subroutine cs_init
  character*12 csub0
  common/mtxcom/ltrace,mtx,mtxstate,csub0
  ltrace=0
  mtxstate=0
  csub0='**unlocked**'
  call fthread_mutex_init(mtx)
  return
end subroutine cs_init

subroutine cs_destroy
  character*12 csub0
  common/mtxcom/ltrace,mtx,mtxstate,csub0
  call fthread_mutex_destroy(mtx)
  return
end subroutine cs_destroy

subroutine th_create(sub)
  call fthread_create(sub,id)
  return
end subroutine th_create

subroutine th_exit
  call fthread_exit
  return
end subroutine th_exit

subroutine cs_lock(csub)
  character*(*) csub
  character*12 csub0
  integer fthread_mutex_lock,fthread_mutex_trylock
  common/mtxcom/ltrace,mtx,mtxstate,csub0
  n=fthread_mutex_trylock(mtx)
  if(n.ne.0) then
! Another thread has already locked the mutex
     n=fthread_mutex_lock(mtx)
     iz=index(csub0,' ')
     if(ltrace.ge.1) print*,'"',csub,'" requested mutex when "',   &
          csub0(:iz-1),'" owned it.'
  endif
  mtxstate=1
  csub0=csub
  if(ltrace.ge.3) print*,'Mutex locked by ',csub
  return
end subroutine cs_lock

subroutine cs_unlock
  character*12 csub0
  common/mtxcom/ltrace,mtx,mtxstate,csub0
  if(ltrace.ge.3) print*,'Mutex unlocked,',ltrace,mtx,mtxstate,csub0
  mtxstate=0
  call fthread_mutex_unlock(mtx)
  return
end subroutine cs_unlock