Guard vRecvGetData (now in net processing) with its own mutex

This requires slightly reorganizing the logic in GETBLOCKTXN to
maintain locking order.
This commit is contained in:
Neha Narula 2020-09-13 20:34:41 -04:00
parent 2d9f2fca43
commit ba951812ec

View file

@ -515,8 +515,10 @@ struct Peer {
/** Set of txids to reconsider once their parent transactions have been accepted **/
std::set<uint256> m_orphan_work_set GUARDED_BY(g_cs_orphans);
/** Protects vRecvGetData **/
Mutex m_getdata_requests_mutex;
/** Work queue of items requested by this peer **/
std::deque<CInv> vRecvGetData;
std::deque<CInv> vRecvGetData GUARDED_BY(m_getdata_requests_mutex);
Peer(NodeId id) : m_id(id) {}
};
@ -1753,14 +1755,11 @@ static CTransactionRef FindTxForGetData(const CTxMemPool& mempool, const CNode&
return {};
}
void static ProcessGetData(CNode& pfrom, const CChainParams& chainparams, CConnman& connman, CTxMemPool& mempool, const std::atomic<bool>& interruptMsgProc) LOCKS_EXCLUDED(cs_main)
void static ProcessGetData(CNode& pfrom, Peer& peer, const CChainParams& chainparams, CConnman& connman, CTxMemPool& mempool, const std::atomic<bool>& interruptMsgProc) EXCLUSIVE_LOCKS_REQUIRED(!cs_main, peer.m_getdata_requests_mutex)
{
AssertLockNotHeld(cs_main);
PeerRef peer = GetPeerRef(pfrom.GetId());
if (peer == nullptr) return;
std::deque<CInv>::iterator it = peer->vRecvGetData.begin();
std::deque<CInv>::iterator it = peer.vRecvGetData.begin();
std::vector<CInv> vNotFound;
const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
@ -1772,7 +1771,7 @@ void static ProcessGetData(CNode& pfrom, const CChainParams& chainparams, CConnm
// Process as many TX items from the front of the getdata queue as
// possible, since they're common and it's efficient to batch process
// them.
while (it != peer->vRecvGetData.end() && it->IsGenTxMsg()) {
while (it != peer.vRecvGetData.end() && it->IsGenTxMsg()) {
if (interruptMsgProc) return;
// The send buffer provides backpressure. If there's no space in
// the buffer, pause processing until the next call.
@ -1820,7 +1819,7 @@ void static ProcessGetData(CNode& pfrom, const CChainParams& chainparams, CConnm
// Only process one BLOCK item per call, since they're uncommon and can be
// expensive to process.
if (it != peer->vRecvGetData.end() && !pfrom.fPauseSend) {
if (it != peer.vRecvGetData.end() && !pfrom.fPauseSend) {
const CInv &inv = *it++;
if (inv.IsGenBlkMsg()) {
ProcessGetBlockData(pfrom, chainparams, inv, connman);
@ -1829,7 +1828,7 @@ void static ProcessGetData(CNode& pfrom, const CChainParams& chainparams, CConnm
// and continue processing the queue on the next call.
}
peer->vRecvGetData.erase(peer->vRecvGetData.begin(), it);
peer.vRecvGetData.erase(peer.vRecvGetData.begin(), it);
if (!vNotFound.empty()) {
// Let the peer know that we didn't find what it asked for, so it doesn't
@ -2811,8 +2810,12 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat
LogPrint(BCLog::NET, "received getdata for: %s peer=%d\n", vInv[0].ToString(), pfrom.GetId());
}
peer->vRecvGetData.insert(peer->vRecvGetData.end(), vInv.begin(), vInv.end());
ProcessGetData(pfrom, m_chainparams, m_connman, m_mempool, interruptMsgProc);
{
LOCK(peer->m_getdata_requests_mutex);
peer->vRecvGetData.insert(peer->vRecvGetData.end(), vInv.begin(), vInv.end());
ProcessGetData(pfrom, *peer, m_chainparams, m_connman, m_mempool, interruptMsgProc);
}
return;
}
@ -2900,36 +2903,38 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat
return;
}
LOCK(cs_main);
{
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(req.blockhash);
if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) {
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom.GetId());
return;
const CBlockIndex* pindex = LookupBlockIndex(req.blockhash);
if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) {
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom.GetId());
return;
}
if (pindex->nHeight >= ::ChainActive().Height() - MAX_BLOCKTXN_DEPTH) {
CBlock block;
bool ret = ReadBlockFromDisk(block, pindex, m_chainparams.GetConsensus());
assert(ret);
SendBlockTransactions(pfrom, block, req);
return;
}
}
if (pindex->nHeight < ::ChainActive().Height() - MAX_BLOCKTXN_DEPTH) {
// If an older block is requested (should never happen in practice,
// but can happen in tests) send a block response instead of a
// blocktxn response. Sending a full block response instead of a
// small blocktxn response is preferable in the case where a peer
// might maliciously send lots of getblocktxn requests to trigger
// expensive disk reads, because it will require the peer to
// actually receive all the data read from disk over the network.
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom.GetId(), MAX_BLOCKTXN_DEPTH);
CInv inv;
inv.type = State(pfrom.GetId())->fWantsCmpctWitness ? MSG_WITNESS_BLOCK : MSG_BLOCK;
inv.hash = req.blockhash;
peer->vRecvGetData.push_back(inv);
// The message processing loop will go around again (without pausing) and we'll respond then (without cs_main)
return;
}
CBlock block;
bool ret = ReadBlockFromDisk(block, pindex, m_chainparams.GetConsensus());
assert(ret);
SendBlockTransactions(pfrom, block, req);
// If an older block is requested (should never happen in practice,
// but can happen in tests) send a block response instead of a
// blocktxn response. Sending a full block response instead of a
// small blocktxn response is preferable in the case where a peer
// might maliciously send lots of getblocktxn requests to trigger
// expensive disk reads, because it will require the peer to
// actually receive all the data read from disk over the network.
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom.GetId(), MAX_BLOCKTXN_DEPTH);
CInv inv;
WITH_LOCK(cs_main, inv.type = State(pfrom.GetId())->fWantsCmpctWitness ? MSG_WITNESS_BLOCK : MSG_BLOCK);
inv.hash = req.blockhash;
WITH_LOCK(peer->m_getdata_requests_mutex, peer->vRecvGetData.push_back(inv));
// The message processing loop will go around again (without pausing) and we'll respond then
return;
}
@ -3879,8 +3884,11 @@ bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgP
PeerRef peer = GetPeerRef(pfrom->GetId());
if (peer == nullptr) return false;
if (!peer->vRecvGetData.empty()) {
ProcessGetData(*pfrom, m_chainparams, m_connman, m_mempool, interruptMsgProc);
{
LOCK(peer->m_getdata_requests_mutex);
if (!peer->vRecvGetData.empty()) {
ProcessGetData(*pfrom, *peer, m_chainparams, m_connman, m_mempool, interruptMsgProc);
}
}
{
@ -3895,7 +3903,11 @@ bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgP
// this maintains the order of responses
// and prevents vRecvGetData to grow unbounded
if (!peer->vRecvGetData.empty()) return true;
{
LOCK(peer->m_getdata_requests_mutex);
if (!peer->vRecvGetData.empty()) return true;
}
{
LOCK(g_cs_orphans);
if (!peer->m_orphan_work_set.empty()) return true;
@ -3926,10 +3938,11 @@ bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgP
try {
ProcessMessage(*pfrom, msg_type, msg.m_recv, msg.m_time, interruptMsgProc);
if (interruptMsgProc)
return false;
if (!peer->vRecvGetData.empty())
fMoreWork = true;
if (interruptMsgProc) return false;
{
LOCK(peer->m_getdata_requests_mutex);
if (!peer->vRecvGetData.empty()) fMoreWork = true;
}
} catch (const std::exception& e) {
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' (%s) caught\n", __func__, SanitizeString(msg_type), nMessageSize, e.what(), typeid(e).name());
} catch (...) {