/*****************************************************************************
#   Copyright (C) 1994-2008 by David Gordon.
#   All rights reserved.                           
#                                                                           
#   This software is part of a beta-test version of the Consed/Autofinish
#   package.  It should not be redistributed or
#   used for any commercial purpose, including commercially funded
#   sequencing, without written permission from the author and the
#   University of Washington.
#   
#   This software is provided ``AS IS'' and any express or implied
#   warranties, including, but not limited to, the implied warranties of
#   merchantability and fitness for a particular purpose, are disclaimed.
#   In no event shall the authors or the University of Washington be
#   liable for any direct, indirect, incidental, special, exemplary, or
#   consequential damages (including, but not limited to, procurement of
#   substitute goods or services; loss of use, data, or profits; or
#   business interruption) however caused and on any theory of liability,
#   whether in contract, strict liability, or tort (including negligence
#   or otherwise) arising in any way out of the use of this software, even
#   if advised of the possibility of such damage.
#
#   Building Consed from source is error prone and not simple which is
#   why I provide executables.  Due to time limitations I cannot
#   provide any assistance in building Consed.  Even if you do not
#   modify the source, you may introduce errors due to using a
#   different version of the compiler, a different version of motif,
#   different versions of other libraries than I used, etc.  For this
#   reason, if you discover Consed bugs, I can only offer help with
#   those bugs if you first reproduce those bugs with an executable
#   provided by me--not an executable you have built.
# 
#   Modifying Consed is also difficult.  Although Consed is modular,
#   some modules are used by many other modules.  Thus making a change
#   in one place can have unforeseen effects on many other features.
#   It may takes months for you to notice these other side-effects
#   which may not seen connected at all.  It is not feasable for me to
#   provide help with modifying Consed sources because of the
#   potentially huge amount of time involved.
#
#*****************************************************************************/
#include    "maybeTerminateIfAnotherReadWriteConsed.h"
#include    "consedParameters.h"
#include    <cstdio>
using namespace std;
#include    <fcntl.h>
#include    <sys/types.h>
#include    <sys/stat.h>
#include    <cerrno>
#include    <unistd.h>
#include    <cstdlib>
 




void maybeTerminateIfAnotherReadWriteConsed() {

   if ( !pCP->bOnlyAllowOneReadWriteConsedAtATime_ ) return;

   // now this process needs to determine if it is read-write

   if ( pCP->bReadOnly_ ) return;

   if ( ( pCP->nWhatIsRunning_ == nAutoFinishIsRunning ) 
        && !pCP->bWillDoExperiments_ ) return;

   

   FileName fil( ".consed_write_lock_do_not_delete" );
   if ( !fil.bFileByThisNameExists() ) {
      if ( !fil.bCreateFile() ) {
         cerr << "You do not have write access to this directory.  You can only start consed as consed -read_only" << endl;
         exit( 1 );
      }
   }

   int nFileDescriptor = open( fil.data(),  O_WRONLY );
   if ( nFileDescriptor == -1 ) {
      fprintf( stderr, "failed to open file due to %d %s\n",
               errno, strerror( errno) );
    
      exit( 1 );
   }

   struct flock myflock;
   int nLockReturn;

   myflock.l_type = F_WRLCK;
   myflock.l_whence = 0;
   myflock.l_start = 0;
   myflock.l_len = 0;

   nLockReturn = fcntl( nFileDescriptor,  F_SETLK, &myflock  );
   if ( nLockReturn == -1 ) {
      fprintf( stderr, "errno = %d %s\n",
               errno, strerror( errno ) );
      fprintf( stderr, "There is another read-write Consed or Autofinish \nrunning in this same directory.  \nIf you are trying to run Consed, you can run it read-only \nby typing \"consed -read_only\"" );

      exit( 1 );
   }
}