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！
if (!request.params[1].isNull()) {
        target_confirms = request.params[1].get_int();
        if (target_confirms < 1) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter");
        }
    }
    if (ParseIncludeWatchonly(request.params[2], *pwallet)) {
        filter |= ISMINE_WATCH_ONLY;
    }
    bool include_removed = (request.params[3].isNull() || request.params[3].get_bool());
    const Optional<int> tip_height = locked_chain->getHeight();
    int depth = tip_height && height ? (1 + *tip_height - *height) : -1;
    UniValue transactions(UniValue::VARR);
    for (const std::pair<const uint256, CWalletTx>& pairWtx : pwallet->mapWallet) {
        CWalletTx tx = pairWtx.second;
        if (depth == -1 || abs(tx.GetDepthInMainChain()) < depth) {
            ListTransactions(*locked_chain, pwallet, tx, 0, true, transactions, filter, nullptr );
        }
    }
    
    
    UniValue removed(UniValue::VARR);
    while (include_removed && altheight && *altheight > *height) {
        CBlock block;
        if (!pwallet->chain().findBlock(blockId, &block) || block.IsNull()) {
            throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
        }
        for (const CTransactionRef& tx : block.vtx) {
            auto it = pwallet->mapWallet.find(tx->GetHash());
            if (it != pwallet->mapWallet.end()) {