mirror of
https://github.com/alsa-project/alsa-utils
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1c17128410
A call of select(2) returns negative code and report errors via errno local variable, howver current waiter implementation for select(2) returns the negative code instead of errno. This commit fixes it. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
110 lines
2.4 KiB
C
110 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// waiter-select.c - Waiter for event notification by select(2).
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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 <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/select.h>
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// Except for POLLERR.
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#ifdef POLLRDNORM
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// This program is for userspace compliant to POSIX 2008 (IEEE 1003.1:2008).
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// This is the default compliance level since glibc-2.12 or later.
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# define POLLIN_SET (POLLRDNORM | POLLRDBAND | POLLIN | POLLHUP)
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# define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT)
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#else
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// However it's allowed to be for old compliance levels.
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# define POLLIN_SET (POLLIN | POLLHUP)
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# define POLLOUT_SET (POLLOUT)
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#endif
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#define POLLEX_SET (POLLPRI)
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struct select_state {
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fd_set rfds_rd;
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fd_set rfds_wr;
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fd_set rfds_ex;
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};
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static int select_prepare(struct waiter_context *waiter)
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{
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return 0;
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}
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static int select_wait_event(struct waiter_context *waiter, int timeout_msec)
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{
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struct select_state *state = waiter->private_data;
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struct pollfd *pfd;
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int fd_max;
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struct timeval tv, *tv_ptr;
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int i;
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int err;
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FD_ZERO(&state->rfds_rd);
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FD_ZERO(&state->rfds_wr);
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FD_ZERO(&state->rfds_ex);
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fd_max = 0;
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for (i = 0; i < waiter->pfd_count; ++i) {
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pfd = &waiter->pfds[i];
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if (pfd->events & POLLIN_SET)
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FD_SET(pfd->fd, &state->rfds_rd);
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if (pfd->events & POLLOUT_SET)
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FD_SET(pfd->fd, &state->rfds_wr);
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if (pfd->events & POLLEX_SET)
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FD_SET(pfd->fd, &state->rfds_ex);
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if (pfd->fd > fd_max)
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fd_max = pfd->fd;
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}
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if (timeout_msec < 0) {
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tv_ptr = NULL;
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} else {
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tv.tv_sec = 0;
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tv.tv_usec = timeout_msec * 1000;
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tv_ptr = &tv;
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}
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err = select(fd_max + 1, &state->rfds_rd, &state->rfds_wr,
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&state->rfds_ex, tv_ptr);
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if (err < 0)
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return -errno;
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for (i = 0; i < waiter->pfd_count; ++i) {
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pfd = &waiter->pfds[i];
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pfd->revents = 0;
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if (FD_ISSET(pfd->fd, &state->rfds_rd))
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pfd->revents |= POLLIN;
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if (FD_ISSET(pfd->fd, &state->rfds_wr))
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pfd->revents |= POLLOUT;
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if (FD_ISSET(pfd->fd, &state->rfds_ex))
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pfd->revents |= POLLHUP;
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}
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return err;
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}
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static void select_release(struct waiter_context *waiter)
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{
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return;
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}
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const struct waiter_data waiter_select = {
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.ops = {
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.prepare = select_prepare,
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.wait_event = select_wait_event,
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.release = select_release,
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},
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.private_size = sizeof(struct select_state),
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};
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