From cb5021419ea71d204effb65f604978c017dd813f Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 14 Nov 2019 21:04:34 +0100
Subject: [PATCH] Kernel: Move Thread::m_joinee_exit_value into the JoinBlocker

There's no need for this to be a permanent Thread member. Just use a
reference in the JoinBlocker instead.
---
 Kernel/Process.cpp   | 6 ++++--
 Kernel/Scheduler.cpp | 3 ++-
 Kernel/Thread.cpp    | 2 +-
 Kernel/Thread.h      | 6 +++---
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index d1f3ab495be..f37ffdd0803 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -2906,15 +2906,17 @@ int Process::sys$join_thread(int tid, void** exit_value)
 
     // FIXME: EINVAL: 'thread' is not a joinable thread
 
+    void* joinee_exit_value = nullptr;
+
     // FIXME: pthread_join() should not be interruptable. Enforce this somehow?
-    auto result = current->block<Thread::JoinBlocker>(*thread);
+    auto result = current->block<Thread::JoinBlocker>(*thread, joinee_exit_value);
     (void)result;
 
     // NOTE: 'thread' is very possibly deleted at this point. Clear it just to be safe.
     thread = nullptr;
 
     if (exit_value)
-        *exit_value = current->m_joinee_exit_value;
+        *exit_value = joinee_exit_value;
     return 0;
 }
 
diff --git a/Kernel/Scheduler.cpp b/Kernel/Scheduler.cpp
index b072fdfcde5..816abd5fed7 100644
--- a/Kernel/Scheduler.cpp
+++ b/Kernel/Scheduler.cpp
@@ -68,8 +68,9 @@ void Scheduler::beep()
     s_beep_timeout = g_uptime + 100;
 }
 
-Thread::JoinBlocker::JoinBlocker(Thread& joinee)
+Thread::JoinBlocker::JoinBlocker(Thread& joinee, void*& joinee_exit_value)
     : m_joinee(joinee)
+    , m_joinee_exit_value(joinee_exit_value)
 {
     ASSERT(m_joinee.m_joiner == nullptr);
     m_joinee.m_joiner = current;
diff --git a/Kernel/Thread.cpp b/Kernel/Thread.cpp
index 208b14cec64..c99d8170522 100644
--- a/Kernel/Thread.cpp
+++ b/Kernel/Thread.cpp
@@ -240,7 +240,7 @@ void Thread::finalize()
 
     if (m_joiner) {
         ASSERT(m_joiner->m_joinee == this);
-        m_joiner->m_joinee_exit_value = m_exit_value;
+        static_cast<JoinBlocker*>(m_joiner->m_blocker)->set_joinee_exit_value(m_exit_value);
         m_joiner->m_joinee = nullptr;
         // NOTE: We clear the joiner pointer here as well, to be tidy.
         m_joiner = nullptr;
diff --git a/Kernel/Thread.h b/Kernel/Thread.h
index 0d43a197d5b..2f3d89d2a05 100644
--- a/Kernel/Thread.h
+++ b/Kernel/Thread.h
@@ -97,12 +97,14 @@ public:
 
     class JoinBlocker final : public Blocker {
     public:
-        explicit JoinBlocker(Thread& joinee);
+        explicit JoinBlocker(Thread& joinee, void*& joinee_exit_value);
         virtual bool should_unblock(Thread&, time_t now_s, long us) override;
         virtual const char* state_string() const override { return "Joining"; }
+        void set_joinee_exit_value(void* value) { m_joinee_exit_value = value; }
 
     private:
         Thread& m_joinee;
+        void*& m_joinee_exit_value;
     };
 
     class FileDescriptionBlocker : public Blocker {
@@ -367,10 +369,8 @@ private:
     SignalActionData m_signal_action_data[32];
     Blocker* m_blocker { nullptr };
 
-    // FIXME: Some of these could probably live in the JoinBlocker object instead.
     Thread* m_joiner { nullptr };
     Thread* m_joinee { nullptr };
-    void* m_joinee_exit_value { nullptr };
     void* m_exit_value { nullptr };
 
     FPUState* m_fpu_state { nullptr };