Initial Commit

include/asio/detail/impl/kqueue_reactor.ipp

@@ -0,0 +1,614 @@
+//
+// detail/impl/kqueue_reactor.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2005 Stefan Arentz (stefan at soze dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP
+#define ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_KQUEUE)
+
+#include "asio/config.hpp"
+#include "asio/detail/kqueue_reactor.hpp"
+#include "asio/detail/scheduler.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#if defined(__NetBSD__)
+# include <sys/param.h>
+#endif
+
+#include "asio/detail/push_options.hpp"
+
+#if defined(__NetBSD__) && __NetBSD_Version__ < 999001500
+# define ASIO_KQUEUE_EV_SET(ev, ident, filt, flags, fflags, data, udata) \
+    EV_SET(ev, ident, filt, flags, fflags, data, \
+      reinterpret_cast<intptr_t>(static_cast<void*>(udata)))
+#else
+# define ASIO_KQUEUE_EV_SET(ev, ident, filt, flags, fflags, data, udata) \
+    EV_SET(ev, ident, filt, flags, fflags, data, udata)
+#endif
+
+namespace asio {
+namespace detail {
+
+kqueue_reactor::kqueue_reactor(asio::execution_context& ctx)
+  : execution_context_service_base<kqueue_reactor>(ctx),
+    scheduler_(use_service<scheduler>(ctx)),
+    mutex_(config(ctx).get("reactor", "registration_locking", true),
+        config(ctx).get("reactor", "registration_locking_spin_count", 0)),
+    kqueue_fd_(do_kqueue_create()),
+    interrupter_(),
+    shutdown_(false),
+    io_locking_(config(ctx).get("reactor", "io_locking", true)),
+    io_locking_spin_count_(
+        config(ctx).get("reactor", "io_locking_spin_count", 0)),
+    registered_descriptors_mutex_(mutex_.enabled()),
+    registered_descriptors_(execution_context::allocator<void>(ctx),
+        config(ctx).get("reactor", "preallocated_io_objects", 0U),
+        io_locking_, io_locking_spin_count_)
+{
+  struct kevent events[1];
+  ASIO_KQUEUE_EV_SET(&events[0], interrupter_.read_descriptor(),
+      EVFILT_READ, EV_ADD, 0, 0, &interrupter_);
+  if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+  {
+    asio::error_code error(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(error);
+  }
+}
+
+kqueue_reactor::~kqueue_reactor()
+{
+  close(kqueue_fd_);
+}
+
+void kqueue_reactor::shutdown()
+{
+  mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  lock.unlock();
+
+  op_queue<operation> ops;
+
+  while (descriptor_state* state = registered_descriptors_.first())
+  {
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(state->op_queue_[i]);
+    state->shutdown_ = true;
+    registered_descriptors_.free(state);
+  }
+
+  timer_queues_.get_all_timers(ops);
+
+  scheduler_.abandon_operations(ops);
+}
+
+void kqueue_reactor::notify_fork(
+    asio::execution_context::fork_event fork_ev)
+{
+  if (fork_ev == asio::execution_context::fork_child)
+  {
+    // The kqueue descriptor is automatically closed in the child.
+    kqueue_fd_ = -1;
+    kqueue_fd_ = do_kqueue_create();
+
+    interrupter_.recreate();
+
+    struct kevent events[2];
+    ASIO_KQUEUE_EV_SET(&events[0], interrupter_.read_descriptor(),
+        EVFILT_READ, EV_ADD, 0, 0, &interrupter_);
+    if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+    {
+      asio::error_code ec(errno,
+          asio::error::get_system_category());
+      asio::detail::throw_error(ec, "kqueue interrupter registration");
+    }
+
+    // Re-register all descriptors with kqueue.
+    mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+    for (descriptor_state* state = registered_descriptors_.first();
+        state != 0; state = state->next_)
+    {
+      if (state->num_kevents_ > 0)
+      {
+        ASIO_KQUEUE_EV_SET(&events[0], state->descriptor_,
+            EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, state);
+        ASIO_KQUEUE_EV_SET(&events[1], state->descriptor_,
+            EVFILT_WRITE, EV_ADD | EV_CLEAR, 0, 0, state);
+        if (::kevent(kqueue_fd_, events, state->num_kevents_, 0, 0, 0) == -1)
+        {
+          asio::error_code ec(errno,
+              asio::error::get_system_category());
+          asio::detail::throw_error(ec, "kqueue re-registration");
+        }
+      }
+    }
+  }
+}
+
+void kqueue_reactor::init_task()
+{
+  scheduler_.init_task();
+}
+
+int kqueue_reactor::register_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  mutex::scoped_lock lock(descriptor_data->mutex_);
+
+  descriptor_data->descriptor_ = descriptor;
+  descriptor_data->num_kevents_ = 0;
+  descriptor_data->shutdown_ = false;
+
+  return 0;
+}
+
+int kqueue_reactor::register_internal_descriptor(
+    int op_type, socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, reactor_op* op)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  mutex::scoped_lock lock(descriptor_data->mutex_);
+
+  descriptor_data->descriptor_ = descriptor;
+  descriptor_data->num_kevents_ = 1;
+  descriptor_data->shutdown_ = false;
+  descriptor_data->op_queue_[op_type].push(op);
+
+  struct kevent events[1];
+  ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+      EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+  if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+    return errno;
+
+  return 0;
+}
+
+void kqueue_reactor::move_descriptor(socket_type,
+    kqueue_reactor::per_descriptor_data& target_descriptor_data,
+    kqueue_reactor::per_descriptor_data& source_descriptor_data)
+{
+  target_descriptor_data = source_descriptor_data;
+  source_descriptor_data = 0;
+}
+
+void kqueue_reactor::call_post_immediate_completion(
+    operation* op, bool is_continuation, const void* self)
+{
+  static_cast<const kqueue_reactor*>(self)->post_immediate_completion(
+      op, is_continuation);
+}
+
+void kqueue_reactor::start_op(int op_type, socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, reactor_op* op,
+    bool is_continuation, bool allow_speculative,
+    void (*on_immediate)(operation*, bool, const void*),
+    const void* immediate_arg)
+{
+  if (!descriptor_data)
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    on_immediate(op, is_continuation, immediate_arg);
+    return;
+  }
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (descriptor_data->shutdown_)
+  {
+    on_immediate(op, is_continuation, immediate_arg);
+    return;
+  }
+
+  if (descriptor_data->op_queue_[op_type].empty())
+  {
+    static const int num_kevents[max_ops] = { 1, 2, 1 };
+
+    if (allow_speculative
+        && (op_type != read_op
+          || descriptor_data->op_queue_[except_op].empty()))
+    {
+      if (op->perform())
+      {
+        descriptor_lock.unlock();
+        on_immediate(op, is_continuation, immediate_arg);
+        return;
+      }
+
+      if (descriptor_data->num_kevents_ < num_kevents[op_type])
+      {
+        struct kevent events[2];
+        ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+            EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+        ASIO_KQUEUE_EV_SET(&events[1], descriptor, EVFILT_WRITE,
+            EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+        if (::kevent(kqueue_fd_, events, num_kevents[op_type], 0, 0, 0) != -1)
+        {
+          descriptor_data->num_kevents_ = num_kevents[op_type];
+        }
+        else
+        {
+          op->ec_ = asio::error_code(errno,
+              asio::error::get_system_category());
+          on_immediate(op, is_continuation, immediate_arg);
+          return;
+        }
+      }
+    }
+    else
+    {
+      if (descriptor_data->num_kevents_ < num_kevents[op_type])
+        descriptor_data->num_kevents_ = num_kevents[op_type];
+
+      struct kevent events[2];
+      ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+          EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+      ASIO_KQUEUE_EV_SET(&events[1], descriptor, EVFILT_WRITE,
+          EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+      ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+    }
+  }
+
+  descriptor_data->op_queue_[op_type].push(op);
+  scheduler_.work_started();
+}
+
+void kqueue_reactor::cancel_ops(socket_type,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+  {
+    while (reactor_op* op = descriptor_data->op_queue_[i].front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      descriptor_data->op_queue_[i].pop();
+      ops.push(op);
+    }
+  }
+
+  descriptor_lock.unlock();
+
+  scheduler_.post_deferred_completions(ops);
+}
+
+void kqueue_reactor::cancel_ops_by_key(socket_type,
+    kqueue_reactor::per_descriptor_data& descriptor_data,
+    int op_type, void* cancellation_key)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  op_queue<operation> ops;
+  op_queue<reactor_op> other_ops;
+  while (reactor_op* op = descriptor_data->op_queue_[op_type].front())
+  {
+    descriptor_data->op_queue_[op_type].pop();
+    if (op->cancellation_key_ == cancellation_key)
+    {
+      op->ec_ = asio::error::operation_aborted;
+      ops.push(op);
+    }
+    else
+      other_ops.push(op);
+  }
+  descriptor_data->op_queue_[op_type].push(other_ops);
+
+  descriptor_lock.unlock();
+
+  scheduler_.post_deferred_completions(ops);
+}
+
+void kqueue_reactor::deregister_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, bool closing)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    if (closing)
+    {
+      // The descriptor will be automatically removed from the kqueue when it
+      // is closed.
+    }
+    else
+    {
+      struct kevent events[2];
+      ASIO_KQUEUE_EV_SET(&events[0], descriptor,
+          EVFILT_READ, EV_DELETE, 0, 0, 0);
+      ASIO_KQUEUE_EV_SET(&events[1], descriptor,
+          EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+      ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+    }
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+    {
+      while (reactor_op* op = descriptor_data->op_queue_[i].front())
+      {
+        op->ec_ = asio::error::operation_aborted;
+        descriptor_data->op_queue_[i].pop();
+        ops.push(op);
+      }
+    }
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    scheduler_.post_deferred_completions(ops);
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::deregister_internal_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    struct kevent events[2];
+    ASIO_KQUEUE_EV_SET(&events[0], descriptor,
+        EVFILT_READ, EV_DELETE, 0, 0, 0);
+    ASIO_KQUEUE_EV_SET(&events[1], descriptor,
+        EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+    ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(descriptor_data->op_queue_[i]);
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::cleanup_descriptor_data(
+    per_descriptor_data& descriptor_data)
+{
+  if (descriptor_data)
+  {
+    free_descriptor_state(descriptor_data);
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::run(long usec, op_queue<operation>& ops)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  // Determine how long to block while waiting for events.
+  timespec timeout_buf = { 0, 0 };
+  timespec* timeout = usec ? get_timeout(usec, timeout_buf) : &timeout_buf;
+
+  lock.unlock();
+
+  // Block on the kqueue descriptor.
+  struct kevent events[128];
+  int num_events = kevent(kqueue_fd_, 0, 0, events, 128, timeout);
+
+#if defined(ASIO_ENABLE_HANDLER_TRACKING)
+  // Trace the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = reinterpret_cast<void*>(events[i].udata);
+    if (ptr != &interrupter_)
+    {
+      unsigned event_mask = 0;
+      switch (events[i].filter)
+      {
+      case EVFILT_READ:
+        event_mask |= ASIO_HANDLER_REACTOR_READ_EVENT;
+        break;
+      case EVFILT_WRITE:
+        event_mask |= ASIO_HANDLER_REACTOR_WRITE_EVENT;
+        break;
+      }
+      if ((events[i].flags & (EV_ERROR | EV_OOBAND)) != 0)
+        event_mask |= ASIO_HANDLER_REACTOR_ERROR_EVENT;
+      ASIO_HANDLER_REACTOR_EVENTS((context(),
+            reinterpret_cast<uintmax_t>(ptr), event_mask));
+    }
+  }
+#endif // defined(ASIO_ENABLE_HANDLER_TRACKING)
+
+  // Dispatch the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = reinterpret_cast<void*>(events[i].udata);
+    if (ptr == &interrupter_)
+    {
+      interrupter_.reset();
+    }
+    else
+    {
+      descriptor_state* descriptor_data = static_cast<descriptor_state*>(ptr);
+      mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+      if (events[i].filter == EVFILT_WRITE
+          && descriptor_data->num_kevents_ == 2
+          && descriptor_data->op_queue_[write_op].empty())
+      {
+        // Some descriptor types, like serial ports, don't seem to support
+        // EV_CLEAR with EVFILT_WRITE. Since we have no pending write
+        // operations we'll remove the EVFILT_WRITE registration here so that
+        // we don't end up in a tight spin.
+        struct kevent delete_events[1];
+        ASIO_KQUEUE_EV_SET(&delete_events[0],
+            descriptor_data->descriptor_, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+        ::kevent(kqueue_fd_, delete_events, 1, 0, 0, 0);
+        descriptor_data->num_kevents_ = 1;
+      }
+
+      // Exception operations must be processed first to ensure that any
+      // out-of-band data is read before normal data.
+#if defined(__NetBSD__)
+      static const unsigned int filter[max_ops] =
+#else
+      static const int filter[max_ops] =
+#endif
+        { EVFILT_READ, EVFILT_WRITE, EVFILT_READ };
+      for (int j = max_ops - 1; j >= 0; --j)
+      {
+        if (events[i].filter == filter[j])
+        {
+          if (j != except_op || events[i].flags & EV_OOBAND)
+          {
+            while (reactor_op* op = descriptor_data->op_queue_[j].front())
+            {
+              if (events[i].flags & EV_ERROR)
+              {
+                op->ec_ = asio::error_code(
+                    static_cast<int>(events[i].data),
+                    asio::error::get_system_category());
+                descriptor_data->op_queue_[j].pop();
+                ops.push(op);
+              }
+              if (op->perform())
+              {
+                descriptor_data->op_queue_[j].pop();
+                ops.push(op);
+              }
+              else
+                break;
+            }
+          }
+        }
+      }
+    }
+  }
+
+  lock.lock();
+  timer_queues_.get_ready_timers(ops);
+}
+
+void kqueue_reactor::interrupt()
+{
+  interrupter_.interrupt();
+}
+
+int kqueue_reactor::do_kqueue_create()
+{
+  int fd = ::kqueue();
+  if (fd == -1)
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "kqueue");
+  }
+  return fd;
+}
+
+kqueue_reactor::descriptor_state* kqueue_reactor::allocate_descriptor_state()
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  return registered_descriptors_.alloc(io_locking_, io_locking_spin_count_);
+}
+
+void kqueue_reactor::free_descriptor_state(kqueue_reactor::descriptor_state* s)
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  registered_descriptors_.free(s);
+}
+
+void kqueue_reactor::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void kqueue_reactor::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+timespec* kqueue_reactor::get_timeout(long usec, timespec& ts)
+{
+  // By default we will wait no longer than 5 minutes. This will ensure that
+  // any changes to the system clock are detected after no longer than this.
+  const long max_usec = 5 * 60 * 1000 * 1000;
+  usec = timer_queues_.wait_duration_usec(
+      (usec < 0 || max_usec < usec) ? max_usec : usec);
+  ts.tv_sec = usec / 1000000;
+  ts.tv_nsec = (usec % 1000000) * 1000;
+  return &ts;
+}
+
+} // namespace detail
+} // namespace asio
+
+#undef ASIO_KQUEUE_EV_SET
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_KQUEUE)
+
+#endif // ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP