1 files changed, 94 insertions, 0 deletions
diff --git a/include/lldb/Host/MainLoopBase.h b/include/lldb/Host/MainLoopBase.h
new file mode 100644
index 000000000000..bff2ce78110d
--- /dev/null
+++ b/include/lldb/Host/MainLoopBase.h
@@ -0,0 +1,94 @@
+//===-- MainLoopBase.h ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef lldb_Host_posix_MainLoopBase_h_
+#define lldb_Host_posix_MainLoopBase_h_
+
+#include <functional>
+
+#include "llvm/Support/ErrorHandling.h"
+
+#include "lldb/Core/Error.h"
+#include "lldb/Host/IOObject.h"
+
+namespace lldb_private {
+
+// The purpose of this class is to enable multiplexed processing of data from different sources
+// without resorting to multi-threading. Clients can register IOObjects, which will be monitored
+// for readability, and when they become ready, the specified callback will be invoked.
+// Monitoring for writability is not supported, but can be easily added if needed.
+//
+// The RegisterReadObject function return a handle, which controls the duration of the monitoring. When
+// this handle is destroyed, the callback is deregistered.
+//
+// This class simply defines the interface common for all platforms, actual implementations are
+// platform-specific.
+class MainLoopBase
+{
+private:
+    class ReadHandle;
+
+public:
+    MainLoopBase() { }
+    virtual ~MainLoopBase() { }
+
+    typedef std::unique_ptr<ReadHandle> ReadHandleUP;
+
+    typedef std::function<void(MainLoopBase &)> Callback;
+
+    virtual ReadHandleUP
+    RegisterReadObject(const lldb::IOObjectSP &object_sp, const Callback &callback, Error &error)
+    { llvm_unreachable("Not implemented"); }
+
+    // Waits for registered events and invoke the proper callbacks. Returns when all callbacks
+    // deregister themselves or when someone requests termination.
+    virtual Error
+    Run()
+    { llvm_unreachable("Not implemented"); }
+
+    // Requests the exit of the Run() function.
+    virtual void
+    RequestTermination()
+    { llvm_unreachable("Not implemented"); }
+
+protected:
+    ReadHandleUP
+    CreateReadHandle(const lldb::IOObjectSP &object_sp)
+    { return ReadHandleUP(new ReadHandle(*this, object_sp)); }
+
+    virtual void
+    UnregisterReadObject(const lldb::IOObjectSP &object_sp)
+    { llvm_unreachable("Not implemented"); }
+
+private:
+    class ReadHandle
+    {
+    public:
+        ~ReadHandle() { m_mainloop.UnregisterReadObject(m_object_sp); }
+
+    private:
+        ReadHandle(MainLoopBase &mainloop, const lldb::IOObjectSP &object_sp)
+            : m_mainloop(mainloop), m_object_sp(object_sp)
+        { }
+
+        MainLoopBase &m_mainloop;
+        lldb::IOObjectSP m_object_sp;
+
+        friend class MainLoopBase;
+        DISALLOW_COPY_AND_ASSIGN(ReadHandle);
+    };
+
+private:
+    DISALLOW_COPY_AND_ASSIGN(MainLoopBase);
+};
+
+} // namespace lldb_private
+
+
+#endif // lldb_Host_posix_MainLoopBase_h_