From 670027c507e99521d416994a18a498def9ef2ea3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Sat, 22 Oct 2016 19:31:08 -0300 Subject: Linux-libre 4.8.3-gnu --- Documentation/DocBook/media/v4l/func-select.xml | 130 ------------------------ 1 file changed, 130 deletions(-) delete mode 100644 Documentation/DocBook/media/v4l/func-select.xml (limited to 'Documentation/DocBook/media/v4l/func-select.xml') diff --git a/Documentation/DocBook/media/v4l/func-select.xml b/Documentation/DocBook/media/v4l/func-select.xml deleted file mode 100644 index e12a60d9b..000000000 --- a/Documentation/DocBook/media/v4l/func-select.xml +++ /dev/null @@ -1,130 +0,0 @@ - - - V4L2 select() - &manvol; - - - - v4l2-select - Synchronous I/O multiplexing - - - - - -#include <sys/time.h> -#include <sys/types.h> -#include <unistd.h> - - int select - int nfds - fd_set *readfds - fd_set *writefds - fd_set *exceptfds - struct timeval *timeout - - - - - - Description - - With the select() function applications -can suspend execution until the driver has captured data or is ready -to accept data for output. - - When streaming I/O has been negotiated this function waits -until a buffer has been filled or displayed and can be dequeued with -the &VIDIOC-DQBUF; ioctl. When buffers are already in the outgoing -queue of the driver the function returns immediately. - - On success select() returns the total -number of bits set in the fd_sets. When the -function timed out it returns a value of zero. On failure it returns --1 and the errno -variable is set appropriately. When the application did not call -&VIDIOC-QBUF; or &VIDIOC-STREAMON; yet the -select() function succeeds, setting the bit of -the file descriptor in readfds or -writefds, but subsequent &VIDIOC-DQBUF; calls -will fail.The Linux kernel implements -select() like the &func-poll; function, but -select() cannot return a -POLLERR. - - - When use of the read() function has -been negotiated and the driver does not capture yet, the -select() function starts capturing. When that -fails, select() returns successful and a -subsequent read() call, which also attempts to -start capturing, will return an appropriate error code. When the -driver captures continuously (as opposed to, for example, still -images) and data is already available the -select() function returns immediately. - - When use of the write() function has -been negotiated the select() function just waits -until the driver is ready for a non-blocking -write() call. - - All drivers implementing the read() or -write() function or streaming I/O must also -support the select() function. - - For more details see the select() -manual page. - - - - - Return Value - - On success, select() returns the number -of descriptors contained in the three returned descriptor sets, which -will be zero if the timeout expired. On error --1 is returned, and the -errno variable is set appropriately; the sets and -timeout are undefined. Possible error codes -are: - - - - EBADF - - One or more of the file descriptor sets specified a -file descriptor that is not open. - - - - EBUSY - - The driver does not support multiple read or write -streams and the device is already in use. - - - - EFAULT - - The readfds, -writefds, exceptfds or -timeout pointer references an inaccessible memory -area. - - - - EINTR - - The call was interrupted by a signal. - - - - EINVAL - - The nfds argument is less than -zero or greater than FD_SETSIZE. - - - - - -- cgit v1.2.3