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！
{ "wallet",             "backupwallet",                     &backupwallet,                  {"destination"} },
    { "wallet",             "bumpfee",                          &bumpfee,                       {"txid", "options"} },
    { "wallet",             "createwallet",                     &createwallet,                  {"wallet_name", "disable_private_keys", "blank", "passphrase", "avoid_reuse"} },
    { "wallet",             "dumpprivkey",                      &dumpprivkey,                   {"address"}  },
    { "wallet",             "dumpwallet",                       &dumpwallet,                    {"filename"} },
    { "wallet",             "encryptwallet",                    &encryptwallet,                 {"passphrase"} },
    { "wallet",             "getaddressesbylabel",              &getaddressesbylabel,           {"label"} },
    { "wallet",             "getaddressinfo",                   &getaddressinfo,                {"address"} },
    { "wallet",             "getbalance",                       &getbalance,                    {"dummy","minconf","include_watchonly","avoid_reuse"} },
    { "wallet",             "getnewaddress",                    &getnewaddress,                 {"label","address_type"} },
    { "wallet",             "getrawchangeaddress",              &getrawchangeaddress,           {"address_type"} },
    { "wallet",             "getreceivedbyaddress",             &getreceivedbyaddress,          {"address","minconf"} },
    { "wallet",             "getreceivedbylabel",               &getreceivedbylabel,            {"label","minconf"} },
    { "wallet",             "gettransaction",                   &gettransaction,                {"txid","include_watchonly","verbose"} },
    { "wallet",             "getunconfirmedbalance",            &getunconfirmedbalance,         {} },
    { "wallet",             "getbalances",                      &getbalances,                   {} },
    { "wallet",             "getwalletinfo",                    &getwalletinfo,                 {} },
    { "wallet",             "importaddress",                    &importaddress,                 {"address","label","rescan","p2sh"} },
    { "wallet",             "importmulti",                      &importmulti,                   {"requests","options"} },
    { "wallet",             "importprivkey",                    &importprivkey,                 {"privkey","label","rescan"} },
    { "wallet",             "importprunedfunds",                &importprunedfunds,             {"rawtransaction","txoutproof"} },
    { "wallet",             "importpubkey",                     &importpubkey,                  {"pubkey","label","rescan"} },
    { "wallet",             "importwallet",                     &importwallet,                  {"filename"} },
    { "wallet",             "keypoolrefill",                    &keypoolrefill,                 {"newsize"} },
    { "wallet",             "listaddressgroupings",             &listaddressgroupings,          {} },
    { "wallet",             "listlabels",                       &listlabels,                    {"purpose"} },
    { "wallet",             "listlockunspent",                  &listlockunspent,               {} },
    { "wallet",             "listreceivedbyaddress",            &listreceivedbyaddress,         {"minconf","include_empty","include_watchonly","address_filter"} },
    { "wallet",             "listreceivedbylabel",              &listreceivedbylabel,           {"minconf","include_empty","include_watchonly"} },
    { "wallet",             "listsinceblock",                   &listsinceblock,                {"blockhash","target_confirmations","include_watchonly","include_removed"} },