From 669164bada9e469122f4a619b7a2215635435fb4 Mon Sep 17 00:00:00 2001
From: Greg Fitzgerald <greg@solana.com>
Date: Sun, 1 Jul 2018 14:31:13 -0600
Subject: [PATCH] Boot EntryWriter's Mutex

Finally!
---
 src/bin/genesis.rs  |  5 ++---
 src/entry_writer.rs | 21 ++++++++++-----------
 src/write_stage.rs  |  8 ++++----
 3 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/src/bin/genesis.rs b/src/bin/genesis.rs
index bc0698cd41..f927ecb007 100644
--- a/src/bin/genesis.rs
+++ b/src/bin/genesis.rs
@@ -10,7 +10,6 @@ use solana::mint::Mint;
 use std::error;
 use std::io::{stdin, stdout, Read};
 use std::process::exit;
-use std::sync::Mutex;
 
 fn main() -> Result<(), Box<error::Error>> {
     if is(Stream::Stdin) {
@@ -26,7 +25,7 @@ fn main() -> Result<(), Box<error::Error>> {
     }
 
     let mint: Mint = serde_json::from_str(&buffer)?;
-    let writer = Mutex::new(stdout());
-    EntryWriter::write_entries(&writer, &mint.create_entries())?;
+    let mut writer = stdout();
+    EntryWriter::write_entries(&mut writer, &mint.create_entries())?;
     Ok(())
 }
diff --git a/src/entry_writer.rs b/src/entry_writer.rs
index d8d8d73b79..0932653974 100644
--- a/src/entry_writer.rs
+++ b/src/entry_writer.rs
@@ -6,40 +6,39 @@ use bank::Bank;
 use entry::Entry;
 use serde_json;
 use std::io::{self, Write};
-use std::sync::Mutex;
 
 pub struct EntryWriter<'a, W> {
     bank: &'a Bank,
-    writer: Mutex<W>,
+    writer: W,
 }
 
 impl<'a, W: Write> EntryWriter<'a, W> {
     /// Create a new Tpu that wraps the given Bank.
-    pub fn new(bank: &'a Bank, writer: Mutex<W>) -> Self {
+    pub fn new(bank: &'a Bank, writer: W) -> Self {
         EntryWriter { bank, writer }
     }
 
-    fn write_entry(writer: &Mutex<W>, entry: &Entry) -> io::Result<()> {
+    fn write_entry(writer: &mut W, entry: &Entry) -> io::Result<()> {
         let serialized = serde_json::to_string(&entry).unwrap();
-        writeln!(writer.lock().unwrap(), "{}", serialized)
+        writeln!(writer, "{}", serialized)
     }
 
-    pub fn write_entries(writer: &Mutex<W>, entries: &[Entry]) -> io::Result<()> {
+    pub fn write_entries(writer: &mut W, entries: &[Entry]) -> io::Result<()> {
         for entry in entries {
             Self::write_entry(writer, entry)?;
         }
         Ok(())
     }
 
-    fn write_and_register_entry(&self, entry: &Entry) -> io::Result<()> {
+    fn write_and_register_entry(&mut self, entry: &Entry) -> io::Result<()> {
         trace!("write_and_register_entry entry");
         if !entry.has_more {
             self.bank.register_entry_id(&entry.id);
         }
-        Self::write_entry(&self.writer, entry)
+        Self::write_entry(&mut self.writer, entry)
     }
 
-    pub fn write_and_register_entries(&self, entries: &[Entry]) -> io::Result<()> {
+    pub fn write_and_register_entries(&mut self, entries: &[Entry]) -> io::Result<()> {
         for entry in entries {
             self.write_and_register_entry(&entry)?;
         }
@@ -61,8 +60,8 @@ mod tests {
         let mint = Mint::new(1);
         let bank = Bank::new(&mint);
 
-        let writer = Mutex::new(io::sink());
-        let entry_writer = EntryWriter::new(&bank, writer);
+        let writer = io::sink();
+        let mut entry_writer = EntryWriter::new(&bank, writer);
         let keypair = KeyPair::new();
         let tx = Transaction::new(&mint.keypair(), keypair.pubkey(), 1, mint.last_id());
 
diff --git a/src/write_stage.rs b/src/write_stage.rs
index cdcd221c45..ecdf773d3c 100644
--- a/src/write_stage.rs
+++ b/src/write_stage.rs
@@ -12,7 +12,7 @@ use std::collections::VecDeque;
 use std::io::Write;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc::{channel, Receiver};
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 use std::thread::{Builder, JoinHandle};
 use std::time::Duration;
 use streamer::{BlobReceiver, BlobSender};
@@ -26,7 +26,7 @@ impl WriteStage {
     /// Process any Entry items that have been published by the Historian.
     /// continuosly broadcast blobs of entries out
     pub fn write_and_send_entries<W: Write>(
-        entry_writer: &EntryWriter<W>,
+        entry_writer: &mut EntryWriter<W>,
         blob_sender: &BlobSender,
         blob_recycler: &BlobRecycler,
         entry_receiver: &Receiver<Vec<Entry>>,
@@ -55,10 +55,10 @@ impl WriteStage {
         let thread_hdl = Builder::new()
             .name("solana-writer".to_string())
             .spawn(move || {
-                let entry_writer = EntryWriter::new(&bank, Mutex::new(writer));
+                let mut entry_writer = EntryWriter::new(&bank, writer);
                 loop {
                     let _ = Self::write_and_send_entries(
-                        &entry_writer,
+                        &mut entry_writer,
                         &blob_sender,
                         &blob_recycler,
                         &entry_receiver,