1 files changed, 171 insertions, 0 deletions

diff --git a/src/core/hle/kernel/k_synchronization_object.cpp b/src/core/hle/kernel/k_synchronization_object.cpp
new file mode 100644
index 000000000..e7fd119d8
--- /dev/null
+++ b/src/core/hle/kernel/k_synchronization_object.cpp
@@ -0,0 +1,171 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "core/hle/kernel/k_scheduler.h"
+#include "core/hle/kernel/k_scoped_scheduler_lock_and_sleep.h"
+#include "core/hle/kernel/k_synchronization_object.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/svc_results.h"
+#include "core/hle/kernel/thread.h"
+
+namespace Kernel {
+
+ResultCode KSynchronizationObject::Wait(KernelCore& kernel, s32* out_index,
+                                        KSynchronizationObject** objects, const s32 num_objects,
+                                        s64 timeout) {
+    // Allocate space on stack for thread nodes.
+    std::vector<ThreadListNode> thread_nodes(num_objects);
+
+    // Prepare for wait.
+    Thread* thread = kernel.CurrentScheduler()->GetCurrentThread();
+    Handle timer = InvalidHandle;
+
+    {
+        // Setup the scheduling lock and sleep.
+        KScopedSchedulerLockAndSleep slp(kernel, timer, thread, timeout);
+
+        // Check if any of the objects are already signaled.
+        for (auto i = 0; i < num_objects; ++i) {
+            ASSERT(objects[i] != nullptr);
+
+            if (objects[i]->IsSignaled()) {
+                *out_index = i;
+                slp.CancelSleep();
+                return RESULT_SUCCESS;
+            }
+        }
+
+        // Check if the timeout is zero.
+        if (timeout == 0) {
+            slp.CancelSleep();
+            return Svc::ResultTimedOut;
+        }
+
+        // Check if the thread should terminate.
+        if (thread->IsTerminationRequested()) {
+            slp.CancelSleep();
+            return Svc::ResultTerminationRequested;
+        }
+
+        // Check if waiting was canceled.
+        if (thread->IsWaitCancelled()) {
+            slp.CancelSleep();
+            thread->ClearWaitCancelled();
+            return Svc::ResultCancelled;
+        }
+
+        // Add the waiters.
+        for (auto i = 0; i < num_objects; ++i) {
+            thread_nodes[i].thread = thread;
+            thread_nodes[i].next = nullptr;
+
+            if (objects[i]->thread_list_tail == nullptr) {
+                objects[i]->thread_list_head = std::addressof(thread_nodes[i]);
+            } else {
+                objects[i]->thread_list_tail->next = std::addressof(thread_nodes[i]);
+            }
+
+            objects[i]->thread_list_tail = std::addressof(thread_nodes[i]);
+        }
+
+        // For debugging only
+        thread->SetWaitObjectsForDebugging(objects, num_objects);
+
+        // Mark the thread as waiting.
+        thread->SetCancellable();
+        thread->SetSyncedObject(nullptr, Svc::ResultTimedOut);
+        thread->SetState(ThreadState::WaitSynch);
+    }
+
+    // The lock/sleep is done, so we should be able to get our result.
+
+    // Thread is no longer cancellable.
+    thread->ClearCancellable();
+
+    // For debugging only
+    thread->SetWaitObjectsForDebugging(nullptr, 0);
+
+    // Cancel the timer as needed.
+    if (timer != InvalidHandle) {
+        auto& time_manager = kernel.TimeManager();
+        time_manager.UnscheduleTimeEvent(timer);
+    }
+
+    // Get the wait result.
+    ResultCode wait_result{RESULT_SUCCESS};
+    s32 sync_index = -1;
+    {
+        KScopedSchedulerLock lock(kernel);
+        KSynchronizationObject* synced_obj;
+        wait_result = thread->GetWaitResult(std::addressof(synced_obj));
+
+        for (auto i = 0; i < num_objects; ++i) {
+            // Unlink the object from the list.
+            ThreadListNode* prev_ptr =
+                reinterpret_cast<ThreadListNode*>(std::addressof(objects[i]->thread_list_head));
+            ThreadListNode* prev_val = nullptr;
+            ThreadListNode *prev, *tail_prev;
+
+            do {
+                prev = prev_ptr;
+                prev_ptr = prev_ptr->next;
+                tail_prev = prev_val;
+                prev_val = prev_ptr;
+            } while (prev_ptr != std::addressof(thread_nodes[i]));
+
+            if (objects[i]->thread_list_tail == std::addressof(thread_nodes[i])) {
+                objects[i]->thread_list_tail = tail_prev;
+            }
+
+            prev->next = thread_nodes[i].next;
+
+            if (objects[i] == synced_obj) {
+                sync_index = i;
+            }
+        }
+    }
+
+    // Set output.
+    *out_index = sync_index;
+    return wait_result;
+}
+
+KSynchronizationObject::KSynchronizationObject(KernelCore& kernel) : Object{kernel} {}
+
+KSynchronizationObject ::~KSynchronizationObject() = default;
+
+void KSynchronizationObject::NotifyAvailable(ResultCode result) {
+    KScopedSchedulerLock lock(kernel);
+
+    // If we're not signaled, we've nothing to notify.
+    if (!this->IsSignaled()) {
+        return;
+    }
+
+    // Iterate over each thread.
+    for (auto* cur_node = thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
+        Thread* thread = cur_node->thread;
+        if (thread->GetState() == ThreadSchedStatus::Paused) {
+            thread->SetSyncedObject(this, result);
+            thread->SetState(ThreadStatus::Ready);
+        }
+    }
+}
+
+std::vector<Thread*> KSynchronizationObject::GetWaitingThreadsForDebugging() const {
+    std::vector<Thread*> threads;
+
+    // If debugging, dump the list of waiters.
+    {
+        KScopedSchedulerLock lock(kernel);
+        for (auto* cur_node = thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
+            threads.emplace_back(cur_node->thread);
+        }
+    }
+
+    return threads;
+}
+} // namespace Kernel