pthread_cond_init() returns zero after completing successfully. Any other return value indicates that an error occurred. When any of the following conditions occurs, the function fails and returns the corresponding value.
EINVAL
Description:The value specified by cattr is invalid.
EBUSY
Description:The condition variable is being used.
EAGAIN
Description:The necessary resources are not available.
ENOMEM
Description:Insufficient memory exists to initialize the condition variable.