Amm v2 - Exit mode and pool reuse

packages/loopring_v3/contracts/amm/AmplifiedAmmController.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // Copyright 2017 Loopring Technology Limited.
 pragma solidity ^0.7.0;
+pragma experimental ABIEncoderV2;
 
 import "./IAmmController.sol";
 import "../amm/LoopringAmmPool.sol";
@@ -77,4 +78,21 @@ contract AmplifiedAmmController is IAmmController, Claimable
             amplificationFactor = AMPLIFICATION_FACTOR_BASE;
         }
     }
+
+    function setupPool(
+        LoopringAmmPool pool,
+        AmmData.PoolConfig calldata config
+        )
+        external
+        onlyOwner
+    {
+        pool.setupPool(config);
+    }
+
+    function enableExitMode(LoopringAmmPool pool)
+        external
+        onlyOwner
+    {
+        pool.enableExitMode();
+    }
 }

packages/loopring_v3/contracts/amm/LoopringAmmPool.sol

@@ -98,9 +98,17 @@ contract LoopringAmmPool is
         external
         nonReentrant
     {
+        require(state.accountID == 0 || msg.sender == address(controller), "UNAUTHORIZED");
         state.setupPool(config);
     }
 
+    function enableExitMode()
+        external
+        onlyFromController
+    {
+        state.exitMode = true;
+    }
+
     // Anyone is able to shut down the pool when requests aren't being processed any more.
     function shutdown(address exitOwner)
         external
@@ -113,7 +121,6 @@ contract LoopringAmmPool is
 
     function shutdownByController()
         external
-        payable
         onlyWhenOnline
         nonReentrant
         onlyFromController

packages/loopring_v3/contracts/amm/libamm/AmmData.sol

@@ -142,5 +142,6 @@ library AmmData
         mapping (bytes32 => bool) approvedTx;
 
         mapping (address => uint96) balancesL1;
+        bool exitMode;
     }
 }

packages/loopring_v3/contracts/amm/libamm/AmmExitProcess.sol

@@ -49,14 +49,18 @@ library AmmExitProcess
         bool isForcedExit = false;
 
         if (signature.length == 0) {
-            bytes32 forcedExitHash = AmmExitRequest.hash(ctx.domainSeparator, S.forcedExit[exit.owner]);
-            if (txHash == forcedExitHash) {
-                delete S.forcedExit[exit.owner];
-                S.forcedExitCount--;
-                isForcedExit = true;
+            if (S.exitMode) {
+                require(exit.fee == 0, "INVALID_FEE");
             } else {
-                require(S.approvedTx[txHash], "INVALID_ONCHAIN_APPROVAL");
-                delete S.approvedTx[txHash];
+                bytes32 forcedExitHash = AmmExitRequest.hash(ctx.domainSeparator, S.forcedExit[exit.owner]);
+                if (txHash == forcedExitHash) {
+                    delete S.forcedExit[exit.owner];
+                    S.forcedExitCount--;
+                    isForcedExit = true;
+                } else {
+                    require(S.approvedTx[txHash], "INVALID_ONCHAIN_APPROVAL");
+                    delete S.approvedTx[txHash];
+                }
             }
         } else if (signature.length == 1) {
             ctx.verifySignatureL2(exit.owner, txHash, signature);

packages/loopring_v3/contracts/amm/libamm/AmmPoolToken.sol

@@ -80,7 +80,7 @@ library AmmPoolToken
         uint256               deadline,
         bytes        calldata signature
         )
-        internal
+        public
     {
         require(deadline >= block.timestamp, 'EXPIRED');
 

packages/loopring_v3/contracts/amm/libamm/AmmStatus.sol

@@ -42,26 +42,26 @@ library AmmStatus
             bytes(config.poolName).length > 0 && bytes(config.tokenSymbol).length > 0,
             "INVALID_NAME_OR_SYMBOL"
         );
+
         require(config.sharedConfig != address(0), "INVALID_SHARED_CONFIG");
         require(config.tokens.length == config.weights.length, "INVALID_DATA");
         require(config.tokens.length >= 2, "INVALID_DATA");
         require(config.exchange != address(0), "INVALID_EXCHANGE");
         require(config.accountID != 0, "INVALID_ACCOUNT_ID");
-        require(S.tokens.length == 0, "ALREADY_INITIALIZED");
 
-        S.sharedConfig = IAmmSharedConfig(config.sharedConfig);
-        IExchangeV3 exchange = IExchangeV3(config.exchange);
-        S.exchange = exchange;
-        S.exchangeOwner = exchange.owner();
-        S.exchangeDomainSeparator = exchange.getDomainSeparator();
-        S.accountID = config.accountID;
-        S.poolTokenID = exchange.getTokenID(address(this));
+        require(S._totalSupply == 0, "POOL_IN_USE");
+
         S.feeBips = config.feeBips;
         S.domainSeparator = EIP712.hash(EIP712.Domain(config.poolName, "1.0.0", address(this)));
 
         S.poolName = config.poolName;
         S.symbol = config.tokenSymbol;
+        S.shutdownTimestamp = 0;
+        S.exitMode = false;
 
+        IExchangeV3 exchange = IExchangeV3(config.exchange);
+
+        delete S.tokens;
         for (uint i = 0; i < config.tokens.length; i++) {
             address token = config.tokens[i];
             S.tokens.push(AmmData.Token({
@@ -71,16 +71,26 @@ library AmmStatus
             }));
         }
 
-        // Mint all liquidity tokens to the pool account on L2
-        S.balanceOf[address(this)] = AmmData.POOL_TOKEN_MINTED_SUPPLY;
-        S.allowance[address(this)][address(exchange.getDepositContract())] = type(uint256).max;
-        exchange.deposit(
-            address(this), // from
-            address(this), // to
-            address(this), // token
-            uint96(AmmData.POOL_TOKEN_MINTED_SUPPLY),
-            new bytes(0)
-        );
+        bool newPool = (S.accountID == 0);
+        if (newPool) {
+            S.sharedConfig = IAmmSharedConfig(config.sharedConfig);
+            S.exchange = exchange;
+            S.exchangeOwner = exchange.owner();
+            S.exchangeDomainSeparator = exchange.getDomainSeparator();
+            S.accountID = config.accountID;
+            S.poolTokenID = exchange.getTokenID(address(this));
+
+            // Mint all liquidity tokens to the pool account on L2
+            S.balanceOf[address(this)] = AmmData.POOL_TOKEN_MINTED_SUPPLY;
+            S.allowance[address(this)][address(exchange.getDepositContract())] = type(uint256).max;
+            exchange.deposit(
+                address(this), // from
+                address(this), // to
+                address(this), // token
+                uint96(AmmData.POOL_TOKEN_MINTED_SUPPLY),
+                new bytes(0)
+            );
+        }
     }
 
     // Anyone is able to shut down the pool when requests aren't being processed any more.

packages/loopring_v3/migrations/7_deploy_amm.js

@@ -8,18 +8,21 @@ const AmmExitRequest = artifacts.require("AmmExitRequest");
 const AmmStatus = artifacts.require("AmmStatus");
 const AmmWithdrawal = artifacts.require("AmmWithdrawal");
 const AmmAssetManagement = artifacts.require("AmmAssetManagement");
+const AmmPoolToken = artifacts.require("AmmPoolToken");
 const AmplifiedAmmController = artifacts.require("AmplifiedAmmController");
 
 module.exports = function(deployer, network, accounts) {
   if (network != "live" && network != "live-fork") {
     deployer.then(async () => {
       await deployer.deploy(AmplifiedAmmController);
 
+      await deployer.deploy(AmmPoolToken);
       await deployer.deploy(AmmAssetManagement);
       await deployer.deploy(AmmJoinRequest);
       await deployer.deploy(AmmExitRequest);
       await deployer.deploy(AmmStatus);
       await deployer.deploy(AmmWithdrawal);
+      await deployer.link(AmmPoolToken, LoopringAmmPool);
       await deployer.link(AmmAssetManagement, LoopringAmmPool);
       await deployer.link(AmmJoinRequest, LoopringAmmPool);
       await deployer.link(AmmExitRequest, LoopringAmmPool);
@@ -32,6 +35,7 @@ module.exports = function(deployer, network, accounts) {
         false
       );
 
+      await deployer.link(AmmPoolToken, LoopringAmmPoolCopy);
       await deployer.link(AmmAssetManagement, LoopringAmmPoolCopy);
       await deployer.link(AmmJoinRequest, LoopringAmmPoolCopy);
       await deployer.link(AmmExitRequest, LoopringAmmPoolCopy);