https://github.com/libsdl-org/Maelstrom/commit/2c59ee2707c4cc4d352889b5c9f804d272b19e44
From 2c59ee2707c4cc4d352889b5c9f804d272b19e44 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sun, 20 Nov 2011 13:43:50 -0500
Subject: [PATCH] Don't advance the frame or process input while we're still
trying to sync from the last frame.
---
game/game.cpp | 24 +++--------
game/netplay.cpp | 105 ++++++++++++++++++++++++++++-------------------
game/netplay.h | 1 +
game/replay.cpp | 10 ++---
4 files changed, 74 insertions(+), 66 deletions(-)
diff --git a/game/game.cpp b/game/game.cpp
index a7b90cdf..ea09726c 100644
--- a/game/game.cpp
+++ b/game/game.cpp
@@ -243,11 +243,6 @@ GamePanelDelegate::OnTick()
return;
}
- // Delay processing until after bonus screen is done
- if (gGameInfo.GetLocalState() & STATE_BONUS) {
- return;
- }
-
/* -- Read in keyboard input for our ship */
HandleEvents(0);
@@ -256,19 +251,13 @@ GamePanelDelegate::OnTick()
gGameOn = 0;
return;
}
- if ( SyncNetwork() < 0 ) {
- if ( gPaused ) {
- /* One of the other players may be minimized and not
- be able to send packets (iOS), so don't abort yet.
- */
- return;
- }
- error("Game aborted!\n");
+ int syncResult = SyncNetwork();
+ if ( !UpdateGameState() ) {
gGameOn = 0;
return;
}
- if ( !UpdateGameState() ) {
- gGameOn = 0;
+ if (syncResult < 0) {
+ // We didn't get a full frame yet, don't process it
return;
}
gReplay.HandleRecording();
@@ -700,9 +689,8 @@ GamePanelDelegate::DoBonus()
gGameInfo.SetLocalState(STATE_BONUS, true);
- // Update the state afterward so playback stops for replays
- SyncNetwork();
- UpdateGameState();
+ // Lock state into place (synchronize with other players and replay)
+ OnTick();
/* Fade out */
screen->FadeOut();
diff --git a/game/netplay.cpp b/game/netplay.cpp
index 6c344420..5592a833 100644
--- a/game/netplay.cpp
+++ b/game/netplay.cpp
@@ -32,7 +32,7 @@
#include "protocol.h"
// Set this to 1 for normal debug info, and 2 for verbose packet logging
-#define DEBUG_NETWORK 1
+#define DEBUG_NETWORK 2
// Define this to simulate packet loss
//#define DEBUG_PACKETLOSS 10
@@ -41,7 +41,8 @@
UDPsocket gNetFD;
static SDLNet_SocketSet SocketSet;
-static Uint32 NextFrame;
+Uint32 NextFrame;
+static bool AdvancedFrame;
/* We keep one packet backlogged for retransmission */
static DynamicPacket OutBound[2];
@@ -49,6 +50,9 @@ static int CurrOut;
#define CurrPacket OutBound[CurrOut]
#define LastPacket OutBound[!CurrOut]
+/* The nodes we're currently waiting on for sync acks */
+static Uint32 WaitingAcks[MAX_NODES];
+
/* We cache one packet if the other player is ahead of us */
static DynamicPacket Packet;
static DynamicPacket CachedPacket[MAX_NODES];
@@ -93,9 +97,11 @@ int InitNetData(bool hosting)
/* Initialize network game variables */
NextFrame = 0;
+ AdvancedFrame = true;
OutBound[0].Reset();
OutBound[1].Reset();
CurrOut = 0;
+ SDL_zero(WaitingAcks);
for (i = 0; i < MAX_NODES; ++i) {
CachedPacket[i].Reset();
}
@@ -158,6 +164,16 @@ void QueueInput(Uint8 value)
QueuedInput.Write(value);
}
+static bool WaitingForAck()
+{
+ for (int i = 0; i < MAX_NODES; ++i) {
+ if (WaitingAcks[i]) {
+ return true;
+ }
+ }
+ return false;
+}
+
static bool ProcessSync(int index, DynamicPacket &packet)
{
Uint32 seed;
@@ -170,7 +186,7 @@ static bool ProcessSync(int index, DynamicPacket &packet)
if (seed != GetRandSeed()) {
/* We're hosed, to correct this we would have to sync the complete game state */
- error("Error!! \a Frame consistency problem, aborting!!\r\n");
+ error("Error!! \a consistency problem expecting seed %8.8x, got seed %8.8x, aborting!!\r\n", GetRandSeed(), seed);
return false;
}
@@ -183,7 +199,7 @@ static bool ProcessSync(int index, DynamicPacket &packet)
return true;
}
-static int AwaitSync(int nleft, Uint32 waiting[MAX_NODES])
+static int AwaitSync()
{
int i;
int timeout;
@@ -191,19 +207,25 @@ static int AwaitSync(int nleft, Uint32 waiting[MAX_NODES])
// See if we have cached network packets
for (i = 0; i < MAX_NODES; ++i) {
- if (CachedPacket[i].len > 0 && waiting[i]) {
+ if (CachedPacket[i].len > 0 && WaitingAcks[i]) {
if (!ProcessSync(i, CachedPacket[i])) {
return -1;
}
- waiting[i] = 0;
- --nleft;
+ WaitingAcks[i] = 0;
}
CachedPacket[i].Reset();
}
+ // Send the packet to anyone still waiting
+ for (i = 0; i < MAX_NODES; ++i) {
+ if (WaitingAcks[i]) {
+ SDLNet_UDP_Send(gNetFD, i+1, &CurrPacket);
+ }
+ }
+
/* Wait for Ack's */
timeout = 0;
- while ( nleft ) {
+ while (WaitingForAck()) {
int ready = SDLNet_CheckSockets(SocketSet, 100);
if (ready < 0) {
error("Network error: SDLNet_CheckSockets()\r\n");
@@ -215,7 +237,7 @@ error("Timed out waiting for frame %ld\r\n", NextFrame);
#endif
/* Timeout, resend the sync packet */
for (i = 0; i < MAX_NODES; ++i) {
- if (waiting[i]) {
+ if (WaitingAcks[i]) {
SDLNet_UDP_Send(gNetFD, i+1, &CurrPacket);
}
}
@@ -291,7 +313,7 @@ error("Received a packet of frame %lu from player %d\r\n", frame, index+1);
#endif
if (frame == NextFrame) {
/* Ignore it if it is a duplicate packet */
- if (!waiting[index]) {
+ if (!WaitingAcks[index]) {
#if DEBUG_NETWORK >= 1
error("Ignoring duplicate packet for frame %lu from player %d\r\n", frame, index+1);
#endif
@@ -302,8 +324,7 @@ error("Ignoring duplicate packet for frame %lu from player %d\r\n", frame, index
if (!ProcessSync(index, Packet)) {
return -1;
}
- waiting[index] = 0;
- --nleft;
+ WaitingAcks[index] = 0;
} else if (frame == (NextFrame-1)) {
/* We kept the last frame cached, so send it */
#if DEBUG_NETWORK >= 1
@@ -334,6 +355,15 @@ error("Received packet for really old frame! (%lu, current = %lu)\r\n",
return 0;
}
+static int AdvanceFrame()
+{
+ CurrOut = !CurrOut;
+ QueuedInput.Reset();
+ ++NextFrame;
+ AdvancedFrame = true;
+ return 0;
+}
+
/* This function is called every frame, and is used to flush the network
buffers, sending sync and keystroke packets.
It is called AFTER the keyboard is polled, and BEFORE GetSyncBuf() is
@@ -346,25 +376,28 @@ error("Received packet for really old frame! (%lu, current = %lu)\r\n",
int SyncNetwork(void)
{
int i;
- int nleft;
- Uint32 waiting[MAX_NODES];
- // Get the queued input
+ if (!AdvancedFrame) {
+ // We still have some nodes we're waiting on...
+ if (AwaitSync() < 0) {
+ return -1;
+ }
+ return AdvanceFrame();
+ }
+
FrameInput.Reset();
QueuedInput.Seek(0);
FrameInput.Write(QueuedInput);
// See if we need to do network synchronization
- nleft = 0;
for (i = 0; i < gGameInfo.GetNumNodes(); ++i) {
if (gGameInfo.IsNetworkNode(i)) {
- ++nleft;
- waiting[i] = gGameInfo.GetNode(i)->nodeID;
+ WaitingAcks[i] = gGameInfo.GetNode(i)->nodeID;
} else {
- waiting[i] = 0;
+ WaitingAcks[i] = 0;
}
}
- if (nleft > 0) {
+ if (WaitingForAck()) {
// Create the sync packet
CurrPacket.Reset();
CurrPacket.Write((Uint8)SYNC_MSG);
@@ -376,21 +409,14 @@ int SyncNetwork(void)
QueuedInput.Seek(0);
CurrPacket.Write(QueuedInput);
- // Send the packet to all the players
- SDLNet_UDP_Send(gNetFD, 0, &CurrPacket);
-
// Wait for sync packets from them
- if (AwaitSync(nleft, waiting) < 0) {
+ if (AwaitSync() < 0) {
+ AdvancedFrame = false;
return -1;
}
-
- CurrOut = !CurrOut;
}
- QueuedInput.Reset();
- ++NextFrame;
-
- return(0);
+ return AdvanceFrame();
}
/* This function retrieves the input for the frame */
@@ -406,8 +432,6 @@ int GetSyncBuf(Uint8 **bufptr)
int Send_NewGame()
{
char message[BUFSIZ];
- int nleft;
- Uint32 waiting[MAX_NODES];
int i, j;
DynamicPacket newgame;
@@ -417,24 +441,22 @@ int Send_NewGame()
SDLNet_UDP_Send(gNetFD, 0, &newgame);
/* Get ready for responses */
- nleft = 0;
for (i = 0; i < gGameInfo.GetNumNodes(); ++i) {
if (gGameInfo.IsNetworkNode(i)) {
- ++nleft;
- waiting[i] = gGameInfo.GetNode(i)->nodeID;
+ WaitingAcks[i] = gGameInfo.GetNode(i)->nodeID;
} else {
- waiting[i] = 0;
+ WaitingAcks[i] = 0;
}
}
/* Wait for Ack's */
- while (nleft > 0) {
+ while (WaitingForAck()) {
/* Show a status */
strcpy(message, "Waiting for players:");
for (i = 0; i < MAX_PLAYERS; ++i) {
const GameInfoPlayer *player = gGameInfo.GetPlayer(i);
for (j = 0; j < MAX_NODES; ++j) {
- if (player->nodeID == waiting[j]) {
+ if (player->nodeID == WaitingAcks[j]) {
sprintf(&message[strlen(message)], " %d", i+1);
break;
}
@@ -449,7 +471,7 @@ int Send_NewGame()
}
if (ready == 0) {
for (i = 0; i < MAX_NODES; ++i) {
- if (waiting[i]) {
+ if (WaitingAcks[i]) {
SDLNet_UDP_Send(gNetFD, i+1, &newgame);
}
}
@@ -482,9 +504,8 @@ int Send_NewGame()
continue;
}
for (i = 0; i < MAX_NODES; ++i) {
- if (nodeID == waiting[i]) {
- waiting[i] = 0;
- --nleft;
+ if (nodeID == WaitingAcks[i]) {
+ WaitingAcks[i] = 0;
break;
}
}
diff --git a/game/netplay.h b/game/netplay.h
index 9ff5ca51..0754bfd9 100644
--- a/game/netplay.h
+++ b/game/netplay.h
@@ -33,3 +33,4 @@ extern int Send_NewGame();
/* Variables from netplay.cpp */
extern UDPsocket gNetFD;
+extern Uint32 NextFrame; // Exposed for debugging purposes
diff --git a/game/replay.cpp b/game/replay.cpp
index b7548d97..bc9f8c21 100644
--- a/game/replay.cpp
+++ b/game/replay.cpp
@@ -100,7 +100,7 @@ printf("Replay complete!\n");
}
}
if (m_seed != GetRandSeed()) {
- error("Error!! \a Frame consistency problem, aborting!!\r\n");
+ error("Error!! \a consistency problem expecting seed %8.8x, got seed %8.8x, aborting!!\r\n", m_seed, GetRandSeed());
return false;
}
@@ -112,15 +112,14 @@ printf("Replay complete!\n");
return false;
}
#ifdef DEBUG_REPLAY
-static int foo = 0;
-printf("Read %d bytes for frame %d", size, foo++);
+printf("Read %d bytes for frame %d", size, NextFrame);
#endif
while (size--) {
m_data.Read(value);
QueueInput(value);
}
#ifdef DEBUG_REPLAY
-printf(", pos = %d\n", m_data.Tell());
+printf(", pos = %d, seed = %8.8x\n", m_data.Tell(), m_seed);
#endif
return true;
}
@@ -164,7 +163,6 @@ Replay::HandleRecording()
}
m_data.Write(data, size);
#ifdef DEBUG_REPLAY
-static int foo = 0;
-printf("Wrote %d bytes for frame %d, size = %d\n", size, foo++, m_data.Size());
+printf("Wrote %d bytes for frame %d, size = %d, seed = %8.8x\n", size, NextFrame, m_data.Size(), m_seed);
#endif
}