From f7cef4cca5f6d28fc3171792039a4b9872c3acd6 Mon Sep 17 00:00:00 2001
From: Wesley Shillingford <wezrule@hotmail.com>
Date: Thu, 5 Sep 2019 12:44:41 +0100
Subject: [PATCH] Improve bootstrap attempt locking (#2286)

---
 ci/build-travis.sh                          | 4 ++--
 nano/lib/locks.cpp                          | 3 +++
 nano/node/bootstrap/bootstrap.cpp           | 2 +-
 nano/node/bootstrap/bootstrap.hpp           | 5 +++--
 nano/node/bootstrap/bootstrap_bulk_pull.cpp | 1 -
 5 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/ci/build-travis.sh b/ci/build-travis.sh
index 2b58e8d5..6f9d2c89 100755
--- a/ci/build-travis.sh
+++ b/ci/build-travis.sh
@@ -15,8 +15,8 @@ if [[ $(grep -rl --exclude="*asio.hpp" "asio::async_write" ./nano) ]]; then
 fi
 
 # prevent unsolicited use of std::lock_guard & std::unique_lock outside of allowed areas
-if [[ $(grep -rl --exclude={"*random_pool.cpp","*random_pool.hpp","*locks.hpp"} "std::unique_lock\|std::lock_guard" ./nano) ]]; then
-    echo "using std::unique_lock or std::lock_guard is not permitted (except in nano/lib/locks.hpp and non-nano dependent libraries). Use the nano::* versions instead"
+if [[ $(grep -rl --exclude={"*random_pool.cpp","*random_pool.hpp","*locks.hpp","*locks.cpp"} "std::unique_lock\|std::lock_guard\|std::condition_variable" ./nano) ]]; then
+    echo "using std::unique_lock, std::lock_guard or std::condition_variable is not permitted (except in nano/lib/locks.hpp and non-nano dependent libraries). Use the nano::* versions instead"
     exit 1
 fi
 
diff --git a/nano/lib/locks.cpp b/nano/lib/locks.cpp
index 733a9911..4f85560d 100644
--- a/nano/lib/locks.cpp
+++ b/nano/lib/locks.cpp
@@ -7,7 +7,10 @@ namespace
 template <typename Mutex>
 void output (const char * str, std::chrono::milliseconds time, Mutex & mutex)
 {
+	static std::mutex cout_mutex;
 	auto stacktrace = nano::generate_stacktrace ();
+	// Guard standard out to keep the output from being interleaved
+	std::lock_guard<std::mutex> guard (cout_mutex);
 	std::cout << std::addressof (mutex) << " Mutex " << str << " for: " << time.count () << "ms\n"
 	          << stacktrace << std::endl;
 }
diff --git a/nano/node/bootstrap/bootstrap.cpp b/nano/node/bootstrap/bootstrap.cpp
index ea736351..bbfca3d6 100644
--- a/nano/node/bootstrap/bootstrap.cpp
+++ b/nano/node/bootstrap/bootstrap.cpp
@@ -85,7 +85,7 @@ nano::bootstrap_attempt::~bootstrap_attempt ()
 
 bool nano::bootstrap_attempt::should_log ()
 {
-	nano::lock_guard<std::mutex> lock (mutex);
+	nano::lock_guard<std::mutex> guard (next_log_mutex);
 	auto result (false);
 	auto now (std::chrono::steady_clock::now ());
 	if (next_log < now)
diff --git a/nano/node/bootstrap/bootstrap.hpp b/nano/node/bootstrap/bootstrap.hpp
index 177e232b..1e447cba 100644
--- a/nano/node/bootstrap/bootstrap.hpp
+++ b/nano/node/bootstrap/bootstrap.hpp
@@ -80,6 +80,7 @@ public:
 	void wallet_run ();
 	void wallet_start (std::deque<nano::account> &);
 	bool wallet_finished ();
+	std::mutex next_log_mutex;
 	std::chrono::steady_clock::time_point next_log;
 	std::deque<std::weak_ptr<nano::bootstrap_client>> clients;
 	std::weak_ptr<nano::bootstrap_client> connection_frontier_request;
@@ -97,7 +98,7 @@ public:
 	std::atomic<bool> stopped;
 	nano::bootstrap_mode mode;
 	std::mutex mutex;
-	std::condition_variable condition;
+	nano::condition_variable condition;
 	// Lazy bootstrap
 	std::unordered_set<nano::block_hash> lazy_blocks;
 	std::unordered_map<nano::block_hash, std::pair<nano::block_hash, nano::uint128_t>> lazy_state_unknown;
@@ -176,7 +177,7 @@ private:
 	std::shared_ptr<nano::bootstrap_attempt> attempt;
 	std::atomic<bool> stopped;
 	std::mutex mutex;
-	std::condition_variable condition;
+	nano::condition_variable condition;
 	std::mutex observers_mutex;
 	std::vector<std::function<void(bool)>> observers;
 	boost::thread thread;
diff --git a/nano/node/bootstrap/bootstrap_bulk_pull.cpp b/nano/node/bootstrap/bootstrap_bulk_pull.cpp
index a479d3db..54122be2 100644
--- a/nano/node/bootstrap/bootstrap_bulk_pull.cpp
+++ b/nano/node/bootstrap/bootstrap_bulk_pull.cpp
@@ -19,7 +19,6 @@ pull (pull_a),
 pull_blocks (0),
 unexpected_count (0)
 {
-	nano::lock_guard<std::mutex> mutex (connection->attempt->mutex);
 	connection->attempt->condition.notify_all ();
 }