kern: unify all waiting semantics to use single api

libraries/libmesosphere/source/kern_k_light_condition_variable.cpp

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <mesosphere.hpp>
+
+namespace ams::kern {
+
+    namespace {
+
+        class ThreadQueueImplForKLightConditionVariable final : public KThreadQueue {
+            private:
+                KThread::WaiterList *m_wait_list;
+                bool m_allow_terminating_thread;
+            public:
+                constexpr ThreadQueueImplForKLightConditionVariable(KThread::WaiterList *wl, bool term) : KThreadQueue(), m_wait_list(wl), m_allow_terminating_thread(term) { /* ... */ }
+
+                virtual void CancelWait(KThread *waiting_thread, Result wait_result, bool cancel_timer_task) override {
+                    /* Only process waits if we're allowed to. */
+                    if (svc::ResultTerminationRequested::Includes(wait_result) && m_allow_terminating_thread) {
+                        return;
+                    }
+
+                    /* Remove the thread from the waiting thread from the light condition variable. */
+                    m_wait_list->erase(m_wait_list->iterator_to(*waiting_thread));
+
+                    /* Invoke the base cancel wait handler. */
+                    KThreadQueue::CancelWait(waiting_thread, wait_result, cancel_timer_task);
+                }
+        };
+
+    }
+
+    void KLightConditionVariable::Wait(KLightLock *lock, s64 timeout, bool allow_terminating_thread) {
+        /* Create thread queue. */
+        KThread *owner = GetCurrentThreadPointer();
+        KHardwareTimer *timer;
+
+        ThreadQueueImplForKLightConditionVariable wait_queue(std::addressof(m_wait_list), allow_terminating_thread);
+
+        /* Sleep the thread. */
+        {
+            KScopedSchedulerLockAndSleep lk(&timer, owner, timeout);
+
+            if (!allow_terminating_thread && owner->IsTerminationRequested()) {
+                lk.CancelSleep();
+                return;
+            }
+
+            lock->Unlock();
+
+            /* Add the thread to the queue. */
+            m_wait_list.push_back(*owner);
+
+            /* Begin waiting. */
+            wait_queue.SetHardwareTimer(timer);
+            owner->BeginWait(std::addressof(wait_queue));
+        }
+
+        /* Re-acquire the lock. */
+        lock->Lock();
+    }
+
+    void KLightConditionVariable::Broadcast() {
+        KScopedSchedulerLock lk;
+
+        /* Signal all threads. */
+        for (auto it = m_wait_list.begin(); it != m_wait_list.end(); it = m_wait_list.erase(it)) {
+            it->EndWait(ResultSuccess());
+        }
+    }
+
+}