dart-sdk/runtime/bin/eventhandler.cc
Zachary Anderson 89dba57bcf [dart:io] Adds a finalizer to _NativeSocket to avoid socket leaks
The finalizer sends the "close" message to the EventHandler for the
file descriptor in the _NativeSocket's native field. To avoid races and
spurious messages, this CL stores a pointer to a wrapper object in the
native field instead of the file descriptor. All messsages about the
_NativeSocket sent to the EventHandler use the wrapper object instead of
the file descriptor. When the EventHandler closes the file, the file
descriptor in the wrapper object is set to -1 so that the finalizer will
instead do nothing.

On Windows, there is another level of indirection since the OS HANDLEs
were already wrapped in various kinds of Handle objects. As an additional
complication, ClientSocket close on Windows is asynchronous, so the
EventHandler may shutdown before all of the ClientSocket Handles can be
destroyed.

related #27898, #28081

R=johnmccutchan@google.com

Review-Url: https://codereview.chromium.org/2760293002 .
2017-03-28 07:44:05 -07:00

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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.
#if !defined(DART_IO_DISABLED)
#include "bin/eventhandler.h"
#include "bin/builtin.h"
#include "bin/dartutils.h"
#include "bin/lockers.h"
#include "bin/socket.h"
#include "bin/thread.h"
#include "include/dart_api.h"
namespace dart {
namespace bin {
void TimeoutQueue::UpdateTimeout(Dart_Port port, int64_t timeout) {
// Find port if present.
Timeout* last = NULL;
Timeout* current = timeouts_;
while (current != NULL) {
if (current->port() == port) {
// Found.
if (timeout < 0) {
// Remove from list and delete existing.
if (last != NULL) {
last->set_next(current->next());
} else {
timeouts_ = current->next();
}
delete current;
} else {
// Update timeout.
current->set_timeout(timeout);
}
break;
}
last = current;
current = current->next();
}
if (current == NULL && timeout >= 0) {
// Not found, create a new.
timeouts_ = new Timeout(port, timeout, timeouts_);
}
// Clear and find next timeout.
next_timeout_ = NULL;
current = timeouts_;
while (current != NULL) {
if ((next_timeout_ == NULL) ||
(current->timeout() < next_timeout_->timeout())) {
next_timeout_ = current;
}
current = current->next();
}
}
static EventHandler* event_handler = NULL;
static Monitor* shutdown_monitor = NULL;
void EventHandler::Start() {
// Initialize global socket registry.
ListeningSocketRegistry::Initialize();
ASSERT(event_handler == NULL);
shutdown_monitor = new Monitor();
event_handler = new EventHandler();
event_handler->delegate_.Start(event_handler);
}
void EventHandler::NotifyShutdownDone() {
MonitorLocker ml(shutdown_monitor);
ml.Notify();
}
void EventHandler::Stop() {
if (event_handler == NULL) {
return;
}
// Wait until it has stopped.
{
MonitorLocker ml(shutdown_monitor);
// Signal to event handler that we want it to stop.
event_handler->delegate_.Shutdown();
ml.Wait(Monitor::kNoTimeout);
}
// Cleanup
delete event_handler;
event_handler = NULL;
delete shutdown_monitor;
shutdown_monitor = NULL;
// Destroy the global socket registry.
ListeningSocketRegistry::Cleanup();
}
EventHandlerImplementation* EventHandler::delegate() {
if (event_handler == NULL) {
return NULL;
}
return &event_handler->delegate_;
}
void EventHandler::SendFromNative(intptr_t id, Dart_Port port, int64_t data) {
event_handler->SendData(id, port, data);
}
/*
* Send data to the EventHandler thread to register for a given instance
* args[0] a ReceivePort args[1] with a notification event args[2].
*/
void FUNCTION_NAME(EventHandler_SendData)(Dart_NativeArguments args) {
// Get the id out of the send port. If the handle is not a send port
// we will get an error and propagate that out.
Dart_Handle handle = Dart_GetNativeArgument(args, 1);
Dart_Port dart_port;
handle = Dart_SendPortGetId(handle, &dart_port);
if (Dart_IsError(handle)) {
Dart_PropagateError(handle);
UNREACHABLE();
}
Dart_Handle sender = Dart_GetNativeArgument(args, 0);
intptr_t id;
if (Dart_IsNull(sender)) {
id = kTimerId;
} else {
Socket* socket = Socket::GetSocketIdNativeField(sender);
ASSERT(dart_port != ILLEGAL_PORT);
socket->set_port(dart_port);
socket->Retain(); // inc refcount before sending to the eventhandler.
id = reinterpret_cast<intptr_t>(socket);
}
int64_t data = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2));
event_handler->SendData(id, dart_port, data);
}
void FUNCTION_NAME(EventHandler_TimerMillisecondClock)(
Dart_NativeArguments args) {
int64_t now = TimerUtils::GetCurrentMonotonicMillis();
Dart_SetReturnValue(args, Dart_NewInteger(now));
}
} // namespace bin
} // namespace dart
#endif // !defined(DART_IO_DISABLED)