lokinet/llarp/util/thread/logic.cpp
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

149 lines
2.9 KiB
C++

#include <util/thread/logic.hpp>
#include <util/logging/logger.hpp>
#include <util/mem.h>
#include <future>
namespace llarp
{
Logic::Logic(size_t sz)
: m_Thread(llarp_init_threadpool(1, "llarp-logic", sz))
{
llarp_threadpool_start(m_Thread);
/// set thread id
std::promise< ID_t > result;
// queue setting id and try to get the result back
llarp_threadpool_queue_job(m_Thread, [&]() {
m_ID.emplace(std::this_thread::get_id());
result.set_value(m_ID.value());
});
// get the result back
ID_t spawned = result.get_future().get();
LogDebug("logic thread spawned on ", spawned);
}
Logic::~Logic()
{
delete m_Thread;
}
size_t
Logic::numPendingJobs() const
{
return m_Thread->pendingJobs();
}
bool
Logic::queue_job(struct llarp_thread_job job)
{
return job.user && job.work
&& LogicCall(this, std::bind(job.work, job.user));
}
void
Logic::stop()
{
llarp::LogDebug("logic thread stop");
// stop all operations on threadpool
llarp_threadpool_stop(m_Thread);
}
bool
Logic::_traceLogicCall(std::function< void(void) > func, const char* tag,
int line)
{
// wrap the function so that we ensure that it's always calling stuff one at
// a time
auto f = [self = this, func]() {
if(self->m_Queue)
{
func();
}
else
{
self->m_Killer.TryAccess(func);
}
};
if(can_flush())
{
f();
return true;
}
if(m_Queue)
{
m_Queue(f);
return true;
}
if(m_Thread->LooksFull(5))
{
LogErrorExplicit(tag ? tag : LOG_TAG, line ? line : __LINE__,
"holy crap, we are trying to queue a job "
"onto the logic thread but it looks full");
std::abort();
}
auto ret = llarp_threadpool_queue_job(m_Thread, f);
if(not ret)
{
}
return ret;
}
void
Logic::SetQueuer(std::function< void(std::function< void(void) >) > q)
{
m_Queue = q;
m_Queue([self = this]() { self->m_ID = std::this_thread::get_id(); });
}
uint32_t
Logic::call_later(llarp_time_t timeout, std::function< void(void) > func)
{
auto loop = m_Loop;
if(loop != nullptr)
{
return loop->call_after_delay(timeout, func);
}
return 0;
}
void
Logic::cancel_call(uint32_t id)
{
auto loop = m_Loop;
if(loop != nullptr)
{
loop->cancel_delayed_call(id);
}
}
void
Logic::remove_call(uint32_t id)
{
auto loop = m_Loop;
if(loop != nullptr)
{
loop->cancel_delayed_call(id);
}
}
bool
Logic::can_flush() const
{
return m_ID.value() == std::this_thread::get_id();
}
void
Logic::set_event_loop(llarp_ev_loop* loop)
{
m_Loop = loop;
}
void
Logic::clear_event_loop()
{
m_Loop = nullptr;
}
} // namespace llarp