// This file is part of the SV-Benchmarks collection of verification tasks:
// https://gitlab.com/sosy-lab/benchmarking/sv-benchmarks
//
// SPDX-FileCopyrightText: 2021 F. Schuessele <schuessf@informatik.uni-freiburg.de>
// SPDX-FileCopyrightText: 2021 D. Klumpp <klumpp@informatik.uni-freiburg.de>
//
// SPDX-License-Identifier: LicenseRef-BSD-3-Clause-Attribution-Vandikas

typedef unsigned long int pthread_t;

union pthread_attr_t
{
  char __size[36];
  long int __align;
};
typedef union pthread_attr_t pthread_attr_t;

extern void __assert_fail(const char *__assertion, const char *__file,
      unsigned int __line, const char *__function)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__noreturn__));
void reach_error() { __assert_fail("0", "test-easy6.wvr.c", 21, __extension__ __PRETTY_FUNCTION__); }
extern int pthread_create (pthread_t *__restrict __newthread,
      const pthread_attr_t *__restrict __attr,
      void *(*__start_routine) (void *),
      void *__restrict __arg) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 3)));
extern int pthread_join (pthread_t __th, void **__thread_return);

extern int  __VERIFIER_nondet_int(void);
extern _Bool __VERIFIER_nondet_bool(void);
extern void __VERIFIER_atomic_begin(void);
extern void __VERIFIER_atomic_end(void);

extern void abort(void);
void assume_abort_if_not(int cond) {
  if(!cond) {abort();}
}

_Bool e1, e2;
int n1, n2, tmp1, tmp2, i, i1, i2;


void* thread1() {
  __VERIFIER_atomic_begin();
  e1 = 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  tmp1 = n2;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  n1 = tmp1 + 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  e1 = 0;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  assume_abort_if_not(!e2);
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  assume_abort_if_not(n2 == 0 || n2 >= n1);
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  i1 = i;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  i = i1 + 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  n1 = 0;
  __VERIFIER_atomic_end();

  return 0;
}

void* thread2() {
  __VERIFIER_atomic_begin();
  e2 = 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  tmp2 = n1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  n2 = tmp2 + 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  e2 = 0;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  assume_abort_if_not(!e1);
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  assume_abort_if_not(n1 == 0 || n1 > n2);
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  i2 = i;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  i = i2 + 1;
  __VERIFIER_atomic_end();
  __VERIFIER_atomic_begin();
  n2 = 0;
  __VERIFIER_atomic_end();

  return 0;
}

int main() {
  pthread_t t1, t2;
  
  // main method
  pthread_create(&t1, 0, thread1, 0);
  pthread_create(&t2, 0, thread2, 0);
  pthread_join(t1, 0);
  pthread_join(t2, 0);

  assume_abort_if_not(i != 2);
  reach_error();

  return 0;
}