From 2ed2d479c67c425a255f8991aa72df3ff4780d48 Mon Sep 17 00:00:00 2001
From: subtly <subtly@users.noreply.github.com>
Date: Sun, 5 Oct 2014 19:48:08 +0200
Subject: [PATCH] Add mutexed askedContains in placed of .asked.contains().
 Issue #333 (dev::RangeMask<unsigned int>::contains), nextFetch clears m_asked
 concurrent to m_asked.contains() iteration.

---
 alethzero/DownloadView.cpp | 2 +-
 libethereum/DownloadMan.h  | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/alethzero/DownloadView.cpp b/alethzero/DownloadView.cpp
index 56dd9c3d2..a6533023c 100644
--- a/alethzero/DownloadView.cpp
+++ b/alethzero/DownloadView.cpp
@@ -63,7 +63,7 @@ void DownloadView::paintEvent(QPaintEvent*)
 			unsigned h = 0;
 			m_man->foreachSub([&](DownloadSub const& sub)
 			{
-				if (sub.asked().contains(i))
+				if (sub.askedContains(i))
 					s = h;
 				h++;
 			});
diff --git a/libethereum/DownloadMan.h b/libethereum/DownloadMan.h
index 3bd401d8e..6f4c4bafb 100644
--- a/libethereum/DownloadMan.h
+++ b/libethereum/DownloadMan.h
@@ -54,6 +54,7 @@ public:
 	/// Nothing doing here.
 	void doneFetch() { resetFetch(); }
 
+	bool askedContains(unsigned _i) const { Guard l(m_fetch); return m_asked.contains(_i); }
 	RangeMask<unsigned> const& asked() const { return m_asked; }
 	RangeMask<unsigned> const& attemped() const { return m_attempted; }
 
@@ -69,7 +70,7 @@ private:
 
 	DownloadMan* m_man = nullptr;
 
-	Mutex m_fetch;
+	mutable Mutex m_fetch;
 	h256Set m_remaining;
 	std::map<h256, unsigned> m_indices;
 	RangeMask<unsigned> m_asked;