RetroArch/network/netplay/netplay_sync.c
2017-01-22 13:40:32 +01:00

573 lines
19 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2014 - Hans-Kristian Arntzen
* Copyright (C) 2011-2017 - Daniel De Matteis
* Copyright (C) 2016-2017 - Gregor Richards
*
* RetroArch is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <boolean.h>
#include "netplay_private.h"
#include "../../autosave.h"
#include "../../driver.h"
#include "../../input/input_driver.h"
#if 0
#define DEBUG_NONDETERMINISTIC_CORES
#endif
/**
* netplay_update_unread_ptr
*
* Update the global unread_ptr and unread_frame_count to correspond to the
* earliest unread frame count of any connected player
*/
void netplay_update_unread_ptr(netplay_t *netplay)
{
if (netplay->is_server && !netplay->connected_players)
{
/* Nothing at all to read! */
netplay->unread_ptr = netplay->self_ptr;
netplay->unread_frame_count = netplay->self_frame_count;
}
else
{
size_t new_unread_ptr = 0;
uint32_t new_unread_frame_count = (uint32_t) -1;
uint32_t player;
for (player = 0; player < MAX_USERS; player++)
{
if (!(netplay->connected_players & (1<<player))) continue;
if (netplay->read_frame_count[player] < new_unread_frame_count)
{
new_unread_ptr = netplay->read_ptr[player];
new_unread_frame_count = netplay->read_frame_count[player];
}
}
if (!netplay->is_server && netplay->server_frame_count < new_unread_frame_count)
{
new_unread_ptr = netplay->server_ptr;
new_unread_frame_count = netplay->server_frame_count;
}
netplay->unread_ptr = new_unread_ptr;
netplay->unread_frame_count = new_unread_frame_count;
}
}
/**
* netplay_simulate_input
* @netplay : pointer to netplay object
* @sim_ptr : frame index for which to simulate input
* @resim : are we resimulating, or simulating this frame for the
* first time?
*
* "Simulate" input by assuming it hasn't changed since the last read input.
*/
void netplay_simulate_input(netplay_t *netplay, size_t sim_ptr, bool resim)
{
uint32_t player;
size_t prev;
struct delta_frame *simframe, *pframe;
simframe = &netplay->buffer[sim_ptr];
for (player = 0; player < MAX_USERS; player++)
{
if (!(netplay->connected_players & (1<<player))) continue;
if (simframe->have_real[player]) continue;
prev = PREV_PTR(netplay->read_ptr[player]);
pframe = &netplay->buffer[prev];
if (resim)
{
/* In resimulation mode, we only copy the buttons. The reason for this
* is nonobvious:
*
* If we resimulated nothing, then the /duration/ with which any input
* was pressed would be approximately correct, since the original
* simulation came in as the input came in, but the /number of times/
* the input was pressed would be wrong, as there would be an
* advancing wavefront of real data overtaking the simulated data
* (which is really just real data offset by some frames).
*
* That's acceptable for arrows in most situations, since the amount
* you move is tied to the duration, but unacceptable for buttons,
* which will seem to jerkily be pressed numerous times with those
* wavefronts.
*/
const uint32_t keep = (1U<<RETRO_DEVICE_ID_JOYPAD_UP) |
(1U<<RETRO_DEVICE_ID_JOYPAD_DOWN) |
(1U<<RETRO_DEVICE_ID_JOYPAD_LEFT) |
(1U<<RETRO_DEVICE_ID_JOYPAD_RIGHT);
uint32_t sim_state = simframe->simulated_input_state[player][0] & keep;
sim_state |= pframe->real_input_state[player][0] & ~keep;
simframe->simulated_input_state[player][0] = sim_state;
}
else
{
memcpy(simframe->simulated_input_state[player],
pframe->real_input_state[player],
WORDS_PER_INPUT * sizeof(uint32_t));
}
}
}
static void netplay_handle_frame_hash(netplay_t *netplay, struct delta_frame *delta)
{
if (netplay->is_server)
{
if (netplay->check_frames &&
delta->frame % abs(netplay->check_frames) == 0)
{
delta->crc = netplay_delta_frame_crc(netplay, delta);
netplay_cmd_crc(netplay, delta);
}
}
else if (delta->crc && netplay->crcs_valid)
{
/* We have a remote CRC, so check it */
uint32_t local_crc = netplay_delta_frame_crc(netplay, delta);
if (local_crc != delta->crc)
{
if (!netplay->crc_validity_checked)
{
/* If the very first check frame is wrong, they probably just don't
* work */
netplay->crcs_valid = false;
}
else if (netplay->crcs_valid)
{
/* Fix this! */
if (netplay->check_frames < 0)
{
/* Just report */
RARCH_ERR("Netplay CRCs mismatch!\n");
}
else
{
netplay_cmd_request_savestate(netplay);
}
}
}
else if (!netplay->crc_validity_checked)
{
netplay->crc_validity_checked = true;
}
}
}
/**
* netplay_sync_pre_frame
* @netplay : pointer to netplay object
*
* Pre-frame for Netplay synchronization.
*/
bool netplay_sync_pre_frame(netplay_t *netplay)
{
retro_ctx_serialize_info_t serial_info;
if (netplay_delta_frame_ready(netplay, &netplay->buffer[netplay->self_ptr], netplay->self_frame_count))
{
serial_info.data_const = NULL;
serial_info.data = netplay->buffer[netplay->self_ptr].state;
serial_info.size = netplay->state_size;
memset(serial_info.data, 0, serial_info.size);
if ((netplay->quirks & NETPLAY_QUIRK_INITIALIZATION) || netplay->self_frame_count == 0)
{
/* Don't serialize until it's safe */
}
else if (!(netplay->quirks & NETPLAY_QUIRK_NO_SAVESTATES) && core_serialize(&serial_info))
{
if (netplay->force_send_savestate && !netplay->stall && !netplay->remote_paused)
{
/* Send this along to the other side */
serial_info.data_const = netplay->buffer[netplay->self_ptr].state;
netplay_load_savestate(netplay, &serial_info, false);
netplay->force_send_savestate = false;
}
}
else
{
/* If the core can't serialize properly, we must stall for the
* remote input on EVERY frame, because we can't recover */
netplay->quirks |= NETPLAY_QUIRK_NO_SAVESTATES;
netplay->stateless_mode = true;
}
/* If we can't transmit savestates, we must stall until the client is ready */
if (netplay->self_frame_count > 0 &&
(netplay->quirks & (NETPLAY_QUIRK_NO_SAVESTATES|NETPLAY_QUIRK_NO_TRANSMISSION)) &&
(netplay->connections_size == 0 || !netplay->connections[0].active ||
netplay->connections[0].mode < NETPLAY_CONNECTION_CONNECTED))
netplay->stall = NETPLAY_STALL_NO_CONNECTION;
}
if (netplay->is_server)
{
fd_set fds;
struct timeval tmp_tv = {0};
int new_fd;
struct sockaddr_storage their_addr;
socklen_t addr_size;
struct netplay_connection *connection;
size_t connection_num;
/* Check for a connection */
FD_ZERO(&fds);
FD_SET(netplay->listen_fd, &fds);
if (socket_select(netplay->listen_fd + 1, &fds, NULL, NULL, &tmp_tv) > 0 &&
FD_ISSET(netplay->listen_fd, &fds))
{
addr_size = sizeof(their_addr);
new_fd = accept(netplay->listen_fd, (struct sockaddr*)&their_addr, &addr_size);
if (new_fd < 0)
{
RARCH_ERR("%s\n", msg_hash_to_str(MSG_NETPLAY_FAILED));
goto process;
}
/* Set the socket nonblocking */
if (!socket_nonblock(new_fd))
{
/* Catastrophe! */
socket_close(new_fd);
goto process;
}
#if defined(IPPROTO_TCP) && defined(TCP_NODELAY)
{
int flag = 1;
if (setsockopt(new_fd, IPPROTO_TCP, TCP_NODELAY,
#ifdef _WIN32
(const char*)
#else
(const void*)
#endif
&flag,
sizeof(int)) < 0)
RARCH_WARN("Could not set netplay TCP socket to nodelay. Expect jitter.\n");
}
#endif
#if defined(F_SETFD) && defined(FD_CLOEXEC)
/* Don't let any inherited processes keep open our port */
if (fcntl(new_fd, F_SETFD, FD_CLOEXEC) < 0)
RARCH_WARN("Cannot set Netplay port to close-on-exec. It may fail to reopen if the client disconnects.\n");
#endif
/* Allocate a connection */
for (connection_num = 0; connection_num < netplay->connections_size; connection_num++)
if (!netplay->connections[connection_num].active) break;
if (connection_num == netplay->connections_size)
{
if (connection_num == 0)
{
netplay->connections = (struct netplay_connection*)malloc(sizeof(struct netplay_connection));
if (netplay->connections == NULL)
{
socket_close(new_fd);
goto process;
}
netplay->connections_size = 1;
}
else
{
size_t new_connections_size = netplay->connections_size * 2;
struct netplay_connection *new_connections = (struct netplay_connection*)
realloc(netplay->connections,
new_connections_size*sizeof(struct netplay_connection));
if (new_connections == NULL)
{
socket_close(new_fd);
goto process;
}
memset(new_connections + netplay->connections_size, 0,
netplay->connections_size * sizeof(struct netplay_connection));
netplay->connections = new_connections;
netplay->connections_size = new_connections_size;
}
}
connection = &netplay->connections[connection_num];
/* Set it up */
memset(connection, 0, sizeof(*connection));
connection->active = true;
connection->fd = new_fd;
connection->mode = NETPLAY_CONNECTION_INIT;
if (!netplay_init_socket_buffer(&connection->send_packet_buffer,
netplay->packet_buffer_size) ||
!netplay_init_socket_buffer(&connection->recv_packet_buffer,
netplay->packet_buffer_size))
{
if (connection->send_packet_buffer.data)
netplay_deinit_socket_buffer(&connection->send_packet_buffer);
connection->active = false;
socket_close(new_fd);
goto process;
}
netplay_handshake_init_send(netplay, connection);
}
}
process:
netplay->can_poll = true;
input_poll_net();
return (netplay->stall != NETPLAY_STALL_NO_CONNECTION);
}
/**
* netplay_sync_post_frame
* @netplay : pointer to netplay object
*
* Post-frame for Netplay synchronization.
* We check if we have new input and replay from recorded input.
*/
void netplay_sync_post_frame(netplay_t *netplay, bool stalled)
{
uint32_t lo_frame_count, hi_frame_count;
/* Unless we're stalling, we've just finished running a frame */
if (!stalled)
{
netplay->self_ptr = NEXT_PTR(netplay->self_ptr);
netplay->self_frame_count++;
}
/* Only relevant if we're connected */
if ((netplay->is_server && !netplay->connected_players) ||
(netplay->self_mode < NETPLAY_CONNECTION_CONNECTED))
{
netplay->other_frame_count = netplay->self_frame_count;
netplay->other_ptr = netplay->self_ptr;
/* FIXME: Duplication */
if (netplay->catch_up)
{
netplay->catch_up = false;
input_driver_unset_nonblock_state();
driver_set_nonblock_state();
}
return;
}
#ifndef DEBUG_NONDETERMINISTIC_CORES
if (!netplay->force_rewind)
{
/* Skip ahead if we predicted correctly.
* Skip until our simulation failed. */
while (netplay->other_frame_count < netplay->unread_frame_count &&
netplay->other_frame_count < netplay->self_frame_count)
{
struct delta_frame *ptr = &netplay->buffer[netplay->other_ptr];
size_t i;
for (i = 0; i < MAX_USERS; i++)
{
if (memcmp(ptr->simulated_input_state[i], ptr->real_input_state[i],
sizeof(ptr->real_input_state[i])) != 0
&& !ptr->used_real[i])
break;
}
if (i != MAX_USERS) break;
netplay_handle_frame_hash(netplay, ptr);
netplay->other_ptr = NEXT_PTR(netplay->other_ptr);
netplay->other_frame_count++;
}
}
#endif
/* Now replay the real input if we've gotten ahead of it */
if (netplay->force_rewind ||
(netplay->other_frame_count < netplay->unread_frame_count &&
netplay->other_frame_count < netplay->self_frame_count))
{
retro_ctx_serialize_info_t serial_info;
/* Replay frames. */
netplay->is_replay = true;
netplay->replay_ptr = netplay->other_ptr;
netplay->replay_frame_count = netplay->other_frame_count;
if (netplay->quirks & NETPLAY_QUIRK_INITIALIZATION)
/* Make sure we're initialized before we start loading things */
netplay_wait_and_init_serialization(netplay);
serial_info.data = NULL;
serial_info.data_const = netplay->buffer[netplay->replay_ptr].state;
serial_info.size = netplay->state_size;
if (!core_unserialize(&serial_info))
{
RARCH_ERR("Netplay savestate loading failed: Prepare for desync!\n");
}
while (netplay->replay_frame_count < netplay->self_frame_count)
{
retro_time_t start, tm;
struct delta_frame *ptr = &netplay->buffer[netplay->replay_ptr];
serial_info.data = ptr->state;
serial_info.size = netplay->state_size;
serial_info.data_const = NULL;
start = cpu_features_get_time_usec();
/* Remember the current state */
memset(serial_info.data, 0, serial_info.size);
core_serialize(&serial_info);
if (netplay->replay_frame_count < netplay->unread_frame_count)
netplay_handle_frame_hash(netplay, ptr);
/* Re-simulate this frame's input */
netplay_simulate_input(netplay, netplay->replay_ptr, true);
autosave_lock();
core_run();
autosave_unlock();
netplay->replay_ptr = NEXT_PTR(netplay->replay_ptr);
netplay->replay_frame_count++;
#ifdef DEBUG_NONDETERMINISTIC_CORES
if (ptr->have_remote && netplay_delta_frame_ready(netplay, &netplay->buffer[netplay->replay_ptr], netplay->replay_frame_count))
{
RARCH_LOG("PRE %u: %X\n", netplay->replay_frame_count-1, netplay_delta_frame_crc(netplay, ptr));
if (netplay->is_server)
RARCH_LOG("INP %X %X\n", ptr->real_input_state[0], ptr->self_state[0]);
else
RARCH_LOG("INP %X %X\n", ptr->self_state[0], ptr->real_input_state[0]);
ptr = &netplay->buffer[netplay->replay_ptr];
serial_info.data = ptr->state;
memset(serial_info.data, 0, serial_info.size);
core_serialize(&serial_info);
RARCH_LOG("POST %u: %X\n", netplay->replay_frame_count-1, netplay_delta_frame_crc(netplay, ptr));
}
#endif
/* Get our time window */
tm = cpu_features_get_time_usec() - start;
netplay->frame_run_time_sum -= netplay->frame_run_time[netplay->frame_run_time_ptr];
netplay->frame_run_time[netplay->frame_run_time_ptr] = tm;
netplay->frame_run_time_sum += tm;
netplay->frame_run_time_ptr++;
if (netplay->frame_run_time_ptr >= NETPLAY_FRAME_RUN_TIME_WINDOW)
netplay->frame_run_time_ptr = 0;
}
/* Average our time */
netplay->frame_run_time_avg = netplay->frame_run_time_sum / NETPLAY_FRAME_RUN_TIME_WINDOW;
if (netplay->unread_frame_count < netplay->self_frame_count)
{
netplay->other_ptr = netplay->unread_ptr;
netplay->other_frame_count = netplay->unread_frame_count;
}
else
{
netplay->other_ptr = netplay->self_ptr;
netplay->other_frame_count = netplay->self_frame_count;
}
netplay->is_replay = false;
netplay->force_rewind = false;
}
if (netplay->is_server)
{
uint32_t player;
lo_frame_count = hi_frame_count = netplay->unread_frame_count;
/* Look for players that are ahead of us */
for (player = 0; player < MAX_USERS; player++)
{
if (!(netplay->connected_players & (1<<player))) continue;
if (netplay->read_frame_count[player] > hi_frame_count)
hi_frame_count = netplay->read_frame_count[player];
}
}
else
{
lo_frame_count = hi_frame_count = netplay->server_frame_count;
}
/* If we're behind, try to catch up */
if (netplay->catch_up)
{
/* Are we caught up? */
if (netplay->self_frame_count >= lo_frame_count)
{
netplay->catch_up = false;
input_driver_unset_nonblock_state();
driver_set_nonblock_state();
}
}
else if (!stalled)
{
if (netplay->self_frame_count + 2 < lo_frame_count)
{
/* Are we falling behind? */
netplay->catch_up = true;
input_driver_set_nonblock_state();
driver_set_nonblock_state();
}
else if (netplay->self_frame_count + 2 < hi_frame_count)
{
size_t i;
/* We're falling behind some clients but not others, so request that
* clients ahead of us stall */
for (i = 0; i < netplay->connections_size; i++)
{
struct netplay_connection *connection = &netplay->connections[i];
int player;
if (!connection->active ||
connection->mode != NETPLAY_CONNECTION_PLAYING)
continue;
player = connection->player;
/* Are they ahead? */
if (netplay->self_frame_count + 2 < netplay->read_frame_count[player])
{
/* Tell them to stall */
if (connection->stall_frame + NETPLAY_MAX_REQ_STALL_FREQUENCY <
netplay->self_frame_count)
{
connection->stall_frame = netplay->self_frame_count;
netplay_cmd_stall(netplay, connection,
netplay->read_frame_count[player] -
netplay->self_frame_count + 1);
}
}
}
}
}
}