From 7baac7005670ac05ad31b7400b3efa1e6b15cded Mon Sep 17 00:00:00 2001
From: Boqin Qin <bobbqqin@bupt.edu.cn>
Date: Tue, 9 Jun 2020 05:08:54 +0800
Subject: [PATCH] beacon_node, consensus: fix possible deadlocks when comparing
 with itself (#1241)

---
 beacon_node/operation_pool/src/lib.rs                         | 4 ++++
 .../proto_array_fork_choice/src/proto_array_fork_choice.rs    | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/beacon_node/operation_pool/src/lib.rs b/beacon_node/operation_pool/src/lib.rs
index 79eb3f890a..d91aa2cc56 100644
--- a/beacon_node/operation_pool/src/lib.rs
+++ b/beacon_node/operation_pool/src/lib.rs
@@ -20,6 +20,7 @@ use state_processing::per_block_processing::{
 };
 use std::collections::{hash_map, HashMap, HashSet};
 use std::marker::PhantomData;
+use std::ptr;
 use types::{
     typenum::Unsigned, Attestation, AttesterSlashing, BeaconState, BeaconStateError, ChainSpec,
     EthSpec, Fork, Hash256, ProposerSlashing, RelativeEpoch, SignedVoluntaryExit, Validator,
@@ -408,6 +409,9 @@ fn prune_validator_hash_map<T, F, E: EthSpec>(
 /// Compare two operation pools.
 impl<T: EthSpec + Default> PartialEq for OperationPool<T> {
     fn eq(&self, other: &Self) -> bool {
+        if ptr::eq(self, other) {
+            return true;
+        }
         *self.attestations.read() == *other.attestations.read()
             && *self.attester_slashings.read() == *other.attester_slashings.read()
             && *self.proposer_slashings.read() == *other.proposer_slashings.read()
diff --git a/consensus/proto_array_fork_choice/src/proto_array_fork_choice.rs b/consensus/proto_array_fork_choice/src/proto_array_fork_choice.rs
index 8fc390003f..2ce28483be 100644
--- a/consensus/proto_array_fork_choice/src/proto_array_fork_choice.rs
+++ b/consensus/proto_array_fork_choice/src/proto_array_fork_choice.rs
@@ -5,6 +5,7 @@ use parking_lot::{RwLock, RwLockReadGuard};
 use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
 use std::collections::HashMap;
+use std::ptr;
 use types::{Epoch, Hash256, Slot};
 
 pub const DEFAULT_PRUNE_THRESHOLD: usize = 256;
@@ -51,6 +52,9 @@ pub struct ProtoArrayForkChoice {
 
 impl PartialEq for ProtoArrayForkChoice {
     fn eq(&self, other: &Self) -> bool {
+        if ptr::eq(self, other) {
+            return true;
+        }
         *self.proto_array.read() == *other.proto_array.read()
             && *self.votes.read() == *other.votes.read()
             && *self.balances.read() == *other.balances.read()