gecko-dev/ipc/unixfd/UnixFdWatcher.cpp
Thomas Zimmermann b1f27db3bd Bug 977672: Assert O_NONBLOCK for watched file descriptors, r=kyle
We cannot use blocking file-descriptor I/O on the I/O thread. This
patch adds an assertion to UnixFdWatcher the tests for the O_NONBLOCK
flag, when installing a file descriptor. In UnixFileWatcher, the
Open method tests for the O_NONBLOCK flag for the opened file.

File-descriptor flags for UnixSocketImpl et al are currently set by
UnixSocketImpl itself. Later patches should move this into the
methods of connector classes.
2014-02-28 10:16:52 +01:00

129 lines
2.8 KiB
C++

/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <fcntl.h>
#include "UnixFdWatcher.h"
#ifdef CHROMIUM_LOG
#undef CHROMIUM_LOG
#endif
#if defined(MOZ_WIDGET_GONK)
#include <android/log.h>
#define CHROMIUM_LOG(args...) __android_log_print(ANDROID_LOG_INFO, "I/O", args);
#else
#include <stdio.h>
#define IODEBUG true
#define CHROMIUM_LOG(args...) if (IODEBUG) printf(args);
#endif
namespace mozilla {
namespace ipc {
UnixFdWatcher::~UnixFdWatcher()
{
NS_WARN_IF(IsOpen()); /* mFd should have been closed already */
}
void
UnixFdWatcher::Close()
{
MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
if (NS_WARN_IF(!IsOpen())) {
/* mFd should have been open */
return;
}
OnClose();
RemoveWatchers(READ_WATCHER|WRITE_WATCHER);
mFd.dispose();
}
void
UnixFdWatcher::AddWatchers(unsigned long aWatchers, bool aPersistent)
{
MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
MOZ_ASSERT(IsOpen());
// Before we add a watcher, we need to remove it! Removing is always
// safe, but adding the same watcher twice can lead to endless loops
// inside libevent.
RemoveWatchers(aWatchers);
if (aWatchers & READ_WATCHER) {
MessageLoopForIO::current()->WatchFileDescriptor(
mFd,
aPersistent,
MessageLoopForIO::WATCH_READ,
&mReadWatcher,
this);
}
if (aWatchers & WRITE_WATCHER) {
MessageLoopForIO::current()->WatchFileDescriptor(
mFd,
aPersistent,
MessageLoopForIO::WATCH_WRITE,
&mWriteWatcher,
this);
}
}
void
UnixFdWatcher::RemoveWatchers(unsigned long aWatchers)
{
MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
MOZ_ASSERT(IsOpen());
if (aWatchers & READ_WATCHER) {
mReadWatcher.StopWatchingFileDescriptor();
}
if (aWatchers & WRITE_WATCHER) {
mWriteWatcher.StopWatchingFileDescriptor();
}
}
void
UnixFdWatcher::OnError(const char* aFunction, int aErrno)
{
MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
CHROMIUM_LOG("%s failed with error %d (%s)",
aFunction, aErrno, strerror(aErrno));
}
UnixFdWatcher::UnixFdWatcher(MessageLoop* aIOLoop)
: mIOLoop(aIOLoop)
{
MOZ_ASSERT(mIOLoop);
}
UnixFdWatcher::UnixFdWatcher(MessageLoop* aIOLoop, int aFd)
: mIOLoop(aIOLoop)
, mFd(aFd)
{
MOZ_ASSERT(mIOLoop);
}
void
UnixFdWatcher::SetFd(int aFd)
{
MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
MOZ_ASSERT(!IsOpen());
MOZ_ASSERT(FdIsNonBlocking(aFd));
mFd = aFd;
}
bool
UnixFdWatcher::FdIsNonBlocking(int aFd)
{
int flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFL));
return (flags > 0) && (flags & O_NONBLOCK);
}
}
}