From 3b6245536cf55da9e8bfcdb03c845fe9ef931d7f Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Fri, 3 Apr 2026 16:26:47 +0900
Subject: [PATCH] LeakChecker: skip CLOSE_WAIT sockets

Those FDs still live in the kernel space but have been closed in the
user space.
---
 tool/lib/leakchecker.rb | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/tool/lib/leakchecker.rb b/tool/lib/leakchecker.rb
index 513ffd23eb5f7c..36662e9a46761d 100644
--- a/tool/lib/leakchecker.rb
+++ b/tool/lib/leakchecker.rb
@@ -77,6 +77,7 @@ def check_fd_leak(test_name)
         end
         (h[fd] ||= []) << [io, autoclose, inspect]
       }
+      inspect = {}
       fd_leaked.select! {|fd|
         str = ''.dup
         pos = nil
@@ -98,6 +99,7 @@ def check_fd_leak(test_name)
             s = io.stat
           rescue Errno::EBADF
             # something un-stat-able
+            live2.delete(fd)
             next
           else
             next if /darwin/ =~ RUBY_PLATFORM and [0, -1].include?(s.dev)
@@ -106,15 +108,35 @@ def check_fd_leak(test_name)
             io&.close
           end
         end
-        puts "Leaked file descriptor: #{test_name}: #{fd}#{str}"
-        puts "  The IO was created at #{pos}" if pos
+        inspect[fd] = [str, pos]
         true
       }
       unless fd_leaked.empty?
         unless @@try_lsof == false
-          @@try_lsof |= system(*%W[lsof -w -a -d #{fd_leaked.minmax.uniq.join("-")} -p #$$], out: Test::Unit::Runner.output)
+          open_list = IO.popen(%W[lsof -w -a -d #{fd_leaked.minmax.uniq.join("-")} -p #$$], &:readlines)
+          if @@try_lsof |= $?.success?
+            columns = (header = open_list.shift).split
+            fd_index, node_index = columns.index('FD'), columns.index('NODE')
+            open_list.reject! do |of|
+              of = of.chomp.split(' ', node_index + 2)
+              if of[node_index] == 'TCP' and of.last.end_with?('(CLOSE_WAIT)')
+                fd = of[fd_index].to_i
+                inspect.delete(fd)
+                h.delete(fd)
+                live2.delete(fd)
+                true
+              else
+                false
+              end
+            end
+          end
+          puts(header, open_list) unless open_list.empty?
         end
       end
+      inspect.each {|fd, (str, pos)|
+        puts "Leaked file descriptor: #{test_name}: #{fd}#{str}"
+        puts "  The IO was created at #{pos}" if pos
+      }
       h.each {|fd, list|
         next if list.length <= 1
         if 1 < list.count {|io, autoclose, inspect| autoclose }