From e8c3f89fc6f82d816913c26bceadf2a64ffa7dd0 Mon Sep 17 00:00:00 2001
From: Guilherme Lawless <guilherme@nano.org>
Date: Mon, 14 Sep 2020 17:21:41 +0100
Subject: [PATCH] Retrieve copy of wallets in scan_receivable (#2934)

Locking the wallets items mutex
---
 nano/node/node.cpp   | 3 +--
 nano/node/wallet.cpp | 6 ++++++
 nano/node/wallet.hpp | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/nano/node/node.cpp b/nano/node/node.cpp
index 7fd61f63..047d3464 100644
--- a/nano/node/node.cpp
+++ b/nano/node/node.cpp
@@ -1178,9 +1178,8 @@ public:
 	virtual ~confirmed_visitor () = default;
 	void scan_receivable (nano::account const & account_a)
 	{
-		for (auto i (node.wallets.items.begin ()), n (node.wallets.items.end ()); i != n; ++i)
+		for (auto const & [id /*unused*/, wallet] : node.wallets.get_wallets ())
 		{
-			auto const & wallet (i->second);
 			auto transaction_l (node.wallets.tx_begin_read ());
 			if (wallet->store.exists (transaction_l, account_a))
 			{
diff --git a/nano/node/wallet.cpp b/nano/node/wallet.cpp
index f048779f..95d8123c 100644
--- a/nano/node/wallet.cpp
+++ b/nano/node/wallet.cpp
@@ -1876,6 +1876,12 @@ void nano::wallets::move_table (std::string const & name_a, MDB_txn * tx_source,
 	debug_assert (!error6);
 }
 
+std::unordered_map<nano::wallet_id, std::shared_ptr<nano::wallet>> nano::wallets::get_wallets ()
+{
+	nano::lock_guard<std::mutex> guard (mutex);
+	return items;
+}
+
 nano::uint128_t const nano::wallets::generate_priority = std::numeric_limits<nano::uint128_t>::max ();
 nano::uint128_t const nano::wallets::high_priority = std::numeric_limits<nano::uint128_t>::max () - 1;
 
diff --git a/nano/node/wallet.hpp b/nano/node/wallet.hpp
index f646ec18..78a9a498 100644
--- a/nano/node/wallet.hpp
+++ b/nano/node/wallet.hpp
@@ -229,6 +229,7 @@ public:
 	void ongoing_compute_reps ();
 	void split_if_needed (nano::transaction &, nano::block_store &);
 	void move_table (std::string const &, MDB_txn *, MDB_txn *);
+	std::unordered_map<nano::wallet_id, std::shared_ptr<nano::wallet>> get_wallets ();
 	nano::network_params network_params;
 	std::function<void(bool)> observer;
 	std::unordered_map<nano::wallet_id, std::shared_ptr<nano::wallet>> items;