Network part requires SharedBuffers to be pass as value

This can trigger unreproductible crashes due to concurrency problem on SharedBuffers This fixes #6354
minetest · Sep 3, 2017 · eabf04b · eabf04b
1 parent 2ac5a45
commit eabf04b
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Showing 4 changed files with 8 additions and 10 deletions.
diff --git a/src/network/connection.cpp b/src/network/connection.cpp
@@ -55,7 +55,7 @@ std::mutex log_message_mutex;
 
 #define PING_TIMEOUT 5.0
 
-BufferedPacket makePacket(Address &address, const SharedBuffer<u8> &data,
+BufferedPacket makePacket(Address &address, SharedBuffer<u8> data,
 		u32 protocol_id, u16 sender_peer_id, u8 channel)
 {
 	u32 packet_size = data.getSize() + BASE_HEADER_SIZE;
@@ -125,7 +125,7 @@ void makeSplitPacket(const SharedBuffer<u8> &data, u32 chunksize_max, u16 seqnum
 	}
 }
 
-void makeAutoSplitPacket(const SharedBuffer<u8> &data, u32 chunksize_max,
+void makeAutoSplitPacket(SharedBuffer<u8> data, u32 chunksize_max,
 		u16 &split_seqnum, std::list<SharedBuffer<u8>> *list)
 {
 	u32 original_header_size = 1;
@@ -139,9 +139,7 @@ void makeAutoSplitPacket(const SharedBuffer<u8> &data, u32 chunksize_max,
 	list->push_back(makeOriginalPacket(data));
 }
 
-SharedBuffer<u8> makeReliablePacket(
-		const SharedBuffer<u8> &data,
-		u16 seqnum)
+SharedBuffer<u8> makeReliablePacket(SharedBuffer<u8> data, u16 seqnum)
 {
 	u32 header_size = 3;
 	u32 packet_size = data.getSize() + header_size;

diff --git a/src/network/connection.h b/src/network/connection.h
@@ -102,16 +102,16 @@ struct BufferedPacket
 };
 
 // This adds the base headers to the data and makes a packet out of it
-BufferedPacket makePacket(Address &address, const SharedBuffer<u8> &data,
+BufferedPacket makePacket(Address &address, SharedBuffer<u8> data,
 		u32 protocol_id, u16 sender_peer_id, u8 channel);
 
 // Depending on size, make a TYPE_ORIGINAL or TYPE_SPLIT packet
 // Increments split_seqnum if a split packet is made
-void makeAutoSplitPacket(const SharedBuffer<u8> &data, u32 chunksize_max,
+void makeAutoSplitPacket(SharedBuffer<u8> data, u32 chunksize_max,
 		u16 &split_seqnum, std::list<SharedBuffer<u8>> *list);
 
 // Add the TYPE_RELIABLE header to the data
-SharedBuffer<u8> makeReliablePacket(const SharedBuffer<u8> &data, u16 seqnum);
+SharedBuffer<u8> makeReliablePacket(SharedBuffer<u8> data, u16 seqnum);
 
 struct IncomingSplitPacket
 {

diff --git a/src/network/connectionthreads.cpp b/src/network/connectionthreads.cpp
@@ -330,7 +330,7 @@ void ConnectionSendThread::sendAsPacketReliable(BufferedPacket &p, Channel *chan
 }
 
 bool ConnectionSendThread::rawSendAsPacket(u16 peer_id, u8 channelnum,
-	const SharedBuffer<u8> &data, bool reliable)
+	SharedBuffer<u8> data, bool reliable)
 {
 	PeerHelper peer = m_connection->getPeerNoEx(peer_id);
 	if (!peer) {

diff --git a/src/network/connectionthreads.h b/src/network/connectionthreads.h
@@ -52,7 +52,7 @@ class ConnectionSendThread : public Thread
 private:
 	void runTimeouts(float dtime);
 	void rawSend(const BufferedPacket &packet);
-	bool rawSendAsPacket(u16 peer_id, u8 channelnum, const SharedBuffer<u8> &data,
+	bool rawSendAsPacket(u16 peer_id, u8 channelnum, SharedBuffer<u8> data,
 			bool reliable);
 
 	void processReliableCommand(ConnectionCommand &c);