os: implement BusyMutex

libraries/libstratosphere/source/os/os_busy_mutex.cpp

@@ -0,0 +1,86 @@
+/*
+ * 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 <stratosphere.hpp>
+#include "impl/os_thread_manager.hpp"
+
+#if defined(ATMOSPHERE_OS_HORIZON)
+    #include "impl/os_internal_busy_mutex_impl.os.horizon.hpp"
+#else
+    #error "Unknown OS for ams::os::impl::InternalBusyMutexImpl"
+#endif
+
+namespace ams::os {
+
+
+    void InitializeBusyMutex(BusyMutexType *mutex) {
+        /* Create object. */
+        util::ConstructAt(mutex->_storage);
+
+        /* Set member variables. */
+        mutex->owner_thread = nullptr;
+
+        /* Mark initialized. */
+        mutex->state = BusyMutexType::State_Initialized;
+    }
+
+    void FinalizeBusyMutex(BusyMutexType *mutex) {
+        /* Check pre-conditions. */
+        AMS_ASSERT(mutex->state == BusyMutexType::State_Initialized);
+        AMS_ASSERT(!util::GetReference(mutex->_storage).IsLocked());
+
+        /* Mark not intialized. */
+        mutex->state = MutexType::State_NotInitialized;
+
+        /* Destroy object. */
+        util::DestroyAt(mutex->_storage);
+    }
+
+    void LockBusyMutex(BusyMutexType *mutex) {
+        /* Check pre-conditions. */
+        AMS_ASSERT(mutex->state == BusyMutexType::State_Initialized);
+
+        /* Lock mutex. */
+        util::GetReference(mutex->_storage).Lock();
+
+        /* Set owner thread. */
+        mutex->owner_thread = impl::GetCurrentThread();
+    }
+
+    bool TryLockBusyMutex(BusyMutexType *mutex) {
+        /* Check pre-conditions. */
+        AMS_ASSERT(mutex->state == BusyMutexType::State_Initialized);
+
+        /* Try to lock mutex. */
+        const bool locked = util::GetReference(mutex->_storage).TryLock();
+
+        /* Set owner thread. */
+        if (locked) {
+            mutex->owner_thread = impl::GetCurrentThread();
+        }
+
+        return locked;
+    }
+
+    void UnlockBusyMutex(BusyMutexType *mutex) {
+        /* Check pre-conditions. */
+        AMS_ASSERT(mutex->state == BusyMutexType::State_Initialized);
+        AMS_ASSERT(util::GetReference(mutex->_storage).IsLocked() && mutex->owner_thread == impl::GetCurrentThread());
+
+        /* Unlock. */
+        util::GetReference(mutex->_storage).Unlock();
+    }
+
+}