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WindowServer: Port to the new IPC system

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This patch introduces code generation for the WindowServer IPC with
its clients. The client/server endpoints are defined by the two .ipc
files in Servers/WindowServer/: WindowServer.ipc and WindowClient.ipc

It now becomes significantly easier to add features and capabilities
to WindowServer since you don't have to know nearly as much about all
the intricate paths that IPC messages take between LibGUI and WSWindow.

The new system also uses significantly less IPC bandwidth since we're
now doing packed serialization instead of passing fixed-sized structs
of ~600 bytes for each message.

Some repaint coalescing optimizations are lost in this conversion and
we'll need to look at how to implement those in the new world.

The old CoreIPC::Client::Connection and CoreIPC::Server::Connection
classes are removed by this patch and replaced by use of ConnectionNG,
which will be renamed eventually.

Goodbye, old WindowServer IPC. You served us well :^)
This commit is contained in:
Andreas Kling 2019-12-02 09:33:37 +01:00
parent 30db7813de
commit 272d65e3e2
42 changed files with 843 additions and 2853 deletions
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192
Libraries/LibCore/CoreIPCServer.h
View file

@ -49,204 +49,12 @@ namespace Server {
int m_client_id { 0 };
};
template<typename T, class... Args>
NonnullRefPtr<T> new_connection_for_client(Args&&... args)
{
auto conn = T::construct(forward<Args>(args)...);
conn->send_greeting();
return conn;
}
template<typename T, class... Args>
NonnullRefPtr<T> new_connection_ng_for_client(Args&&... args)
{
return T::construct(forward<Args>(args)...) /* arghs */;
}
template<typename ServerMessage, typename ClientMessage>
class Connection : public CObject {
protected:
Connection(CLocalSocket& socket, int client_id)
: m_socket(socket)
, m_client_id(client_id)
{
add_child(socket);
m_socket->on_ready_to_read = [this] {
drain_client();
flush_outgoing_messages();
};
#if defined(CIPC_DEBUG)
dbg() << "S: Created new Connection " << fd << client_id << " and said hello";
#endif
}
public:
~Connection()
{
#if defined(CIPC_DEBUG)
dbg() << "S: Destroyed Connection " << m_socket->fd() << client_id();
#endif
}
void post_message(const ServerMessage& message, const ByteBuffer& extra_data = {})
{
#if defined(CIPC_DEBUG)
dbg() << "S: -> C " << int(message.type) << " extra " << extra_data.size();
#endif
flush_outgoing_messages();
if (try_send_message(message, extra_data))
return;
if (m_queue.size() >= max_queued_messages) {
dbg() << "Connection::post_message: Client has too many queued messages already, disconnecting it.";
shutdown();
return;
}
QueuedMessage queued_message { message, extra_data };
if (!extra_data.is_empty())
queued_message.message.extra_size = extra_data.size();
m_queue.enqueue(move(queued_message));
}
bool try_send_message(const ServerMessage& message, const ByteBuffer& extra_data)
{
struct iovec iov[2];
int iov_count = 1;
iov[0].iov_base = const_cast<ServerMessage*>(&message);
iov[0].iov_len = sizeof(message);
if (!extra_data.is_empty()) {
iov[1].iov_base = const_cast<u8*>(extra_data.data());
iov[1].iov_len = extra_data.size();
++iov_count;
}
int nwritten = writev(m_socket->fd(), iov, iov_count);
if (nwritten < 0) {
switch (errno) {
case EPIPE:
dbgprintf("Connection::post_message: Disconnected from peer.\n");
shutdown();
return false;
case EAGAIN:
#ifdef CIPC_DEBUG
dbg() << "EAGAIN when trying to send WindowServer message, queue size: " << m_queue.size();
#endif
return false;
default:
perror("Connection::post_message writev");
ASSERT_NOT_REACHED();
}
}
ASSERT(nwritten == (int)(sizeof(message) + extra_data.size()));
return true;
}
void flush_outgoing_messages()
{
while (!m_queue.is_empty()) {
auto& queued_message = m_queue.head();
if (!try_send_message(queued_message.message, queued_message.extra_data))
break;
m_queue.dequeue();
}
}
void drain_client()
{
unsigned messages_received = 0;
for (;;) {
ClientMessage message;
// FIXME: Don't go one message at a time, that's so much context switching, oof.
ssize_t nread = recv(m_socket->fd(), &message, sizeof(ClientMessage), MSG_DONTWAIT);
if (nread == 0 || (nread == -1 && errno == EAGAIN)) {
if (!messages_received) {
CEventLoop::current().post_event(*this, make<DisconnectedEvent>(client_id()));
}
break;
}
if (nread < 0) {
perror("recv");
ASSERT_NOT_REACHED();
}
ByteBuffer extra_data;
if (message.extra_size) {
if (message.extra_size >= 32768) {
dbgprintf("message.extra_size is way too large\n");
return did_misbehave();
}
extra_data = ByteBuffer::create_uninitialized(message.extra_size);
// FIXME: We should allow this to time out. Maybe use a socket timeout?
int extra_nread = read(m_socket->fd(), extra_data.data(), extra_data.size());
if (extra_nread != (int)message.extra_size) {
dbgprintf("extra_nread(%d) != extra_size(%d)\n", extra_nread, extra_data.size());
if (extra_nread < 0)
perror("read");
return did_misbehave();
}
}
#if defined(CIPC_DEBUG)
dbg() << "S: <- C " << int(message.type) << " extra " << extra_data.size();
#endif
if (!handle_message(message, move(extra_data)))
return;
++messages_received;
}
}
void did_misbehave()
{
dbgprintf("Connection{%p} (id=%d, pid=%d) misbehaved, disconnecting.\n", this, client_id(), m_client_pid);
shutdown();
}
void shutdown()
{
m_socket->close();
die();
}
int client_id() const { return m_client_id; }
pid_t client_pid() const { return m_client_pid; }
void set_client_pid(pid_t pid) { m_client_pid = pid; }
// ### having this public is sad
virtual void send_greeting() = 0;
virtual void die() = 0;
protected:
void event(CEvent& event)
{
if (event.type() == Event::Disconnected) {
int client_id = static_cast<const DisconnectedEvent&>(event).client_id();
dbgprintf("Connection: Client disconnected: %d\n", client_id);
die();
return;
}
CObject::event(event);
}
virtual bool handle_message(const ClientMessage&, const ByteBuffer&& = {}) = 0;
private:
RefPtr<CLocalSocket> m_socket;
struct QueuedMessage {
ServerMessage message;
ByteBuffer extra_data;
};
static const int max_queued_messages = 200;
Queue<QueuedMessage, 16> m_queue;
int m_client_id { -1 };
int m_client_pid { -1 };
};
template<typename Endpoint>
class ConnectionNG : public CObject {
public: