From 1fb3c9f08ccd54ad28765f46ca04a80062c579d0 Mon Sep 17 00:00:00 2001
From: Hamish Milne <hamishmilne83@gmail.com>
Date: Sat, 18 Apr 2020 15:10:54 +0100
Subject: [PATCH] Fix Address Arbiter serialization

---
 src/core/hle/kernel/address_arbiter.cpp | 36 ++++++++++++++++++++-----
 src/core/hle/kernel/address_arbiter.h   | 28 +++++++++++++++----
 2 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/src/core/hle/kernel/address_arbiter.cpp b/src/core/hle/kernel/address_arbiter.cpp
index 5074e352f..97228f153 100644
--- a/src/core/hle/kernel/address_arbiter.cpp
+++ b/src/core/hle/kernel/address_arbiter.cpp
@@ -16,8 +16,6 @@
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // Kernel namespace
 
-SERIALIZE_EXPORT_IMPL(Kernel::AddressArbiter)
-
 namespace Kernel {
 
 void AddressArbiter::WaitThread(std::shared_ptr<Thread> thread, VAddr wait_address) {
@@ -80,19 +78,36 @@ std::shared_ptr<AddressArbiter> KernelSystem::CreateAddressArbiter(std::string n
     return address_arbiter;
 }
 
+class AddressArbiter::Callback : public WakeupCallback {
+public:
+    Callback(AddressArbiter& _parent) : parent(SharedFrom(&_parent)) {}
+    std::shared_ptr<AddressArbiter> parent;
+
+    void WakeUp(ThreadWakeupReason reason, std::shared_ptr<Thread> thread,
+        std::shared_ptr<WaitObject> object) override {
+        parent->WakeUp(reason, thread, object);
+    }
+
+private:
+    Callback() = default;
+    template <class Archive>
+    void serialize(Archive& ar, const unsigned int) {
+        ar& boost::serialization::base_object<WakeupCallback>(*this);
+        ar& parent;
+    }
+    friend class boost::serialization::access;
+};
+
 void AddressArbiter::WakeUp(ThreadWakeupReason reason, std::shared_ptr<Thread> thread,
                             std::shared_ptr<WaitObject> object) {
     ASSERT(reason == ThreadWakeupReason::Timeout);
     // Remove the newly-awakened thread from the Arbiter's waiting list.
     waiting_threads.erase(std::remove(waiting_threads.begin(), waiting_threads.end(), thread),
-                          waiting_threads.end());
+                            waiting_threads.end());
 };
 
 ResultCode AddressArbiter::ArbitrateAddress(std::shared_ptr<Thread> thread, ArbitrationType type,
                                             VAddr address, s32 value, u64 nanoseconds) {
-
-    auto timeout_callback = std::dynamic_pointer_cast<WakeupCallback>(shared_from_this());
-
     switch (type) {
 
     // Signal thread(s) waiting for arbitrate address...
@@ -114,6 +129,9 @@ ResultCode AddressArbiter::ArbitrateAddress(std::shared_ptr<Thread> thread, Arbi
         }
         break;
     case ArbitrationType::WaitIfLessThanWithTimeout:
+        if (!timeout_callback) {
+            timeout_callback = std::make_shared<Callback>(*this);
+        }
         if ((s32)kernel.memory.Read32(address) < value) {
             thread->wakeup_callback = timeout_callback;
             thread->WakeAfterDelay(nanoseconds);
@@ -130,6 +148,9 @@ ResultCode AddressArbiter::ArbitrateAddress(std::shared_ptr<Thread> thread, Arbi
         break;
     }
     case ArbitrationType::DecrementAndWaitIfLessThanWithTimeout: {
+        if (!timeout_callback) {
+            timeout_callback = std::make_shared<Callback>(*this);
+        }
         s32 memory_value = kernel.memory.Read32(address);
         if (memory_value < value) {
             // Only change the memory value if the thread should wait
@@ -157,3 +178,6 @@ ResultCode AddressArbiter::ArbitrateAddress(std::shared_ptr<Thread> thread, Arbi
 }
 
 } // namespace Kernel
+
+SERIALIZE_EXPORT_IMPL(Kernel::AddressArbiter)
+SERIALIZE_EXPORT_IMPL(Kernel::AddressArbiter::Callback)
diff --git a/src/core/hle/kernel/address_arbiter.h b/src/core/hle/kernel/address_arbiter.h
index c7a263d9e..de7631066 100644
--- a/src/core/hle/kernel/address_arbiter.h
+++ b/src/core/hle/kernel/address_arbiter.h
@@ -59,8 +59,7 @@ public:
     ResultCode ArbitrateAddress(std::shared_ptr<Thread> thread, ArbitrationType type, VAddr address,
                                 s32 value, u64 nanoseconds);
 
-    void WakeUp(ThreadWakeupReason reason, std::shared_ptr<Thread> thread,
-                std::shared_ptr<WaitObject> object);
+    class Callback;
 
 private:
     KernelSystem& kernel;
@@ -78,20 +77,39 @@ private:
     /// Threads waiting for the address arbiter to be signaled.
     std::vector<std::shared_ptr<Thread>> waiting_threads;
 
+    std::shared_ptr<Callback> timeout_callback;
+
+    void WakeUp(ThreadWakeupReason reason, std::shared_ptr<Thread> thread,
+                std::shared_ptr<WaitObject> object);
+
+    class DummyCallback : public WakeupCallback {
+    public:
+        void WakeUp(ThreadWakeupReason reason, std::shared_ptr<Thread> thread,
+                    std::shared_ptr<WaitObject> object) override {}
+    };
+
     friend class boost::serialization::access;
     template <class Archive>
     void serialize(Archive& ar, const unsigned int file_version) {
         ar& boost::serialization::base_object<Object>(*this);
-        if (file_version > 0) {
-            ar& boost::serialization::base_object<WakeupCallback>(*this);
+        if (file_version == 1) {
+            // This rigmarole is needed because in past versions, AddressArbiter inherited WakeupCallback
+            // But it turns out this breaks shared_from_this, so we split it out.
+            // Using a dummy class to deserialize a base_object allows compatibility to be maintained.
+            DummyCallback x;
+            ar& boost::serialization::base_object<WakeupCallback>(x);
         }
         ar& name;
         ar& waiting_threads;
+        if (file_version > 1) {
+            ar& timeout_callback;
+        }
     }
 };
 
 } // namespace Kernel
 
 BOOST_CLASS_EXPORT_KEY(Kernel::AddressArbiter)
-BOOST_CLASS_VERSION(Kernel::AddressArbiter, 1)
+BOOST_CLASS_EXPORT_KEY(Kernel::AddressArbiter::Callback)
+BOOST_CLASS_VERSION(Kernel::AddressArbiter, 2)
 CONSTRUCT_KERNEL_OBJECT(Kernel::AddressArbiter)