gecko/hal/gonk/UeventPoller.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* Copyright 2012 Mozilla Foundation and Mozilla contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include "base/message_loop.h"
#include "mozilla/FileUtils.h"
#include "nsAutoPtr.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "UeventPoller.h"
namespace mozilla {
namespace hal_impl {
static void ShutdownUevent();
class NetlinkPoller : public MessageLoopForIO::Watcher
{
public:
NetlinkPoller() : mSocket(-1),
mIOLoop(MessageLoopForIO::current())
{
}
virtual ~NetlinkPoller() {}
bool OpenSocket();
virtual void OnFileCanReadWithoutBlocking(int fd);
// no writing to the netlink socket
virtual void OnFileCanWriteWithoutBlocking(int fd)
{
MOZ_CRASH("Must not write to netlink socket");
}
MessageLoopForIO *GetIOLoop () const { return mIOLoop; }
void RegisterObserver(IUeventObserver *aObserver)
{
mUeventObserverList.AddObserver(aObserver);
}
void UnregisterObserver(IUeventObserver *aObserver)
{
mUeventObserverList.RemoveObserver(aObserver);
if (mUeventObserverList.Length() == 0)
ShutdownUevent(); // this will destroy self
}
private:
ScopedClose mSocket;
MessageLoopForIO* mIOLoop;
MessageLoopForIO::FileDescriptorWatcher mReadWatcher;
const static int kBuffsize = 64 * 1024;
uint8_t mBuffer [kBuffsize];
typedef ObserverList<NetlinkEvent> UeventObserverList;
UeventObserverList mUeventObserverList;
};
bool
NetlinkPoller::OpenSocket()
{
mSocket.rwget() = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (mSocket.get() < 0)
return false;
int sz = kBuffsize;
if (setsockopt(mSocket.get(), SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)) < 0)
return false;
// add FD_CLOEXEC flag
int flags = fcntl(mSocket.get(), F_GETFD);
if (flags == -1) {
return false;
}
flags |= FD_CLOEXEC;
if (fcntl(mSocket.get(), F_SETFD, flags) == -1)
return false;
// set non-blocking
if (fcntl(mSocket.get(), F_SETFL, O_NONBLOCK) == -1)
return false;
struct sockaddr_nl saddr;
bzero(&saddr, sizeof(saddr));
saddr.nl_family = AF_NETLINK;
saddr.nl_groups = 1;
saddr.nl_pid = getpid();
if (bind(mSocket.get(), (struct sockaddr *)&saddr, sizeof(saddr)) == -1)
return false;
if (!mIOLoop->WatchFileDescriptor(mSocket.get(),
true,
MessageLoopForIO::WATCH_READ,
&mReadWatcher,
this)) {
return false;
}
return true;
}
static nsAutoPtr<NetlinkPoller> sPoller;
class UeventInitTask : public Task
{
virtual void Run()
{
if (!sPoller) {
return;
}
if (sPoller->OpenSocket()) {
return;
}
sPoller->GetIOLoop()->PostDelayedTask(FROM_HERE, new UeventInitTask(), 1000);
}
};
void
NetlinkPoller::OnFileCanReadWithoutBlocking(int fd)
{
MOZ_ASSERT(fd == mSocket.get());
while (true) {
int ret = read(fd, mBuffer, kBuffsize);
if (ret == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
return;
}
if (errno == EINTR) {
continue;
}
}
if (ret <= 0) {
// fatal error on netlink socket which should not happen
_exit(1);
}
NetlinkEvent netlinkEvent;
netlinkEvent.decode(reinterpret_cast<char*>(mBuffer), ret);
mUeventObserverList.Broadcast(netlinkEvent);
}
}
static void
InitializeUevent()
{
MOZ_ASSERT(!sPoller);
sPoller = new NetlinkPoller();
sPoller->GetIOLoop()->PostTask(FROM_HERE, new UeventInitTask());
}
static void
ShutdownUevent()
{
sPoller = nullptr;
}
void
RegisterUeventListener(IUeventObserver *aObserver)
{
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
if (!sPoller)
InitializeUevent();
sPoller->RegisterObserver(aObserver);
}
void
UnregisterUeventListener(IUeventObserver *aObserver)
{
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
sPoller->UnregisterObserver(aObserver);
}
} // hal_impl
} // mozilla