When i used the encrypted wallet to test transfer parallelly,i frequently got the trouble: The rpc server is not responding.My test script is like below:
#!/bin/sh
while [ 1 ]
do
./bitcoin-cli listaddressgroupings>null
./bitcoin-cli walletpassphrase "!@#$%^&*" 2
./bitcoin sendtoaddress "mhAW6mzs5DeCbzBUHXBi4U446Fdnr1z8U7" 0.01
done

When i open the dead lock trace macro and check the debug log,i found the last print is as below:
2018-12-17 08:27:58 ThreadRPCServer method=walletpassphrase
2018-12-17 08:27:58 LOCKCONTENTION: cs_main
2018-12-17 08:27:58 Locker: wallet/rpcwallet.cpp:2642
2018-12-17 08:27:58 LOCKCONTENTION: pWallet->cs_wallet
2018-12-17 08:27:58 Locker: wallet/rpcwallet.cpp:2607

The line no 2642 is walletpassphrase and 2607 is LockWallet. I checked the code,i found there is no log printed for this line in function "walletpassphrase":
"LogPrint(BCLog::RPC, "queue run of timer %s in %i seconds (using %s)\n", name, nSeconds, timerInterface->Name());" So i guess the reason may be:
When "walletpassphrase" is running and lock the cs_wallet,the last relock timer triggered and call "LockWallet"."LockWallet" want to lock the cs_wallet but it has been locked by "walletpassphrase",so "LockWallet" is blocked.When "walletpassphrase" run to call "RPCRunLater",the function will erase the timer from the std::map "deadlineTimers",but the timer's timeout call is blocked,so the dead lock take place.
Is my guess right?
How to reslove the issue?
Any help will be appreciative！
std::vector<COutput> vecOutputs;
    {
        CCoinControl cctl;
        cctl.m_avoid_address_reuse = false;
        cctl.m_min_depth = nMinDepth;
        cctl.m_max_depth = nMaxDepth;
        auto locked_chain = pwallet->chain().lock();
        LOCK(pwallet->cs_wallet);
        pwallet->AvailableCoins(*locked_chain, vecOutputs, !include_unsafe, &cctl, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount);
    }
    LOCK(pwallet->cs_wallet);
    const bool avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
    for (const COutput& out : vecOutputs) {
        CTxDestination address;
        const CScript& scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;
        bool fValidAddress = ExtractDestination(scriptPubKey, address);
        bool reused = avoid_reuse && pwallet->IsSpentKey(out.tx->GetHash(), out.i);
        if (destinations.size() && (!fValidAddress || !destinations.count(address)))
            continue;
        UniValue entry(UniValue::VOBJ);
        entry.pushKV("txid", out.tx->GetHash().GetHex());
        entry.pushKV("vout", out.i);
        if (fValidAddress) {
            entry.pushKV("address", EncodeDestination(address));
            auto i = pwallet->mapAddressBook.find(address);
            if (i != pwallet->mapAddressBook.end()) {
                entry.pushKV("label", i->second.name);
            }
            std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
            if (provider) {