class IO - io/wait: Ruby Standard Library Documentation

nread → int click to toggle source

Returns number of bytes that can be read without blocking. Returns zero if no information available.

static VALUE
io_nread(VALUE io)
{
    rb_io_t *fptr;
    int len;
    ioctl_arg n;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    len = rb_io_read_pending(fptr);
    if (len > 0) return INT2FIX(len);
    if (!FIONREAD_POSSIBLE_P(fptr->fd)) return INT2FIX(0);
    if (ioctl(fptr->fd, FIONREAD, &n)) return INT2FIX(0);
    if (n > 0) return ioctl_arg2num(n);
    return INT2FIX(0);
}

ready? → true or false click to toggle source

Returns true if input available without blocking, or false.

static VALUE
io_ready_p(VALUE io)
{
    rb_io_t *fptr;
    struct timeval tv = {0, 0};

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    if (rb_io_read_pending(fptr)) return Qtrue;
    if (wait_for_single_fd(fptr, RB_WAITFD_IN, &tv))
        return Qtrue;
    return Qfalse;
}

wait(timeout = nil, mode = :read) → IO, true or nil click to toggle source

Waits until IO is readable or writable without blocking and returns self, or nil when times out. Returns true immediately when buffered data is available. Optional parameter mode is one of :read, :write, or :read_write.

static VALUE
io_wait_readwrite(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr;
    struct timeval timerec;
    struct timeval *tv = NULL;
    int event = 0;
    int i;

    GetOpenFile(io, fptr);
    for (i = 0; i < argc; ++i) {
        if (SYMBOL_P(argv[i])) {
            event |= wait_mode_sym(argv[i]);
        }
        else {
            *(tv = &timerec) = rb_time_interval(argv[i]);
        }
    }
    /* rb_time_interval() and might_mode() might convert the argument */
    rb_io_check_closed(fptr);
    if (!event) event = RB_WAITFD_IN;
    if ((event & RB_WAITFD_IN) && rb_io_read_pending(fptr))
        return Qtrue;
    if (wait_for_single_fd(fptr, event, tv))
        return io;
    return Qnil;
}

wait_readable → IO, true or nil click to toggle source

wait_readable(timeout) → IO, true or nil

Waits until IO is readable without blocking and returns self, or nil when times out. Returns true immediately when buffered data is available.

static VALUE
io_wait_readable(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr;
    struct timeval timerec;
    struct timeval *tv;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    tv = get_timeout(argc, argv, &timerec);
    if (rb_io_read_pending(fptr)) return Qtrue;
    if (wait_for_single_fd(fptr, RB_WAITFD_IN, tv)) {
        return io;
    }
    return Qnil;
}

wait_writable → IO click to toggle source

wait_writable(timeout) → IO or nil

Waits until IO is writable without blocking and returns self or nil when times out.

static VALUE
io_wait_writable(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr;
    struct timeval timerec;
    struct timeval *tv;

    GetOpenFile(io, fptr);
    rb_io_check_writable(fptr);
    tv = get_timeout(argc, argv, &timerec);
    if (wait_for_single_fd(fptr, RB_WAITFD_OUT, tv)) {
        return io;
    }
    return Qnil;
}