Checks if @stream is actually pollable. Some classes may implement #GPollableOutputStream but have only certain instances of that class be pollable. If this method returns %FALSE, then the behavior of other #GPollableOutputStream methods is undefined.
Creates a #GSource that triggers when @stream can be written, or @cancellable is triggered or an error occurs. The callback on the source is of the #GPollableSourceFunc type.
Get the main Gtk struct
the main Gtk struct as a void*
Checks if @stream can be written.
Attempts to write up to @count bytes from @buffer to @stream, as with g_output_stream_write(). If @stream is not currently writable, this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can use g_pollable_output_stream_create_source() to create a #GSource that will be triggered when @stream is writable.
#GPollableOutputStream is implemented by #GOutputStreams that can be polled for readiness to write. This can be used when interfacing with a non-GIO API that expects UNIX-file-descriptor-style asynchronous I/O rather than GIO-style.