os: implement waitable management.

This implements waitable management for Events (and
implements Events). It also refactors PM to use new
Event/Waitable semantics, and also adds STS_ASSERT
as a macro for asserting a boolean expression. The
rest of stratosphere has been refactored to use
STS_ASSERT whenever possible.

stratosphere/libstratosphere/source/os/impl/os_inter_process_event.hpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2018-2019 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/>.
+ */
+
+#pragma once
+#include <stratosphere.hpp>
+
+namespace sts::os::impl {
+
+    class WaitableHolderOfInterProcessEvent;
+
+    class InterProcessEvent {
+        friend class WaitableHolderOfInterProcessEvent;
+        NON_COPYABLE(InterProcessEvent);
+        NON_MOVEABLE(InterProcessEvent);
+        private:
+            Handle read_handle;
+            Handle write_handle;
+            bool manage_read_handle;
+            bool manage_write_handle;
+            bool auto_clear;
+            bool is_initialized;
+        public:
+            InterProcessEvent() : is_initialized(false) { /* ... */ }
+            InterProcessEvent(bool autoclear);
+            ~InterProcessEvent();
+
+            Result Initialize(bool autoclear = true);
+            void   Initialize(Handle read_handle, bool manage_read_handle, Handle write_handle, bool manage_write_handle, bool autoclear = true);
+            Handle DetachReadableHandle();
+            Handle DetachWritableHandle();
+            Handle GetReadableHandle() const;
+            Handle GetWritableHandle() const;
+            void Finalize();
+
+            void Signal();
+            void Reset();
+            void Wait();
+            bool TryWait();
+            bool TimedWait(u64 ns);
+    };
+
+}