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Netplay: First Attempt at creating a rolling checksum for desync detection

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HeatXD 2023-04-30 00:08:54 +02:00
parent df4e21a170
commit f89965b570
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GPG Key ID: BF30D71B2F1305C7
1 changed files with 26 additions and 4 deletions
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30
src/core/netplay.cpp
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@ -13,6 +13,9 @@
#include "system.h"
#include <bitset>
#include <deque>
#include <xxhash.h>
#include "host.h"
Log_SetChannel(Netplay);
#ifdef _WIN32
@ -57,6 +60,9 @@ static void InitializeFramePacing();
static void HandleTimeSyncEvent(float frame_delta, int update_interval);
static void Throttle();
// Desync Detection
static void GenerateChecksumForFrame(int* checksum, int frame, unsigned char* buffer, int buffer_size);
//////////////////////////////////////////////////////////////////////////
// Variables
//////////////////////////////////////////////////////////////////////////
@ -107,8 +113,8 @@ s32 Netplay::Start(s32 lhandle, u16 lport, std::string& raddr, u16 rport, s32 ld
ggpo_start_session(&s_ggpo, &cb, "Duckstation-Netplay", 2, sizeof(Netplay::Input), lport, MAX_ROLLBACK_FRAMES);
// result = ggpo_start_synctest(&s_ggpo, &cb, (char*)"asdf", 2, sizeof(Netplay::Input), 1);
ggpo_set_disconnect_timeout(s_ggpo, 3000);
ggpo_set_disconnect_notify_start(s_ggpo, 1000);
ggpo_set_disconnect_timeout(s_ggpo, 10000);
ggpo_set_disconnect_notify_start(s_ggpo, 2000);
for (int i = 1; i <= 2; i++)
{
@ -206,7 +212,7 @@ void Netplay::HandleTimeSyncEvent(float frame_delta, int update_interval)
// Distribute the frame difference over the next N * 0.75 frames.
// only part of the interval time is used since we want to come back to normal speed.
// otherwise we will keep spiraling into unplayable gameplay.
float total_time = (frame_delta / 8) * s_frame_period;
float total_time = (frame_delta * s_frame_period) / 4;
float mun_timesync_frames = update_interval * 0.75f;
float added_time_per_frame = -(total_time / mun_timesync_frames);
float iterations_per_frame = 1.0f / s_frame_period;
@ -264,6 +270,15 @@ void Netplay::Throttle()
}
}
void Netplay::GenerateChecksumForFrame(int* checksum, int frame, unsigned char* buffer, int buffer_size)
{
u32 sliding_window_size = 4096;
u32 num_pages = buffer_size / sliding_window_size;
u32 start_position = (frame % num_pages) * sliding_window_size;
*checksum = XXH32(buffer + start_position, sliding_window_size, frame);
Log_VerbosePrintf("check: f:%d c:%u", frame, *checksum);
}
void Netplay::AdvanceFrame(u16 checksum)
{
ggpo_advance_frame(s_ggpo, checksum);
@ -314,7 +329,7 @@ Netplay::Input Netplay::ReadLocalInput()
Netplay::Input inp{0};
for (u32 i = 0; i < (u32)DigitalController::Button::Count; i++)
{
if (s_net_input[0][i] >= 0.25f)
if (s_net_input[0][i] >= 0.4f)
inp.button_data |= 1 << i;
}
return inp;
@ -425,6 +440,7 @@ bool Netplay::NpBeginGameCb(void* ctx, const char* game_name)
while (System::GetInternalFrameNumber() < 2)
System::RunFrame();
SPU::SetAudioOutputMuted(false);
// Set Initial Frame Pacing
InitializeFramePacing();
return true;
}
@ -457,8 +473,13 @@ bool Netplay::NpSaveFrameCb(void* ctx, unsigned char** buffer, int* len, int* ch
return false;
}
Netplay::GenerateChecksumForFrame(checksum, frame,
reinterpret_cast<unsigned char*>(our_buffer.get()->state_stream.get()->GetMemoryPointer()),
our_buffer.get()->state_stream.get()->GetMemorySize());
*len = sizeof(System::MemorySaveState);
*buffer = reinterpret_cast<unsigned char*>(our_buffer.release());
return true;
}
@ -521,6 +542,7 @@ bool Netplay::NpOnEventCb(void* ctx, GGPOEvent* ev)
sprintf(buff, "Netplay Desync Detected!: Frame: %d, L:%u, R:%u", ev->u.desync.nFrameOfDesync,
ev->u.desync.ourCheckSum, ev->u.desync.remoteChecksum);
msg = buff;
Host::AddKeyedOSDMessage("Netplay", msg);
break;
default:
sprintf(buff, "Netplay Event Code: %d", ev->code);