scorched3d/scorched3d-44-fix-hang-on-fast-machines.patch

54 lines
2.5 KiB
Diff

diff -up scorched/src/common/coms/ComsLoadLevelMessage.cpp~ scorched/src/common/coms/ComsLoadLevelMessage.cpp
--- scorched/src/common/coms/ComsLoadLevelMessage.cpp~ 2014-08-01 18:47:31.000000000 +0200
+++ scorched/src/common/coms/ComsLoadLevelMessage.cpp 2020-08-13 21:33:59.895250469 +0200
@@ -108,6 +108,49 @@ bool ComsLoadLevelMessage::loadState(Sco
bool ComsLoadLevelMessage::loadTanks(ScorchedContext &context)
{
+ /*
+ * There is a timing bug which shows on really fast machines
+ * where the client starts talking to the server before the
+ * server initial setup is done.
+ * In sofar as I have managed to debug this, the following
+ * happens on slower machines, aka the GOOD case:
+ *
+ * Server TankAddSimAction::invokeAction() new Tank "(Bot) Fred"
+ * Server TankAddSimAction::invokeAction() new Tank "(Bot) Ted"
+ * Server TankAddSimAction::invokeAction() new Tank "Player 1"
+ * Server TankAddSimAction::invokeAction() new Tank "Spectator"
+ * Client TankAddSimAction::invokeAction() new Tank "(Bot) Fred"
+ * Client TankAddSimAction::invokeAction() new Tank "(Bot) Ted"
+ * Client TankAddSimAction::invokeAction() new Tank "Player 1"
+ * Client TankAddSimAction::invokeAction() new Tank "Spectator"
+ *
+ * Note the server internally creates all tanks before the
+ * client does and thus before the client starts sending
+ * messages related to these tanks to the server.
+ *
+ * On a fast enough system (i7-10610U) the following order
+ * has been observed instead:
+ *
+ * Server TankAddSimAction::invokeAction() new Tank "(Bot) Fred"
+ * Server TankAddSimAction::invokeAction() new Tank "(Bot) Ted"
+ * Client TankAddSimAction::invokeAction() new Tank "(Bot) Fred"
+ * Client TankAddSimAction::invokeAction() new Tank "(Bot) Ted"
+ * Client TankAddSimAction::invokeAction() new Tank "Player 1"
+ * Client TankAddSimAction::invokeAction() new Tank "Spectator"
+ * Server TankAddSimAction::invokeAction() new Tank "Player 1"
+ * Server TankAddSimAction::invokeAction() new Tank "Spectator"
+ *
+ * Note the server creates the "Player 1" and "Spectator"
+ * tanks after the client, this causes the server to ignore
+ * some initial messages from the client related to these
+ * tanks, after which things get stuck, breaking non-networked
+ * games on fast machines.
+ *
+ * The sleep below is an ugly but effective workaround for this
+ * issue.
+ */
+ SDL_Delay(100);
+
NetBufferReader reader(tanksBuffer_);
// Add any new tanks