feat(lotus-sim): fund from a funding account

Instead of funding the simulation from the burnt-funds actor, fund from
a custom account and take a "tax" to fund that account.

Otherwise, we run out of funds...

cmd/lotus-sim/simulation/funding.go

@@ -0,0 +1,287 @@
+package simulation
+
+import (
+	"bytes"
+	"context"
+	"sort"
+	"time"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/big"
+	"github.com/filecoin-project/go-state-types/exitcode"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/actors"
+	"github.com/filecoin-project/lotus/chain/actors/aerrors"
+	"github.com/filecoin-project/lotus/chain/actors/builtin"
+	"github.com/filecoin-project/lotus/chain/actors/builtin/multisig"
+	"github.com/filecoin-project/lotus/chain/types"
+)
+
+var (
+	fundAccount = func() address.Address {
+		addr, err := address.NewIDAddress(100)
+		if err != nil {
+			panic(err)
+		}
+		return addr
+	}()
+	minFundAcctFunds = abi.TokenAmount(types.MustParseFIL("1000000FIL"))
+	maxFundAcctFunds = abi.TokenAmount(types.MustParseFIL("100000000FIL"))
+	taxMin           = abi.TokenAmount(types.MustParseFIL("1000FIL"))
+)
+
+func fund(send packFunc, target address.Address) error {
+	_, err := send(&types.Message{
+		From:   fundAccount,
+		To:     target,
+		Value:  targetFunds,
+		Method: builtin.MethodSend,
+	})
+	return err
+}
+
+// sendAndFund "packs" the given message, funding the actor if necessary. It:
+//
+// 1. Tries to send the given message.
+// 2. If that fails, it checks to see if the exit code was ErrInsufficientFunds.
+// 3. If so, it sends 1K FIL from the "burnt funds actor" (because we need to send it from
+//    somewhere) and re-tries the message.0
+//
+// NOTE: If the message fails a second time, the funds won't be "unsent".
+func sendAndFund(send packFunc, msg *types.Message) (*types.MessageReceipt, error) {
+	res, err := send(msg)
+	aerr, ok := err.(aerrors.ActorError)
+	if !ok || aerr.RetCode() != exitcode.ErrInsufficientFunds {
+		return res, err
+	}
+	// Ok, insufficient funds. Let's fund this miner and try again.
+	err = fund(send, msg.To)
+	if err != nil {
+		if err != ErrOutOfGas {
+			err = xerrors.Errorf("failed to fund %s: %w", msg.To, err)
+		}
+		return nil, err
+	}
+	return send(msg)
+}
+
+func (ss *simulationState) packFunding(ctx context.Context, cb packFunc) (_err error) {
+	st, err := ss.stateTree(ctx)
+	if err != nil {
+		return err
+	}
+	fundAccActor, err := st.GetActor(fundAccount)
+	if err != nil {
+		return err
+	}
+	if minFundAcctFunds.LessThan(fundAccActor.Balance) {
+		return nil
+	}
+
+	// Ok, we're going to go fund this thing.
+	start := time.Now()
+
+	type actor struct {
+		types.Actor
+		Address address.Address
+	}
+
+	var targets []*actor
+	err = st.ForEach(func(addr address.Address, act *types.Actor) error {
+		if act.Balance.LessThan(taxMin) {
+			return nil
+		}
+		if !(builtin.IsAccountActor(act.Code) || builtin.IsMultisigActor(act.Code)) {
+			return nil
+		}
+		targets = append(targets, &actor{*act, addr})
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	balance := fundAccActor.Balance.Copy()
+
+	sort.Slice(targets, func(i, j int) bool {
+		return targets[i].Balance.GreaterThan(targets[j].Balance)
+	})
+
+	store := ss.Chainstore.ActorStore(ctx)
+
+	epoch := ss.nextEpoch()
+
+	nv := ss.StateManager.GetNtwkVersion(ctx, epoch)
+	actorsVersion := actors.VersionForNetwork(nv)
+
+	var accounts, multisigs int
+	defer func() {
+		if _err != nil {
+			return
+		}
+		log.Infow("finished funding the simulation",
+			"duration", time.Since(start),
+			"targets", len(targets),
+			"epoch", epoch,
+			"new-balance", types.FIL(balance),
+			"old-balance", types.FIL(fundAccActor.Balance),
+			"multisigs", multisigs,
+			"accounts", accounts,
+		)
+	}()
+
+	for _, actor := range targets {
+		switch {
+		case builtin.IsAccountActor(actor.Code):
+			if _, err := cb(&types.Message{
+				From:  actor.Address,
+				To:    fundAccount,
+				Value: actor.Balance,
+			}); err == ErrOutOfGas {
+				return nil
+			} else if err != nil {
+				return err
+			}
+			accounts++
+		case builtin.IsMultisigActor(actor.Code):
+			msigState, err := multisig.Load(store, &actor.Actor)
+			if err != nil {
+				return err
+			}
+
+			threshold, err := msigState.Threshold()
+			if err != nil {
+				return err
+			}
+
+			if threshold > 16 {
+				log.Debugw("ignoring multisig with high threshold",
+					"multisig", actor.Address,
+					"threshold", threshold,
+					"max", 16,
+				)
+				continue
+			}
+
+			locked, err := msigState.LockedBalance(epoch)
+			if err != nil {
+				return err
+			}
+
+			if locked.LessThan(taxMin) {
+				continue // not worth it.
+			}
+
+			allSigners, err := msigState.Signers()
+			if err != nil {
+				return err
+			}
+			signers := make([]address.Address, 0, threshold)
+			for _, signer := range allSigners {
+				actor, err := st.GetActor(signer)
+				if err != nil {
+					return err
+				}
+				if !builtin.IsAccountActor(actor.Code) {
+					// I am so not dealing with this mess.
+					continue
+				}
+				if uint64(len(signers)) >= threshold {
+					break
+				}
+			}
+			// Ok, we're not dealing with this one.
+			if uint64(len(signers)) < threshold {
+				continue
+			}
+
+			available := big.Sub(actor.Balance, locked)
+
+			var txnId uint64
+			{
+				msg, err := multisig.Message(actorsVersion, signers[0]).Propose(
+					actor.Address, fundAccount, available,
+					builtin.MethodSend, nil,
+				)
+				if err != nil {
+					return err
+				}
+				res, err := cb(msg)
+				if err != nil {
+					if err == ErrOutOfGas {
+						err = nil
+					}
+					return err
+				}
+				var ret multisig.ProposeReturn
+				err = ret.UnmarshalCBOR(bytes.NewReader(res.Return))
+				if err != nil {
+					return err
+				}
+				if ret.Applied {
+					if !ret.Code.IsSuccess() {
+						log.Errorw("failed to tax multisig",
+							"multisig", actor.Address,
+							"exitcode", ret.Code,
+						)
+					}
+					break
+				}
+				txnId = uint64(ret.TxnID)
+			}
+			var ret multisig.ProposeReturn
+			for _, signer := range signers[1:] {
+				msg, err := multisig.Message(actorsVersion, signer).Approve(actor.Address, txnId, nil)
+				if err != nil {
+					return err
+				}
+				res, err := cb(msg)
+				if err != nil {
+					if err == ErrOutOfGas {
+						err = nil
+					}
+					return err
+				}
+				var ret multisig.ProposeReturn
+				err = ret.UnmarshalCBOR(bytes.NewReader(res.Return))
+				if err != nil {
+					return err
+				}
+				// A bit redundant, but nice.
+				if ret.Applied {
+					break
+				}
+
+			}
+			if !ret.Applied {
+				log.Errorw("failed to apply multisig transaction",
+					"multisig", actor.Address,
+					"txnid", txnId,
+					"signers", len(signers),
+					"threshold", threshold,
+				)
+				continue
+			}
+			if !ret.Code.IsSuccess() {
+				log.Errorw("failed to tax multisig",
+					"multisig", actor.Address,
+					"txnid", txnId,
+					"exitcode", ret.Code,
+				)
+			} else {
+				multisigs++
+			}
+		default:
+			panic("impossible case")
+		}
+		balance = big.Int{Int: balance.Add(balance.Int, actor.Balance.Int)}
+		if balance.GreaterThanEqual(maxFundAcctFunds) {
+			// There's no need to get greedy.
+			// Well, really, we're trying to avoid messing with state _too_ much.
+			return nil
+		}
+	}
+	return nil
+}

cmd/lotus-sim/simulation/precommit.go

@@ -9,7 +9,6 @@ import (
 	"github.com/filecoin-project/go-state-types/big"
 	"github.com/filecoin-project/go-state-types/network"
 	"github.com/filecoin-project/lotus/chain/actors"
-	"github.com/filecoin-project/lotus/chain/actors/builtin"
 	"github.com/filecoin-project/lotus/chain/actors/builtin/miner"
 	"github.com/filecoin-project/lotus/chain/actors/policy"
 	"github.com/filecoin-project/lotus/chain/types"
@@ -118,15 +117,12 @@ func (ss *simulationState) packPreCommitsMiner(ctx context.Context, cb packFunc,
 	}
 
 	if big.Cmp(minerBalance, minFunds) < 0 {
-		if _, err := cb(&types.Message{
-			From:   builtin.BurntFundsActorAddr,
-			To:     minerAddr,
-			Value:  targetFunds,
-			Method: builtin.MethodSend,
-		}); err == ErrOutOfGas {
-			return 0, true, nil
-		} else if err != nil {
-			return 0, false, xerrors.Errorf("failed to fund miner %s: %w", minerAddr, err)
+		err := fund(cb, minerAddr)
+		if err != nil {
+			if err == ErrOutOfGas {
+				return 0, true, nil
+			}
+			return 0, false, err
 		}
 	}
 

cmd/lotus-sim/simulation/provecommit.go

@@ -4,7 +4,6 @@ import (
 	"context"
 
 	"github.com/filecoin-project/go-bitfield"
-	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"
@@ -12,7 +11,6 @@ import (
 	"github.com/filecoin-project/go-state-types/network"
 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/actors/aerrors"
-	"github.com/filecoin-project/lotus/chain/actors/builtin"
 	"github.com/filecoin-project/lotus/chain/actors/builtin/miner"
 	"github.com/filecoin-project/lotus/chain/actors/policy"
 	"github.com/filecoin-project/lotus/chain/types"
@@ -68,36 +66,6 @@ type proveCommitResult struct {
 	full                    bool
 }
 
-// sendAndFund "packs" the given message, funding the actor if necessary. It:
-//
-// 1. Tries to send the given message.
-// 2. If that fails, it checks to see if the exit code was ErrInsufficientFunds.
-// 3. If so, it sends 1K FIL from the "burnt funds actor" (because we need to send it from
-//    somewhere) and re-tries the message.0
-//
-// NOTE: If the message fails a second time, the funds won't be "unsent".
-func sendAndFund(send packFunc, msg *types.Message) (*types.MessageReceipt, error) {
-	res, err := send(msg)
-	aerr, ok := err.(aerrors.ActorError)
-	if !ok || aerr.RetCode() != exitcode.ErrInsufficientFunds {
-		return res, err
-	}
-	// Ok, insufficient funds. Let's fund this miner and try again.
-	_, err = send(&types.Message{
-		From:   builtin.BurntFundsActorAddr,
-		To:     msg.To,
-		Value:  targetFunds,
-		Method: builtin.MethodSend,
-	})
-	if err != nil {
-		if err != ErrOutOfGas {
-			err = xerrors.Errorf("failed to fund %s: %w", msg.To, err)
-		}
-		return nil, err
-	}
-	return send(msg)
-}
-
 // packProveCommitsMiner enqueues a prove commits from the given miner until it runs out of
 // available prove-commits, batching as much as possible.
 //

cmd/lotus-sim/simulation/step.go

@@ -244,10 +244,12 @@ func (ss *simulationState) packMessages(ctx context.Context, cb packFunc) error
 	// We pack messages in-order:
 	// 1. Any window posts. We pack window posts as soon as the deadline opens to ensure we only
 	//    miss them if/when we run out of chain bandwidth.
-	// 2. Prove commits. We do this eagerly to ensure they don't expire.
-	// 3. Finally, we fill the rest of the space with pre-commits.
+	// 2. We then move funds to our "funding" account, if it's running low.
+	// 3. Prove commits. We do this eagerly to ensure they don't expire.
+	// 4. Finally, we fill the rest of the space with pre-commits.
 	messageGenerators := []messageGenerator{
 		ss.packWindowPoSts,
+		ss.packFunding,
 		ss.packProveCommits,
 		ss.packPreCommits,
 	}