/*
 * Copyright (c) 1996 Gunther Schadow.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef CXX_PROC_H
#define CXX_PROC_H

#pragma interface

#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdarg.h>

class ProcInfo
{
 public:
  enum {
    now   = 0x0001, // start process now (meaningful only in ctor)
    join  = 0x0002, // join process wait if necessary (for dtor)
    term  = 0x0004, // process is to be terminated (meaningful for join)
    kill  = 0x0010, // process is to be killed     (meaningful for join)    
    cont  = 0x0020, // send stopped process a continue signal
    dead  = 0x0040, // process is dead
    start = 0x0080, // process is started
    chld  = 0x0100, // process info for child
    clean = 0x0200, // clean proc info entry if process died

    user_mask = ( now | join | term | kill | cont ),
  };

        ProcInfo(int flags = 0);
       ~ProcInfo();

  int   flags(int f = 0, int m = 0);

  pid_t pid()      const { return _pid; }
  bool  parent()   const { return (_flags & start) && !(_flags & chld); }
  bool  child()    const { return (_flags & start) &&  (_flags & chld); }

  bool  started()  const { return _flags & start; }
  bool  running()  const { return (_flags & start) && !(_flags & dead); }
  bool  exited()   const { return _flags & dead & WIFEXITED(_wstatus); }
  bool  stopped()  const { return _flags & dead & WIFSTOPPED(_wstatus); }
  bool  signaled() const { return _flags & dead & WIFSIGNALED(_wstatus); }

  int   exitstatus() const { return WEXITSTATUS(_wstatus); }
  int   termsignal() const { return WTERMSIG(_wstatus); }
  int   stopsignal() const { return WSTOPSIG(_wstatus); }

 private:
            int       _flags;
            pid_t     _pid;
            int       _wstatus; 
            ProcInfo *_next_proc;
            ProcInfo *_prev_proc;  
  static    ProcInfo *_root_proc;
  static class Signal _sigchld;
  static       int    reaper(Signal &s);

  friend class Proc;
};

inline
int ProcInfo::flags(int f, int m)
{ 
  int old=_flags;
  _flags=_flags&~(m&user_mask)|(f&user_mask);
  return old;
}

class Proc
{
 public:
        Proc(int flags = 0);
       ~Proc();

  void  run();
  void  raise(int sig) { kill(_info->pid(), sig); }
  int   flags(int f = 0, int m = 0) { return _info->flags(f, m); }

  typedef void (*vinit_t)(va_list);
  void vrun(vinit_t, ...);

 public:
  pid_t pid()        const { return _info->pid(); }
  bool  parent()     const { return _info->parent(); }
  bool  child()      const { return _info->child(); }

  bool  started()    const { return _info->started(); }
  bool  running()    const { return _info->running(); }
  bool  exited()     const { return _info->exited(); }
  bool  stopped()    const { return _info->stopped(); }
  bool  signaled()   const { return _info->signaled(); }

  int   exitstatus() const { return _info->exitstatus(); }
  int   termsignal() const { return _info->termsignal(); }
  int   stopsignal() const { return _info->stopsignal(); }

 private:
  ProcInfo *_info;
};

#endif