Merge pull request #3114 from FernandoS27/cond-var

Kernel: Correct behavior of Condition Variables to be more similar to real hardware.

src/core/hle/kernel/kernel.cpp

@@ -64,8 +64,11 @@ static void ThreadWakeupCallback(u64 thread_handle, [[maybe_unused]] s64 cycles_
     } else if (thread->GetStatus() == ThreadStatus::WaitMutex ||
                thread->GetStatus() == ThreadStatus::WaitCondVar) {
         thread->SetMutexWaitAddress(0);
-        thread->SetCondVarWaitAddress(0);
         thread->SetWaitHandle(0);
+        if (thread->GetStatus() == ThreadStatus::WaitCondVar) {
+            thread->GetOwnerProcess()->RemoveConditionVariableThread(thread);
+            thread->SetCondVarWaitAddress(0);
+        }
 
         auto* const lock_owner = thread->GetLockOwner();
         // Threads waking up by timeout from WaitProcessWideKey do not perform priority inheritance

src/core/hle/kernel/process.cpp

@@ -142,6 +142,48 @@ u64 Process::GetTotalPhysicalMemoryUsedWithoutSystemResource() const {
     return GetTotalPhysicalMemoryUsed() - GetSystemResourceUsage();
 }
 
+void Process::InsertConditionVariableThread(SharedPtr<Thread> thread) {
+    VAddr cond_var_addr = thread->GetCondVarWaitAddress();
+    std::list<SharedPtr<Thread>>& thread_list = cond_var_threads[cond_var_addr];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        const SharedPtr<Thread> current_thread = *it;
+        if (current_thread->GetPriority() > thread->GetPriority()) {
+            thread_list.insert(it, thread);
+            return;
+        }
+        ++it;
+    }
+    thread_list.push_back(thread);
+}
+
+void Process::RemoveConditionVariableThread(SharedPtr<Thread> thread) {
+    VAddr cond_var_addr = thread->GetCondVarWaitAddress();
+    std::list<SharedPtr<Thread>>& thread_list = cond_var_threads[cond_var_addr];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        const SharedPtr<Thread> current_thread = *it;
+        if (current_thread.get() == thread.get()) {
+            thread_list.erase(it);
+            return;
+        }
+        ++it;
+    }
+    UNREACHABLE();
+}
+
+std::vector<SharedPtr<Thread>> Process::GetConditionVariableThreads(const VAddr cond_var_addr) {
+    std::vector<SharedPtr<Thread>> result{};
+    std::list<SharedPtr<Thread>>& thread_list = cond_var_threads[cond_var_addr];
+    auto it = thread_list.begin();
+    while (it != thread_list.end()) {
+        SharedPtr<Thread> current_thread = *it;
+        result.push_back(current_thread);
+        ++it;
+    }
+    return result;
+}
+
 void Process::RegisterThread(const Thread* thread) {
     thread_list.push_back(thread);
 }

src/core/hle/kernel/process.h

@@ -8,6 +8,7 @@
 #include <cstddef>
 #include <list>
 #include <string>
+#include <unordered_map>
 #include <vector>
 #include "common/common_types.h"
 #include "core/hle/kernel/address_arbiter.h"
@@ -232,6 +233,15 @@ public:
         return thread_list;
     }
 
+    /// Insert a thread into the condition variable wait container
+    void InsertConditionVariableThread(SharedPtr<Thread> thread);
+
+    /// Remove a thread from the condition variable wait container
+    void RemoveConditionVariableThread(SharedPtr<Thread> thread);
+
+    /// Obtain all condition variable threads waiting for some address
+    std::vector<SharedPtr<Thread>> GetConditionVariableThreads(VAddr cond_var_addr);
+
     /// Registers a thread as being created under this process,
     /// adding it to this process' thread list.
     void RegisterThread(const Thread* thread);
@@ -375,6 +385,9 @@ private:
     /// List of threads that are running with this process as their owner.
     std::list<const Thread*> thread_list;
 
+    /// List of threads waiting for a condition variable
+    std::unordered_map<VAddr, std::list<SharedPtr<Thread>>> cond_var_threads;
+
     /// System context
     Core::System& system;
 

src/core/hle/kernel/svc.cpp

@@ -1631,6 +1631,7 @@ static ResultCode WaitProcessWideKeyAtomic(Core::System& system, VAddr mutex_add
     current_thread->SetWaitHandle(thread_handle);
     current_thread->SetStatus(ThreadStatus::WaitCondVar);
     current_thread->InvalidateWakeupCallback();
+    current_process->InsertConditionVariableThread(current_thread);
 
     current_thread->WakeAfterDelay(nano_seconds);
 
@@ -1649,38 +1650,23 @@ static ResultCode SignalProcessWideKey(Core::System& system, VAddr condition_var
     ASSERT(condition_variable_addr == Common::AlignDown(condition_variable_addr, 4));
 
     // Retrieve a list of all threads that are waiting for this condition variable.
-    std::vector<SharedPtr<Thread>> waiting_threads;
-    const auto& scheduler = system.GlobalScheduler();
-    const auto& thread_list = scheduler.GetThreadList();
+    auto* const current_process = system.Kernel().CurrentProcess();
+    std::vector<SharedPtr<Thread>> waiting_threads =
+        current_process->GetConditionVariableThreads(condition_variable_addr);
 
-    for (const auto& thread : thread_list) {
-        if (thread->GetCondVarWaitAddress() == condition_variable_addr) {
-            waiting_threads.push_back(thread);
-        }
-    }
-
-    // Sort them by priority, such that the highest priority ones come first.
-    std::sort(waiting_threads.begin(), waiting_threads.end(),
-              [](const SharedPtr<Thread>& lhs, const SharedPtr<Thread>& rhs) {
-                  return lhs->GetPriority() < rhs->GetPriority();
-              });
-
-    // Only process up to 'target' threads, unless 'target' is -1, in which case process
+    // Only process up to 'target' threads, unless 'target' is less equal 0, in which case process
     // them all.
     std::size_t last = waiting_threads.size();
-    if (target != -1)
+    if (target > 0)
         last = std::min(waiting_threads.size(), static_cast<std::size_t>(target));
 
-    // If there are no threads waiting on this condition variable, just exit
-    if (last == 0)
-        return RESULT_SUCCESS;
-
     for (std::size_t index = 0; index < last; ++index) {
         auto& thread = waiting_threads[index];
 
         ASSERT(thread->GetCondVarWaitAddress() == condition_variable_addr);
 
         // liberate Cond Var Thread.
+        current_process->RemoveConditionVariableThread(thread);
         thread->SetCondVarWaitAddress(0);
 
         const std::size_t current_core = system.CurrentCoreIndex();

src/core/hle/kernel/thread.cpp

@@ -309,8 +309,16 @@ void Thread::UpdatePriority() {
         return;
     }
 
+    if (GetStatus() == ThreadStatus::WaitCondVar) {
+        owner_process->RemoveConditionVariableThread(this);
+    }
+
     SetCurrentPriority(new_priority);
 
+    if (GetStatus() == ThreadStatus::WaitCondVar) {
+        owner_process->InsertConditionVariableThread(this);
+    }
+
     if (!lock_owner) {
         return;
     }