SelectPoller.h

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * SelectPoller.h
 * A Poller which uses select()
 * Copyright (C) 2013 Simon Newton
 */

#ifndef COMMON_IO_SELECTPOLLER_H_
#define COMMON_IO_SELECTPOLLER_H_

#include <ola/Clock.h>
#include <ola/ExportMap.h>
#include <ola/base/Macro.h>
#include <ola/io/Descriptor.h>

#include <set>

#include "common/io/PollerInterface.h"
#include "common/io/TimeoutManager.h"

namespace ola {
namespace io {

class SelectPoller : public PollerInterface {
 public :
 SelectPoller(ExportMap *export_map, Clock *clock);

 ~SelectPoller();

 bool AddReadDescriptor(class ReadFileDescriptor *descriptor);
 bool AddReadDescriptor(class ConnectedDescriptor *descriptor,
 bool delete_on_close);
 bool RemoveReadDescriptor(class ReadFileDescriptor *descriptor);
 bool RemoveReadDescriptor(class ConnectedDescriptor *descriptor);

 bool AddWriteDescriptor(class WriteFileDescriptor *descriptor);
 bool RemoveWriteDescriptor(class WriteFileDescriptor *descriptor);

 const TimeStamp *WakeUpTime() const { return &m_wake_up_time; }

 bool Poll(TimeoutManager *timeout_manager,
 const TimeInterval &poll_interval);

 private:
 typedef struct {
 ConnectedDescriptor *descriptor;
 bool delete_on_close;
 } connected_descriptor_t;

 struct connected_descriptor_t_lt {
 bool operator()(const connected_descriptor_t &c1,
 const connected_descriptor_t &c2) const {
 return c1.descriptor->ReadDescriptor() <
 c2.descriptor->ReadDescriptor();
 }
 };

 typedef std::set<ReadFileDescriptor*> ReadDescriptorSet;
 typedef std::set<WriteFileDescriptor*> WriteDescriptorSet;
 typedef std::set<connected_descriptor_t, connected_descriptor_t_lt>
 ConnectedDescriptorSet;

 ExportMap *m_export_map;
 CounterVariable *m_loop_iterations;
 CounterVariable *m_loop_time;
 Clock *m_clock;
 TimeStamp m_wake_up_time;

 ReadDescriptorSet m_read_descriptors;
 ConnectedDescriptorSet m_connected_read_descriptors;
 WriteDescriptorSet m_write_descriptors;

 void CheckDescriptors(fd_set *r_set, fd_set *w_set);
 bool AddDescriptorsToSet(fd_set *r_set, fd_set *w_set, int *max_sd);

 DISALLOW_COPY_AND_ASSIGN(SelectPoller);
};
} // namespace io
} // namespace ola
#endif // COMMON_IO_SELECTPOLLER_H_