Commit c6fdd7c0 authored by eta's avatar eta
Browse files

arti-client: Unlock the state manager on failure to bootstrap 

`StateMgr` got a new `unlock()` method that does what it says on the
tin. We now call it from `bootstrap()` using the new
`util::StateMgrUnlockGuard`, which works in a manner similar to the
`BoolResetter` from `tor_dirmgr`.

(A decent small little task in future might be to unify these types in
some sort of general arti utility crate?)

closes arti#335
parent d9df4d64

crates/arti-client/src/client.rs

+8 −1
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ use std::sync::{Arc, Mutex, Weak}; 
use std::time::Duration;



use crate::err::ErrorDetail;

use crate::{status, TorClientBuilder};

use crate::{status, util, TorClientBuilder};

#[cfg(feature = "async-std")]

use tor_rtcompat::async_std::PreferredRuntime as PreferredAsyncStdRuntime;

#[cfg(feature = "tokio")]
@@ -472,11 +472,18 @@ impl<R: Runtime> TorClient<R> { 
            );

        }



        // If we fail to bootstrap (i.e. we return before the disarm() point below), attempt to

        // unlock the state files.

        let unlock_guard = util::StateMgrUnlockGuard::new(&self.statemgr);



        self.dirmgr.bootstrap().await?;



        self.circmgr

            .update_network_parameters(self.dirmgr.netdir()?.params());



        // Since we succeeded, disarm the unlock guard.

        unlock_guard.disarm();



        Ok(())

    }

crates/arti-client/src/lib.rs

+1 −0
Original line number Diff line number Diff line
@@ -192,6 +192,7 @@ 
mod address;

mod builder;

mod client;

mod util;



pub mod config;

pub mod status;

crates/arti-client/src/util.rs

0 → 100644
+29 −0
Original line number Diff line number Diff line 
//! Utility functions for the rest of the crate.



use tor_persist::StateMgr;

use tracing::error;



/// A RAII guard that calls `<T as StateMgr>::unlock` on drop.

pub(crate) struct StateMgrUnlockGuard<'a, T: StateMgr + 'a> {

    /// The inner manager.

    mgr: &'a T,

}



impl<'a, T: StateMgr + 'a> Drop for StateMgrUnlockGuard<'a, T> {

    fn drop(&mut self) {

        if let Err(e) = self.mgr.unlock() {

            error!("Failed to unlock state manager: {}", e);

        }

    }

}



impl<'a, T: StateMgr + 'a> StateMgrUnlockGuard<'a, T> {

    /// Create an unlock guard.

    pub(crate) fn new(mgr: &'a T) -> Self {

        Self { mgr }

    }

    /// Consume the unlock guard without unlocking the state manager.

    pub(crate) fn disarm(self) {

        std::mem::forget(self);

    }

}

crates/tor-persist/src/fs.rs

+11 −0
Original line number Diff line number Diff line
@@ -117,6 +117,17 @@ impl StateMgr for FsStateMgr { 
            Ok(LockStatus::NoLock)

        }

    }

    fn unlock(&self) -> Result<()> {

        let mut lockfile = self

            .inner

            .lockfile

            .lock()

            .expect("Poisoned lock on state lockfile");

        if lockfile.owns_lock() {

            lockfile.unlock()?;

        }

        Ok(())

    }

    fn load<D>(&self, key: &str) -> Result<Option<D>>

    where

        D: DeserializeOwned,

crates/tor-persist/src/lib.rs

+4 −0
Original line number Diff line number Diff line
@@ -98,6 +98,10 @@ pub trait StateMgr: Clone { 
    /// `[StateMgr::can_store()`] to see if the lock is held.

    fn try_lock(&self) -> Result<LockStatus>;



    /// Release any locks held and become a read-only state manager

    /// again. If no locks were held, do nothing.

    fn unlock(&self) -> Result<()>;



    /// Make a new [`StorageHandle`] to store values of particular type

    /// at a particular key.

    fn create_handle<T>(self, key: impl Into<String>) -> DynStorageHandle<T>