runtime/bin/eventhandler_linux.cc - sdk.git - Git at Google

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)

 #include "bin/eventhandler.h"

 #include <errno.h>  // NOLINT
 #include <pthread.h>  // NOLINT
 #include <stdio.h>  // NOLINT
 #include <string.h>  // NOLINT
 #include <sys/epoll.h>  // NOLINT
 #include <sys/stat.h>  // NOLINT
 #include <sys/timerfd.h>  // NOLINT
 #include <unistd.h>  // NOLINT
 #include <fcntl.h>  // NOLINT

 #include "bin/dartutils.h"
 #include "bin/fdutils.h"
 #include "bin/log.h"
 #include "bin/socket.h"
 #include "platform/hashmap.h"
 #include "platform/thread.h"
 #include "platform/utils.h"


 namespace dart {
 namespace bin {

 static const int kTimerId = -1;


 static void AddToEpollInstance(intptr_t epoll_fd_,
                                int fd, Dart_Port port,
                                int mask) {
   struct epoll_event event;
   event.events = EPOLLET | EPOLLRDHUP;
   if ((mask & (1 << kInEvent)) != 0) event.events |= EPOLLIN;
   if ((mask & (1 << kOutEvent)) != 0) event.events |= EPOLLOUT;
   // Be sure we don't collide with the TIMER_BIT.
   if (port == ILLEGAL_PORT) {
     FATAL("Illigal port sent to event handler");
   }
   event.data.u64 = port;
   int status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
                                             EPOLL_CTL_ADD,
                                             fd,
                                             &event));
   if (status == -1) {
     // Epoll does not accept the file descriptor. It could be due to
     // already closed file descriptor, or unuspported devices, such
     // as /dev/null. In such case, mark the file descriptor as closed,
     // so dart will handle it accordingly.
     DartUtils::PostInt32(port, 1 << kCloseEvent);
   }
 }


 EventHandlerImplementation::EventHandlerImplementation() : shutdown_(false) {
   // The initial size passed to epoll_create is ignore on newer (>=
   // 2.6.8) Linux versions
   static const int kEpollInitialSize = 64;
   epoll_fd_ = TEMP_FAILURE_RETRY(epoll_create(kEpollInitialSize));
   if (epoll_fd_ == -1) {
     FATAL1("Failed creating epoll file descriptor: %i", errno);
   }
   FDUtils::SetCloseOnExec(epoll_fd_);
   timer_fd_ = TEMP_FAILURE_RETRY(timerfd_create(CLOCK_REALTIME, TFD_CLOEXEC));
   if (timer_fd_ == -1) {
     FATAL1("Failed creating timerfd file descriptor: %i", errno);
   }
   // Register the timer_fd_ with the epoll instance.
   struct epoll_event event;
   event.events = EPOLLIN;
   event.data.u64 = ILLEGAL_PORT;  // Use ILLEGAL_PORT to identify timer-fd.
   int status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
                                             EPOLL_CTL_ADD,
                                             timer_fd_,
                                             &event));
   if (status == -1) {
     FATAL2(
         "Failed adding timerfd fd(%i) to epoll instance: %i", timer_fd_, errno);
   }
 }


 EventHandlerImplementation::~EventHandlerImplementation() {
   TEMP_FAILURE_RETRY(close(epoll_fd_));
   TEMP_FAILURE_RETRY(close(timer_fd_));
 }

 #ifdef DEBUG_POLL
 static void PrintEventMask(intptr_t events) {
   // TODO(ajohnsen): When DEBUG_POLL is enabled, we could add the fd to the
   // epoll-data as well.
   if ((events & EPOLLIN) != 0) Log::Print("EPOLLIN ");
   if ((events & EPOLLPRI) != 0) Log::Print("EPOLLPRI ");
   if ((events & EPOLLOUT) != 0) Log::Print("EPOLLOUT ");
   if ((events & EPOLLERR) != 0) Log::Print("EPOLLERR ");
   if ((events & EPOLLHUP) != 0) Log::Print("EPOLLHUP ");
   if ((events & EPOLLRDHUP) != 0) Log::Print("EPOLLRDHUP ");
   int all_events = EPOLLIN | EPOLLPRI | EPOLLOUT |
       EPOLLERR | EPOLLHUP | EPOLLRDHUP;
   if ((events & ~all_events) != 0) {
     Log::Print("(and %08x) ", events & ~all_events);
   }

   Log::Print("\n");
 }
 #endif

 intptr_t EventHandlerImplementation::GetPollEvents(intptr_t events) {
 #ifdef DEBUG_POLL
   PrintEventMask(events);
 #endif
   if (events & EPOLLERR) {
     // Return only error if EPOLLIN is present.
     return (events & EPOLLIN) ? (1 << kErrorEvent) : 0;
   }
   intptr_t event_mask = 0;
   if (events & EPOLLIN) event_mask |= (1 << kInEvent);
   if (events & EPOLLOUT) event_mask |= (1 << kOutEvent);
   if (events & (EPOLLHUP | EPOLLRDHUP)) event_mask |= (1 << kCloseEvent);
   return event_mask;
 }


 void EventHandlerImplementation::HandleEvents(struct epoll_event* events,
                                               int size) {
   for (int i = 0; i < size; i++) {
     uint64_t data = events[i].data.u64;
     // ILLEGAL_PORT is used to identify timer-fd.
     if (data == ILLEGAL_PORT) {
       int64_t val;
       VOID_TEMP_FAILURE_RETRY(read(timer_fd_, &val, sizeof(val)));
       timer_mutex_.Lock();
       if (timeout_queue_.HasTimeout()) {
         DartUtils::PostNull(timeout_queue_.CurrentPort());
         timeout_queue_.RemoveCurrent();
       }
       timer_mutex_.Unlock();
     } else {
       int32_t event_mask = GetPollEvents(events[i].events);
       if (event_mask != 0) {
         Dart_Port port = data;
         ASSERT(port != 0);
         DartUtils::PostInt32(port, event_mask);
       }
     }
   }
 }


 void EventHandlerImplementation::Poll(uword args) {
   // Main event-handler thread loop.
   static const intptr_t kMaxEvents = 16;
   struct epoll_event events[kMaxEvents];
   EventHandler* handler = reinterpret_cast<EventHandler*>(args);
   EventHandlerImplementation* handler_impl = &handler->delegate_;
   ASSERT(handler_impl != NULL);
   while (!handler_impl->shutdown_) {
     intptr_t result = TEMP_FAILURE_RETRY(epoll_wait(handler_impl->epoll_fd_,
                                                     events,
                                                     kMaxEvents,
                                                     -1));
     ASSERT(EAGAIN == EWOULDBLOCK);
     if (result <= 0) {
       if (errno != EWOULDBLOCK) {
         perror("Poll failed");
       }
     } else {
       handler_impl->HandleEvents(events, result);
     }
   }
   delete handler;
 }


 void EventHandlerImplementation::Start(EventHandler* handler) {
   int result = dart::Thread::Start(&EventHandlerImplementation::Poll,
                                    reinterpret_cast<uword>(handler));
   if (result != 0) {
     FATAL1("Failed to start event handler thread %d", result);
   }
 }


 void EventHandlerImplementation::Shutdown() {
   shutdown_ = true;
 }


 void EventHandlerImplementation::Notify(intptr_t id,
                                         Dart_Port dart_port,
                                         int64_t data) {
   // This method is called by isolates, that is, not in the event-handler
   // thread.
   if (id == kTimerId) {
     // Lock this region, as multiple isolates may attempt to update
     // timeout_queue_.
     // TODO(ajohnsen): Consider using a timer-fd per isolate to avoid the lock.
     timer_mutex_.Lock();
     timeout_queue_.UpdateTimeout(dart_port, data);
     struct itimerspec it;
     memset(&it, 0, sizeof(it));
     if (timeout_queue_.HasTimeout()) {
       int64_t millis = timeout_queue_.CurrentTimeout();
       it.it_value.tv_sec = millis / 1000;
       it.it_value.tv_nsec = (millis % 1000) * 1000000;
     }
     timerfd_settime(timer_fd_, TFD_TIMER_ABSTIME, &it, NULL);
     timer_mutex_.Unlock();
   } else {
     if ((data & (1 << kShutdownReadCommand)) != 0) {
       ASSERT(data == (1 << kShutdownReadCommand));
       // Close the socket for reading.
       shutdown(id, SHUT_RD);
     } else if ((data & (1 << kShutdownWriteCommand)) != 0) {
       ASSERT(data == (1 << kShutdownWriteCommand));
       // Close the socket for writing.
       shutdown(id, SHUT_WR);
     } else if ((data & (1 << kCloseCommand)) != 0) {
       ASSERT(data == (1 << kCloseCommand));
       // Close the socket and free system resources and move on to
       // next message.
       // This will also remove the file descriptor from epoll.
       Socket::Close(id);
       DartUtils::PostInt32(dart_port, 1 << kDestroyedEvent);
     } else {
       // Add to epoll - this is the first time we see it.
       AddToEpollInstance(epoll_fd_, id, dart_port, data);
     }
   }
 }

 }  // namespace bin
 }  // namespace dart

 #endif  // defined(TARGET_OS_LINUX)
	// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	#include "platform/globals.h"
	#if defined(TARGET_OS_LINUX)

	#include "bin/eventhandler.h"

	#include <errno.h> // NOLINT
	#include <pthread.h> // NOLINT
	#include <stdio.h> // NOLINT
	#include <string.h> // NOLINT
	#include <sys/epoll.h> // NOLINT
	#include <sys/stat.h> // NOLINT
	#include <sys/timerfd.h> // NOLINT
	#include <unistd.h> // NOLINT
	#include <fcntl.h> // NOLINT

	#include "bin/dartutils.h"
	#include "bin/fdutils.h"
	#include "bin/log.h"
	#include "bin/socket.h"
	#include "platform/hashmap.h"
	#include "platform/thread.h"
	#include "platform/utils.h"


	namespace dart {
	namespace bin {

	static const int kTimerId = -1;


	static void AddToEpollInstance(intptr_t epoll_fd_,
	int fd, Dart_Port port,
	int mask) {
	struct epoll_event event;
	event.events = EPOLLET \| EPOLLRDHUP;
	if ((mask & (1 << kInEvent)) != 0) event.events \|= EPOLLIN;
	if ((mask & (1 << kOutEvent)) != 0) event.events \|= EPOLLOUT;
	// Be sure we don't collide with the TIMER_BIT.
	if (port == ILLEGAL_PORT) {
	FATAL("Illigal port sent to event handler");
	}
	event.data.u64 = port;
	int status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
	EPOLL_CTL_ADD,
	fd,
	&event));
	if (status == -1) {
	// Epoll does not accept the file descriptor. It could be due to
	// already closed file descriptor, or unuspported devices, such
	// as /dev/null. In such case, mark the file descriptor as closed,
	// so dart will handle it accordingly.
	DartUtils::PostInt32(port, 1 << kCloseEvent);
	}
	}


	EventHandlerImplementation::EventHandlerImplementation() : shutdown_(false) {
	// The initial size passed to epoll_create is ignore on newer (>=
	// 2.6.8) Linux versions
	static const int kEpollInitialSize = 64;
	epoll_fd_ = TEMP_FAILURE_RETRY(epoll_create(kEpollInitialSize));
	if (epoll_fd_ == -1) {
	FATAL1("Failed creating epoll file descriptor: %i", errno);
	}
	FDUtils::SetCloseOnExec(epoll_fd_);
	timer_fd_ = TEMP_FAILURE_RETRY(timerfd_create(CLOCK_REALTIME, TFD_CLOEXEC));
	if (timer_fd_ == -1) {
	FATAL1("Failed creating timerfd file descriptor: %i", errno);
	}
	// Register the timer_fd_ with the epoll instance.
	struct epoll_event event;
	event.events = EPOLLIN;
	event.data.u64 = ILLEGAL_PORT; // Use ILLEGAL_PORT to identify timer-fd.
	int status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
	EPOLL_CTL_ADD,
	timer_fd_,
	&event));
	if (status == -1) {
	FATAL2(
	"Failed adding timerfd fd(%i) to epoll instance: %i", timer_fd_, errno);
	}
	}


	EventHandlerImplementation::~EventHandlerImplementation() {
	TEMP_FAILURE_RETRY(close(epoll_fd_));
	TEMP_FAILURE_RETRY(close(timer_fd_));
	}

	#ifdef DEBUG_POLL
	static void PrintEventMask(intptr_t events) {
	// TODO(ajohnsen): When DEBUG_POLL is enabled, we could add the fd to the
	// epoll-data as well.
	if ((events & EPOLLIN) != 0) Log::Print("EPOLLIN ");
	if ((events & EPOLLPRI) != 0) Log::Print("EPOLLPRI ");
	if ((events & EPOLLOUT) != 0) Log::Print("EPOLLOUT ");
	if ((events & EPOLLERR) != 0) Log::Print("EPOLLERR ");
	if ((events & EPOLLHUP) != 0) Log::Print("EPOLLHUP ");
	if ((events & EPOLLRDHUP) != 0) Log::Print("EPOLLRDHUP ");
	int all_events = EPOLLIN \| EPOLLPRI \| EPOLLOUT \|
	EPOLLERR \| EPOLLHUP \| EPOLLRDHUP;
	if ((events & ~all_events) != 0) {
	Log::Print("(and %08x) ", events & ~all_events);
	}

	Log::Print("\n");
	}
	#endif

	intptr_t EventHandlerImplementation::GetPollEvents(intptr_t events) {
	#ifdef DEBUG_POLL
	PrintEventMask(events);
	#endif
	if (events & EPOLLERR) {
	// Return only error if EPOLLIN is present.
	return (events & EPOLLIN) ? (1 << kErrorEvent) : 0;
	}
	intptr_t event_mask = 0;
	if (events & EPOLLIN) event_mask \|= (1 << kInEvent);
	if (events & EPOLLOUT) event_mask \|= (1 << kOutEvent);
	if (events & (EPOLLHUP \| EPOLLRDHUP)) event_mask \|= (1 << kCloseEvent);
	return event_mask;
	}


	void EventHandlerImplementation::HandleEvents(struct epoll_event* events,
	int size) {
	for (int i = 0; i < size; i++) {
	uint64_t data = events[i].data.u64;
	// ILLEGAL_PORT is used to identify timer-fd.
	if (data == ILLEGAL_PORT) {
	int64_t val;
	VOID_TEMP_FAILURE_RETRY(read(timer_fd_, &val, sizeof(val)));
	timer_mutex_.Lock();
	if (timeout_queue_.HasTimeout()) {
	DartUtils::PostNull(timeout_queue_.CurrentPort());
	timeout_queue_.RemoveCurrent();
	}
	timer_mutex_.Unlock();
	} else {
	int32_t event_mask = GetPollEvents(events[i].events);
	if (event_mask != 0) {
	Dart_Port port = data;
	ASSERT(port != 0);
	DartUtils::PostInt32(port, event_mask);
	}
	}
	}
	}


	void EventHandlerImplementation::Poll(uword args) {
	// Main event-handler thread loop.
	static const intptr_t kMaxEvents = 16;
	struct epoll_event events[kMaxEvents];
	EventHandler* handler = reinterpret_cast<EventHandler*>(args);
	EventHandlerImplementation* handler_impl = &handler->delegate_;
	ASSERT(handler_impl != NULL);
	while (!handler_impl->shutdown_) {
	intptr_t result = TEMP_FAILURE_RETRY(epoll_wait(handler_impl->epoll_fd_,
	events,
	kMaxEvents,
	-1));
	ASSERT(EAGAIN == EWOULDBLOCK);
	if (result <= 0) {
	if (errno != EWOULDBLOCK) {
	perror("Poll failed");
	}
	} else {
	handler_impl->HandleEvents(events, result);
	}
	}
	delete handler;
	}


	void EventHandlerImplementation::Start(EventHandler* handler) {
	int result = dart::Thread::Start(&EventHandlerImplementation::Poll,
	reinterpret_cast<uword>(handler));
	if (result != 0) {
	FATAL1("Failed to start event handler thread %d", result);
	}
	}


	void EventHandlerImplementation::Shutdown() {
	shutdown_ = true;
	}


	void EventHandlerImplementation::Notify(intptr_t id,
	Dart_Port dart_port,
	int64_t data) {
	// This method is called by isolates, that is, not in the event-handler
	// thread.
	if (id == kTimerId) {
	// Lock this region, as multiple isolates may attempt to update
	// timeout_queue_.
	// TODO(ajohnsen): Consider using a timer-fd per isolate to avoid the lock.
	timer_mutex_.Lock();
	timeout_queue_.UpdateTimeout(dart_port, data);
	struct itimerspec it;
	memset(&it, 0, sizeof(it));
	if (timeout_queue_.HasTimeout()) {
	int64_t millis = timeout_queue_.CurrentTimeout();
	it.it_value.tv_sec = millis / 1000;
	it.it_value.tv_nsec = (millis % 1000) * 1000000;
	}
	timerfd_settime(timer_fd_, TFD_TIMER_ABSTIME, &it, NULL);
	timer_mutex_.Unlock();
	} else {
	if ((data & (1 << kShutdownReadCommand)) != 0) {
	ASSERT(data == (1 << kShutdownReadCommand));
	// Close the socket for reading.
	shutdown(id, SHUT_RD);
	} else if ((data & (1 << kShutdownWriteCommand)) != 0) {
	ASSERT(data == (1 << kShutdownWriteCommand));
	// Close the socket for writing.
	shutdown(id, SHUT_WR);
	} else if ((data & (1 << kCloseCommand)) != 0) {
	ASSERT(data == (1 << kCloseCommand));
	// Close the socket and free system resources and move on to
	// next message.
	// This will also remove the file descriptor from epoll.
	Socket::Close(id);
	DartUtils::PostInt32(dart_port, 1 << kDestroyedEvent);
	} else {
	// Add to epoll - this is the first time we see it.
	AddToEpollInstance(epoll_fd_, id, dart_port, data);
	}
	}
	}

	} // namespace bin
	} // namespace dart

	#endif // defined(TARGET_OS_LINUX)