axfer: add an implementation of waiter for select(2)

This commit adds support of waiter for select(2) system call.

Below lines are examples to use this option:
$ axfer transfer --waiter-type=select -M -P -d 2 -D hw:0,3 /dev/urandom -f dat -vvv
$ axfer transfer --waiter-type=select -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>
This commit is contained in:
Takashi Sakamoto 2018-11-13 15:41:43 +09:00 committed by Takashi Iwai
parent 1521e01550
commit fce16d9279
4 changed files with 106 additions and 1 deletions

View file

@ -51,4 +51,5 @@ axfer_SOURCES = \
xfer-libasound-irq-mmap.c \ xfer-libasound-irq-mmap.c \
waiter.h \ waiter.h \
waiter.c \ waiter.c \
waiter-poll.c waiter-poll.c \
waiter-select.c

100
axfer/waiter-select.c Normal file
View file

@ -0,0 +1,100 @@
// SPDX-License-Identifier: GPL-2.0
//
// waiter-select.c - Waiter for event notification by select(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 <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/select.h>
// Except for POLLERR.
#define POLLIN_SET (POLLRDNORM | POLLRDBAND | POLLIN | POLLHUP)
#define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT)
#define POLLEX_SET (POLLPRI)
struct select_state {
fd_set rfds_rd;
fd_set rfds_wr;
fd_set rfds_ex;
};
static int select_prepare(struct waiter_context *waiter)
{
return 0;
}
static int select_wait_event(struct waiter_context *waiter, int timeout_msec)
{
struct select_state *state = waiter->private_data;
struct pollfd *pfd;
int fd_max;
struct timeval tv, *tv_ptr;
int i;
int err;
FD_ZERO(&state->rfds_rd);
FD_ZERO(&state->rfds_wr);
FD_ZERO(&state->rfds_ex);
fd_max = 0;
for (i = 0; i < waiter->pfd_count; ++i) {
pfd = &waiter->pfds[i];
if (pfd->events & POLLIN_SET)
FD_SET(pfd->fd, &state->rfds_rd);
if (pfd->events & POLLOUT_SET)
FD_SET(pfd->fd, &state->rfds_wr);
if (pfd->events & POLLEX_SET)
FD_SET(pfd->fd, &state->rfds_ex);
if (pfd->fd > fd_max)
fd_max = pfd->fd;
}
if (timeout_msec < 0) {
tv_ptr = NULL;
} else {
tv.tv_sec = 0;
tv.tv_usec = timeout_msec * 1000;
tv_ptr = &tv;
}
err = select(fd_max + 1, &state->rfds_rd, &state->rfds_wr,
&state->rfds_ex, tv_ptr);
if (err < 0)
return err;
for (i = 0; i < waiter->pfd_count; ++i) {
pfd = &waiter->pfds[i];
pfd->revents = 0;
if (FD_ISSET(pfd->fd, &state->rfds_rd))
pfd->revents |= POLLIN;
if (FD_ISSET(pfd->fd, &state->rfds_wr))
pfd->revents |= POLLOUT;
if (FD_ISSET(pfd->fd, &state->rfds_ex))
pfd->revents |= POLLHUP;
}
return 0;
}
static void select_release(struct waiter_context *waiter)
{
return;
}
const struct waiter_data waiter_select = {
.ops = {
.prepare = select_prepare,
.wait_event = select_wait_event,
.release = select_release,
},
.private_size = sizeof(struct select_state),
};

View file

@ -17,6 +17,7 @@
static const char *const waiter_type_labels[] = { static const char *const waiter_type_labels[] = {
[WAITER_TYPE_DEFAULT] = "default", [WAITER_TYPE_DEFAULT] = "default",
[WAITER_TYPE_POLL] = "poll", [WAITER_TYPE_POLL] = "poll",
[WAITER_TYPE_SELECT] = "select",
}; };
enum waiter_type waiter_type_from_label(const char *label) enum waiter_type waiter_type_from_label(const char *label)
@ -44,6 +45,7 @@ int waiter_context_init(struct waiter_context *waiter,
const struct waiter_data *waiter; const struct waiter_data *waiter;
} entries[] = { } entries[] = {
{WAITER_TYPE_POLL, &waiter_poll}, {WAITER_TYPE_POLL, &waiter_poll},
{WAITER_TYPE_SELECT, &waiter_select},
}; };
int i; int i;

View file

@ -14,6 +14,7 @@
enum waiter_type { enum waiter_type {
WAITER_TYPE_DEFAULT = 0, WAITER_TYPE_DEFAULT = 0,
WAITER_TYPE_POLL, WAITER_TYPE_POLL,
WAITER_TYPE_SELECT,
WAITER_TYPE_COUNT, WAITER_TYPE_COUNT,
}; };
@ -53,5 +54,6 @@ struct waiter_data {
}; };
extern const struct waiter_data waiter_poll; extern const struct waiter_data waiter_poll;
extern const struct waiter_data waiter_select;
#endif #endif