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/* Test for sched_getaffinity and sched_setaffinity, PID version.
Copyright (C) 2015-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Function definitions for the benefit of tst-skeleton-affinity.c.
This variant forks a child process which then invokes
sched_getaffinity and sched_setaffinity on the parent PID. */
#include <errno.h>
#include <stdlib.h>
#include <sched.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
static int
write_fully (int fd, const void *buffer, size_t length)
{
const void *end = buffer + length;
while (buffer < end)
{
ssize_t bytes_written = TEMP_FAILURE_RETRY
(write (fd, buffer, end - buffer));
if (bytes_written < 0)
return -1;
if (bytes_written == 0)
{
errno = ENOSPC;
return -1;
}
buffer += bytes_written;
}
return 0;
}
static ssize_t
read_fully (int fd, void *buffer, size_t length)
{
const void *start = buffer;
const void *end = buffer + length;
while (buffer < end)
{
ssize_t bytes_read = TEMP_FAILURE_RETRY
(read (fd, buffer, end - buffer));
if (bytes_read < 0)
return -1;
if (bytes_read == 0)
return buffer - start;
buffer += bytes_read;
}
return length;
}
static int
process_child_response (int *pipes, pid_t child,
cpu_set_t *set, size_t size)
{
close (pipes[1]);
int value_from_child;
ssize_t bytes_read = read_fully
(pipes[0], &value_from_child, sizeof (value_from_child));
if (bytes_read < 0)
{
printf ("error: read from child: %m\n");
exit (1);
}
if (bytes_read != sizeof (value_from_child))
{
printf ("error: not enough bytes from child: %zd\n", bytes_read);
exit (1);
}
if (value_from_child == 0)
{
bytes_read = read_fully (pipes[0], set, size);
if (bytes_read < 0)
{
printf ("error: read: %m\n");
exit (1);
}
if (bytes_read != size)
{
printf ("error: not enough bytes from child: %zd\n", bytes_read);
exit (1);
}
}
int status;
if (waitpid (child, &status, 0) < 0)
{
printf ("error: waitpid: %m\n");
exit (1);
}
if (!(WIFEXITED (status) && WEXITSTATUS (status) == 0))
{
printf ("error: invalid status from : %m\n");
exit (1);
}
close (pipes[0]);
if (value_from_child != 0)
{
errno = value_from_child;
return -1;
}
return 0;
}
static int
getaffinity (size_t size, cpu_set_t *set)
{
int pipes[2];
if (pipe (pipes) < 0)
{
printf ("error: pipe: %m\n");
exit (1);
}
int ret = fork ();
if (ret < 0)
{
printf ("error: fork: %m\n");
exit (1);
}
if (ret == 0)
{
/* Child. */
int ret = sched_getaffinity (getppid (), size, set);
if (ret < 0)
ret = errno;
if (write_fully (pipes[1], &ret, sizeof (ret)) < 0
|| write_fully (pipes[1], set, size) < 0
|| (ret == 0 && write_fully (pipes[1], set, size) < 0))
{
printf ("error: write: %m\n");
_exit (1);
}
_exit (0);
}
/* Parent. */
return process_child_response (pipes, ret, set, size);
}
static int
setaffinity (size_t size, const cpu_set_t *set)
{
int pipes[2];
if (pipe (pipes) < 0)
{
printf ("error: pipe: %m\n");
exit (1);
}
int ret = fork ();
if (ret < 0)
{
printf ("error: fork: %m\n");
exit (1);
}
if (ret == 0)
{
/* Child. */
int ret = sched_setaffinity (getppid (), size, set);
if (write_fully (pipes[1], &ret, sizeof (ret)) < 0)
{
printf ("error: write: %m\n");
_exit (1);
}
_exit (0);
}
/* Parent. There is no affinity mask to read from the child, so the
size is 0. */
return process_child_response (pipes, ret, NULL, 0);
}
struct conf;
static bool early_test (struct conf *unused)
{
return true;
}
#include "tst-skeleton-affinity.c"
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