Checks if stream can be read.
Note that some stream types may not be able to implement this 100%
reliably, and it is possible that a call to g_input_stream_read()
after this returns TRUE would still block. To guarantee
non-blocking behavior, you should always use
g_pollable_input_stream_read_nonblocking(), which will return a
G_IO_ERROR_WOULD_BLOCK error rather than blocking.
Since 2.28
TRUE if stream is readable, FALSE if not. If an error has occurred on stream, this will result in g_pollable_input_stream_is_readable() returning TRUE, and the next attempt to read will return the error.
Checks if stream can be read. Note that some stream types may not be able to implement this 100% reliably, and it is possible that a call to g_input_stream_read() after this returns TRUE would still block. To guarantee non-blocking behavior, you should always use g_pollable_input_stream_read_nonblocking(), which will return a G_IO_ERROR_WOULD_BLOCK error rather than blocking. Since 2.28