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Merged
Mysticial merged 2 commits into from
Oct 31, 2026
Merged

Sockets: fixes to ClientSocket_POSIX #1783

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c614694
Sockets: fixes to ClientSocket_POSIX
pa-devbot Oct 31, 2026
51484f3
Sockets: start the receive thread with dispatch()
pa-devbot Oct 31, 2026
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247 changes: 178 additions & 69 deletions Common/Cpp/Sockets/ClientSocket_POSIX.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2,13 +2,13 @@
*
* From: https://github.com/PokemonAutomation/
*
* This file is mostly untested!
*
*/

#ifndef PokemonAutomation_ClientSocket_POSIX_H
#define PokemonAutomation_ClientSocket_POSIX_H

#include <atomic>
#include <poll.h>
#include <signal.h>
#include <iostream>
#include <cerrno>
Expand All @@ -32,58 +32,115 @@ class ClientSocket_POSIX final : public AbstractClientSocket{
public:
ClientSocket_POSIX(ThreadPool& thread_pool)
: m_thread_pool(thread_pool)
, m_socket(socket(AF_INET, SOCK_STREAM, 0)){
{
// Ignore SIGPIPE. Handle errors via errno instead
signal(SIGPIPE, SIG_IGN);

if (m_socket != -1){
fcntl(m_socket, F_SETFL, O_NONBLOCK);
}
}

virtual ~ClientSocket_POSIX(){
close();
m_thread.wait_and_ignore_exceptions();
close_socket();
}

// Stops the receive thread, closes the socket, and returns the socket to
// State::NOT_RUNNING so "connect()" can be called again. This is safe to
// call multiple times.
//
// This blocks until the receive thread has exited, so it must not be
// called from within a listener callback (which runs on that thread).
virtual void close() noexcept override{
AsyncTask thread;
{
std::lock_guard<Mutex> lg1(m_lock);
m_state.store(State::DESTRUCTING, std::memory_order_relaxed);
std::lock_guard<Mutex> lg(m_lock);
if (m_state.load(std::memory_order_relaxed) == State::NOT_RUNNING && !m_thread){
// Never connected, or already fully closed.
return;
}
m_state.store(State::DESTRUCTING, std::memory_order_release);
m_cv.notify_all();
thread = std::move(m_thread);
}

thread.wait_and_ignore_exceptions();

{
std::lock_guard<Mutex> lg(m_lock);
close_socket_locked();
m_state.store(State::NOT_RUNNING, std::memory_order_release);
m_cv.notify_all();
}
}

virtual void connect(const std::string& address, uint16_t port) override{
std::lock_guard<Mutex> lg1(m_lock);
if (m_state.load(std::memory_order_relaxed) != State::NOT_RUNNING){
std::string error;
{
std::lock_guard<Mutex> lg(m_lock);
if (m_state.load(std::memory_order_relaxed) != State::NOT_RUNNING){
return;
}

// A socket whose previous connection has ended cannot be
// reconnected, so always start from a fresh socket.
close_socket_locked();

int socket = ::socket(AF_INET, SOCK_STREAM, 0);
if (socket == -1){
error = "socket() failed: " + std::string(strerror(errno));
}else{
int flags = fcntl(socket, F_GETFL, 0);
if (flags == -1 || fcntl(socket, F_SETFL, flags | O_NONBLOCK) == -1){
error = "fcntl() failed: " + std::string(strerror(errno));
::close(socket);
}else{
m_socket.store(socket, std::memory_order_release);
}
}
if (!error.empty()){
m_error = error;
return;
}

m_state.store(State::CONNECTING, std::memory_order_relaxed);
}
if (!error.empty()){
m_listeners.run_method(&Listener::on_connect_finished, error);
return;
}

// Use the plain dispatch() rather than dispatch_now_blocking():
// connect() may be called from a thread that is itself running on
// this pool, and blocking here until a pool thread is free could
// deadlock a capped pool. The returned AsyncTask still lets
// close() join the receive thread.
try{
m_state.store(State::CONNECTING, std::memory_order_relaxed);
m_thread = m_thread_pool.dispatch_now_blocking([=, this]{
m_thread = m_thread_pool.dispatch([=, this]{
thread_loop(address, port);
});
}catch (...){
m_state.store(State::NOT_RUNNING, std::memory_order_relaxed);
{
std::lock_guard<Mutex> lg(m_lock);
m_error = "Failed to start the receive thread.";
close_socket_locked();
m_state.store(State::NOT_RUNNING, std::memory_order_relaxed);
}
m_listeners.run_method(&Listener::on_connect_finished, m_error);
throw;
}
}


virtual size_t send(const void* data, size_t bytes) override{
if (m_socket == -1){
return 0;
}

constexpr int BLOCK_SIZE = (int)1 << 30;
const char* ptr = (const char*)data;
size_t sent = 0;

while (bytes > 0 && state() == State::CONNECTED){
int socket = m_socket.load(std::memory_order_acquire);
if (socket == -1){
return sent;
}

constexpr int BLOCK_SIZE = (int)1 << 30;
size_t current = std::min<size_t>(bytes, BLOCK_SIZE);
ssize_t current_sent = ::send(m_socket, ptr, (int)current, MSG_DONTWAIT | MSG_NOSIGNAL);
ssize_t current_sent = ::send(socket, ptr, (int)current, MSG_DONTWAIT | MSG_NOSIGNAL);
if (current_sent != -1){
sent += current_sent;
if ((size_t)current_sent < current){
Expand All @@ -94,13 +151,14 @@ class ClientSocket_POSIX final : public AbstractClientSocket{
continue;
}

int error = errno;
// cout << "error = " << error << endl;

std::unique_lock<Mutex> lg(m_lock);
if (state() == State::DESTRUCTING){
break;
}

int error = errno;
// cout << "error = " << error << endl;
switch (error){
case EAGAIN:
#if EAGAIN != EWOULDBLOCK
Expand All @@ -124,18 +182,41 @@ class ClientSocket_POSIX final : public AbstractClientSocket{


private:
void close_socket(){
if (m_socket == -1){
// Closes the underlying socket, if any. Requires "m_lock" to be held.
void close_socket_locked(){
int socket = m_socket.exchange(-1, std::memory_order_acquire);
if (socket == -1){
return;
}
int ret = ::close(m_socket);
if (ret != 0){
if (::close(socket) != 0){
try{
std::cout << "Failed close(): errno = " << errno << " (" << strerror(errno) << ")" << std::endl;
}catch (...){}
}
}

// A connection ended on its own (the connect attempt failed, the server
// closed the connection, or a socket error occurred). This returns the
// socket to State::NOT_RUNNING so "connect()" can be called again, and
// fires the appropriate callback outside of "m_lock".
// Requires "lg" to be locked. It unlocks it.
void connection_lost_locked(
std::unique_lock<Mutex>& lg,
const std::string& error_message,
bool was_connected
){
m_error = error_message;
m_state.store(State::NOT_RUNNING, std::memory_order_release);
close_socket_locked();
lg.unlock();

if (was_connected){
m_listeners.run_method(&Listener::on_disconnect, error_message);
}else{
m_listeners.run_method(&Listener::on_connect_finished, error_message);
}
}

void thread_loop(std::string address, uint16_t port){
try{
thread_loop_internal(std::move(address), port);
Expand All @@ -159,51 +240,74 @@ class ClientSocket_POSIX final : public AbstractClientSocket{
server.sin_addr.s_addr = inet_addr(address.c_str());

// Connect
int socket = m_socket.load(std::memory_order_acquire);
if (socket == -1){
return;
}

bool in_progress = false;
while (true){
State state = m_state.load(std::memory_order_relaxed);
if (state == State::DESTRUCTING){
return;
}

if (::connect(m_socket, (struct sockaddr*)&server, sizeof(server)) != -1){
break;
if (!in_progress){
int ret = ::connect(socket, (struct sockaddr*)&server, sizeof(server));
if (ret == 0){
break;
}

int error = errno;
// cout << "error = " << error << endl;
if (error != EAGAIN && error != EALREADY && error != EINPROGRESS){
if (error == ETIMEDOUT){
connection_lost_locked(lg, "Connection timed out.", false);
}else{
connection_lost_locked(lg, "Connect error (errno " + std::to_string(error) + "): " + std::string(strerror(error)), false);
}
return;
}
in_progress = true;
}

int error = errno;
// cout << "error = " << error << endl;
// While the connect is in progress, calling connect() again
// returns EISCONN, so instead wait for the socket to become
// writable, then check SO_ERROR for the result.
pollfd pf;
pf.fd = socket;
pf.events = POLLOUT;
pf.revents = 0;
int pret = poll(&pf, 1, 10);
if (pret == -1){
if (errno != EINTR){
connection_lost_locked(lg, "poll() error: " + std::string(strerror(errno)), false);
return;
}
continue;
}
if (pret == 0){
continue;
}

switch (error){
case EISCONN:
goto Connected;
case EAGAIN:
case EALREADY:
case EINPROGRESS:
int so_error = 0;
socklen_t slen = sizeof(so_error);
if (getsockopt(socket, SOL_SOCKET, SO_ERROR, &so_error, &slen) != 0){
so_error = errno;
}
if (so_error == 0){
break;
case ETIMEDOUT:
m_state.store(State::NOT_RUNNING, std::memory_order_relaxed);
m_error = "Connection timed out.";
lg.unlock();
m_listeners.run_method(&Listener::on_connect_finished, m_error);
return;
case ECONNREFUSED:
m_state.store(State::NOT_RUNNING, std::memory_order_relaxed);
m_error = "Connection refused.";
lg.unlock();
m_listeners.run_method(&Listener::on_connect_finished, m_error);
return;
default:
m_state.store(State::NOT_RUNNING, std::memory_order_relaxed);
m_error = "Connect error (errno " + std::to_string(error) + "): " + std::string(strerror(error));
lg.unlock();
m_listeners.run_method(&Listener::on_connect_finished, m_error);
return;
}

m_cv.wait_for(lg, std::chrono::milliseconds(10));

if (so_error == ETIMEDOUT){
connection_lost_locked(lg, "Connection timed out.", false);
}else if (so_error == ECONNREFUSED){
connection_lost_locked(lg, "Connection refused.", false);
}else{
connection_lost_locked(lg, "Connect error (errno " + std::to_string(so_error) + "): " + std::string(strerror(so_error)), false);
}
return;
}

Connected:
m_state.store(State::CONNECTED, std::memory_order_relaxed);
}

Expand All @@ -222,7 +326,13 @@ class ClientSocket_POSIX final : public AbstractClientSocket{
if (state == State::DESTRUCTING){
return;
}
bytes = ::recv(m_socket, buffer, BUFFER_SIZE, 0);

int socket = m_socket.load(std::memory_order_acquire);
if (socket == -1){
return;
}

bytes = ::recv(socket, buffer, BUFFER_SIZE, 0);
// cout << "error = " << error << endl;
if (bytes == -1){
error = errno;
Expand All @@ -239,21 +349,20 @@ class ClientSocket_POSIX final : public AbstractClientSocket{
return;
}

// cout << "error = " << error << endl;
if (bytes == 0){
connection_lost_locked(lg, "Connection closed by server.", true);
return;
}

if (bytes == -1){
switch (error){
case EAGAIN:
#if EAGAIN != EWOULDBLOCK
case EWOULDBLOCK:
#endif
break;
case ECONNRESET:
case ENOTCONN:
case EPIPE:
m_error = "Receive error (errno " + std::to_string(error) + "): " + std::string(strerror(error));
return;
default:
m_error = "Receive error (errno " + std::to_string(error) + "): " + std::string(strerror(error));
connection_lost_locked(lg, "Receive error (errno " + std::to_string(error) + "): " + std::string(strerror(error)), true);
return;
}
}
Expand All @@ -266,7 +375,7 @@ class ClientSocket_POSIX final : public AbstractClientSocket{

private:
ThreadPool& m_thread_pool;
const int m_socket;
std::atomic<int> m_socket{-1};

std::string m_error;

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