The following is the current FSM. I wish there was a way to generate graphics for it, but not familiar with a good way to do that.
With the various tweaks along the way, I fear it has drifted a bit, but at least here is a rigorous definition of the atomic FSM.
It is a bit tricky as some things are implicit (sending of the tx) but the events for a state responsible for that transition is usually a direct map from the protocol description
// Two initial states are BOB_idle and ALICE_idle
// Inconvenient to start statemachines before this as typically after posting something in the orderbook, it is possible for multiple offers to come in. In that case the user or designated tradebot will need to choose among the acceptable offers and also to determine how much longer to wait. Also, an orderbook entry is technically a state, but there is no assurance it will ever proceed beyond the initial state and not just expire. Once an incoming offer is accepted, then the statemachine is created to push the swap toward completion.
// the initiator includes a deck of INSTANTDEX_DECKSIZE keypairs
//
// "BTC are message events from other party (message events capped at length 8)
// "" are special events
// types: , osit, payment, is altcoin claim, claim and claim are bob's and alice's reclaiming of their payments, and claim are bob's and alice's reclaim of fee for failed trade, is alice claiming the deposit
// "found" means the other party's is confirmed at user specified confidence level
// BTC_cleanup state just unwinds pending swap as nothing has been committed yet
// states instantdex_statecreate(s,n,,handlerfunc,errorhandler,,
// a given state has a couple of handlers and custom events, with timeouts and errors invoking a bypass
// events instantdex_addevent(s,*n,,,,)
*n = 2;
s = instantdex_statecreate(s,n,"BTC_cleanup",BTC_cleanupfunc,0,0,0,-1); // from states without any commits
memset(s,0,sizeof(*s) * 2);
// terminal [BLOCKING] states for the corresponding transaction
// if all goes well both alice and bob get to claim the other's payments
s = instantdex_statecreate(s,n,"ALICE_claimedbtc",ALICE_claimbtcfunc,0,0,0,0);
instantdex_addevent(s,*n,"ALICE_claimedbtc","aclfound","poll","BTC_cleanup");
instantdex_addevent(s,*n,"ALICE_claimedbtc","poll","poll","ALICE_claimedbtc");
s = instantdex_statecreate(s,n,"BOB_depclaimed",BOB_reclaimfunc,0,0,0,0); // deposit back
instantdex_addevent(s,*n,"BOB_depclaimed","brefound","poll","BTC_cleanup");
instantdex_addevent(s,*n,"BOB_depclaimed","poll","poll","BOB_depclaimed");
s = instantdex_statecreate(s,n,"BOB_claimedalt",BOB_claimaltfunc,0,0,0,0);
instantdex_addevent(s,*n,"BOB_claimedalt","bclfound","poll","BOB_depclaimed");
instantdex_addevent(s,*n,"BOB_claimedalt","poll","poll","BOB_claimedalt");
// if things go wrong, bob gets his deposit and fee back
s = instantdex_statecreate(s,n,"BOB_feereclaimed",BOB_feereclaimfunc,0,0,0,0);
instantdex_addevent(s,*n,"BOB_feereclaimed","bfrfound","poll","BTC_cleanup");
instantdex_addevent(s,*n,"BOB_feereclaimed","poll","poll","BOB_feereclaimed");
s = instantdex_statecreate(s,n,"BOB_reclaimed",BOB_reclaimfunc,0,0,0,0); // deposit back
instantdex_addevent(s,*n,"BOB_reclaimed","brefound","poll","BOB_feereclaimed");
instantdex_addevent(s,*n,"BOB_reclaimed","poll","poll","BOB_reclaimed");
// if things go wrong, alice reclaims her altpayment or claims the deposit and then fee
s = instantdex_statecreate(s,n,"ALICE_feereclaimed",ALICE_feereclaimfunc,0,0,0,0);
instantdex_addevent(s,*n,"ALICE_feereclaimed","afrfound","poll","BTC_cleanup");
instantdex_addevent(s,*n,"ALICE_feereclaimed","poll","poll","ALICE_feereclaimed");
s = instantdex_statecreate(s,n,"ALICE_reclaimed",ALICE_reclaimfunc,0,0,0,0); // altpayment
instantdex_addevent(s,*n,"ALICE_reclaimed","arefound","poll","ALICE_feereclaimed");
instantdex_addevent(s,*n,"ALICE_reclaimed","poll","poll","ALICE_reclaimed");
s = instantdex_statecreate(s,n,"ALICE_depositclaimed",ALICE_claimdepositfunc,0,0,0,0); // altpayment
instantdex_addevent(s,*n,"ALICE_depositclaimed","adpfound","poll","ALICE_feereclaimed");
instantdex_addevent(s,*n,"ALICE_depositclaimed","poll","poll","ALICE_depositclaimed");
// end terminal [BLOCKING] states
// need to create states before they can be referred to, that way a one pass FSM compile is possible
s = instantdex_statecreate(s,n,"BOB_gotoffer",BTC_waitprivCfunc,0,"BTC_cleanup",0,1);
s = instantdex_statecreate(s,n,"ALICE_gotoffer",BTC_waitprivCfunc,0,"BTC_cleanup",0,1);
s = instantdex_statecreate(s,n,"BOB_sentprivs",BTC_waitprivsfunc,0,"BTC_cleanup",0,0);
s = instantdex_statecreate(s,n,"BOB_waitfee",BOB_waitfeefunc,0,"BTC_cleanup",0,0);
s = instantdex_statecreate(s,n,"BOB_sentdeposit",BOB_waitBTCalttxfunc,0,"BOB_reclaimed",0,0);
s = instantdex_statecreate(s,n,"BOB_altconfirm",BOB_waitaltconfirmfunc,0,"BOB_reclaimed",0,0);
s = instantdex_statecreate(s,n,"BOB_sentpayment",BOB_waitprivMfunc,0,"BOB_reclaimed",0,0);
s = instantdex_statecreate(s,n,"ALICE_sentprivs",BTC_waitprivsfunc,0,"BTC_cleanup",0,0);
s = instantdex_statecreate(s,n,"Alice_waitfee",ALICE_waitfeefunc,0,"BTC_cleanup",0,0);
s = instantdex_statecreate(s,n,"ALICE_waitdeposit",ALICE_waitdepositfunc,0,"BTC_cleanup",0,0);
s = instantdex_statecreate(s,n,"ALICE_sentalt",ALICE_waitBTCpaytxfunc,0,"ALICE_reclaimed",0,0);
s = instantdex_statecreate(s,n,"ALICE_waitconfirms",ALICE_waitconfirmsfunc,0,"ALICE_reclaimed",0,0);
s = instantdex_statecreate(s,n,"ALICE_checkbobreclaim",ALICE_checkbobreclaimfunc,0,"ALICE_reclaimed",0,0);
if ( 0 ) // following are implicit states and events handled externally to setup datastructures
{
instantdex_addevent(s,*n,"BOB_idle","usrorder","BTCoffer","BOB_sentoffer"); // send deck
instantdex_addevent(s,*n,"ALICE_idle","usrorder","BTCoffer","ALICE_sentoffer");
}
s = instantdex_statecreate(s,n,"BOB_idle",BTC_idlerecvfunc,0,"BTC_cleanup",0,1);
instantdex_addevent(s,*n,"BOB_idle","BTCoffer","BTCdeckC","BOB_gotoffer"); // send deck + Chose
s = instantdex_statecreate(s,n,"ALICE_idle",BTC_idlerecvfunc,0,"BTC_cleanup",0,1);
instantdex_addevent(s,*n,"ALICE_idle","BTCoffer","BTCdeckC","ALICE_gotoffer");
// after offer is sent, wait for other side to choose and sent their deck, then send privs
s = instantdex_statecreate(s,n,"BOB_sentoffer",BTC_waitdeckCfunc,0,"BTC_cleanup",0,1);
s = instantdex_statecreate(s,n,"ALICE_sentoffer",BTC_waitdeckCfunc,0,"BTC_cleanup",0,1);
instantdex_addevent(s,*n,"BOB_sentoffer","BTCdeckC","BTCprivC","BOB_sentprivs"); // send privs + Chose
instantdex_addevent(s,*n,"ALICE_sentoffer","BTCdeckC","BTCprivC","ALICE_sentprivs");
// gotoffer states have received deck and sent BTCdeckC already (along with deck)
s = instantdex_statecreate(s,n,"BOB_gotoffer",BTC_waitprivCfunc,0,"BTC_cleanup",0,1);
s = instantdex_statecreate(s,n,"ALICE_gotoffer",BTC_waitprivCfunc,0,"BTC_cleanup",0,1);
instantdex_addevent(s,*n,"BOB_gotoffer","BTCprivC","BTCprivs","BOB_sentprivs"); // send privs
instantdex_addevent(s,*n,"ALICE_gotoffer","BTCprivC","BTCprivs","ALICE_sentprivs");
// to reach sentprivs, all paths must have sent/recv deck and Chose and verified cut and choose
s = instantdex_statecreate(s,n,"BOB_sentprivs",BTC_waitprivsfunc,0,"BTC_cleanup",0,0);
instantdex_addevent(s,*n,"BOB_sentprivs","BTCprivs","poll","BOB_waitfee");
instantdex_addevent(s,*n,"BOB_sentprivs","poll","poll","BOB_sentprivs");
s = instantdex_statecreate(s,n,"ALICE_sentprivs",BTC_waitprivsfunc,0,"BTC_cleanup",0,0);
instantdex_addevent(s,*n,"ALICE_sentprivs","BTCprivs","poll","Alice_waitfee");
instantdex_addevent(s,*n,"ALICE_sentprivs","poll","poll","ALICE_sentprivs");
// [BLOCKING: fee] Bob waits for fee and sends deposit when it appears
s = instantdex_statecreate(s,n,"BOB_waitfee",BOB_waitfeefunc,0,"BTC_cleanup",0,0);
instantdex_addevent(s,*n,"BOB_waitfee","feefound","BTCdeptx","BOB_sentdeposit");
instantdex_addevent(s,*n,"BOB_waitfee","poll","poll","BOB_waitfee");
// [BLOCKING: fee and deposit] Alice waits for fee and then waits for deposit to confirm and sends altpayment
s = instantdex_statecreate(s,n,"Alice_waitfee",ALICE_waitfeefunc,0,"BTC_cleanup",0,0);
instantdex_addevent(s,*n,"Alice_waitfee","feefound","poll","ALICE_waitdeposit");
instantdex_addevent(s,*n,"Alice_waitfee","poll","poll","Alice_waitfee");
s = instantdex_statecreate(s,n,"ALICE_waitdeposit",ALICE_waitdepositfunc,0,"BTC_cleanup",0,0);
instantdex_addevent(s,*n,"ALICE_waitdeposit","depfound","BTCalttx","ALICE_sentalt");
instantdex_addevent(s,*n,"ALICE_waitdeposit","poll","poll","ALICE_waitdeposit");
// [BLOCKING: BTCalttx and altfound] now Bob's turn to make sure altpayment is confirmed and send real payment
s = instantdex_statecreate(s,n,"BOB_sentdeposit",BOB_waitBTCalttxfunc,0,"BOB_reclaimed",0,0);
instantdex_addevent(s,*n,"BOB_sentdeposit","BTCalttx","poll","BOB_altconfirm");
s = instantdex_statecreate(s,n,"BOB_altconfirm",BOB_waitaltconfirmfunc,0,"BOB_reclaimed",0,0);
instantdex_addevent(s,*n,"BOB_altconfirm","altfound","BTCpaytx","BOB_sentpayment");
instantdex_addevent(s,*n,"BOB_altconfirm","poll","poll","BOB_altconfirm");
// [BLOCKING: BTCpaytx] now Alice's turn to make sure payment is confrmed and send in claim or see bob's reclaim and reclaim
s = instantdex_statecreate(s,n,"ALICE_sentalt",ALICE_waitBTCpaytxfunc,0,"ALICE_reclaimed",0,0);
instantdex_addevent(s,*n,"ALICE_sentalt","BTCpaytx","poll","ALICE_waitconfirms");
s = instantdex_statecreate(s,n,"ALICE_waitconfirms",ALICE_waitconfirmsfunc,0,"ALICE_reclaimed",0,0);
instantdex_addevent(s,*n,"ALICE_waitconfirms","altfound","BTCprivM","ALICE_claimedbtc");
instantdex_addevent(s,*n,"ALICE_waitconfirms","poll","poll","ALICE_checkbobreclaim");
s = instantdex_statecreate(s,n,"ALICE_checkbobreclaim",ALICE_checkbobreclaimfunc,0,"ALICE_reclaimed",0,0);
instantdex_addevent(s,*n,"ALICE_checkbobreclaim","brefound","poll","ALICE_reclaimed");
instantdex_addevent(s,*n,"ALICE_checkbobreclaim","poll","poll","ALICE_waitconfirms");
// [BLOCKING: privM] Bob waits for privM either from Alice or alt blockchain
s = instantdex_statecreate(s,n,"BOB_sentpayment",BOB_waitprivMfunc,0,"BOB_reclaimed",0,0);
instantdex_addevent(s,*n,"BOB_sentpayment","aclfound","BTCdone","BOB_claimedalt");
instantdex_addevent(s,*n,"BOB_sentpayment","BTCprivM","BTCdone","BOB_claimedalt");
instantdex_addevent(s,*n,"BOB_sentpayment","poll","poll","BOB_sentpayment");
If you want to specify the protocol using FSM description, that would eliminate any ambiguities and blatant mistakes by silly coders like me.
