3 files changed, 19 insertions, 10 deletions

diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index 6f61d526a..955f50a9b 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -55,10 +55,16 @@ SharedPtr<Thread> WaitObject::GetHighestPriorityReadyThread() {
         if (ShouldWait(thread.get()))
             continue;
 
-        bool ready_to_run = std::none_of(thread->wait_objects.begin(), thread->wait_objects.end(),
+        // A thread is ready to run if it's either in THREADSTATUS_WAIT_SYNCH_ANY or
+        // in THREADSTATUS_WAIT_SYNCH_ALL and the rest of the objects it is waiting on are ready.
+        bool ready_to_run = true;
+        if (thread->status == THREADSTATUS_WAIT_SYNCH_ALL) {
+            ready_to_run = std::none_of(thread->wait_objects.begin(), thread->wait_objects.end(),
                                         [&thread](const SharedPtr<WaitObject>& object) {
                                             return object->ShouldWait(thread.get());
                                         });
+        }
+
         if (ready_to_run) {
             candidate = thread.get();
             candidate_priority = thread->current_priority;
diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index aa99d18c7..568cef5b9 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -579,6 +579,11 @@ void Thread::SetWaitSynchronizationOutput(s32 output) {
     context.cpu_registers[1] = output;
 }
 
+s32 Thread::GetWaitObjectIndex(WaitObject* object) const {
+    auto match = std::find(wait_objects.rbegin(), wait_objects.rend(), object);
+    return std::distance(match, wait_objects.rend()) - 1;
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 void ThreadingInit() {
diff --git a/src/core/hle/kernel/thread.h b/src/core/hle/kernel/thread.h
index 6cd8c20e2..af72b76ea 100644
--- a/src/core/hle/kernel/thread.h
+++ b/src/core/hle/kernel/thread.h
@@ -135,13 +135,14 @@ public:
 
     /**
      * Retrieves the index that this particular object occupies in the list of objects
-     * that the thread passed to WaitSynchronizationN.
+     * that the thread passed to WaitSynchronizationN, starting the search from the last element.
      * It is used to set the output value of WaitSynchronizationN when the thread is awakened.
+     * When a thread wakes up due to an object signal, the kernel will use the index of the last
+     * matching object in the wait objects list in case of having multiple instances of the same
+     * object in the list.
      * @param object Object to query the index of.
      */
-    s32 GetWaitObjectIndex(const WaitObject* object) const {
-        return wait_objects_index.at(object->GetObjectId());
-    }
+    s32 GetWaitObjectIndex(WaitObject* object) const;
 
     /**
      * Stops a thread, invalidating it from further use
@@ -190,13 +191,10 @@ public:
 
     SharedPtr<Process> owner_process; ///< Process that owns this thread
 
-    /// Objects that the thread is waiting on.
-    /// This is only populated when the thread should wait for all the objects to become ready.
+    /// Objects that the thread is waiting on, in the same order as they were
+    // passed to WaitSynchronization1/N.
     std::vector<SharedPtr<WaitObject>> wait_objects;
 
-    /// Mapping of Object ids to their position in the last waitlist that this object waited on.
-    boost::container::flat_map<int, s32> wait_objects_index;
-
     VAddr wait_address; ///< If waiting on an AddressArbiter, this is the arbitration address
 
     /// True if the WaitSynchronizationN output parameter should be set on thread wakeup.