lokinet/llarp/router/rc_lookup_handler.hpp
Jason Rhinelander b4440094b0 De-abseil, part 2: mutex, locks, (most) time
- util::Mutex is now a std::shared_timed_mutex, which is capable of
  exclusive and shared locks.

- util::Lock is still present as a std::lock_guard<util::Mutex>.

- the locking annotations are preserved, but updated to the latest
  supported by clang rather than using abseil's older/deprecated ones.

- ACQUIRE_LOCK macro is gone since we don't pass mutexes by pointer into
  locks anymore (WTF abseil).

- ReleasableLock is gone.  Instead there are now some llarp::util helper
  methods to obtain unique and/or shared locks:
    - `auto lock = util::unique_lock(mutex);` gets an RAII-but-also
      unlockable object (std::unique_lock<T>, with T inferred from
      `mutex`).
    - `auto lock = util::shared_lock(mutex);` gets an RAII shared (i.e.
      "reader") lock of the mutex.
    - `auto lock = util::unique_locks(mutex1, mutex2, mutex3);` can be
      used to atomically lock multiple mutexes at once (returning a
      tuple of the locks).
  This are templated on the mutex which makes them a bit more flexible
  than using a concrete type: they can be used for any type of lockable
  mutex, not only util::Mutex.  (Some of the code here uses them for
  getting locks around a std::mutex).  Until C++17, using the RAII types
  is painfully verbose:

  ```C++
  // pre-C++17 - needing to figure out the mutex type here is annoying:
  std::unique_lock<util::Mutex> lock(mutex);
  // pre-C++17 and even more verbose (but at least the type isn't needed):
  std::unique_lock<decltype(mutex)> lock(mutex);
  // our compromise:
  auto lock = util::unique_lock(mutex);
  // C++17:
  std::unique_lock lock(mutex);
  ```

  All of these functions will also warn (under gcc or clang) if you
  discard the return value.  You can also do fancy things like
  `auto l = util::unique_lock(mutex, std::adopt_lock)` (which lets a
  lock take over an already-locked mutex).

- metrics code is gone, which also removes a big pile of code that was
  only used by metrics:
  - llarp::util::Scheduler
  - llarp:🧵:TimerQueue
  - llarp::util::Stopwatch
2020-02-21 23:22:47 -04:00

126 lines
3.4 KiB
C++

#ifndef LLARP_RC_LOOKUP_HANDLER_HPP
#define LLARP_RC_LOOKUP_HANDLER_HPP
#include <chrono>
#include <router/i_rc_lookup_handler.hpp>
#include <util/thread/threading.hpp>
#include <util/thread/thread_pool.hpp>
#include <unordered_map>
#include <set>
#include <list>
struct llarp_nodedb;
struct llarp_dht_context;
namespace llarp
{
namespace service
{
struct Context;
} // namespace service
struct ILinkManager;
struct RCLookupHandler final : public I_RCLookupHandler
{
public:
using CallbacksQueue = std::list< RCRequestCallback >;
~RCLookupHandler() override = default;
void
AddValidRouter(const RouterID &router) override EXCLUDES(_mutex);
void
RemoveValidRouter(const RouterID &router) override EXCLUDES(_mutex);
void
SetRouterWhitelist(const std::vector< RouterID > &routers) override
EXCLUDES(_mutex);
bool
HaveReceivedWhitelist();
void
GetRC(const RouterID &router, RCRequestCallback callback,
bool forceLookup = false) override EXCLUDES(_mutex);
bool
RemoteIsAllowed(const RouterID &remote) const override EXCLUDES(_mutex);
bool
CheckRC(const RouterContact &rc) const override;
bool
GetRandomWhitelistRouter(RouterID &router) const override EXCLUDES(_mutex);
bool
CheckRenegotiateValid(RouterContact newrc, RouterContact oldrc) override;
void
PeriodicUpdate(llarp_time_t now) override;
void
ExploreNetwork() override;
size_t
NumberOfStrictConnectRouters() const override;
void
Init(llarp_dht_context *dht, llarp_nodedb *nodedb,
std::shared_ptr< llarp::thread::ThreadPool > threadpool,
ILinkManager *linkManager, service::Context *hiddenServiceContext,
const std::set< RouterID > &strictConnectPubkeys,
const std::set< RouterContact > &bootstrapRCList,
bool useWhitelist_arg, bool isServiceNode_arg);
private:
void
HandleDHTLookupResult(RouterID remote,
const std::vector< RouterContact > &results);
bool
HavePendingLookup(RouterID remote) const EXCLUDES(_mutex);
bool
RemoteInBootstrap(const RouterID &remote) const;
void
FinalizeRequest(const RouterID &router, const RouterContact *const rc,
RCRequestResult result) EXCLUDES(_mutex);
mutable util::Mutex _mutex; // protects pendingCallbacks, whitelistRouters
llarp_dht_context *_dht = nullptr;
llarp_nodedb *_nodedb = nullptr;
std::shared_ptr< llarp::thread::ThreadPool > _threadpool = nullptr;
service::Context *_hiddenServiceContext = nullptr;
ILinkManager *_linkManager = nullptr;
/// explicit whitelist of routers we will connect to directly (not for
/// service nodes)
std::set< RouterID > _strictConnectPubkeys;
std::set< RouterContact > _bootstrapRCList;
std::set< RouterID > _bootstrapRouterIDList;
std::unordered_map< RouterID, CallbacksQueue, RouterID::Hash >
pendingCallbacks GUARDED_BY(_mutex);
bool useWhitelist = false;
bool isServiceNode = false;
std::set< RouterID > whitelistRouters GUARDED_BY(_mutex);
using TimePoint = std::chrono::steady_clock::time_point;
std::unordered_map< RouterID, TimePoint, RouterID::Hash >
_routerLookupTimes;
};
} // namespace llarp
#endif // LLARP_RC_LOOKUP_HANDLER_HPP