From 4b2bfc87f97764fbb60ab3a69a61dd0a7e09520c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Kohlschu=CC=88tter?=
 <christian@kohlschutter.com>
Date: Thu, 9 Nov 2023 15:02:41 +0100
Subject: [PATCH] Revert "Fix concurrency issue from modifying the
 selectedKeysSet"

This reverts commit b8386a1d8391ffb4402edb1e1f0a070606debdb5.
---
 .../org/newsclub/net/unix/AFSelectionKey.java |  6 ++----
 .../org/newsclub/net/unix/AFSelector.java     | 19 -------------------
 2 files changed, 2 insertions(+), 23 deletions(-)

diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelectionKey.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelectionKey.java
index 9f615dfbd..e5db4dc2d 100644
--- a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelectionKey.java
+++ b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelectionKey.java
@@ -80,10 +80,8 @@ boolean isSelected() {
 
   @Override
   public void cancel() {
-    if (!cancelled.compareAndSet(false, true) || !chann.isOpen()) {
-      return;
-    }
-    sel.prepareRemove(this);
+    sel.remove(this);
+    cancelNoRemove();
   }
 
   void cancelNoRemove() {
diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelector.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelector.java
index fedfab7b1..433aac740 100644
--- a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelector.java
+++ b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSelector.java
@@ -49,7 +49,6 @@ final class AFSelector extends AbstractSelector {
 
   private final Set<SelectionKey> selectedKeysSet = new HashSet<>();
   private final Set<SelectionKey> selectedKeysPublic = new UngrowableSet<>(selectedKeysSet);
-  private final Set<SelectionKey> cancelledKeysSet = new HashSet<>();
 
   private PollFd pollFd = null;
 
@@ -113,7 +112,6 @@ private int select0(int timeout) throws IOException {
         throw new ClosedSelectorException();
       }
       pfd = pollFd = initPollFd(pollFd);
-      performRemove();
       selectedKeysSet.clear();
     }
     int num;
@@ -301,23 +299,6 @@ synchronized void remove(AFSelectionKey key) {
     pollFd = null;
   }
 
-  void prepareRemove(AFSelectionKey key) {
-    synchronized (cancelledKeysSet) {
-      cancelledKeysSet.add(key);
-    }
-  }
-
-  void performRemove() {
-    synchronized (cancelledKeysSet) {
-      for (SelectionKey key : cancelledKeysSet) {
-        selectedKeysSet.remove(key);
-        deregister((AFSelectionKey) key);
-        pollFd = null;
-      }
-      cancelledKeysSet.clear();
-    }
-  }
-
   private void deregister(AFSelectionKey key) {
     // super.deregister unnecessarily casts SelectionKey to AbstractSelectionKey, and
     // ((AbstractSelectableChannel)key.channel()).removeKey(key); is not visible.