mirror of
https://github.com/alsa-project/alsa-utils
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107 lines
2.3 KiB
C
107 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// waiter-epoll.c - Waiter for event notification by epoll(7).
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//
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// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
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//
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// Licensed under the terms of the GNU General Public License, version 2.
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#include "waiter.h"
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#include "misc.h"
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <sys/types.h>
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#include <sys/epoll.h>
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struct epoll_state {
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int epfd;
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struct epoll_event *events;
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unsigned int ev_count;
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};
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static int epoll_prepare(struct waiter_context *waiter)
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{
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struct epoll_state *state = waiter->private_data;
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int i;
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state->ev_count = waiter->pfd_count;
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state->events = calloc(state->ev_count, sizeof(*state->events));
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if (state->events == NULL)
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return -ENOMEM;
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state->epfd = epoll_create(1);
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if (state->epfd < 0)
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return -errno;
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for (i = 0; i < (int)waiter->pfd_count; ++i) {
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struct epoll_event ev = {
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.data.fd = waiter->pfds[i].fd,
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.events = waiter->pfds[i].events,
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};
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if (epoll_ctl(state->epfd, EPOLL_CTL_ADD, ev.data.fd, &ev) < 0)
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return -errno;
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}
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return 0;
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}
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static int epoll_wait_event(struct waiter_context *waiter, int timeout_msec)
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{
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struct epoll_state *state = waiter->private_data;
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unsigned int ev_count;
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int i, j;
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int err;
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memset(state->events, 0, state->ev_count * sizeof(*state->events));
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err = epoll_wait(state->epfd, state->events, state->ev_count,
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timeout_msec);
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if (err < 0)
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return -errno;
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ev_count = (unsigned int)err;
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if (ev_count > 0) {
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// Reconstruct data of pollfd structure.
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for (i = 0; i < (int)ev_count; ++i) {
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struct epoll_event *ev = &state->events[i];
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for (j = 0; j < (int)waiter->pfd_count; ++j) {
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if (waiter->pfds[i].fd == ev->data.fd) {
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waiter->pfds[i].revents = ev->events;
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break;
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}
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}
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}
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}
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return ev_count;
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}
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static void epoll_release(struct waiter_context *waiter)
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{
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struct epoll_state *state = waiter->private_data;
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int i;
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for (i = 0; i < (int)waiter->pfd_count; ++i) {
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int fd = waiter->pfds[i].fd;
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epoll_ctl(state->epfd, EPOLL_CTL_DEL, fd, NULL);
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}
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free(state->events);
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state->events = NULL;
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close(state->epfd);
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state->ev_count = 0;
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state->epfd = 0;
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}
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const struct waiter_data waiter_epoll = {
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.ops = {
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.prepare = epoll_prepare,
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.wait_event = epoll_wait_event,
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.release = epoll_release,
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},
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.private_size = sizeof(struct epoll_state),
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};
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