After starting from command line bitocoind, it can require minutes to have bitocoind to be real responsive, for example:
`$ ./bitcoin-cli stop`
`error: {"code":-28,"message":"Activating best chain..."}`

In such situation, I had sometimes to "kill -9" bitcoind to stop it.
I would like to be able to stop bitcoind in clean way.

p.s.:
`$ uname -a`
`Darwin isghe.local 14.4.0 Darwin Kernel Version 14.4.0: Thu May 28 11:35:04 PDT 2015; root:xnu-2782.30.5~1/RELEASE_X86_64 x86_64`

{
    
    CAutoFile fileout(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
    if (fileout.IsNull())
        return error("%s: OpenUndoFile failed", __func__);
    
    unsigned int nSize = fileout.GetSerializeSize(blockundo);
    fileout << FLATDATA(messageStart) << nSize;
    
    long fileOutPos = ftell(fileout.Get());
    if (fileOutPos < 0)
        return error("%s: ftell failed", __func__);
    pos.nPos = (unsigned int)fileOutPos;
    fileout << blockundo;
    
    CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
    hasher << hashBlock;
    hasher << blockundo;
    fileout << hasher.GetHash();
    return true;
}
bool UndoReadFromDisk(CBlockUndo& blockundo, const CDiskBlockPos& pos, const uint256& hashBlock)