January 30, 2003 PTHREAD_BARRIER_WAIT 3

### NAME

pthread_barrier_wait - wait for a barrier

### LIBRARY

POSIX Thread Library (libpthread, -lpthread)

### SYNOPSIS

```int` pthread_barrier_wait(```pthread_barrier_t *barrier`)

### DESCRIPTION

The pthread_barrier_wait(``) function causes the current thread to wait on the barrier specified. Once as many threads as specified by the ```count` parameter to the corresponding pthread_barrier_init(``) call have called pthread_barrier_wait(``), all threads will wake up, return from their respective pthread_barrier_wait(``) calls and continue execution.

### RETURN VALUES

If successful, pthread_barrier_wait(``) will return zero for all waiting threads except for one. One thread will receive status ```PTHREAD_BARRIER_SERIAL_THREAD`, which is intended to indicate that this thread may be used to update shared data. It is the responsibility of this thread to insure the visibility and atomicity of any updates to shared data with respect to the other threads participating in the barrier. In the case of failure, an error value will be returned.

### ERRORS

pthread_barrier_wait(``) may fail if:

[```EINVAL`]
  The value specified by ```barrier` is invalid.

### SEE ALSO

pthread_barrier_destroy(3), pthread_barrier_init(3), pthread_barrierattr_destroy(3), pthread_barrierattr_init(3)

### STANDARDS

pthread_barrier_wait(``) conforms to IEEE Std 1003.1-2001 (``POSIX.1'') .