From 4a534d6abb5ee1c3ac8bd6bb34e23b10cec50ba7 Mon Sep 17 00:00:00 2001
From: Greg Fitzgerald <greg@solana.com>
Date: Mon, 25 Jun 2018 16:50:58 -0600
Subject: [PATCH] Don't clone() Arc before recycling

This might fix an awful bug where the streamer reuses a Blob
before the current user is done with it. Recycler should probably
assert ref count is one?

* Also don't collect() an iterator before iterating over it.
---
 src/streamer.rs | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/streamer.rs b/src/streamer.rs
index abd25ff4d..958724b82 100644
--- a/src/streamer.rs
+++ b/src/streamer.rs
@@ -6,6 +6,7 @@ use erasure;
 use packet::{Blob, BlobRecycler, PacketRecycler, SharedBlob, SharedPackets, BLOB_SIZE};
 use result::{Error, Result};
 use std::collections::VecDeque;
+use std::mem;
 use std::net::{SocketAddr, UdpSocket};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc;
@@ -452,10 +453,7 @@ fn broadcast(
 
     // We could receive more blobs than window slots so
     // break them up into window-sized chunks to process
-    let blobs_chunked: Vec<_> = blobs_vec
-        .chunks(WINDOW_SIZE)
-        .map(|x| x.to_vec())
-        .collect();
+    let blobs_chunked = blobs_vec.chunks(WINDOW_SIZE).map(|x| x.to_vec());
 
     print_window(window, *receive_index as usize);
 
@@ -476,17 +474,15 @@ fn broadcast(
             for b in &blobs {
                 let ix = b.read().unwrap().get_index().expect("blob index");
                 let pos = (ix as usize) % WINDOW_SIZE;
-                if let Some(x) = &win[pos] {
+                if let Some(x) = mem::replace(&mut win[pos], None) {
                     trace!(
                         "popped {} at {}",
                         x.read().unwrap().get_index().unwrap(),
                         pos
                     );
-                    recycler.recycle(x.clone());
+                    recycler.recycle(x);
                 }
                 trace!("null {}", pos);
-                win[pos] = None;
-                assert!(win[pos].is_none());
             }
             while let Some(b) = blobs.pop() {
                 let ix = b.read().unwrap().get_index().expect("blob index");