rs b/core/src/ledger_cleanup_service.rs
index 3486a24ad2..841609d3cc 100644
--- a/core/src/ledger_cleanup_service.rs
+++ b/core/src/ledger_cleanup_service.rs
@@ -164,12 +164,9 @@ impl LedgerCleanupService {
     }
 
     fn receive_new_roots(new_root_receiver: &Receiver<Slot>) -> Result<Slot, RecvTimeoutError> {
-        let mut root = new_root_receiver.recv_timeout(Duration::from_secs(1))?;
+        let root = new_root_receiver.recv_timeout(Duration::from_secs(1))?;
         // Get the newest root
-        while let Ok(new_root) = new_root_receiver.try_recv() {
-            root = new_root;
-        }
-        Ok(root)
+        Ok(new_root_receiver.try_iter().last().unwrap_or(root))
     }
 
     pub fn cleanup_ledger(
diff --git a/core/src/verified_vote_packets.rs b/core/src/verified_vote_packets.rs
index b1d708cbe3..2db544df3f 100644
--- a/core/src/verified_vote_packets.rs
+++ b/core/src/verified_vote_packets.rs
@@ -1,6 +1,5 @@
 use {
     crate::{cluster_info_vote_listener::VerifiedLabelVotePacketsReceiver, result::Result},
-    crossbeam_channel::Select,
     solana_perf::packet::PacketBatch,
     solana_runtime::bank::Bank,
     solana_sdk::{
@@ -141,10 +140,10 @@ impl VerifiedVotePackets {
         vote_packets_receiver: &VerifiedLabelVotePacketsReceiver,
         would_be_leader: bool,
     ) -> Result<()> {
-        let mut sel = Select::new();
-        sel.recv(vote_packets_receiver);
-        let _ = sel.ready_timeout(Duration::from_millis(200))?;
-        for gossip_votes in vote_packets_receiver.try_iter() {
+        const RECV_TIMEOUT: Duration = Duration::from_millis(200);
+        let vote_packets = vote_packets_receiver.recv_timeout(RECV_TIMEOUT)?;
+        let vote_packets = std::iter::once(vote_packets).chain(vote_packets_receiver.try_iter());
+        for gossip_votes in vote_packets {
             if would_be_leader {
                 for verfied_vote_metadata in gossip_votes {
                     let VerifiedVoteMetadata {
@@ -283,7 +282,7 @@ mod tests {
         // No new messages, should time out
         assert_matches!(
             verified_vote_packets.receive_and_process_vote_packets(&r, true),
-            Err(Error::ReadyTimeout)
+            Err(Error::CrossbeamRecvTimeout(_))
         );
     }
 
diff --git a/core/src/window_service.rs b/core/src/window_service.rs
index 7f20dc89cf..fe41fb5ebe 100644
--- a/core/src/window_service.rs
+++ b/core/src/window_service.rs
@@ -233,14 +233,10 @@ fn run_check_duplicate(
 
         Ok(())
     };
-    let timer = Duration::from_millis(200);
-    let shred = shred_receiver.recv_timeout(timer)?;
-    check_duplicate(shred)?;
-    while let Ok(shred) = shred_receiver.try_recv() {
-        check_duplicate(shred)?;
-    }
-
-    Ok(())
+    const RECV_TIMEOUT: Duration = Duration::from_millis(200);
+    std::iter::once(shred_receiver.recv_timeout(RECV_TIMEOUT)?)
+        .chain(shred_receiver.try_iter())
+        .try_for_each(check_duplicate)
 }
 
 fn verify_repair(