. /include/boost/corosio /native /detail /epoll /epoll_scheduler.hpp
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1   // 1   //
2   // Copyright (c) 2026 Steve Gerbino 2   // Copyright (c) 2026 Steve Gerbino
3   // 3   //
4   // Distributed under the Boost Software License, Version 1.0. (See accompanying 4   // Distributed under the Boost Software License, Version 1.0. (See accompanying
5   // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5   // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   // 6   //
7   // Official repository: https://github.com/cppalliance/corosio 7   // Official repository: https://github.com/cppalliance/corosio
8   // 8   //
9   9  
10   #ifndef BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP 10   #ifndef BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP
11   #define BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP 11   #define BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP
12   12  
13   #include <boost/corosio/detail/platform.hpp> 13   #include <boost/corosio/detail/platform.hpp>
14   14  
15   #if BOOST_COROSIO_HAS_EPOLL 15   #if BOOST_COROSIO_HAS_EPOLL
16   16  
17   #include <boost/corosio/detail/config.hpp> 17   #include <boost/corosio/detail/config.hpp>
18   #include <boost/capy/ex/execution_context.hpp> 18   #include <boost/capy/ex/execution_context.hpp>
19   19  
20   #include <boost/corosio/native/detail/reactor/reactor_scheduler.hpp> 20   #include <boost/corosio/native/detail/reactor/reactor_scheduler.hpp>
21   21  
22   #include <boost/corosio/native/detail/epoll/epoll_traits.hpp> 22   #include <boost/corosio/native/detail/epoll/epoll_traits.hpp>
23   #include <boost/corosio/detail/timer_service.hpp> 23   #include <boost/corosio/detail/timer_service.hpp>
24   #include <boost/corosio/native/detail/make_err.hpp> 24   #include <boost/corosio/native/detail/make_err.hpp>
25   #include <boost/corosio/native/detail/posix/posix_resolver_service.hpp> 25   #include <boost/corosio/native/detail/posix/posix_resolver_service.hpp>
26   #include <boost/corosio/native/detail/posix/posix_signal_service.hpp> 26   #include <boost/corosio/native/detail/posix/posix_signal_service.hpp>
27   #include <boost/corosio/native/detail/posix/posix_stream_file_service.hpp> 27   #include <boost/corosio/native/detail/posix/posix_stream_file_service.hpp>
28   #include <boost/corosio/native/detail/posix/posix_random_access_file_service.hpp> 28   #include <boost/corosio/native/detail/posix/posix_random_access_file_service.hpp>
29   29  
30   #include <boost/corosio/detail/except.hpp> 30   #include <boost/corosio/detail/except.hpp>
31   31  
32   #include <atomic> 32   #include <atomic>
33   #include <chrono> 33   #include <chrono>
34   #include <cstdint> 34   #include <cstdint>
35   #include <mutex> 35   #include <mutex>
36   #include <vector> 36   #include <vector>
37   37  
38   #include <errno.h> 38   #include <errno.h>
39   #include <sys/epoll.h> 39   #include <sys/epoll.h>
40   #include <sys/eventfd.h> 40   #include <sys/eventfd.h>
41   #include <sys/timerfd.h> 41   #include <sys/timerfd.h>
42   #include <unistd.h> 42   #include <unistd.h>
43   43  
44   namespace boost::corosio::detail { 44   namespace boost::corosio::detail {
45   45  
46   /** Linux scheduler using epoll for I/O multiplexing. 46   /** Linux scheduler using epoll for I/O multiplexing.
47   47  
48   This scheduler implements the scheduler interface using Linux epoll 48   This scheduler implements the scheduler interface using Linux epoll
49   for efficient I/O event notification. It uses a single reactor model 49   for efficient I/O event notification. It uses a single reactor model
50   where one thread runs epoll_wait while other threads 50   where one thread runs epoll_wait while other threads
51   wait on a condition variable for handler work. This design provides: 51   wait on a condition variable for handler work. This design provides:
52   52  
53   - Handler parallelism: N posted handlers can execute on N threads 53   - Handler parallelism: N posted handlers can execute on N threads
54   - No thundering herd: condition_variable wakes exactly one thread 54   - No thundering herd: condition_variable wakes exactly one thread
55   - IOCP parity: Behavior matches Windows I/O completion port semantics 55   - IOCP parity: Behavior matches Windows I/O completion port semantics
56   56  
57   When threads call run(), they first try to execute queued handlers. 57   When threads call run(), they first try to execute queued handlers.
58   If the queue is empty and no reactor is running, one thread becomes 58   If the queue is empty and no reactor is running, one thread becomes
59   the reactor and runs epoll_wait. Other threads wait on a condition 59   the reactor and runs epoll_wait. Other threads wait on a condition
60   variable until handlers are available. 60   variable until handlers are available.
61   61  
62   @par Thread Safety 62   @par Thread Safety
63   All public member functions are thread-safe. 63   All public member functions are thread-safe.
64   */ 64   */
65   class BOOST_COROSIO_DECL epoll_scheduler final : public reactor_scheduler 65   class BOOST_COROSIO_DECL epoll_scheduler final : public reactor_scheduler
66   { 66   {
67   public: 67   public:
68   /** Construct the scheduler. 68   /** Construct the scheduler.
69   69  
70   Creates an epoll instance, eventfd for reactor interruption, 70   Creates an epoll instance, eventfd for reactor interruption,
71   and timerfd for kernel-managed timer expiry. 71   and timerfd for kernel-managed timer expiry.
72   72  
73   @param ctx Reference to the owning execution_context. 73   @param ctx Reference to the owning execution_context.
74   @param concurrency_hint Hint for expected thread count (unused). 74   @param concurrency_hint Hint for expected thread count (unused).
75   */ 75   */
76   epoll_scheduler(capy::execution_context& ctx, int concurrency_hint = -1); 76   epoll_scheduler(capy::execution_context& ctx, int concurrency_hint = -1);
77   77  
78   /// Destroy the scheduler. 78   /// Destroy the scheduler.
79   ~epoll_scheduler() override; 79   ~epoll_scheduler() override;
80   80  
81   epoll_scheduler(epoll_scheduler const&) = delete; 81   epoll_scheduler(epoll_scheduler const&) = delete;
82   epoll_scheduler& operator=(epoll_scheduler const&) = delete; 82   epoll_scheduler& operator=(epoll_scheduler const&) = delete;
83   83  
84   /// Shut down the scheduler, draining pending operations. 84   /// Shut down the scheduler, draining pending operations.
85   void shutdown() override; 85   void shutdown() override;
86   86  
87   /// Apply runtime configuration, resizing the event buffer. 87   /// Apply runtime configuration, resizing the event buffer.
88   void configure_reactor( 88   void configure_reactor(
89   unsigned max_events, 89   unsigned max_events,
90   unsigned budget_init, 90   unsigned budget_init,
91   unsigned budget_max, 91   unsigned budget_max,
92   unsigned unassisted) override; 92   unsigned unassisted) override;
93   93  
94   /** Return the epoll file descriptor. 94   /** Return the epoll file descriptor.
95   95  
96   Used by socket services to register file descriptors 96   Used by socket services to register file descriptors
97   for I/O event notification. 97   for I/O event notification.
98   98  
99   @return The epoll file descriptor. 99   @return The epoll file descriptor.
100   */ 100   */
101   int epoll_fd() const noexcept 101   int epoll_fd() const noexcept
102   { 102   {
103   return epoll_fd_; 103   return epoll_fd_;
104   } 104   }
105   105  
106   /** Register a descriptor for persistent monitoring. 106   /** Register a descriptor for persistent monitoring.
107   107  
108   The fd is registered once and stays registered until explicitly 108   The fd is registered once and stays registered until explicitly
109   deregistered. Events are dispatched via reactor_descriptor_state which 109   deregistered. Events are dispatched via reactor_descriptor_state which
110   tracks pending read/write/connect operations. 110   tracks pending read/write/connect operations.
111   111  
112   @param fd The file descriptor to register. 112   @param fd The file descriptor to register.
113   @param desc Pointer to descriptor data (stored in epoll_event.data.ptr). 113   @param desc Pointer to descriptor data (stored in epoll_event.data.ptr).
114   */ 114   */
115   void register_descriptor(int fd, reactor_descriptor_state* desc) const; 115   void register_descriptor(int fd, reactor_descriptor_state* desc) const;
116   116  
117   /** Deregister a persistently registered descriptor. 117   /** Deregister a persistently registered descriptor.
118   118  
119   @param fd The file descriptor to deregister. 119   @param fd The file descriptor to deregister.
120   */ 120   */
121   void deregister_descriptor(int fd) const; 121   void deregister_descriptor(int fd) const;
122   122  
123   private: 123   private:
124   void 124   void
125   run_task(lock_type& lock, context_type* ctx, 125   run_task(lock_type& lock, context_type* ctx,
126   long timeout_us) override; 126   long timeout_us) override;
127   void interrupt_reactor() const override; 127   void interrupt_reactor() const override;
128   void update_timerfd() const; 128   void update_timerfd() const;
129   129  
130   int epoll_fd_; 130   int epoll_fd_;
131   int event_fd_; 131   int event_fd_;
132   int timer_fd_; 132   int timer_fd_;
133   133  
134   // Edge-triggered eventfd state 134   // Edge-triggered eventfd state
135   mutable std::atomic<bool> eventfd_armed_{false}; 135   mutable std::atomic<bool> eventfd_armed_{false};
136   136  
137   // Set when the earliest timer changes; flushed before epoll_wait 137   // Set when the earliest timer changes; flushed before epoll_wait
138   mutable std::atomic<bool> timerfd_stale_{false}; 138   mutable std::atomic<bool> timerfd_stale_{false};
139   139  
140   // Event buffer sized from max_events_per_poll_ (set at construction, 140   // Event buffer sized from max_events_per_poll_ (set at construction,
141   // resized by configure_reactor via io_context_options). 141   // resized by configure_reactor via io_context_options).
142   std::vector<epoll_event> event_buffer_; 142   std::vector<epoll_event> event_buffer_;
143   }; 143   };
144   144  
HITCBC 145   366 inline epoll_scheduler::epoll_scheduler(capy::execution_context& ctx, int) 145   366 inline epoll_scheduler::epoll_scheduler(capy::execution_context& ctx, int)
HITCBC 146   366 : epoll_fd_(-1) 146   366 : epoll_fd_(-1)
HITCBC 147   366 , event_fd_(-1) 147   366 , event_fd_(-1)
HITCBC 148   366 , timer_fd_(-1) 148   366 , timer_fd_(-1)
HITCBC 149   732 , event_buffer_(max_events_per_poll_) 149   732 , event_buffer_(max_events_per_poll_)
150   { 150   {
HITCBC 151   366 epoll_fd_ = ::epoll_create1(EPOLL_CLOEXEC); 151   366 epoll_fd_ = ::epoll_create1(EPOLL_CLOEXEC);
HITCBC 152   366 if (epoll_fd_ < 0) 152   366 if (epoll_fd_ < 0)
MISUBC 153   ✗ detail::throw_system_error(make_err(errno), "epoll_create1"); 153   ✗ detail::throw_system_error(make_err(errno), "epoll_create1");
154   154  
HITCBC 155   366 event_fd_ = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); 155   366 event_fd_ = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
HITCBC 156   366 if (event_fd_ < 0) 156   366 if (event_fd_ < 0)
157   { 157   {
MISUBC 158   ✗ int errn = errno; 158   ✗ int errn = errno;
MISUBC 159   ✗ ::close(epoll_fd_); 159   ✗ ::close(epoll_fd_);
MISUBC 160   ✗ detail::throw_system_error(make_err(errn), "eventfd"); 160   ✗ detail::throw_system_error(make_err(errn), "eventfd");
161   } 161   }
162   162  
HITCBC 163   366 timer_fd_ = ::timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC); 163   366 timer_fd_ = ::timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
HITCBC 164   366 if (timer_fd_ < 0) 164   366 if (timer_fd_ < 0)
165   { 165   {
MISUBC 166   ✗ int errn = errno; 166   ✗ int errn = errno;
MISUBC 167   ✗ ::close(event_fd_); 167   ✗ ::close(event_fd_);
MISUBC 168   ✗ ::close(epoll_fd_); 168   ✗ ::close(epoll_fd_);
MISUBC 169   ✗ detail::throw_system_error(make_err(errn), "timerfd_create"); 169   ✗ detail::throw_system_error(make_err(errn), "timerfd_create");
170   } 170   }
171   171  
HITCBC 172   366 epoll_event ev{}; 172   366 epoll_event ev{};
HITCBC 173   366 ev.events = EPOLLIN | EPOLLET; 173   366 ev.events = EPOLLIN | EPOLLET;
HITCBC 174   366 ev.data.ptr = nullptr; 174   366 ev.data.ptr = nullptr;
HITCBC 175   366 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, event_fd_, &ev) < 0) 175   366 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, event_fd_, &ev) < 0)
176   { 176   {
MISUBC 177   ✗ int errn = errno; 177   ✗ int errn = errno;
MISUBC 178   ✗ ::close(timer_fd_); 178   ✗ ::close(timer_fd_);
MISUBC 179   ✗ ::close(event_fd_); 179   ✗ ::close(event_fd_);
MISUBC 180   ✗ ::close(epoll_fd_); 180   ✗ ::close(epoll_fd_);
MISUBC 181   ✗ detail::throw_system_error(make_err(errn), "epoll_ctl"); 181   ✗ detail::throw_system_error(make_err(errn), "epoll_ctl");
182   } 182   }
183   183  
HITCBC 184   366 epoll_event timer_ev{}; 184   366 epoll_event timer_ev{};
HITCBC 185   366 timer_ev.events = EPOLLIN | EPOLLERR; 185   366 timer_ev.events = EPOLLIN | EPOLLERR;
HITCBC 186   366 timer_ev.data.ptr = &timer_fd_; 186   366 timer_ev.data.ptr = &timer_fd_;
HITCBC 187   366 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &timer_ev) < 0) 187   366 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &timer_ev) < 0)
188   { 188   {
MISUBC 189   ✗ int errn = errno; 189   ✗ int errn = errno;
MISUBC 190   ✗ ::close(timer_fd_); 190   ✗ ::close(timer_fd_);
MISUBC 191   ✗ ::close(event_fd_); 191   ✗ ::close(event_fd_);
MISUBC 192   ✗ ::close(epoll_fd_); 192   ✗ ::close(epoll_fd_);
MISUBC 193   ✗ detail::throw_system_error(make_err(errn), "epoll_ctl (timerfd)"); 193   ✗ detail::throw_system_error(make_err(errn), "epoll_ctl (timerfd)");
194   } 194   }
195   195  
HITCBC 196   366 timer_svc_ = &get_timer_service(ctx, *this); 196   366 timer_svc_ = &get_timer_service(ctx, *this);
HITCBC 197   366 timer_svc_->set_on_earliest_changed( 197   366 timer_svc_->set_on_earliest_changed(
HITCBC 198   4693 timer_service::callback(this, [](void* p) { 198   3224 timer_service::callback(this, [](void* p) {
HITCBC 199   4327 auto* self = static_cast<epoll_scheduler*>(p); 199   2858 auto* self = static_cast<epoll_scheduler*>(p);
HITCBC 200   4327 self->timerfd_stale_.store(true, std::memory_order_release); 200   2858 self->timerfd_stale_.store(true, std::memory_order_release);
HITCBC 201   4327 self->interrupt_reactor(); 201   2858 self->interrupt_reactor();
HITCBC 202   4327 })); 202   2858 }));
203   203  
HITCBC 204   366 get_resolver_service(ctx, *this); 204   366 get_resolver_service(ctx, *this);
HITCBC 205   366 get_signal_service(ctx, *this); 205   366 get_signal_service(ctx, *this);
HITCBC 206   366 get_stream_file_service(ctx, *this); 206   366 get_stream_file_service(ctx, *this);
HITCBC 207   366 get_random_access_file_service(ctx, *this); 207   366 get_random_access_file_service(ctx, *this);
208   208  
HITCBC 209   366 completed_ops_.push(&task_op_); 209   366 completed_ops_.push(&task_op_);
HITCBC 210   366 } 210   366 }
211   211  
HITCBC 212   732 inline epoll_scheduler::~epoll_scheduler() 212   732 inline epoll_scheduler::~epoll_scheduler()
213   { 213   {
HITCBC 214   366 if (timer_fd_ >= 0) 214   366 if (timer_fd_ >= 0)
HITCBC 215   366 ::close(timer_fd_); 215   366 ::close(timer_fd_);
HITCBC 216   366 if (event_fd_ >= 0) 216   366 if (event_fd_ >= 0)
HITCBC 217   366 ::close(event_fd_); 217   366 ::close(event_fd_);
HITCBC 218   366 if (epoll_fd_ >= 0) 218   366 if (epoll_fd_ >= 0)
HITCBC 219   366 ::close(epoll_fd_); 219   366 ::close(epoll_fd_);
HITCBC 220   732 } 220   732 }
221   221  
222   inline void 222   inline void
HITCBC 223   366 epoll_scheduler::shutdown() 223   366 epoll_scheduler::shutdown()
224   { 224   {
HITCBC 225   366 shutdown_drain(); 225   366 shutdown_drain();
226   226  
HITCBC 227   366 if (event_fd_ >= 0) 227   366 if (event_fd_ >= 0)
HITCBC 228   366 interrupt_reactor(); 228   366 interrupt_reactor();
HITCBC 229   366 } 229   366 }
230   230  
231   inline void 231   inline void
MISUBC 232   ✗ epoll_scheduler::configure_reactor( 232   ✗ epoll_scheduler::configure_reactor(
233   unsigned max_events, 233   unsigned max_events,
234   unsigned budget_init, 234   unsigned budget_init,
235   unsigned budget_max, 235   unsigned budget_max,
236   unsigned unassisted) 236   unsigned unassisted)
237   { 237   {
MISUBC 238   ✗ reactor_scheduler::configure_reactor( 238   ✗ reactor_scheduler::configure_reactor(
239   max_events, budget_init, budget_max, unassisted); 239   max_events, budget_init, budget_max, unassisted);
MISUBC 240   ✗ event_buffer_.resize(max_events_per_poll_); 240   ✗ event_buffer_.resize(max_events_per_poll_);
MISUBC 241   ✗ } 241   ✗ }
242   242  
243   inline void 243   inline void
HITCBC 244   8376 epoll_scheduler::register_descriptor(int fd, reactor_descriptor_state* desc) const 244   5462 epoll_scheduler::register_descriptor(int fd, reactor_descriptor_state* desc) const
245   { 245   {
HITCBC 246   8376 epoll_event ev{}; 246   5462 epoll_event ev{};
HITCBC 247   8376 ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLERR | EPOLLHUP; 247   5462 ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLERR | EPOLLHUP;
HITCBC 248   8376 ev.data.ptr = desc; 248   5462 ev.data.ptr = desc;
249   249  
HITCBC 250   8376 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &ev) < 0) 250   5462 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &ev) < 0)
MISUBC 251   ✗ detail::throw_system_error(make_err(errno), "epoll_ctl (register)"); 251   ✗ detail::throw_system_error(make_err(errno), "epoll_ctl (register)");
252   252  
HITCBC 253   8376 desc->registered_events = ev.events; 253   5462 desc->registered_events = ev.events;
HITCBC 254   8376 desc->fd = fd; 254   5462 desc->fd = fd;
HITCBC 255   8376 desc->scheduler_ = this; 255   5462 desc->scheduler_ = this;
HITCBC 256   8376 desc->mutex.set_enabled(!single_threaded_); 256   5462 desc->mutex.set_enabled(!single_threaded_);
HITCBC 257   8376 desc->ready_events_.store(0, std::memory_order_relaxed); 257   5462 desc->ready_events_.store(0, std::memory_order_relaxed);
258   258  
HITCBC 259   8376 conditionally_enabled_mutex::scoped_lock lock(desc->mutex); 259   5462 conditionally_enabled_mutex::scoped_lock lock(desc->mutex);
HITCBC 260   8376 desc->impl_ref_.reset(); 260   5462 desc->impl_ref_.reset();
HITCBC 261   8376 desc->read_ready = false; 261   5462 desc->read_ready = false;
HITCBC 262   8376 desc->write_ready = false; 262   5462 desc->write_ready = false;
HITCBC 263   8376 } 263   5462 }
264   264  
265   inline void 265   inline void
HITCBC 266   8376 epoll_scheduler::deregister_descriptor(int fd) const 266   5462 epoll_scheduler::deregister_descriptor(int fd) const
267   { 267   {
HITCBC 268   8376 ::epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, nullptr); 268   5462 ::epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, nullptr);
HITCBC 269   8376 } 269   5462 }
270   270  
271   inline void 271   inline void
HITCBC 272   5005 epoll_scheduler::interrupt_reactor() const 272   3537 epoll_scheduler::interrupt_reactor() const
273   { 273   {
HITCBC 274   5005 bool expected = false; 274   3537 bool expected = false;
HITCBC 275   5005 if (eventfd_armed_.compare_exchange_strong( 275   3537 if (eventfd_armed_.compare_exchange_strong(
276   expected, true, std::memory_order_release, 276   expected, true, std::memory_order_release,
277   std::memory_order_relaxed)) 277   std::memory_order_relaxed))
278   { 278   {
HITCBC 279   4778 std::uint64_t val = 1; 279   3303 std::uint64_t val = 1;
HITCBC 280   4778 [[maybe_unused]] auto r = ::write(event_fd_, &val, sizeof(val)); 280   3303 [[maybe_unused]] auto r = ::write(event_fd_, &val, sizeof(val));
281   } 281   }
HITCBC 282   5005 } 282   3537 }
283   283  
284   inline void 284   inline void
HITCBC 285   8613 epoll_scheduler::update_timerfd() const 285   5673 epoll_scheduler::update_timerfd() const
286   { 286   {
HITCBC 287   8613 auto nearest = timer_svc_->nearest_expiry(); 287   5673 auto nearest = timer_svc_->nearest_expiry();
288   288  
HITCBC 289   8613 itimerspec ts{}; 289   5673 itimerspec ts{};
HITCBC 290   8613 int flags = 0; 290   5673 int flags = 0;
291   291  
HITCBC 292   8613 if (nearest == timer_service::time_point::max()) 292   5673 if (nearest == timer_service::time_point::max())
293   { 293   {
294   // No timers — disarm by setting to 0 (relative) 294   // No timers — disarm by setting to 0 (relative)
295   } 295   }
296   else 296   else
297   { 297   {
HITCBC 298   8557 auto now = std::chrono::steady_clock::now(); 298   5616 auto now = std::chrono::steady_clock::now();
HITCBC 299   8557 if (nearest <= now) 299   5616 if (nearest <= now)
300   { 300   {
301   // Use 1ns instead of 0 — zero disarms the timerfd 301   // Use 1ns instead of 0 — zero disarms the timerfd
HITCBC 302   352 ts.it_value.tv_nsec = 1; 302   439 ts.it_value.tv_nsec = 1;
303   } 303   }
304   else 304   else
305   { 305   {
HITCBC 306   8205 auto nsec = std::chrono::duration_cast<std::chrono::nanoseconds>( 306   5177 auto nsec = std::chrono::duration_cast<std::chrono::nanoseconds>(
HITCBC 307   8205 nearest - now) 307   5177 nearest - now)
HITCBC 308   8205 .count(); 308   5177 .count();
HITCBC 309   8205 ts.it_value.tv_sec = nsec / 1000000000; 309   5177 ts.it_value.tv_sec = nsec / 1000000000;
HITCBC 310   8205 ts.it_value.tv_nsec = nsec % 1000000000; 310   5177 ts.it_value.tv_nsec = nsec % 1000000000;
HITCBC 311   8205 if (ts.it_value.tv_sec == 0 && ts.it_value.tv_nsec == 0) 311   5177 if (ts.it_value.tv_sec == 0 && ts.it_value.tv_nsec == 0)
MISUBC 312   ✗ ts.it_value.tv_nsec = 1; 312   ✗ ts.it_value.tv_nsec = 1;
313   } 313   }
314   } 314   }
315   315  
HITCBC 316   8613 if (::timerfd_settime(timer_fd_, flags, &ts, nullptr) < 0) 316   5673 if (::timerfd_settime(timer_fd_, flags, &ts, nullptr) < 0)
MISUBC 317   ✗ detail::throw_system_error(make_err(errno), "timerfd_settime"); 317   ✗ detail::throw_system_error(make_err(errno), "timerfd_settime");
HITCBC 318   8613 } 318   5673 }
319   319  
320   inline void 320   inline void
HITCBC 321   50503 epoll_scheduler::run_task( 321   27699 epoll_scheduler::run_task(
322   lock_type& lock, context_type* ctx, long timeout_us) 322   lock_type& lock, context_type* ctx, long timeout_us)
323   { 323   {
324   int timeout_ms; 324   int timeout_ms;
HITCBC 325   50503 if (task_interrupted_) 325   27699 if (task_interrupted_)
HITCBC 326   38365 timeout_ms = 0; 326   20019 timeout_ms = 0;
HITCBC 327   12138 else if (timeout_us < 0) 327   7680 else if (timeout_us < 0)
HITCBC 328   12130 timeout_ms = -1; 328   7672 timeout_ms = -1;
329   else 329   else
HITCBC 330   8 timeout_ms = static_cast<int>((timeout_us + 999) / 1000); 330   8 timeout_ms = static_cast<int>((timeout_us + 999) / 1000);
331   331  
HITCBC 332   50503 if (lock.owns_lock()) 332   27699 if (lock.owns_lock())
HITCBC 333   12138 lock.unlock(); 333   7680 lock.unlock();
334   334  
HITCBC 335   50503 task_cleanup on_exit{this, &lock, ctx}; 335   27699 task_cleanup on_exit{this, &lock, ctx};
336   336  
337   // Flush deferred timerfd programming before blocking 337   // Flush deferred timerfd programming before blocking
HITCBC 338   50503 if (timerfd_stale_.exchange(false, std::memory_order_acquire)) 338   27699 if (timerfd_stale_.exchange(false, std::memory_order_acquire))
HITCBC 339   4305 update_timerfd(); 339   2836 update_timerfd();
340   340  
HITCBC 341   50503 int nfds = ::epoll_wait( 341   27699 int nfds = ::epoll_wait(
342   epoll_fd_, event_buffer_.data(), 342   epoll_fd_, event_buffer_.data(),
HITCBC 343   50503 static_cast<int>(event_buffer_.size()), timeout_ms); 343   27699 static_cast<int>(event_buffer_.size()), timeout_ms);
344   344  
HITCBC 345   50503 if (nfds < 0 && errno != EINTR) 345   27699 if (nfds < 0 && errno != EINTR)
MISUBC 346   ✗ detail::throw_system_error(make_err(errno), "epoll_wait"); 346   ✗ detail::throw_system_error(make_err(errno), "epoll_wait");
347   347  
HITCBC 348   50503 bool check_timers = false; 348   27699 bool check_timers = false;
HITCBC 349   50503 op_queue local_ops; 349   27699 op_queue local_ops;
350   350  
HITCBC 351   116766 for (int i = 0; i < nfds; ++i) 351   64827 for (int i = 0; i < nfds; ++i)
352   { 352   {
HITCBC 353   66263 if (event_buffer_[i].data.ptr == nullptr) 353   37128 if (event_buffer_[i].data.ptr == nullptr)
354   { 354   {
355   std::uint64_t val; 355   std::uint64_t val;
356   // NOLINTNEXTLINE(clang-analyzer-unix.BlockInCriticalSection) 356   // NOLINTNEXTLINE(clang-analyzer-unix.BlockInCriticalSection)
HITCBC 357   4412 [[maybe_unused]] auto r = ::read(event_fd_, &val, sizeof(val)); 357   2937 [[maybe_unused]] auto r = ::read(event_fd_, &val, sizeof(val));
HITCBC 358   4412 eventfd_armed_.store(false, std::memory_order_relaxed); 358   2937 eventfd_armed_.store(false, std::memory_order_relaxed);
HITCBC 359   4412 continue; 359   2937 continue;
HITCBC 360   4412 } 360   2937 }
361   361  
HITCBC 362   61851 if (event_buffer_[i].data.ptr == &timer_fd_) 362   34191 if (event_buffer_[i].data.ptr == &timer_fd_)
363   { 363   {
364   std::uint64_t expirations; 364   std::uint64_t expirations;
365   // NOLINTNEXTLINE(clang-analyzer-unix.BlockInCriticalSection) 365   // NOLINTNEXTLINE(clang-analyzer-unix.BlockInCriticalSection)
366   [[maybe_unused]] auto r = 366   [[maybe_unused]] auto r =
HITCBC 367   4308 ::read(timer_fd_, &expirations, sizeof(expirations)); 367   2837 ::read(timer_fd_, &expirations, sizeof(expirations));
HITCBC 368   4308 check_timers = true; 368   2837 check_timers = true;
HITCBC 369   4308 continue; 369   2837 continue;
HITCBC 370   4308 } 370   2837 }
371   371  
372   auto* desc = 372   auto* desc =
HITCBC 373   57543 static_cast<reactor_descriptor_state*>(event_buffer_[i].data.ptr); 373   31354 static_cast<reactor_descriptor_state*>(event_buffer_[i].data.ptr);
HITCBC 374   57543 desc->add_ready_events(event_buffer_[i].events); 374   31354 desc->add_ready_events(event_buffer_[i].events);
375   375  
HITCBC 376   57543 bool expected = false; 376   31354 bool expected = false;
HITCBC 377   57543 if (desc->is_enqueued_.compare_exchange_strong( 377   31354 if (desc->is_enqueued_.compare_exchange_strong(
378   expected, true, std::memory_order_release, 378   expected, true, std::memory_order_release,
379   std::memory_order_relaxed)) 379   std::memory_order_relaxed))
380   { 380   {
HITCBC 381   57543 local_ops.push(desc); 381   31354 local_ops.push(desc);
382   } 382   }
383   } 383   }
384   384  
HITCBC 385   50503 if (check_timers) 385   27699 if (check_timers)
386   { 386   {
HITCBC 387   4308 timer_svc_->process_expired(); 387   2837 timer_svc_->process_expired();
HITCBC 388   4308 update_timerfd(); 388   2837 update_timerfd();
389   } 389   }
390   390  
HITCBC 391   50503 lock.lock(); 391   27699 lock.lock();
392   392  
HITCBC 393   50503 if (!local_ops.empty()) 393   27699 if (!local_ops.empty())
HITCBC 394   37821 completed_ops_.splice(local_ops); 394   19491 completed_ops_.splice(local_ops);
HITCBC 395   50503 } 395   27699 }
396   396  
397   } // namespace boost::corosio::detail 397   } // namespace boost::corosio::detail
398   398  
399   #endif // BOOST_COROSIO_HAS_EPOLL 399   #endif // BOOST_COROSIO_HAS_EPOLL
400   400  
401   #endif // BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP 401   #endif // BOOST_COROSIO_NATIVE_DETAIL_EPOLL_EPOLL_SCHEDULER_HPP