Initial in-process implementation of some Mojo primitives.

mojo/system/core_impl.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_SYSTEM_CORE_IMPL_H_
+#define MOJO_SYSTEM_CORE_IMPL_H_
+
+#include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "mojo/public/system/core.h"
+
+namespace mojo {
+namespace system {
+
+class CoreImpl;
+class Dispatcher;
+
+namespace test {
+class CoreTestBase;
+}
+
+// |CoreImpl| is a singleton object that implements the Mojo system calls. With
+// the (obvious) exception of |Init()|, which must be called first (and the call
+// completed) before making any other calls, all the public methods are
+// thread-safe.
+class CoreImpl {
+ public:
+  static void Init();
+
+  static CoreImpl* Get() {
+    return singleton_;
+  }
+
+  MojoResult Close(MojoHandle handle);
+
+  MojoResult Wait(MojoHandle handle,
+                  MojoWaitFlags flags,
+                  MojoDeadline deadline);
+
+  MojoResult WaitMany(const MojoHandle* handles,
+                      const MojoWaitFlags* flags,
+                      uint32_t num_handles,
+                      MojoDeadline deadline);
+
+  MojoResult CreateMessagePipe(MojoHandle* handle_0, MojoHandle* handle_1);
+
+  MojoResult WriteMessage(MojoHandle handle,
+                          const void* bytes, uint32_t num_bytes,
+                          const MojoHandle* handles, uint32_t num_handles,
+                          MojoWriteMessageFlags flags);
+
+  MojoResult ReadMessage(MojoHandle handle,
+                         void* bytes, uint32_t* num_bytes,
+                         MojoHandle* handles, uint32_t* num_handles,
+                         MojoReadMessageFlags flags);
+
+ private:
+  friend class test::CoreTestBase;
+
+  typedef base::hash_map<MojoHandle, scoped_refptr<Dispatcher> >
+      HandleTableMap;
+
+  CoreImpl();
+  ~CoreImpl();
+
+  // Looks up the dispatcher for the given handle. Returns null if the handle is
+  // invalid.
+  scoped_refptr<Dispatcher> GetDispatcher(MojoHandle handle);
+
+  // Assigns a new handle for the given dispatcher (which must be valid);
+  // returns |MOJO_HANDLE_INVALID| on failure (due to hitting resource limits).
+  // Must be called under |handle_table_lock_|.
+  MojoHandle AddDispatcherNoLock(scoped_refptr<Dispatcher> dispatcher);
+
+  // Internal implementation of |Wait()| and |WaitMany()|; doesn't do basic
+  // validation of arguments.
+  MojoResult WaitManyInternal(const MojoHandle* handles,
+                              const MojoWaitFlags* flags,
+                              uint32_t num_handles,
+                              MojoDeadline deadline);
+
+  // ---------------------------------------------------------------------------
+
+  static CoreImpl* singleton_;
+
+  // ---------------------------------------------------------------------------
+
+  // TODO(vtl): |handle_table_lock_| should be a reader-writer lock (if only we
+  // had them).
+  base::Lock handle_table_lock_;  // Protects the immediately-following members.
+  HandleTableMap handle_table_;
+  MojoHandle next_handle_;  // Invariant: never |MOJO_HANDLE_INVALID|.
+
+  // ---------------------------------------------------------------------------
+
+  DISALLOW_COPY_AND_ASSIGN(CoreImpl);
+};
+
+}  // namespace system
+}  // namespace mojo
+
+#endif  // MOJO_SYSTEM_CORE_IMPL_H_