refactor: optimize reentrancy guard

src/contracts/core/AVSDirectory.sol

@@ -3,18 +3,20 @@ pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 
-import "../mixins/SignatureUtils.sol";
 import "../permissions/Pausable.sol";
+
+import "../mixins/ReentrancyGuardMixin.sol";
+import "../mixins/SignatureUtils.sol";
+
 import "./AVSDirectoryStorage.sol";
 
 contract AVSDirectory is
     Initializable,
     OwnableUpgradeable,
     Pausable,
     AVSDirectoryStorage,
-    ReentrancyGuardUpgradeable,
+    ReentrancyGuardMixin,
     SignatureUtils
 {
     /**

src/contracts/core/AllocationManager.sol

@@ -3,8 +3,8 @@ pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 
+import "../mixins/ReentrancyGuardMixin.sol";
 import "../mixins/PermissionControllerMixin.sol";
 import "../permissions/Pausable.sol";
 import "../libraries/SlashingLib.sol";
@@ -16,7 +16,7 @@ contract AllocationManager is
     OwnableUpgradeable,
     Pausable,
     AllocationManagerStorage,
-    ReentrancyGuardUpgradeable,
+    ReentrancyGuardMixin,
     PermissionControllerMixin
 {
     using DoubleEndedQueue for DoubleEndedQueue.Bytes32Deque;

src/contracts/core/DelegationManager.sol

@@ -3,13 +3,16 @@ pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 
+import "../permissions/Pausable.sol";
+
+import "../mixins/ReentrancyGuardMixin.sol";
 import "../mixins/SignatureUtils.sol";
 import "../mixins/PermissionControllerMixin.sol";
-import "../permissions/Pausable.sol";
+
 import "../libraries/SlashingLib.sol";
 import "../libraries/Snapshots.sol";
+
 import "./DelegationManagerStorage.sol";
 
 /**
@@ -27,7 +30,7 @@ contract DelegationManager is
     OwnableUpgradeable,
     Pausable,
     DelegationManagerStorage,
-    ReentrancyGuardUpgradeable,
+    ReentrancyGuardMixin,
     SignatureUtils,
     PermissionControllerMixin
 {

src/contracts/core/RewardsCoordinator.sol

@@ -3,9 +3,9 @@ pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
+import "../mixins/ReentrancyGuardMixin.sol";
 import "../libraries/Merkle.sol";
 import "../permissions/Pausable.sol";
 import "./RewardsCoordinatorStorage.sol";
@@ -24,7 +24,7 @@ contract RewardsCoordinator is
     Initializable,
     OwnableUpgradeable,
     Pausable,
-    ReentrancyGuardUpgradeable,
+    ReentrancyGuardMixin,
     RewardsCoordinatorStorage,
     PermissionControllerMixin
 {

src/contracts/core/StrategyManager.sol

@@ -3,9 +3,9 @@ pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
+import "../mixins/ReentrancyGuardMixin.sol";
 import "../mixins/SignatureUtils.sol";
 import "../interfaces/IEigenPodManager.sol";
 import "../permissions/Pausable.sol";
@@ -23,7 +23,7 @@ import "./StrategyManagerStorage.sol";
 contract StrategyManager is
     Initializable,
     OwnableUpgradeable,
-    ReentrancyGuardUpgradeable,
+    ReentrancyGuardMixin,
     Pausable,
     StrategyManagerStorage,
     SignatureUtils

src/contracts/mixins/ReentrancyGuardMixin.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.27;
+
+/**
+ * @dev Variant of {ReentrancyGuard} that uses transient storage.
+ *
+ * NOTE: This variant only works on networks where EIP-1153 is available.
+ */
+abstract contract ReentrancyGuardMixin {
+    // keccak256(abi.encode(uint256(keccak256("eigenlayer.storage.ReentrancyGuardMixin")) - 1)) & ~bytes32(uint256(0xff))
+    uint256 private constant _REENTRANCY_GUARD_SLOT =
+        0x61bb794ad7a504b3613420bc192fca11ecb0ea36bf99527d17aa6bd66a5db500;
+
+    /// @dev Unauthorized reentrant call.
+    error Reentrancy();
+
+    /// @dev Guards a function from reentrancy.
+    modifier nonReentrant() virtual {
+        uint256 s = _REENTRANCY_GUARD_SLOT;
+        /// @solidity memory-safe-assembly
+        assembly {
+            if tload(s) {
+                mstore(0x00, 0xab143c06) // `Reentrancy()`.
+                revert(0x1c, 0x04)
+            }
+            tstore(s, address())
+        }
+        _;
+        /// @solidity memory-safe-assembly
+        assembly {
+            tstore(s, 0)
+        }
+    }
+}

src/contracts/pods/EigenPod.sol

@@ -2,9 +2,10 @@
 pragma solidity ^0.8.27;
 
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
+import "../mixins/ReentrancyGuardMixin.sol";
+
 import "../libraries/BeaconChainProofs.sol";
 import "../libraries/BytesLib.sol";
 
@@ -23,7 +24,7 @@ import "./EigenPodStorage.sol";
  * @dev Note that all beacon chain balances are stored as gwei within the beacon chain datastructures. We choose
  *   to account balances in terms of gwei in the EigenPod contract and convert to wei when making calls to other contracts
  */
-contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingConstants, EigenPodStorage {
+contract EigenPod is Initializable, ReentrancyGuardMixin, EigenPodPausingConstants, EigenPodStorage {
     using BytesLib for bytes;
     using SafeERC20 for IERC20;
     using BeaconChainProofs for *;

src/contracts/pods/EigenPodManager.sol

@@ -4,8 +4,8 @@ pragma solidity ^0.8.27;
 import "@openzeppelin/contracts/utils/Create2.sol";
 import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
 import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
-import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
 
+import "../mixins/ReentrancyGuardMixin.sol";
 import "../libraries/SlashingLib.sol";
 import "../permissions/Pausable.sol";
 import "./EigenPodPausingConstants.sol";
@@ -27,7 +27,7 @@ contract EigenPodManager is
     Pausable,
     EigenPodPausingConstants,
     EigenPodManagerStorage,
-    ReentrancyGuardUpgradeable
+    ReentrancyGuardMixin
 {
     using SlashingLib for *;
     using Math for *;