Kernel: Correct behavior of Address Arbiter threads. (#3165)

* Kernel: Correct behavior of Address Arbiter threads.

This corrects arbitration threads to behave just like in Horizon OS.
They are added into a container and released according to what priority
they had when added. Horizon OS does not reorder them if their priority
changes.

* Kernel: Address Feedback.

src/core/hle/kernel/address_arbiter.cpp

@@ -17,10 +17,10 @@
 #include "core/memory.h"
 
 namespace Kernel {
-namespace {
+
 // Wake up num_to_wake (or all) threads in a vector.
-void WakeThreads(const std::vector<std::shared_ptr<Thread>>& waiting_threads, s32 num_to_wake) {
-    auto& system = Core::System::GetInstance();
+void AddressArbiter::WakeThreads(const std::vector<std::shared_ptr<Thread>>& waiting_threads,
+                                 s32 num_to_wake) {
     // Only process up to 'target' threads, unless 'target' is <= 0, in which case process
     // them all.
     std::size_t last = waiting_threads.size();
@@ -32,12 +32,12 @@ void WakeThreads(const std::vector<std::shared_ptr<Thread>>& waiting_threads, s3
     for (std::size_t i = 0; i < last; i++) {
         ASSERT(waiting_threads[i]->GetStatus() == ThreadStatus::WaitArb);
         waiting_threads[i]->SetWaitSynchronizationResult(RESULT_SUCCESS);
+        RemoveThread(waiting_threads[i]);
         waiting_threads[i]->SetArbiterWaitAddress(0);
         waiting_threads[i]->ResumeFromWait();
         system.PrepareReschedule(waiting_threads[i]->GetProcessorID());
     }
 }
-} // Anonymous namespace
 
 AddressArbiter::AddressArbiter(Core::System& system) : system{system} {}
 AddressArbiter::~AddressArbiter() = default;
@@ -184,6 +184,7 @@ ResultCode AddressArbiter::WaitForAddressIfEqual(VAddr address, s32 value, s64 t
 ResultCode AddressArbiter::WaitForAddressImpl(VAddr address, s64 timeout) {
     Thread* current_thread = system.CurrentScheduler().GetCurrentThread();
     current_thread->SetArbiterWaitAddress(address);
+    InsertThread(SharedFrom(current_thread));
     current_thread->SetStatus(ThreadStatus::WaitArb);
     current_thread->InvalidateWakeupCallback();
     current_thread->WakeAfterDelay(timeout);
@@ -192,26 +193,51 @@ ResultCode AddressArbiter::WaitForAddressImpl(VAddr address, s64 timeout) {
     return RESULT_TIMEOUT;
 }
 
-std::vector<std::shared_ptr<Thread>> AddressArbiter::GetThreadsWaitingOnAddress(
-    VAddr address) const {
+void AddressArbiter::HandleWakeupThread(std::shared_ptr<Thread> thread) {
+    ASSERT(thread->GetStatus() == ThreadStatus::WaitArb);
+    RemoveThread(thread);
+    thread->SetArbiterWaitAddress(0);
+}
 
-    // Retrieve all threads that are waiting for this address.
-    std::vector<std::shared_ptr<Thread>> threads;
-    const auto& scheduler = system.GlobalScheduler();
-    const auto& thread_list = scheduler.GetThreadList();
-
-    for (const auto& thread : thread_list) {
-        if (thread->GetArbiterWaitAddress() == address) {
-            threads.push_back(thread);
+void AddressArbiter::InsertThread(std::shared_ptr<Thread> thread) {
+    const VAddr arb_addr = thread->GetArbiterWaitAddress();
+    std::list<std::shared_ptr<Thread>>& thread_list = arb_threads[arb_addr];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        const std::shared_ptr<Thread>& current_thread = *it;
+        if (current_thread->GetPriority() >= thread->GetPriority()) {
+            thread_list.insert(it, thread);
+            return;
         }
+        ++it;
     }
+    thread_list.push_back(std::move(thread));
+}
 
-    // Sort them by priority, such that the highest priority ones come first.
-    std::sort(threads.begin(), threads.end(),
-              [](const std::shared_ptr<Thread>& lhs, const std::shared_ptr<Thread>& rhs) {
-                  return lhs->GetPriority() < rhs->GetPriority();
-              });
+void AddressArbiter::RemoveThread(std::shared_ptr<Thread> thread) {
+    const VAddr arb_addr = thread->GetArbiterWaitAddress();
+    std::list<std::shared_ptr<Thread>>& thread_list = arb_threads[arb_addr];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        const std::shared_ptr<Thread>& current_thread = *it;
+        if (current_thread.get() == thread.get()) {
+            thread_list.erase(it);
+            return;
+        }
+        ++it;
+    }
+    UNREACHABLE();
+}
 
-    return threads;
+std::vector<std::shared_ptr<Thread>> AddressArbiter::GetThreadsWaitingOnAddress(VAddr address) {
+    std::vector<std::shared_ptr<Thread>> result;
+    std::list<std::shared_ptr<Thread>>& thread_list = arb_threads[address];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        std::shared_ptr<Thread> current_thread = *it;
+        result.push_back(std::move(current_thread));
+        ++it;
+    }
+    return result;
 }
 } // namespace Kernel

src/core/hle/kernel/address_arbiter.h

@@ -4,7 +4,9 @@
 
 #pragma once
 
+#include <list>
 #include <memory>
+#include <unordered_map>
 #include <vector>
 
 #include "common/common_types.h"
@@ -48,6 +50,9 @@ public:
     /// Waits on an address with a particular arbitration type.
     ResultCode WaitForAddress(VAddr address, ArbitrationType type, s32 value, s64 timeout_ns);
 
+    /// Removes a thread from the container and resets its address arbiter adress to 0
+    void HandleWakeupThread(std::shared_ptr<Thread> thread);
+
 private:
     /// Signals an address being waited on.
     ResultCode SignalToAddressOnly(VAddr address, s32 num_to_wake);
@@ -71,8 +76,20 @@ private:
     // Waits on the given address with a timeout in nanoseconds
     ResultCode WaitForAddressImpl(VAddr address, s64 timeout);
 
+    /// Wake up num_to_wake (or all) threads in a vector.
+    void WakeThreads(const std::vector<std::shared_ptr<Thread>>& waiting_threads, s32 num_to_wake);
+
+    /// Insert a thread into the address arbiter container
+    void InsertThread(std::shared_ptr<Thread> thread);
+
+    /// Removes a thread from the address arbiter container
+    void RemoveThread(std::shared_ptr<Thread> thread);
+
     // Gets the threads waiting on an address.
-    std::vector<std::shared_ptr<Thread>> GetThreadsWaitingOnAddress(VAddr address) const;
+    std::vector<std::shared_ptr<Thread>> GetThreadsWaitingOnAddress(VAddr address);
+
+    /// List of threads waiting for a address arbiter
+    std::unordered_map<VAddr, std::list<std::shared_ptr<Thread>>> arb_threads;
 
     Core::System& system;
 };

src/core/hle/kernel/kernel.cpp

@@ -78,9 +78,9 @@ static void ThreadWakeupCallback(u64 thread_handle, [[maybe_unused]] s64 cycles_
         }
     }
 
-    if (thread->GetArbiterWaitAddress() != 0) {
-        ASSERT(thread->GetStatus() == ThreadStatus::WaitArb);
-        thread->SetArbiterWaitAddress(0);
+    if (thread->GetStatus() == ThreadStatus::WaitArb) {
+        auto& address_arbiter = thread->GetOwnerProcess()->GetAddressArbiter();
+        address_arbiter.HandleWakeupThread(thread);
     }
 
     if (resume) {