/*

 * lftp - file transfer program

 *

 * Copyright (c) 1996-2012 by Alexander V. Lukyanov (lav@yars.free.net)

 *

 * 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 3 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, see <http://www.gnu.org/licenses/>.

 */

#include <config.h>

#include <sys/wait.h>

#include <errno.h>

#include "trio.h"

#include "ProcWait.h"

#include "SignalHook.h"

xmap<ProcWait*> ProcWait::all_proc;

const xstring& ProcWait::proc_key(pid_t p)

{

   static xstring tmp_key;

   tmp_key.nset((const char*)&p,sizeof(p));

   return tmp_key;

}

int ProcWait::Do()

{

   int m=STALL;

   if(status!=RUNNING)

   {

   final:

      if(auto_die)

      {

	 Delete(this);

	 return MOVED;

      }

      return m;

   }

   int info;

   int res=waitpid(pid,&info,WNOHANG|WUNTRACED);

   if(res==-1)

   {

      if(status!=RUNNING)

	 return MOVED;

      // waitpid failed, check the process existence

      if(kill(pid,0)==-1)

      {

	 status=TERMINATED;

	 term_info=255;

	 m=MOVED;

	 goto final;

      }

      goto leave;

   }

   if(res==pid)

   {

      if(handle_info(info))

      {

	 m=MOVED;

	 goto final;

      }

   }

leave:

   Timeout(500); // check from time to time, in case SIGCHLD fails

   return m;

}

bool ProcWait::handle_info(int info)

{

   if(WIFSTOPPED(info))

   {

      SignalHook::IncreaseCount(SIGTSTP);

      return false;

   }

   else

   {

      if(WIFSIGNALED(info) && WTERMSIG(info)==SIGINT)

	 SignalHook::IncreaseCount(SIGINT);

      status=TERMINATED;

      term_info=info;

      return true;

   }

}

int ProcWait::Kill(int sig)

{

   Do();

   if(status!=RUNNING)

      return -1;

   int res;

   res=kill(-pid,sig);

   if(res==-1)

      res=kill(pid,sig);

   return res;

}

ProcWait::ProcWait(pid_t p)

   : pid(p)

{

   auto_die=false;

   status=RUNNING;

   term_info=-1;

   saved_errno=0;

   all_proc.add(proc_key(pid),this);

}

ProcWait::~ProcWait()

{

   all_proc.remove(proc_key(pid));

}

void ProcWait::Signal(bool yes)

{

   if(yes)

   {

      SignalHook::DoCount(SIGCHLD);   // select() will return -1 with EINTR

      SignalHook::Unblock(SIGCHLD);

   }

   else

      SignalHook::Block(SIGCHLD);

}

void ProcWait::DeleteAll()

{

   Signal(false);

   for(ProcWait *w=all_proc.each_begin(); w; w=all_proc.each_next())

      Delete(w);

}