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//===-- MainLoopBase.h ------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_HOST_MAINLOOPBASE_H
#define LLDB_HOST_MAINLOOPBASE_H
#include "lldb/Utility/IOObject.h"
#include "lldb/Utility/Status.h"
#include "llvm/Support/ErrorHandling.h"
#include <functional>
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() = default;
virtual ~MainLoopBase() = default;
typedef std::unique_ptr<ReadHandle> ReadHandleUP;
typedef std::function<void(MainLoopBase &)> Callback;
virtual ReadHandleUP RegisterReadObject(const lldb::IOObjectSP &object_sp,
const Callback &callback,
Status &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 Status 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->GetWaitableHandle()));
}
virtual void UnregisterReadObject(IOObject::WaitableHandle handle) {
llvm_unreachable("Not implemented");
}
private:
class ReadHandle {
public:
~ReadHandle() { m_mainloop.UnregisterReadObject(m_handle); }
private:
ReadHandle(MainLoopBase &mainloop, IOObject::WaitableHandle handle)
: m_mainloop(mainloop), m_handle(handle) {}
MainLoopBase &m_mainloop;
IOObject::WaitableHandle m_handle;
friend class MainLoopBase;
ReadHandle(const ReadHandle &) = delete;
const ReadHandle &operator=(const ReadHandle &) = delete;
};
MainLoopBase(const MainLoopBase &) = delete;
const MainLoopBase &operator=(const MainLoopBase &) = delete;
};
} // namespace lldb_private
#endif // LLDB_HOST_MAINLOOPBASE_H