KFIFO_FROM_USER(9) FIFO Buffer KFIFO_FROM_USER(9)NAME
kfifo_from_user - puts some data from user space into the fifo
kfifo_from_user(fifo, from, len, copied);
address of the fifo to be used
pointer to the data to be added
the length of the data to be added
pointer to output variable to store the number of copied bytes
This macro copies at most len bytes from the from into the fifo, depending of the available space and returns -EFAULT/0.
Note that with only one concurrent reader and one concurrent writer, you don't need extra locking to use these macro.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 KFIFO_FROM_USER(9)
Check Out this Related Man Page
fifo - Create and manipulate u-turn fifo channels
package require Tcl
package require memchan
fifo creates a stream-oriented in-memory channel and returns its handle. There is no restriction on the ultimate size of the channel, it
will always grow as much as is necessary to accommodate the data written into it.
In contrast to the channels generated by memchan a channel created here effectively represents an U-turn. All data written into it
can be read out, but only in the same order. This also means that a fifo channel is not seekable.
The channels created here can be transferred between interpreters in the same thread and between threads, but only as a whole. It is
not possible to use them to create a bi- or unidirectional connection between two interpreters.
Memory channels created by fifo provide two read-only options which can be queried via the standard fconfigure command. These are
The value of this option is the number of bytes currently stored in the queried memory channel.
The value of this option is the number of bytes currently allocated by the queried memory channel. This number is at least as big as
the value of -length.
As the channels generated by fifo grow as necessary they are always writable. This means that a writable fileevent-handler will fire con-
The channels are also readable if they contain more than zero bytes. Under this conditions a readable fileevent-handler will fire continu-
One possible application of memory channels created by memchan or fifo is as temporary storage device to collect data coming in over a pipe
or a socket. If part of the processing of the incoming data is to read and process header bytes or similar fifo are easier to use as they
do not require seeking back and forth to switch between the assimilation of headers at the beginning and writing new data at the end.
fifo2, memchan, null
channel, fifo, i/o, in-memory channel, memchan, stream
Copyright (c) 1996-2003 Andreas Kupries <firstname.lastname@example.org>
Memory channels 2.1 fifo(3tcl)
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