From 406907d57055965780e04769482556995de8c50a Mon Sep 17 00:00:00 2001
From: Subv <subv2112@gmail.com>
Date: Sat, 10 Dec 2016 13:29:31 -0500
Subject: [PATCH] Properly remove a thread from its wait_objects' waitlist when
 it is awoken by a timeout.

---
 src/core/hle/kernel/kernel.cpp | 7 ++++++-
 src/core/hle/kernel/thread.cpp | 4 ++++
 src/core/hle/svc.cpp           | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index 653697843..2ddeffcdd 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -38,6 +38,11 @@ SharedPtr<Thread> WaitObject::GetHighestPriorityReadyThread() {
         return thread->status == THREADSTATUS_RUNNING || thread->status == THREADSTATUS_READY;
     });
 
+    // TODO(Subv): This call should be performed inside the loop below to check if an object can be
+    // acquired by a particular thread. This is useful for things like recursive locking of Mutexes.
+    if (ShouldWait())
+        return nullptr;
+
     Thread* candidate = nullptr;
     s32 candidate_priority = THREADPRIO_LOWEST + 1;
 
@@ -67,7 +72,7 @@ void WaitObject::WakeupAllWaitingThreads() {
                 thread->wait_set_output = false;
             }
         } else {
-            for (auto object : thread->wait_objects) {
+            for (auto& object : thread->wait_objects) {
                 object->Acquire();
                 object->RemoveWaitingThread(thread.get());
             }
diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index 49ed9d899..4bbc08516 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -277,6 +277,10 @@ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
 
     if (thread->status == THREADSTATUS_WAIT_SYNCH || thread->status == THREADSTATUS_WAIT_ARB) {
         thread->wait_set_output = false;
+        // Remove the thread from each of its waiting objects' waitlists
+        for (auto& object : thread->wait_objects)
+            object->RemoveWaitingThread(thread.get());
+        thread->wait_objects.clear();
         thread->SetWaitSynchronizationResult(ResultCode(ErrorDescription::Timeout, ErrorModule::OS,
                                                         ErrorSummary::StatusChanged,
                                                         ErrorLevel::Info));
diff --git a/src/core/hle/svc.cpp b/src/core/hle/svc.cpp
index 14da09883..c81c14443 100644
--- a/src/core/hle/svc.cpp
+++ b/src/core/hle/svc.cpp
@@ -321,7 +321,7 @@ static ResultCode WaitSynchronizationN(s32* out, Handle* handles, s32 handle_cou
         });
         if (all_available) {
             // We can acquire all objects right now, do so.
-            for (auto object : objects)
+            for (auto& object : objects)
                 object->Acquire();
             // Note: In this case, the `out` parameter is not set, and retains whatever value it had before.
             return RESULT_SUCCESS;