. /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   373 inline epoll_scheduler::epoll_scheduler(capy::execution_context& ctx, int) 145   373 inline epoll_scheduler::epoll_scheduler(capy::execution_context& ctx, int)
HITCBC 146   373 : epoll_fd_(-1) 146   373 : epoll_fd_(-1)
HITCBC 147   373 , event_fd_(-1) 147   373 , event_fd_(-1)
HITCBC 148   373 , timer_fd_(-1) 148   373 , timer_fd_(-1)
HITCBC 149   746 , event_buffer_(max_events_per_poll_) 149   746 , event_buffer_(max_events_per_poll_)
150   { 150   {
HITCBC 151   373 epoll_fd_ = ::epoll_create1(EPOLL_CLOEXEC); 151   373 epoll_fd_ = ::epoll_create1(EPOLL_CLOEXEC);
HITCBC 152   373 if (epoll_fd_ < 0) 152   373 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   373 event_fd_ = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); 155   373 event_fd_ = ::eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
HITCBC 156   373 if (event_fd_ < 0) 156   373 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   373 timer_fd_ = ::timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC); 163   373 timer_fd_ = ::timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
HITCBC 164   373 if (timer_fd_ < 0) 164   373 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   373 epoll_event ev{}; 172   373 epoll_event ev{};
HITCBC 173   373 ev.events = EPOLLIN | EPOLLET; 173   373 ev.events = EPOLLIN | EPOLLET;
HITCBC 174   373 ev.data.ptr = nullptr; 174   373 ev.data.ptr = nullptr;
HITCBC 175   373 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, event_fd_, &ev) < 0) 175   373 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   373 epoll_event timer_ev{}; 184   373 epoll_event timer_ev{};
HITCBC 185   373 timer_ev.events = EPOLLIN | EPOLLERR; 185   373 timer_ev.events = EPOLLIN | EPOLLERR;
HITCBC 186   373 timer_ev.data.ptr = &timer_fd_; 186   373 timer_ev.data.ptr = &timer_fd_;
HITCBC 187   373 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &timer_ev) < 0) 187   373 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   373 timer_svc_ = &get_timer_service(ctx, *this); 196   373 timer_svc_ = &get_timer_service(ctx, *this);
HITCBC 197   373 timer_svc_->set_on_earliest_changed( 197   373 timer_svc_->set_on_earliest_changed(
HITCBC 198   5566 timer_service::callback(this, [](void* p) { 198   5383 timer_service::callback(this, [](void* p) {
HITCBC 199   5193 auto* self = static_cast<epoll_scheduler*>(p); 199   5010 auto* self = static_cast<epoll_scheduler*>(p);
HITCBC 200   5193 self->timerfd_stale_.store(true, std::memory_order_release); 200   5010 self->timerfd_stale_.store(true, std::memory_order_release);
HITCBC 201   5193 self->interrupt_reactor(); 201   5010 self->interrupt_reactor();
HITCBC 202   5193 })); 202   5010 }));
203   203  
HITCBC 204   373 get_resolver_service(ctx, *this); 204   373 get_resolver_service(ctx, *this);
HITCBC 205   373 get_signal_service(ctx, *this); 205   373 get_signal_service(ctx, *this);
HITCBC 206   373 get_stream_file_service(ctx, *this); 206   373 get_stream_file_service(ctx, *this);
HITCBC 207   373 get_random_access_file_service(ctx, *this); 207   373 get_random_access_file_service(ctx, *this);
208   208  
HITCBC 209   373 completed_ops_.push(&task_op_); 209   373 completed_ops_.push(&task_op_);
HITCBC 210   373 } 210   373 }
211   211  
HITCBC 212   746 inline epoll_scheduler::~epoll_scheduler() 212   746 inline epoll_scheduler::~epoll_scheduler()
213   { 213   {
HITCBC 214   373 if (timer_fd_ >= 0) 214   373 if (timer_fd_ >= 0)
HITCBC 215   373 ::close(timer_fd_); 215   373 ::close(timer_fd_);
HITCBC 216   373 if (event_fd_ >= 0) 216   373 if (event_fd_ >= 0)
HITCBC 217   373 ::close(event_fd_); 217   373 ::close(event_fd_);
HITCBC 218   373 if (epoll_fd_ >= 0) 218   373 if (epoll_fd_ >= 0)
HITCBC 219   373 ::close(epoll_fd_); 219   373 ::close(epoll_fd_);
HITCBC 220   746 } 220   746 }
221   221  
222   inline void 222   inline void
HITCBC 223   373 epoll_scheduler::shutdown() 223   373 epoll_scheduler::shutdown()
224   { 224   {
HITCBC 225   373 shutdown_drain(); 225   373 shutdown_drain();
226   226  
HITCBC 227   373 if (event_fd_ >= 0) 227   373 if (event_fd_ >= 0)
HITCBC 228   373 interrupt_reactor(); 228   373 interrupt_reactor();
HITCBC 229   373 } 229   373 }
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   10122 epoll_scheduler::register_descriptor(int fd, reactor_descriptor_state* desc) const 244   9761 epoll_scheduler::register_descriptor(int fd, reactor_descriptor_state* desc) const
245   { 245   {
HITCBC 246   10122 epoll_event ev{}; 246   9761 epoll_event ev{};
HITCBC 247   10122 ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLERR | EPOLLHUP; 247   9761 ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLERR | EPOLLHUP;
HITCBC 248   10122 ev.data.ptr = desc; 248   9761 ev.data.ptr = desc;
249   249  
HITCBC 250   10122 if (::epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &ev) < 0) 250   9761 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   10122 desc->registered_events = ev.events; 253   9761 desc->registered_events = ev.events;
HITCBC 254   10122 desc->fd = fd; 254   9761 desc->fd = fd;
HITCBC 255   10122 desc->scheduler_ = this; 255   9761 desc->scheduler_ = this;
HITCBC 256   10122 desc->mutex.set_enabled(!single_threaded_); 256   9761 desc->mutex.set_enabled(!single_threaded_);
HITCBC 257   10122 desc->ready_events_.store(0, std::memory_order_relaxed); 257   9761 desc->ready_events_.store(0, std::memory_order_relaxed);
258   258  
HITCBC 259   10122 conditionally_enabled_mutex::scoped_lock lock(desc->mutex); 259   9761 conditionally_enabled_mutex::scoped_lock lock(desc->mutex);
HITCBC 260   10122 desc->impl_ref_.reset(); 260   9761 desc->impl_ref_.reset();
HITCBC 261   10122 desc->read_ready = false; 261   9761 desc->read_ready = false;
HITCBC 262   10122 desc->write_ready = false; 262   9761 desc->write_ready = false;
HITCBC 263   10122 } 263   9761 }
264   264  
265   inline void 265   inline void
HITCBC 266   10122 epoll_scheduler::deregister_descriptor(int fd) const 266   9761 epoll_scheduler::deregister_descriptor(int fd) const
267   { 267   {
HITCBC 268   10122 ::epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, nullptr); 268   9761 ::epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, nullptr);
HITCBC 269   10122 } 269   9761 }
270   270  
271   inline void 271   inline void
HITCBC 272   5889 epoll_scheduler::interrupt_reactor() const 272   5706 epoll_scheduler::interrupt_reactor() const
273   { 273   {
HITCBC 274   5889 bool expected = false; 274   5706 bool expected = false;
HITCBC 275   5889 if (eventfd_armed_.compare_exchange_strong( 275   5706 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   5652 std::uint64_t val = 1; 279   5469 std::uint64_t val = 1;
HITCBC 280   5652 [[maybe_unused]] auto r = ::write(event_fd_, &val, sizeof(val)); 280   5469 [[maybe_unused]] auto r = ::write(event_fd_, &val, sizeof(val));
281   } 281   }
HITCBC 282   5889 } 282   5706 }
283   283  
284   inline void 284   inline void
HITCBC 285   10346 epoll_scheduler::update_timerfd() const 285   9979 epoll_scheduler::update_timerfd() const
286   { 286   {
HITCBC 287   10346 auto nearest = timer_svc_->nearest_expiry(); 287   9979 auto nearest = timer_svc_->nearest_expiry();
288   288  
HITCBC 289   10346 itimerspec ts{}; 289   9979 itimerspec ts{};
HITCBC 290   10346 int flags = 0; 290   9979 int flags = 0;
291   291  
HITCBC 292   10346 if (nearest == timer_service::time_point::max()) 292   9979 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   10289 auto now = std::chrono::steady_clock::now(); 298   9921 auto now = std::chrono::steady_clock::now();
HITCBC 299   10289 if (nearest <= now) 299   9921 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   303 ts.it_value.tv_nsec = 1; 302   388 ts.it_value.tv_nsec = 1;
303   } 303   }
304   else 304   else
305   { 305   {
HITCBC 306   9986 auto nsec = std::chrono::duration_cast<std::chrono::nanoseconds>( 306   9533 auto nsec = std::chrono::duration_cast<std::chrono::nanoseconds>(
HITCBC 307   9986 nearest - now) 307   9533 nearest - now)
HITCBC 308   9986 .count(); 308   9533 .count();
HITCBC 309   9986 ts.it_value.tv_sec = nsec / 1000000000; 309   9533 ts.it_value.tv_sec = nsec / 1000000000;
HITCBC 310   9986 ts.it_value.tv_nsec = nsec % 1000000000; 310   9533 ts.it_value.tv_nsec = nsec % 1000000000;
HITCBC 311   9986 if (ts.it_value.tv_sec == 0 && ts.it_value.tv_nsec == 0) 311   9533 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   10346 if (::timerfd_settime(timer_fd_, flags, &ts, nullptr) < 0) 316   9979 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   10346 } 318   9979 }
319   319  
320   inline void 320   inline void
HITCBC 321   57850 epoll_scheduler::run_task( 321   57009 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   57850 if (task_interrupted_) 325   57009 if (task_interrupted_)
HITCBC 326   43255 timeout_ms = 0; 326   43249 timeout_ms = 0;
HITCBC 327   14595 else if (timeout_us < 0) 327   13760 else if (timeout_us < 0)
HITCBC 328   14587 timeout_ms = -1; 328   13756 timeout_ms = -1;
329   else 329   else
HITCBC 330   8 timeout_ms = static_cast<int>((timeout_us + 999) / 1000); 330   4 timeout_ms = static_cast<int>((timeout_us + 999) / 1000);
331   331  
HITCBC 332   57850 if (lock.owns_lock()) 332   57009 if (lock.owns_lock())
HITCBC 333   14595 lock.unlock(); 333   13760 lock.unlock();
334   334  
HITCBC 335   57850 task_cleanup on_exit{this, &lock, ctx}; 335   57009 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   57850 if (timerfd_stale_.exchange(false, std::memory_order_acquire)) 338   57009 if (timerfd_stale_.exchange(false, std::memory_order_acquire))
HITCBC 339   5171 update_timerfd(); 339   4988 update_timerfd();
340   340  
HITCBC 341   57850 int nfds = ::epoll_wait( 341   57009 int nfds = ::epoll_wait(
342   epoll_fd_, event_buffer_.data(), 342   epoll_fd_, event_buffer_.data(),
HITCBC 343   57850 static_cast<int>(event_buffer_.size()), timeout_ms); 343   57009 static_cast<int>(event_buffer_.size()), timeout_ms);
344   344  
HITCBC 345   57850 if (nfds < 0 && errno != EINTR) 345   57009 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   57850 bool check_timers = false; 348   57009 bool check_timers = false;
HITCBC 349   57850 op_queue local_ops; 349   57009 op_queue local_ops;
350   350  
HITCBC 351   133056 for (int i = 0; i < nfds; ++i) 351   131385 for (int i = 0; i < nfds; ++i)
352   { 352   {
HITCBC 353   75206 if (event_buffer_[i].data.ptr == nullptr) 353   74376 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   5279 [[maybe_unused]] auto r = ::read(event_fd_, &val, sizeof(val)); 357   5096 [[maybe_unused]] auto r = ::read(event_fd_, &val, sizeof(val));
HITCBC 358   5279 eventfd_armed_.store(false, std::memory_order_relaxed); 358   5096 eventfd_armed_.store(false, std::memory_order_relaxed);
HITCBC 359   5279 continue; 359   5096 continue;
HITCBC 360   5279 } 360   5096 }
361   361  
HITCBC 362   69927 if (event_buffer_[i].data.ptr == &timer_fd_) 362   69280 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   5175 ::read(timer_fd_, &expirations, sizeof(expirations)); 367   4991 ::read(timer_fd_, &expirations, sizeof(expirations));
HITCBC 368   5175 check_timers = true; 368   4991 check_timers = true;
HITCBC 369   5175 continue; 369   4991 continue;
HITCBC 370   5175 } 370   4991 }
371   371  
372   auto* desc = 372   auto* desc =
HITCBC 373   64752 static_cast<reactor_descriptor_state*>(event_buffer_[i].data.ptr); 373   64289 static_cast<reactor_descriptor_state*>(event_buffer_[i].data.ptr);
HITCBC 374   64752 desc->add_ready_events(event_buffer_[i].events); 374   64289 desc->add_ready_events(event_buffer_[i].events);
375   375  
HITCBC 376   64752 bool expected = false; 376   64289 bool expected = false;
HITCBC 377   64752 if (desc->is_enqueued_.compare_exchange_strong( 377   64289 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   64752 local_ops.push(desc); 381   64289 local_ops.push(desc);
382   } 382   }
383   } 383   }
384   384  
HITCBC 385   57850 if (check_timers) 385   57009 if (check_timers)
386   { 386   {
HITCBC 387   5175 timer_svc_->process_expired(); 387   4991 timer_svc_->process_expired();
HITCBC 388   5175 update_timerfd(); 388   4991 update_timerfd();
389   } 389   }
390   390  
HITCBC 391   57850 lock.lock(); 391   57009 lock.lock();
392   392  
HITCBC 393   57850 if (!local_ops.empty()) 393   57009 if (!local_ops.empty())
HITCBC 394   42708 completed_ops_.splice(local_ops); 394   42707 completed_ops_.splice(local_ops);
HITCBC 395   57850 } 395   57009 }
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