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Class: IO

Relationships & Source Files
Inherits: Object
Defined in: ext/io/wait/wait.c

Instance Method Summary

Instance Method Details

#wait(events, timeout) ⇒ event mask, ... #wait(*event_symbols[, timeout]) ⇒ self, ...

Waits until the IO becomes ready for the specified events and returns the subset of events that become ready, or a falsy value when times out.

The events can be a bit mask of IO::READABLE, IO::WRITABLE or IO::PRIORITY.

Returns an event mask (truthy value) immediately when buffered data is available.

The second form: if one or more event symbols (:read, :write, or :read_write) are passed, the event mask is the bit OR of the bitmask corresponding to those symbols. In this form, timeout is optional, the order of the arguments is arbitrary, and returns io if any of the events is ready.

You must require ‘io/wait’ to use this method.

[ GitHub ]

  
# File 'ext/io/wait/wait.c', line 246

static VALUE
io_wait(int argc, VALUE *argv, VALUE io)
{
#ifndef HAVE_RB_IO_WAIT
    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;
#else
    VALUE timeout = Qundef;
    rb_io_event_t events = 0;
    int i, return_io = 0;

    if (argc != 2 || (RB_SYMBOL_P(argv[0]) || RB_SYMBOL_P(argv[1]))) {
        /* We'd prefer to return the actual mask, but this form would return the io itself: */
        return_io = 1;

        /* Slow/messy path: */
        for (i = 0; i < argc; i += 1) {
            if (RB_SYMBOL_P(argv[i])) {
                events |= wait_mode_sym(argv[i]);
            }
            else if (timeout == Qundef) {
                rb_time_interval(timeout = argv[i]);
            }
            else {
                rb_raise(rb_eArgError, "timeout given more than once");
            }
        }

        if (timeout == Qundef) timeout = Qnil;

        if (events == 0) {
            events = RUBY_IO_READABLE;
        }
    }
    else /* argc == 2 and neither are symbols */ {
        /* This is the fast path: */
        events = io_event_from_value(argv[0]);
        timeout = argv[1];
    }

    if (events & RUBY_IO_READABLE) {
        rb_io_t *fptr = NULL;
        RB_IO_POINTER(io, fptr);

        if (rb_io_read_pending(fptr)) {
            /* This was the original behaviour: */
            if (return_io) return Qtrue;
            /* New behaviour always returns an event mask: */
            else return RB_INT2NUM(RUBY_IO_READABLE);
        }
    }

    return io_wait_event(io, events, timeout, return_io);
#endif
}

#wait_prioritytruthy, falsy #wait_priority(timeout) ⇒ truthy, falsy

Waits until IO is priority and returns a truthy value or a falsy value when times out. Priority data is sent and received using the Socket::MSG_OOB flag and is typically limited to streams.

You must require ‘io/wait’ to use this method.

[ GitHub ]

  
# File 'ext/io/wait/wait.c', line 160

static VALUE
io_wait_priority(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr = NULL;

    RB_IO_POINTER(io, fptr);
    rb_io_check_char_readable(fptr);

    if (rb_io_read_pending(fptr)) return Qtrue;

    rb_check_arity(argc, 0, 1);
    VALUE timeout = argc == 1 ? argv[0] : Qnil;

    return io_wait_event(io, RUBY_IO_PRIORITY, timeout, 1);
}

#wait_readabletruthy, falsy #wait_readable(timeout) ⇒ truthy, falsy

Waits until IO is readable and returns a truthy value, or a falsy value when times out. Returns a truthy value immediately when buffered data is available.

You must require ‘io/wait’ to use this method.

[ GitHub ]

  
# File 'ext/io/wait/wait.c', line 82

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

    GetOpenFile(io, fptr);
    rb_io_check_char_readable(fptr);

#ifndef HAVE_RB_IO_WAIT
    tv = get_timeout(argc, argv, &timerec);
#endif
    if (rb_io_read_pending(fptr)) return Qtrue;

#ifndef HAVE_RB_IO_WAIT
    if (wait_for_single_fd(fptr, RB_WAITFD_IN, tv)) {
        return io;
    }
    return Qnil;
#else
    rb_check_arity(argc, 0, 1);
    VALUE timeout = (argc == 1 ? argv[0] : Qnil);

    return io_wait_event(io, RUBY_IO_READABLE, timeout, 1);
#endif
}

#wait_writabletruthy, falsy #wait_writable(timeout) ⇒ truthy, falsy

Waits until IO is writable and returns a truthy value or a falsy value when times out.

You must require ‘io/wait’ to use this method.

[ GitHub ]

  
# File 'ext/io/wait/wait.c', line 122

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

    GetOpenFile(io, fptr);
    rb_io_check_writable(fptr);

#ifndef HAVE_RB_IO_WAIT
    tv = get_timeout(argc, argv, &timerec);
    if (wait_for_single_fd(fptr, RB_WAITFD_OUT, tv)) {
        return io;
    }
    return Qnil;
#else
    rb_check_arity(argc, 0, 1);
    VALUE timeout = (argc == 1 ? argv[0] : Qnil);

    return io_wait_event(io, RUBY_IO_WRITABLE, timeout, 1);
#endif
}