alsa-utils/axfer/waiter-poll.c
Takashi Sakamoto 1521e01550 axfer: add an implementation of waiter for poll(2)
This commit adds support of waiter for poll(2) system call.

Below lines are examples to use this option:
$ axfer transfer --waiter-type=poll -M -P -d 2 -D hw:0,3 /dev/urandom -f dat -vvv
$ axfer transfer --waiter-type=poll -M -C -d 2 -D hw:1,0 /dev/null -r 48000 -vvv

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-11-13 12:04:50 +01:00

45 lines
960 B
C

// SPDX-License-Identifier: GPL-2.0
//
// waiter-poll.c - Waiter for event notification by poll(2).
//
// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
//
// Licensed under the terms of the GNU General Public License, version 2.
#include "waiter.h"
#include "misc.h"
#include <stdlib.h>
#include <errno.h>
#include <poll.h>
static int poll_prepare(struct waiter_context *waiter)
{
// Nothing to do because an instance of waiter has required data.
return 0;
}
static int poll_wait_event(struct waiter_context *waiter, int timeout_msec)
{
int err;
err = poll(waiter->pfds, waiter->pfd_count, timeout_msec);
if (err < 0)
return -errno;
return err;
}
static void poll_release(struct waiter_context *waiter)
{
// Nothing to do because an instance of waiter has required data.
return;
}
const struct waiter_data waiter_poll = {
.ops = {
.prepare = poll_prepare,
.wait_event = poll_wait_event,
.release = poll_release,
},
};