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WindowServer: Port to the new IPC system

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

View file

@ -20,232 +20,6 @@
namespace IPC {
namespace Client {
class Event : public CEvent {
public:
enum Type {
Invalid = 2000,
PostProcess,
};
Event() {}
explicit Event(Type type)
: CEvent(type)
{
}
};
class PostProcessEvent : public Event {
public:
explicit PostProcessEvent(int client_id)
: Event(PostProcess)
, m_client_id(client_id)
{
}
int client_id() const { return m_client_id; }
private:
int m_client_id { 0 };
};
template<typename ServerMessage, typename ClientMessage>
class Connection : public CObject {
public:
Connection(const StringView& address)
: m_connection(CLocalSocket::construct(this))
, m_notifier(CNotifier::construct(m_connection->fd(), CNotifier::Read, this))
{
// We want to rate-limit our clients
m_connection->set_blocking(true);
m_notifier->on_ready_to_read = [this] {
drain_messages_from_server();
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
};
int retries = 100000;
while (retries) {
if (m_connection->connect(CSocketAddress::local(address))) {
break;
}
dbgprintf("Client::Connection: connect failed: %d, %s\n", errno, strerror(errno));
usleep(10000);
--retries;
}
ASSERT(m_connection->is_connected());
}
virtual void handshake() = 0;
virtual void event(CEvent& event) override
{
if (event.type() == Event::PostProcess) {
postprocess_bundles(m_unprocessed_bundles);
} else {
CObject::event(event);
}
}
void set_server_pid(pid_t pid) { m_server_pid = pid; }
pid_t server_pid() const { return m_server_pid; }
void set_my_client_id(int id) { m_my_client_id = id; }
int my_client_id() const { return m_my_client_id; }
template<typename MessageType>
bool wait_for_specific_event(MessageType type, ServerMessage& event)
{
// Double check we don't already have the event waiting for us.
// Otherwise we might end up blocked for a while for no reason.
for (ssize_t i = 0; i < m_unprocessed_bundles.size(); ++i) {
if (m_unprocessed_bundles[i].message.type == type) {
event = move(m_unprocessed_bundles[i].message);
m_unprocessed_bundles.remove(i);
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
return true;
}
}
for (;;) {
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(m_connection->fd(), &rfds);
int rc = CSyscallUtils::safe_syscall(select, m_connection->fd() + 1, &rfds, nullptr, nullptr, nullptr);
if (rc < 0) {
perror("select");
}
ASSERT(rc > 0);
ASSERT(FD_ISSET(m_connection->fd(), &rfds));
bool success = drain_messages_from_server();
if (!success)
return false;
for (ssize_t i = 0; i < m_unprocessed_bundles.size(); ++i) {
if (m_unprocessed_bundles[i].message.type == type) {
event = move(m_unprocessed_bundles[i].message);
m_unprocessed_bundles.remove(i);
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
return true;
}
}
}
}
bool post_message_to_server(const ClientMessage& message, const ByteBuffer&& extra_data = {})
{
#if defined(CIPC_DEBUG)
dbg() << "C: -> S " << int(message.type) << " extra " << extra_data.size();
#endif
if (!extra_data.is_empty())
const_cast<ClientMessage&>(message).extra_size = extra_data.size();
struct iovec iov[2];
int iov_count = 1;
iov[0].iov_base = const_cast<ClientMessage*>(&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;
for (;;) {
nwritten = writev(m_connection->fd(), iov, iov_count);
if (nwritten < 0) {
if (errno == EAGAIN) {
sched_yield();
continue;
}
perror("writev");
ASSERT_NOT_REACHED();
}
break;
}
ASSERT((size_t)nwritten == sizeof(message) + extra_data.size());
return true;
}
template<typename MessageType>
ServerMessage sync_request(const ClientMessage& request, MessageType response_type)
{
bool success = post_message_to_server(request);
ASSERT(success);
ServerMessage response;
success = wait_for_specific_event(response_type, response);
ASSERT(success);
return response;
}
template<typename RequestType, typename... Args>
typename RequestType::ResponseType send_sync(Args&&... args)
{
bool success = post_message_to_server(RequestType(forward<Args>(args)...));
ASSERT(success);
ServerMessage response;
success = wait_for_specific_event(RequestType::ResponseType::message_type(), response);
ASSERT(success);
return response;
}
protected:
struct IncomingMessageBundle {
ServerMessage message;
ByteBuffer extra_data;
};
virtual void postprocess_bundles(Vector<IncomingMessageBundle>& new_bundles)
{
dbg() << "Client::Connection: "
<< " warning: discarding " << new_bundles.size() << " unprocessed bundles; this may not be what you want";
new_bundles.clear();
}
private:
bool drain_messages_from_server()
{
for (;;) {
ServerMessage message;
ssize_t nread = recv(m_connection->fd(), &message, sizeof(ServerMessage), MSG_DONTWAIT);
if (nread < 0) {
if (errno == EAGAIN) {
return true;
}
perror("read");
exit(1);
return false;
}
if (nread == 0) {
dbgprintf("EOF on IPC fd\n");
exit(1);
return false;
}
ASSERT(nread == sizeof(message));
ByteBuffer extra_data;
if (message.extra_size) {
extra_data = ByteBuffer::create_uninitialized(message.extra_size);
int extra_nread = read(m_connection->fd(), extra_data.data(), extra_data.size());
if (extra_nread < 0) {
perror("read");
ASSERT_NOT_REACHED();
}
ASSERT((size_t)extra_nread == message.extra_size);
}
#if defined(CIPC_DEBUG)
dbg() << "C: <- S " << int(message.type) << " extra " << extra_data.size();
#endif
m_unprocessed_bundles.append({ move(message), move(extra_data) });
}
}
RefPtr<CLocalSocket> m_connection;
RefPtr<CNotifier> m_notifier;
Vector<IncomingMessageBundle> m_unprocessed_bundles;
int m_server_pid { -1 };
int m_my_client_id { -1 };
};
template<typename LocalEndpoint, typename PeerEndpoint>
class ConnectionNG : public CObject {
public:
@ -258,7 +32,6 @@ namespace Client {
m_connection->set_blocking(true);
m_notifier->on_ready_to_read = [this] {
drain_messages_from_server();
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
};
int retries = 100000;
@ -276,15 +49,6 @@ namespace Client {
virtual void handshake() = 0;
virtual void event(CEvent& event) override
{
if (event.type() == Event::PostProcess) {
postprocess_messages(m_unprocessed_messages);
} else {
CObject::event(event);
}
}
void set_server_pid(pid_t pid) { m_server_pid = pid; }
pid_t server_pid() const { return m_server_pid; }
void set_my_client_id(int id) { m_my_client_id = id; }
@ -299,7 +63,6 @@ namespace Client {
if (m_unprocessed_messages[i]->id() == MessageType::static_message_id()) {
auto message = move(m_unprocessed_messages[i]);
m_unprocessed_messages.remove(i);
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
return message;
}
}
@ -319,14 +82,13 @@ namespace Client {
if (m_unprocessed_messages[i]->id() == MessageType::static_message_id()) {
auto message = move(m_unprocessed_messages[i]);
m_unprocessed_messages.remove(i);
CEventLoop::current().post_event(*this, make<PostProcessEvent>(m_connection->fd()));
return message;
}
}
}
}
bool post_message_to_server(const IMessage& message)
bool post_message(const IMessage& message)
{
auto buffer = message.encode();
int nwritten = write(m_connection->fd(), buffer.data(), (size_t)buffer.size());
@ -342,19 +104,13 @@ namespace Client {
template<typename RequestType, typename... Args>
OwnPtr<typename RequestType::ResponseType> send_sync(Args&&... args)
{
bool success = post_message_to_server(RequestType(forward<Args>(args)...));
bool success = post_message(RequestType(forward<Args>(args)...));
ASSERT(success);
auto response = wait_for_specific_message<typename RequestType::ResponseType>();
ASSERT(response);
return response;
}
protected:
virtual void postprocess_messages(Vector<OwnPtr<IMessage>>& new_bundles)
{
new_bundles.clear();
}
private:
bool drain_messages_from_server()
{

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: