read_write_lock_true-unreach-call.i

extern void __VERIFIER_assume(int);
extern void __VERIFIER_error() __attribute__ ((__noreturn__));

typedef unsigned char __u_char;
typedef unsigned short int __u_short;
typedef unsigned int __u_int;
typedef unsigned long int __u_long;
typedef signed char __int8_t;
typedef unsigned char __uint8_t;
typedef signed short int __int16_t;
typedef unsigned short int __uint16_t;
typedef signed int __int32_t;
typedef unsigned int __uint32_t;
typedef signed long int __int64_t;
typedef unsigned long int __uint64_t;
typedef long int __quad_t;
typedef unsigned long int __u_quad_t;
typedef unsigned long int __dev_t;
typedef unsigned int __uid_t;
typedef unsigned int __gid_t;
typedef unsigned long int __ino_t;
typedef unsigned long int __ino64_t;
typedef unsigned int __mode_t;
typedef unsigned long int __nlink_t;
typedef long int __off_t;
typedef long int __off64_t;
typedef int __pid_t;
typedef struct { int __val[2]; } __fsid_t;
typedef long int __clock_t;
typedef unsigned long int __rlim_t;
typedef unsigned long int __rlim64_t;
typedef unsigned int __id_t;
typedef long int __time_t;
typedef unsigned int __useconds_t;
typedef long int __suseconds_t;
typedef int __daddr_t;
typedef long int __swblk_t;
typedef int __key_t;
typedef int __clockid_t;
typedef void * __timer_t;
typedef long int __blksize_t;
typedef long int __blkcnt_t;
typedef long int __blkcnt64_t;
typedef unsigned long int __fsblkcnt_t;
typedef unsigned long int __fsblkcnt64_t;
typedef unsigned long int __fsfilcnt_t;
typedef unsigned long int __fsfilcnt64_t;
typedef long int __ssize_t;
typedef __off64_t __loff_t;
typedef __quad_t *__qaddr_t;
typedef char *__caddr_t;
typedef long int __intptr_t;
typedef unsigned int __socklen_t;
typedef long unsigned int size_t;

typedef __time_t time_t;


struct timespec
  {
    __time_t tv_sec;
    long int tv_nsec;
  };
typedef __pid_t pid_t;
struct sched_param
  {
    int __sched_priority;
  };


struct __sched_param
  {
    int __sched_priority;
  };
typedef unsigned long int __cpu_mask;
typedef struct
{
  __cpu_mask __bits[1024 / (8 * sizeof (__cpu_mask))];
} cpu_set_t;

extern int __sched_cpucount (size_t __setsize, const cpu_set_t *__setp)
  __attribute__ ((__nothrow__ , __leaf__));
extern cpu_set_t *__sched_cpualloc (size_t __count) __attribute__ ((__nothrow__ , __leaf__)) ;
extern void __sched_cpufree (cpu_set_t *__set) __attribute__ ((__nothrow__ , __leaf__));


extern int sched_setparam (__pid_t __pid, __const struct sched_param *__param)
     __attribute__ ((__nothrow__ , __leaf__));
extern int sched_getparam (__pid_t __pid, struct sched_param *__param) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_setscheduler (__pid_t __pid, int __policy,
          __const struct sched_param *__param) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_getscheduler (__pid_t __pid) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_yield (void) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_get_priority_max (int __algorithm) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_get_priority_min (int __algorithm) __attribute__ ((__nothrow__ , __leaf__));
extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __attribute__ ((__nothrow__ , __leaf__));



typedef __clock_t clock_t;


typedef __clockid_t clockid_t;



typedef __timer_t timer_t;

struct tm
{
  int tm_sec;
  int tm_min;
  int tm_hour;
  int tm_mday;
  int tm_mon;
  int tm_year;
  int tm_wday;
  int tm_yday;
  int tm_isdst;
  long int tm_gmtoff;
  __const char *tm_zone;
};


struct itimerspec
  {
    struct timespec it_interval;
    struct timespec it_value;
  };
struct sigevent;

extern clock_t clock (void) __attribute__ ((__nothrow__ , __leaf__));
extern time_t time (time_t *__timer) __attribute__ ((__nothrow__ , __leaf__));
extern double difftime (time_t __time1, time_t __time0)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__const__));
extern time_t mktime (struct tm *__tp) __attribute__ ((__nothrow__ , __leaf__));
extern size_t strftime (char *__restrict __s, size_t __maxsize,
   __const char *__restrict __format,
   __const struct tm *__restrict __tp) __attribute__ ((__nothrow__ , __leaf__));

typedef struct __locale_struct
{
  struct __locale_data *__locales[13];
  const unsigned short int *__ctype_b;
  const int *__ctype_tolower;
  const int *__ctype_toupper;
  const char *__names[13];
} *__locale_t;
typedef __locale_t locale_t;
extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
     __const char *__restrict __format,
     __const struct tm *__restrict __tp,
     __locale_t __loc) __attribute__ ((__nothrow__ , __leaf__));

extern struct tm *gmtime (__const time_t *__timer) __attribute__ ((__nothrow__ , __leaf__));
extern struct tm *localtime (__const time_t *__timer) __attribute__ ((__nothrow__ , __leaf__));

extern struct tm *gmtime_r (__const time_t *__restrict __timer,
       struct tm *__restrict __tp) __attribute__ ((__nothrow__ , __leaf__));
extern struct tm *localtime_r (__const time_t *__restrict __timer,
          struct tm *__restrict __tp) __attribute__ ((__nothrow__ , __leaf__));

extern char *asctime (__const struct tm *__tp) __attribute__ ((__nothrow__ , __leaf__));
extern char *ctime (__const time_t *__timer) __attribute__ ((__nothrow__ , __leaf__));

extern char *asctime_r (__const struct tm *__restrict __tp,
   char *__restrict __buf) __attribute__ ((__nothrow__ , __leaf__));
extern char *ctime_r (__const time_t *__restrict __timer,
        char *__restrict __buf) __attribute__ ((__nothrow__ , __leaf__));
extern char *__tzname[2];
extern int __daylight;
extern long int __timezone;
extern char *tzname[2];
extern void tzset (void) __attribute__ ((__nothrow__ , __leaf__));
extern int daylight;
extern long int timezone;
extern int stime (__const time_t *__when) __attribute__ ((__nothrow__ , __leaf__));
extern time_t timegm (struct tm *__tp) __attribute__ ((__nothrow__ , __leaf__));
extern time_t timelocal (struct tm *__tp) __attribute__ ((__nothrow__ , __leaf__));
extern int dysize (int __year) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__const__));
extern int nanosleep (__const struct timespec *__requested_time,
        struct timespec *__remaining);
extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __attribute__ ((__nothrow__ , __leaf__));
extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __attribute__ ((__nothrow__ , __leaf__));
extern int clock_settime (clockid_t __clock_id, __const struct timespec *__tp)
     __attribute__ ((__nothrow__ , __leaf__));
extern int clock_nanosleep (clockid_t __clock_id, int __flags,
       __const struct timespec *__req,
       struct timespec *__rem);
extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __attribute__ ((__nothrow__ , __leaf__));
extern int timer_create (clockid_t __clock_id,
    struct sigevent *__restrict __evp,
    timer_t *__restrict __timerid) __attribute__ ((__nothrow__ , __leaf__));
extern int timer_delete (timer_t __timerid) __attribute__ ((__nothrow__ , __leaf__));
extern int timer_settime (timer_t __timerid, int __flags,
     __const struct itimerspec *__restrict __value,
     struct itimerspec *__restrict __ovalue) __attribute__ ((__nothrow__ , __leaf__));
extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
     __attribute__ ((__nothrow__ , __leaf__));
extern int timer_getoverrun (timer_t __timerid) __attribute__ ((__nothrow__ , __leaf__));

typedef unsigned long int pthread_t;
typedef union
{
  char __size[56];
  long int __align;
} pthread_attr_t;
typedef struct __pthread_internal_list
{
  struct __pthread_internal_list *__prev;
  struct __pthread_internal_list *__next;
} __pthread_list_t;
typedef union
{
  struct __pthread_mutex_s
  {
    int __lock;
    unsigned int __count;
    int __owner;
    unsigned int __nusers;
    int __kind;
    int __spins;
    __pthread_list_t __list;
  } __data;
  char __size[40];
  long int __align;
} pthread_mutex_t;
typedef union
{
  char __size[4];
  int __align;
} pthread_mutexattr_t;
typedef union
{
  struct
  {
    int __lock;
    unsigned int __futex;
    __extension__ unsigned long long int __total_seq;
    __extension__ unsigned long long int __wakeup_seq;
    __extension__ unsigned long long int __woken_seq;
    void *__mutex;
    unsigned int __nwaiters;
    unsigned int __broadcast_seq;
  } __data;
  char __size[48];
  __extension__ long long int __align;
} pthread_cond_t;
typedef union
{
  char __size[4];
  int __align;
} pthread_condattr_t;
typedef unsigned int pthread_key_t;
typedef int pthread_once_t;
typedef union
{
  struct
  {
    int __lock;
    unsigned int __nr_readers;
    unsigned int __readers_wakeup;
    unsigned int __writer_wakeup;
    unsigned int __nr_readers_queued;
    unsigned int __nr_writers_queued;
    int __writer;
    int __shared;
    unsigned long int __pad1;
    unsigned long int __pad2;
    unsigned int __flags;
  } __data;
  char __size[56];
  long int __align;
} pthread_rwlock_t;
typedef union
{
  char __size[8];
  long int __align;
} pthread_rwlockattr_t;
typedef volatile int pthread_spinlock_t;
typedef union
{
  char __size[32];
  long int __align;
} pthread_barrier_t;
typedef union
{
  char __size[4];
  int __align;
} pthread_barrierattr_t;
typedef long int __jmp_buf[8];
enum
{
  PTHREAD_CREATE_JOINABLE,
  PTHREAD_CREATE_DETACHED
};
enum
{
  PTHREAD_MUTEX_TIMED_NP,
  PTHREAD_MUTEX_RECURSIVE_NP,
  PTHREAD_MUTEX_ERRORCHECK_NP,
  PTHREAD_MUTEX_ADAPTIVE_NP
  ,
  PTHREAD_MUTEX_NORMAL = PTHREAD_MUTEX_TIMED_NP,
  PTHREAD_MUTEX_RECURSIVE = PTHREAD_MUTEX_RECURSIVE_NP,
  PTHREAD_MUTEX_ERRORCHECK = PTHREAD_MUTEX_ERRORCHECK_NP,
  PTHREAD_MUTEX_DEFAULT = PTHREAD_MUTEX_NORMAL
};
enum
{
  PTHREAD_MUTEX_STALLED,
  PTHREAD_MUTEX_STALLED_NP = PTHREAD_MUTEX_STALLED,
  PTHREAD_MUTEX_ROBUST,
  PTHREAD_MUTEX_ROBUST_NP = PTHREAD_MUTEX_ROBUST
};
enum
{
  PTHREAD_RWLOCK_PREFER_READER_NP,
  PTHREAD_RWLOCK_PREFER_WRITER_NP,
  PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,
  PTHREAD_RWLOCK_DEFAULT_NP = PTHREAD_RWLOCK_PREFER_READER_NP
};
enum
{
  PTHREAD_INHERIT_SCHED,
  PTHREAD_EXPLICIT_SCHED
};
enum
{
  PTHREAD_SCOPE_SYSTEM,
  PTHREAD_SCOPE_PROCESS
};
enum
{
  PTHREAD_PROCESS_PRIVATE,
  PTHREAD_PROCESS_SHARED
};
struct _pthread_cleanup_buffer
{
  void (*__routine) (void *);
  void *__arg;
  int __canceltype;
  struct _pthread_cleanup_buffer *__prev;
};
enum
{
  PTHREAD_CANCEL_ENABLE,
  PTHREAD_CANCEL_DISABLE
};
enum
{
  PTHREAD_CANCEL_DEFERRED,
  PTHREAD_CANCEL_ASYNCHRONOUS
};

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 void pthread_exit (void *__retval) __attribute__ ((__noreturn__));
extern int pthread_join (pthread_t __th, void **__thread_return);
extern int pthread_detach (pthread_t __th) __attribute__ ((__nothrow__ , __leaf__));
extern pthread_t pthread_self (void) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__const__));
extern int pthread_equal (pthread_t __thread1, pthread_t __thread2) __attribute__ ((__nothrow__ , __leaf__));
extern int pthread_attr_init (pthread_attr_t *__attr) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_destroy (pthread_attr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getdetachstate (__const pthread_attr_t *__attr,
     int *__detachstate)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setdetachstate (pthread_attr_t *__attr,
     int __detachstate)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getguardsize (__const pthread_attr_t *__attr,
          size_t *__guardsize)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setguardsize (pthread_attr_t *__attr,
          size_t __guardsize)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getschedparam (__const pthread_attr_t *__restrict
           __attr,
           struct sched_param *__restrict __param)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setschedparam (pthread_attr_t *__restrict __attr,
           __const struct sched_param *__restrict
           __param) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_getschedpolicy (__const pthread_attr_t *__restrict
     __attr, int *__restrict __policy)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setschedpolicy (pthread_attr_t *__attr, int __policy)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getinheritsched (__const pthread_attr_t *__restrict
      __attr, int *__restrict __inherit)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setinheritsched (pthread_attr_t *__attr,
      int __inherit)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getscope (__const pthread_attr_t *__restrict __attr,
      int *__restrict __scope)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setscope (pthread_attr_t *__attr, int __scope)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getstackaddr (__const pthread_attr_t *__restrict
          __attr, void **__restrict __stackaddr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2))) __attribute__ ((__deprecated__));
extern int pthread_attr_setstackaddr (pthread_attr_t *__attr,
          void *__stackaddr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1))) __attribute__ ((__deprecated__));
extern int pthread_attr_getstacksize (__const pthread_attr_t *__restrict
          __attr, size_t *__restrict __stacksize)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_attr_setstacksize (pthread_attr_t *__attr,
          size_t __stacksize)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_attr_getstack (__const pthread_attr_t *__restrict __attr,
      void **__restrict __stackaddr,
      size_t *__restrict __stacksize)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2, 3)));
extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
      size_t __stacksize) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_setschedparam (pthread_t __target_thread, int __policy,
      __const struct sched_param *__param)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (3)));
extern int pthread_getschedparam (pthread_t __target_thread,
      int *__restrict __policy,
      struct sched_param *__restrict __param)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (2, 3)));
extern int pthread_setschedprio (pthread_t __target_thread, int __prio)
     __attribute__ ((__nothrow__ , __leaf__));
extern int pthread_once (pthread_once_t *__once_control,
    void (*__init_routine) (void)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_setcancelstate (int __state, int *__oldstate);
extern int pthread_setcanceltype (int __type, int *__oldtype);
extern int pthread_cancel (pthread_t __th);
extern void pthread_testcancel (void);
typedef struct
{
  struct
  {
    __jmp_buf __cancel_jmp_buf;
    int __mask_was_saved;
  } __cancel_jmp_buf[1];
  void *__pad[4];
} __pthread_unwind_buf_t __attribute__ ((__aligned__));
struct __pthread_cleanup_frame
{
  void (*__cancel_routine) (void *);
  void *__cancel_arg;
  int __do_it;
  int __cancel_type;
};
extern void __pthread_register_cancel (__pthread_unwind_buf_t *__buf)
     ;
extern void __pthread_unregister_cancel (__pthread_unwind_buf_t *__buf)
  ;
extern void __pthread_unwind_next (__pthread_unwind_buf_t *__buf)
     __attribute__ ((__noreturn__))
     __attribute__ ((__weak__))
     ;
struct __jmp_buf_tag;
extern int __sigsetjmp (struct __jmp_buf_tag *__env, int __savemask) __attribute__ ((__nothrow__ , __leaf__));
extern int pthread_mutex_init (pthread_mutex_t *__mutex,
          __const pthread_mutexattr_t *__mutexattr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutex_destroy (pthread_mutex_t *__mutex)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutex_trylock (pthread_mutex_t *__mutex)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutex_lock (pthread_mutex_t *__mutex)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutex_timedlock (pthread_mutex_t *__restrict __mutex,
        __const struct timespec *__restrict
        __abstime) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutex_unlock (pthread_mutex_t *__mutex)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutex_getprioceiling (__const pthread_mutex_t *
      __restrict __mutex,
      int *__restrict __prioceiling)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutex_setprioceiling (pthread_mutex_t *__restrict __mutex,
      int __prioceiling,
      int *__restrict __old_ceiling)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 3)));
extern int pthread_mutex_consistent (pthread_mutex_t *__mutex)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_init (pthread_mutexattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_destroy (pthread_mutexattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_getpshared (__const pthread_mutexattr_t *
      __restrict __attr,
      int *__restrict __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutexattr_setpshared (pthread_mutexattr_t *__attr,
      int __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_gettype (__const pthread_mutexattr_t *__restrict
          __attr, int *__restrict __kind)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutexattr_settype (pthread_mutexattr_t *__attr, int __kind)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_getprotocol (__const pthread_mutexattr_t *
       __restrict __attr,
       int *__restrict __protocol)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutexattr_setprotocol (pthread_mutexattr_t *__attr,
       int __protocol)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_getprioceiling (__const pthread_mutexattr_t *
          __restrict __attr,
          int *__restrict __prioceiling)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutexattr_setprioceiling (pthread_mutexattr_t *__attr,
          int __prioceiling)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_mutexattr_getrobust (__const pthread_mutexattr_t *__attr,
     int *__robustness)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_mutexattr_setrobust (pthread_mutexattr_t *__attr,
     int __robustness)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_init (pthread_rwlock_t *__restrict __rwlock,
    __const pthread_rwlockattr_t *__restrict
    __attr) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_destroy (pthread_rwlock_t *__rwlock)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock)
  __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_timedrdlock (pthread_rwlock_t *__restrict __rwlock,
           __const struct timespec *__restrict
           __abstime) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlock_timedwrlock (pthread_rwlock_t *__restrict __rwlock,
           __const struct timespec *__restrict
           __abstime) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_rwlock_unlock (pthread_rwlock_t *__rwlock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlockattr_init (pthread_rwlockattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlockattr_destroy (pthread_rwlockattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlockattr_getpshared (__const pthread_rwlockattr_t *
       __restrict __attr,
       int *__restrict __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_rwlockattr_setpshared (pthread_rwlockattr_t *__attr,
       int __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_rwlockattr_getkind_np (__const pthread_rwlockattr_t *
       __restrict __attr,
       int *__restrict __pref)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_rwlockattr_setkind_np (pthread_rwlockattr_t *__attr,
       int __pref) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_cond_init (pthread_cond_t *__restrict __cond,
         __const pthread_condattr_t *__restrict
         __cond_attr) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_cond_destroy (pthread_cond_t *__cond)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_cond_signal (pthread_cond_t *__cond)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_cond_broadcast (pthread_cond_t *__cond)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_cond_wait (pthread_cond_t *__restrict __cond,
         pthread_mutex_t *__restrict __mutex)
     __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond,
       pthread_mutex_t *__restrict __mutex,
       __const struct timespec *__restrict
       __abstime) __attribute__ ((__nonnull__ (1, 2, 3)));
extern int pthread_condattr_init (pthread_condattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_condattr_destroy (pthread_condattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_condattr_getpshared (__const pthread_condattr_t *
     __restrict __attr,
     int *__restrict __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_condattr_setpshared (pthread_condattr_t *__attr,
     int __pshared) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_condattr_getclock (__const pthread_condattr_t *
          __restrict __attr,
          __clockid_t *__restrict __clock_id)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_condattr_setclock (pthread_condattr_t *__attr,
          __clockid_t __clock_id)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_spin_init (pthread_spinlock_t *__lock, int __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_spin_destroy (pthread_spinlock_t *__lock)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_spin_lock (pthread_spinlock_t *__lock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_spin_trylock (pthread_spinlock_t *__lock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_spin_unlock (pthread_spinlock_t *__lock)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrier_init (pthread_barrier_t *__restrict __barrier,
     __const pthread_barrierattr_t *__restrict
     __attr, unsigned int __count)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrier_destroy (pthread_barrier_t *__barrier)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrier_wait (pthread_barrier_t *__barrier)
     __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrierattr_init (pthread_barrierattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrierattr_destroy (pthread_barrierattr_t *__attr)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_barrierattr_getpshared (__const pthread_barrierattr_t *
        __restrict __attr,
        int *__restrict __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1, 2)));
extern int pthread_barrierattr_setpshared (pthread_barrierattr_t *__attr,
        int __pshared)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_key_create (pthread_key_t *__key,
          void (*__destr_function) (void *))
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (1)));
extern int pthread_key_delete (pthread_key_t __key) __attribute__ ((__nothrow__ , __leaf__));
extern void *pthread_getspecific (pthread_key_t __key) __attribute__ ((__nothrow__ , __leaf__));
extern int pthread_setspecific (pthread_key_t __key,
    __const void *__pointer) __attribute__ ((__nothrow__ , __leaf__)) ;
extern int pthread_getcpuclockid (pthread_t __thread_id,
      __clockid_t *__clock_id)
     __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (2)));
extern int pthread_atfork (void (*__prepare) (void),
      void (*__parent) (void),
      void (*__child) (void)) __attribute__ ((__nothrow__ , __leaf__));

int w=0, r=0, x, y;
void __VERIFIER_atomic_take_write_lock() {
  __VERIFIER_assume(w==0 && r==0);
  w = 1;
}
void __VERIFIER_atomic_take_read_lock() {
  __VERIFIER_assume(w==0);
  r = r+1;
}
void __VERIFIER_atomic_release_read_lock() {
  r = r-1;
}
void *writer(void *arg) {
  __VERIFIER_atomic_take_write_lock();
  x = 3;
  w = 0;
}
void *reader(void *arg) {
  int l;
  __VERIFIER_atomic_take_read_lock();
  l = x;
  y = l;
  if (!(y == x)) ERROR: __VERIFIER_error();
  __VERIFIER_atomic_release_read_lock();
}
int main() {
  pthread_t t1, t2, t3, t4;
  pthread_create(&t1, 0, writer, 0);
  pthread_create(&t2, 0, reader, 0);
  pthread_create(&t3, 0, writer, 0);
  pthread_create(&t4, 0, reader, 0);
  pthread_join(t1, 0);
  pthread_join(t2, 0);
  pthread_join(t3, 0);
  pthread_join(t4, 0);
  return 0;
}