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// 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(DART_HOST_OS_LINUX) || defined(DART_HOST_OS_ANDROID)
#include "bin/eventhandler.h"
#include "bin/eventhandler_linux.h"
#include <errno.h> // NOLINT
#include <fcntl.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 "bin/dartutils.h"
#include "bin/fdutils.h"
#include "bin/lockers.h"
#include "bin/process.h"
#include "bin/socket.h"
#include "bin/thread.h"
#include "platform/syslog.h"
#include "platform/utils.h"
namespace dart {
namespace bin {
intptr_t DescriptorInfo::GetPollEvents() {
// Do not ask for EPOLLERR and EPOLLHUP explicitly as they are
// triggered anyway.
intptr_t events = 0;
if ((Mask() & (1 << kInEvent)) != 0) {
events |= EPOLLIN;
}
if ((Mask() & (1 << kOutEvent)) != 0) {
events |= EPOLLOUT;
}
return events;
}
// Unregister the file descriptor for a DescriptorInfo structure with
// epoll.
static void RemoveFromEpollInstance(intptr_t epoll_fd_, DescriptorInfo* di) {
VOID_NO_RETRY_EXPECTED(
epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, di->fd(), nullptr));
}
static void AddToEpollInstance(intptr_t epoll_fd_, DescriptorInfo* di) {
struct epoll_event event;
event.events = EPOLLRDHUP | di->GetPollEvents();
if (!di->IsListeningSocket()) {
event.events |= EPOLLET;
}
event.data.ptr = di;
int status =
NO_RETRY_EXPECTED(epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, di->fd(), &event));
if (status == -1) {
// TODO(dart:io): Verify that the dart end is handling this correctly.
// Epoll does not accept the file descriptor. It could be due to
// already closed file descriptor, or unsupported devices, such
// as /dev/null. In such case, mark the file descriptor as closed,
// so dart will handle it accordingly.
di->NotifyAllDartPorts(1 << kCloseEvent);
}
}
EventHandlerImplementation::EventHandlerImplementation()
: socket_map_(&SimpleHashMap::SamePointerValue, 16) {
intptr_t result;
result = NO_RETRY_EXPECTED(pipe(interrupt_fds_));
if (result != 0) {
FATAL("Pipe creation failed");
}
if (!FDUtils::SetNonBlocking(interrupt_fds_[0])) {
FATAL("Failed to set pipe fd non blocking\n");
}
if (!FDUtils::SetCloseOnExec(interrupt_fds_[0])) {
FATAL("Failed to set pipe fd close on exec\n");
}
if (!FDUtils::SetCloseOnExec(interrupt_fds_[1])) {
FATAL("Failed to set pipe fd close on exec\n");
}
shutdown_ = false;
// The initial size passed to epoll_create is ignore on newer (>=
// 2.6.8) Linux versions
const int kEpollInitialSize = 64;
epoll_fd_ = NO_RETRY_EXPECTED(epoll_create(kEpollInitialSize));
if (epoll_fd_ == -1) {
FATAL("Failed creating epoll file descriptor: %i", errno);
}
if (!FDUtils::SetCloseOnExec(epoll_fd_)) {
FATAL("Failed to set epoll fd close on exec\n");
}
// Register the interrupt_fd with the epoll instance.
struct epoll_event event;
event.events = EPOLLIN;
event.data.ptr = nullptr;
int status = NO_RETRY_EXPECTED(
epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, interrupt_fds_[0], &event));
if (status == -1) {
FATAL("Failed adding interrupt fd to epoll instance");
}
timer_fd_ = NO_RETRY_EXPECTED(timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC));
if (timer_fd_ == -1) {
FATAL("Failed creating timerfd file descriptor: %i", errno);
}
// Register the timer_fd_ with the epoll instance.
event.events = EPOLLIN;
event.data.fd = timer_fd_;
status =
NO_RETRY_EXPECTED(epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &event));
if (status == -1) {
FATAL("Failed adding timerfd fd(%i) to epoll instance: %i", timer_fd_,
errno);
}
}
static void DeleteDescriptorInfo(void* info) {
DescriptorInfo* di = reinterpret_cast<DescriptorInfo*>(info);
di->Close();
delete di;
}
EventHandlerImplementation::~EventHandlerImplementation() {
socket_map_.Clear(DeleteDescriptorInfo);
close(epoll_fd_);
close(timer_fd_);
close(interrupt_fds_[0]);
close(interrupt_fds_[1]);
}
void EventHandlerImplementation::UpdateEpollInstance(intptr_t old_mask,
DescriptorInfo* di) {
intptr_t new_mask = di->Mask();
if ((old_mask != 0) && (new_mask == 0)) {
RemoveFromEpollInstance(epoll_fd_, di);
} else if ((old_mask == 0) && (new_mask != 0)) {
AddToEpollInstance(epoll_fd_, di);
} else if ((old_mask != 0) && (new_mask != 0) && (old_mask != new_mask)) {
ASSERT(!di->IsListeningSocket());
RemoveFromEpollInstance(epoll_fd_, di);
AddToEpollInstance(epoll_fd_, di);
}
}
DescriptorInfo* EventHandlerImplementation::GetDescriptorInfo(
intptr_t fd,
bool is_listening) {
ASSERT(fd >= 0);
SimpleHashMap::Entry* entry = socket_map_.Lookup(
GetHashmapKeyFromFd(fd), GetHashmapHashFromFd(fd), true);
ASSERT(entry != nullptr);
DescriptorInfo* di = reinterpret_cast<DescriptorInfo*>(entry->value);
if (di == nullptr) {
// If there is no data in the hash map for this file descriptor a
// new DescriptorInfo for the file descriptor is inserted.
if (is_listening) {
di = new DescriptorInfoMultiple(fd);
} else {
di = new DescriptorInfoSingle(fd);
}
entry->value = di;
}
ASSERT(fd == di->fd());
return di;
}
void EventHandlerImplementation::WakeupHandler(intptr_t id,
Dart_Port dart_port,
int64_t data) {
InterruptMessage msg;
msg.id = id;
msg.dart_port = dart_port;
msg.data = data;
// WriteToBlocking will write up to 512 bytes atomically, and since our msg
// is smaller than 512, we don't need a thread lock.
// See: http://linux.die.net/man/7/pipe, section 'Pipe_buf'.
ASSERT(kInterruptMessageSize < PIPE_BUF);
intptr_t result =
FDUtils::WriteToBlocking(interrupt_fds_[1], &msg, kInterruptMessageSize);
if (result != kInterruptMessageSize) {
if (result == -1) {
FATAL("Interrupt message failure: %s", strerror(errno));
} else {
FATAL("Interrupt message failure: expected to write %" Pd
" bytes, but wrote %" Pd ".",
kInterruptMessageSize, result);
}
}
}
void EventHandlerImplementation::HandleInterruptFd() {
const intptr_t MAX_MESSAGES = kInterruptMessageSize;
InterruptMessage msg[MAX_MESSAGES];
ssize_t bytes = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
read(interrupt_fds_[0], msg, MAX_MESSAGES * kInterruptMessageSize));
for (ssize_t i = 0; i < bytes / kInterruptMessageSize; i++) {
if (msg[i].id == kTimerId) {
timeout_queue_.UpdateTimeout(msg[i].dart_port, msg[i].data);
UpdateTimerFd();
} else if (msg[i].id == kShutdownId) {
shutdown_ = true;
} else {
ASSERT((msg[i].data & COMMAND_MASK) != 0);
Socket* socket = reinterpret_cast<Socket*>(msg[i].id);
RefCntReleaseScope<Socket> rs(socket);
if (socket->fd() == -1) {
continue;
}
DescriptorInfo* di =
GetDescriptorInfo(socket->fd(), IS_LISTENING_SOCKET(msg[i].data));
if (IS_COMMAND(msg[i].data, kShutdownReadCommand)) {
ASSERT(!di->IsListeningSocket());
// Close the socket for reading.
VOID_NO_RETRY_EXPECTED(shutdown(di->fd(), SHUT_RD));
} else if (IS_COMMAND(msg[i].data, kShutdownWriteCommand)) {
ASSERT(!di->IsListeningSocket());
// Close the socket for writing.
VOID_NO_RETRY_EXPECTED(shutdown(di->fd(), SHUT_WR));
} else if (IS_COMMAND(msg[i].data, kCloseCommand)) {
// Close the socket and free system resources and move on to next
// message.
if (IS_SIGNAL_SOCKET(msg[i].data)) {
Process::ClearSignalHandlerByFd(di->fd(), socket->isolate_port());
}
intptr_t old_mask = di->Mask();
Dart_Port port = msg[i].dart_port;
if (port != ILLEGAL_PORT) {
di->RemovePort(port);
}
intptr_t new_mask = di->Mask();
UpdateEpollInstance(old_mask, di);
intptr_t fd = di->fd();
ASSERT(fd == socket->fd());
if (di->IsListeningSocket()) {
// We only close the socket file descriptor from the operating
// system if there are no other dart socket objects which
// are listening on the same (address, port) combination.
ListeningSocketRegistry* registry =
ListeningSocketRegistry::Instance();
MutexLocker locker(registry->mutex());
if (registry->CloseSafe(socket)) {
ASSERT(new_mask == 0);
socket_map_.Remove(GetHashmapKeyFromFd(fd),
GetHashmapHashFromFd(fd));
di->Close();
delete di;
}
socket->CloseFd();
} else {
ASSERT(new_mask == 0);
socket_map_.Remove(GetHashmapKeyFromFd(fd), GetHashmapHashFromFd(fd));
di->Close();
delete di;
socket->CloseFd();
}
DartUtils::PostInt32(port, 1 << kDestroyedEvent);
} else if (IS_COMMAND(msg[i].data, kReturnTokenCommand)) {
int count = TOKEN_COUNT(msg[i].data);
intptr_t old_mask = di->Mask();
di->ReturnTokens(msg[i].dart_port, count);
UpdateEpollInstance(old_mask, di);
} else if (IS_COMMAND(msg[i].data, kSetEventMaskCommand)) {
// `events` can only have kInEvent/kOutEvent flags set.
intptr_t events = msg[i].data & EVENT_MASK;
ASSERT(0 == (events & ~(1 << kInEvent | 1 << kOutEvent)));
intptr_t old_mask = di->Mask();
di->SetPortAndMask(msg[i].dart_port, msg[i].data & EVENT_MASK);
UpdateEpollInstance(old_mask, di);
} else {
UNREACHABLE();
}
}
}
}
void EventHandlerImplementation::UpdateTimerFd() {
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;
}
VOID_NO_RETRY_EXPECTED(
timerfd_settime(timer_fd_, TFD_TIMER_ABSTIME, &it, nullptr));
}
#ifdef DEBUG_POLL
static void PrintEventMask(intptr_t fd, intptr_t events) {
Syslog::Print("%d ", fd);
if ((events & EPOLLIN) != 0) {
Syslog::Print("EPOLLIN ");
}
if ((events & EPOLLPRI) != 0) {
Syslog::Print("EPOLLPRI ");
}
if ((events & EPOLLOUT) != 0) {
Syslog::Print("EPOLLOUT ");
}
if ((events & EPOLLERR) != 0) {
Syslog::Print("EPOLLERR ");
}
if ((events & EPOLLHUP) != 0) {
Syslog::Print("EPOLLHUP ");
}
if ((events & EPOLLRDHUP) != 0) {
Syslog::Print("EPOLLRDHUP ");
}
int all_events =
EPOLLIN | EPOLLPRI | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDHUP;
if ((events & ~all_events) != 0) {
Syslog::Print("(and %08x) ", events & ~all_events);
}
Syslog::Print("(available %d) ", FDUtils::AvailableBytes(fd));
Syslog::Print("\n");
}
#endif
intptr_t EventHandlerImplementation::GetPollEvents(intptr_t events,
DescriptorInfo* di) {
#ifdef DEBUG_POLL
PrintEventMask(di->fd(), events);
#endif
if ((events & EPOLLERR) != 0) {
// Return error only if EPOLLIN is present.
return ((events & EPOLLIN) != 0) ? (1 << kErrorEvent) : 0;
}
intptr_t event_mask = 0;
if ((events & EPOLLIN) != 0) {
event_mask |= (1 << kInEvent);
}
if ((events & EPOLLOUT) != 0) {
event_mask |= (1 << kOutEvent);
}
if ((events & (EPOLLHUP | EPOLLRDHUP)) != 0) {
event_mask |= (1 << kCloseEvent);
}
return event_mask;
}
void EventHandlerImplementation::HandleEvents(struct epoll_event* events,
int size) {
bool interrupt_seen = false;
for (int i = 0; i < size; i++) {
if (events[i].data.ptr == nullptr) {
interrupt_seen = true;
} else if (events[i].data.fd == timer_fd_) {
int64_t val;
VOID_TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
read(timer_fd_, &val, sizeof(val)));
if (timeout_queue_.HasTimeout()) {
DartUtils::PostNull(timeout_queue_.CurrentPort());
timeout_queue_.RemoveCurrent();
}
UpdateTimerFd();
} else {
DescriptorInfo* di =
reinterpret_cast<DescriptorInfo*>(events[i].data.ptr);
const intptr_t old_mask = di->Mask();
const intptr_t event_mask = GetPollEvents(events[i].events, di);
if ((event_mask & (1 << kErrorEvent)) != 0) {
di->NotifyAllDartPorts(event_mask);
UpdateEpollInstance(old_mask, di);
} else if (event_mask != 0) {
Dart_Port port = di->NextNotifyDartPort(event_mask);
ASSERT(port != 0);
UpdateEpollInstance(old_mask, di);
DartUtils::PostInt32(port, event_mask);
}
}
}
if (interrupt_seen) {
// Handle after socket events, so we avoid closing a socket before we handle
// the current events.
HandleInterruptFd();
}
}
void EventHandlerImplementation::Poll(uword args) {
ThreadSignalBlocker signal_blocker(SIGPROF);
const intptr_t kMaxEvents = 16;
struct epoll_event events[kMaxEvents];
EventHandler* handler = reinterpret_cast<EventHandler*>(args);
EventHandlerImplementation* handler_impl = &handler->delegate_;
ASSERT(handler_impl != nullptr);
while (!handler_impl->shutdown_) {
intptr_t result = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
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);
}
}
DEBUG_ASSERT(ReferenceCounted<Socket>::instances() == 0);
handler->NotifyShutdownDone();
}
void EventHandlerImplementation::Start(EventHandler* handler) {
Thread::Start("dart:io EventHandler", &EventHandlerImplementation::Poll,
reinterpret_cast<uword>(handler));
}
void EventHandlerImplementation::Shutdown() {
SendData(kShutdownId, 0, 0);
}
void EventHandlerImplementation::SendData(intptr_t id,
Dart_Port dart_port,
int64_t data) {
WakeupHandler(id, dart_port, data);
}
void* EventHandlerImplementation::GetHashmapKeyFromFd(intptr_t fd) {
// The hashmap does not support keys with value 0.
return reinterpret_cast<void*>(fd + 1);
}
uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
// The hashmap does not support keys with value 0.
return dart::Utils::WordHash(fd + 1);
}
} // namespace bin
} // namespace dart
#endif // defined(DART_HOST_OS_LINUX) || defined(DART_HOST_OS_ANDROID)