When running walletpassphrase on a large wallet.dat (ie about 300,000 segwit P2SH addresses) the command sometimes takes a very long time, and if command is run multiple times at once (while running slow) it causes bitcoin core to freeze (stops syncing and requires kill -9 to stop/restart)

During the locked up walletpassphrase commands being run the following messages start to appear in the debug.log:

`018-01-24 01:01:04 socket sending timeout: 1201s`

Note that this problem is intermittent, so sometimes the command runs instantly, other times it takes a few minutes, and other times it completely freezes the node.
{
    TOP = 0,        
    P2SH = 1,       
    WITNESS_V0 = 2, 
};
/**
 * This is an internal representation of isminetype + invalidity.
 * Its order is significant, as we return the max of all explored
 * possibilities.
 */
enum class IsMineResult
{
    NO = 0,         
    WATCH_ONLY = 1, 
    SPENDABLE = 2,  
    INVALID = 3,    
};
bool PermitsUncompressed(IsMineSigVersion sigversion)
{
    return sigversion == IsMineSigVersion::TOP || sigversion == IsMineSigVersion::P2SH;
}
bool HaveKeys(const std::vector<valtype>& pubkeys, const LegacyScriptPubKeyMan& keystore)