diff options
| -rw-r--r-- | source/ClientHandle.cpp | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/source/ClientHandle.cpp b/source/ClientHandle.cpp index 9d5bbaeaf..cbe544c1f 100644 --- a/source/ClientHandle.cpp +++ b/source/ClientHandle.cpp @@ -1959,7 +1959,18 @@ void cClientHandle::DataReceived(const char * a_Data, int a_Size) // Data is received from the client, hand it off to the protocol: if ((m_Player != NULL) && (m_Player->GetWorld() != NULL)) { - // Lock the world, so that plugins reacting to protocol events have already the chunkmap locked + /* + _X: Lock the world, so that plugins reacting to protocol events have already the chunkmap locked. + There was a possibility of a deadlock between SocketThreads and TickThreads, resulting from each + holding one CS an requesting the other one (ChunkMap CS vs Plugin CS) (FS #375). To break this, it's + sufficient to break any of the four Coffman conditions for a deadlock. We'll solve this by requiring + the ChunkMap CS for all SocketThreads operations before they lock the PluginCS - thus creating a kind + of a lock hierarchy. However, this incurs a performance penalty, we're de facto locking the chunkmap + for each incoming packet. A better, but more involved solutin would be to lock the chunkmap only when + the incoming packet really has a plugin CS lock request. + Also, it is still possible for a packet to slip through - when a player still doesn't have their world + assigned and several packets arrive at once. + */ cWorld::cLock(*m_Player->GetWorld()); m_Protocol->DataReceived(a_Data, a_Size); |