user13700: I am running Ubuntu 12.04. When I close bitcoin-qt (or any of its derivatives, like litecoin-qt or dogecoin-qt), sometimes it does not completely exit. I then have to run killall -9 bitcoin-qt, or sometimes when even that doesn't work, killall -9 bitcoin-shutoff (apparently the client calls a bitcoin-shutoff process to shut itself down). I am wondering if there is a fix for this, to prevent the client from refusing to close in the future.

user147: Have you set a proxy?
From my experience slow shutdown seems to have to do with slow proxies (for example, Tor).
There is an issue for this: https://github.com/bitcoin/bitcoin/issues/2954
If it is not the network thread that hangs, but database synchronization, then killing with -9 can be dangerous. 
I'd suggest debugging this by running in gdb, Ctrl-Cing when it hangs, and then getting backtraces for every still-running thread.

13700: <p>I am running Ubuntu 12.04. When I close bitcoin-qt (or any of its derivatives, like litecoin-qt or dogecoin-qt), sometimes it does not completely exit. I then have to run <code>killall -9 bitcoin-qt</code>, or sometimes when even that doesn't work, <code>killall -9 bitcoin-shutoff</code> (apparently the client calls a <code>bitcoin-shutoff</code> process to shut itself down). I am wondering if there is a fix for this, to prevent the client from refusing to close in the future.</p>
 147: <p>Have you set a proxy?</p>

<p>From my experience slow shutdown seems to have to do with slow proxies (for example, Tor).
There is an issue for this: <a href="https://github.com/bitcoin/bitcoin/issues/2954" rel="nofollow">https://github.com/bitcoin/bitcoin/issues/2954</a></p>

<p>If it is not the network thread that hangs, but database synchronization, then killing with -9 can be dangerous. </p>

<p>I'd suggest debugging this by running in gdb, Ctrl-Cing when it hangs, and then getting backtraces for every still-running thread.</p>
