104 lines
2.1 KiB
C
104 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2020 FUJITSU LIMITED. All rights reserved.
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* Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
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*
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* Test Description:
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* This case is designed to test whether pipe can wakeup all readers
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* when last writer closes.
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*
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* This is also a regression test for commit 6551d5c56eb0
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* ("pipe: make sure to wake up everybody when the last reader/writer closes").
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* This bug was introduced by commit 0ddad21d3e99 ("pipe: use exclusive
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* waits when reading or writing").
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*/
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <stdlib.h>
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#include "tst_test.h"
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static unsigned int tcases[] = {
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2,
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10,
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27,
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100
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};
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static int fds[2];
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static void do_child(unsigned int i)
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{
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char buf;
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SAFE_CLOSE(fds[1]);
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TST_CHECKPOINT_WAKE(i);
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int ret = SAFE_READ(0, fds[0], &buf, 1);
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if (ret != 0)
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tst_res(TFAIL, "Wrong return from read %i", ret);
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exit(0);
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}
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static void verify_pipe(unsigned int n)
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{
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int ret;
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unsigned int i, cnt = 0, sleep_us = 1, fail = 0;
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unsigned int child_num = tcases[n];
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int pid[child_num];
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SAFE_PIPE(fds);
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tst_res(TINFO, "Creating %d child processes", child_num);
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for (i = 0; i < child_num; i++) {
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pid[i] = SAFE_FORK();
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if (pid[i] == 0)
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do_child(i);
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TST_CHECKPOINT_WAIT(i);
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TST_PROCESS_STATE_WAIT(pid[i], 'S', 0);
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}
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SAFE_CLOSE(fds[0]);
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SAFE_CLOSE(fds[1]);
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while (cnt < child_num && sleep_us < 1000000) {
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ret = waitpid(-1, NULL, WNOHANG);
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if (ret < 0)
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tst_brk(TBROK | TERRNO, "waitpid()");
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if (ret > 0) {
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cnt++;
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for (i = 0; i < child_num; i++) {
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if (pid[i] == ret)
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pid[i] = 0;
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}
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continue;
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}
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usleep(sleep_us);
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sleep_us *= 2;
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}
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for (i = 0; i < child_num; i++) {
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if (pid[i]) {
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tst_res(TINFO, "pid %i still sleeps", pid[i]);
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fail = 1;
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SAFE_KILL(pid[i], SIGKILL);
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SAFE_WAIT(NULL);
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}
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}
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if (fail)
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tst_res(TFAIL, "Closed pipe didn't wake up everyone");
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else
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tst_res(TPASS, "Closed pipe waked up everyone");
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}
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static struct tst_test test = {
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.test = verify_pipe,
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.tcnt = ARRAY_SIZE(tcases),
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.forks_child = 1,
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.needs_checkpoints = 1,
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.tags = (const struct tst_tag[]) {
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{"linux-git", "6551d5c56eb"},
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{}
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}
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};
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