[LTP] [PATCH 1/2 v2] fork07: Rewrite the test to a proper synchronization
Xie Ziyao
xieziyao@huawei.com
Mon Jul 5 09:59:02 CEST 2021
Rewrite fork07 to a proper synchronization with the new API.
Fixes: #774
Signed-off-by: Xie Ziyao <xieziyao@huawei.com>
---
v1->v2:
1. Write a new test as follows,
* Parent writes N bytes (for example 'a') to a file in setup()
* Parent opens a file descriptor for reading pointing to that file
* Parent forks N children
- each child reads a byte from the file checks that the byte is 'a' then exits
* Parent waits the all the children
* Parent checks that the end of file is reached
testcases/kernel/syscalls/fork/fork07.c | 236 +++++-------------------
1 file changed, 45 insertions(+), 191 deletions(-)
diff --git a/testcases/kernel/syscalls/fork/fork07.c b/testcases/kernel/syscalls/fork/fork07.c
index e596867c3..31d8579bc 100644
--- a/testcases/kernel/syscalls/fork/fork07.c
+++ b/testcases/kernel/syscalls/fork/fork07.c
@@ -1,212 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
- *
- * Copyright (c) International Business Machines Corp., 2001
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * NAME
- * fork07.c
- *
- * DESCRIPTION
- * Check that all children inherit parent's file descriptor
- *
- * ALGORITHM
- * Parent opens a file, writes to it; forks Nforks children.
- * Each child attempts to read the file then returns.
- * Parent reports PASS if all children succeed.
- *
- * USAGE
- * fork07
- *
- * HISTORY
- * 07/2001 Ported by Wayne Boyer
- * 07/2002 Limited forking and split "infinite forks" test case to
- * fork12.c by Nate Straz
- *
- * RESTRICTIONS
- * None
+ * Copyright (c) International Business Machines Corp., 2001
+ * 07/2001 Ported by Wayne Boyer
+ * 07/2002 Limited forking and split "infinite forks" testcase to fork12.c by
+ * Nate Straz
+ * Copyright (c) 2021 Xie Ziyao <xieziyao@huawei.com>
*/
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-#include <sys/wait.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include "test.h"
-
-char *TCID = "fork07";
-int TST_TOTAL = 1;
+/*\
+ * [Description]
+ *
+ * Check that all children inherit parent's file descriptor.
+ */
-static void help(void);
-static void setup(void);
-static void cleanup(void);
+#include <stdlib.h>
-static char pbuf[10];
-static char fnamebuf[40];
+#include "tst_test.h"
-static char *Nforkarg;
-static int Nflag;
-static int Nforks;
-static int vflag;
+#define NFORKS 100
+#define TESTFILE "testfile_fork07"
-static option_t options[] = {
- {"N:", &Nflag, &Nforkarg},
- {"v", &vflag, NULL},
- {NULL, NULL, NULL}
-};
+static int fd;
+static char buf;
-int main(int ac, char **av)
+static void run(void)
{
- int status, forks, pid1;
- int ch_r_stat;
- FILE *rea, *writ;
- int c_pass, c_fail;
-
- int lc;
-
- rea = NULL;
- writ = NULL;
-
- tst_parse_opts(ac, av, options, &help);
-
- if (Nflag) {
- if (sscanf(Nforkarg, "%i", &Nforks) != 1)
- tst_brkm(TBROK, cleanup,
- "--N option arg is not a number");
- } else
- Nforks = 100;
-
- setup();
-
- for (lc = 0; TEST_LOOPING(lc); lc++) {
- tst_count = 0;
-
- writ = fopen(fnamebuf, "w");
- if (writ == NULL)
- tst_resm(TFAIL | TERRNO, "fopen(.. \"w\") failed");
- rea = fopen(fnamebuf, "r");
- if (rea == NULL)
- tst_resm(TFAIL | TERRNO, "fopen(.. \"r\") failed");
-
- fprintf(writ, "abcdefghijklmnopqrstuv");
- fflush(writ);
- sleep(1);
-
- if ((getc(rea)) != 'a')
- tst_resm(TFAIL, "getc from read side was confused");
-
- /* fork off the children */
- tst_resm(TINFO, "Forking %d children", Nforks);
- tst_old_flush();
- for (forks = 0; forks < Nforks; forks++) {
- pid1 = fork();
- if (pid1 == 0) {
- ch_r_stat = getc(rea);
-#ifdef DEBUG
- tst_resm(TINFO, "Child got char: %c",
- ch_r_stat);
- tst_resm(TINFO,
- "integer value of getc in child "
- "expected %d got %d", 'b', ch_r_stat);
-#endif
- if (ch_r_stat == 'b') {
- if (vflag) {
- tst_resm(TINFO,
- "%6d: read correct character",
- getpid());
- }
- exit(0);
- } else {
- if (vflag) {
- tst_resm(TINFO,
- "%6d: read '%c' instead of 'b'",
- getpid(),
- (char)ch_r_stat);
- }
- exit(1);
- }
- } else if (pid1 == -1)
- tst_brkm(TBROK | TERRNO, cleanup,
- "fork failed");
- }
- tst_resm(TINFO, "Forked all %d children, now collecting",
- Nforks);
-
- /* Collect all the kids and see how they did */
-
- c_pass = c_fail = 0;
- while (wait(&status) > 0) {
- if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
- c_pass++;
- else
- c_fail++;
- --forks;
+ int ret, i;
+
+ fd = SAFE_OPEN(TESTFILE, O_RDONLY);
+ for (i = 0; i < NFORKS; ++i) {
+ if (!SAFE_FORK()) {
+ SAFE_READ(1, fd, &buf, 1);
+ if (buf != 'a')
+ tst_res(TFAIL, "%6d: read '%c' instead of 'a'",
+ getpid(), buf);
+ exit(0);
}
- if (forks == 0) {
- tst_resm(TINFO, "Collected all %d children", Nforks);
- if (c_fail > 0)
- tst_resm(TFAIL,
- "%d/%d children didn't read correctly from an inheritted fd",
- c_fail, Nforks);
- else
- tst_resm(TPASS,
- "%d/%d children read correctly from an inheritted fd",
- c_pass, Nforks);
- } else if (forks > 0)
- tst_brkm(TBROK, cleanup,
- "There should be %d more children to collect!",
- forks);
- else
-
- tst_brkm(TBROK, cleanup,
- "Collected %d more children then I should have!",
- abs(forks));
}
- fclose(writ);
- fclose(rea);
- cleanup();
+ tst_reap_children();
- tst_exit();
-}
-
-static void help(void)
-{
- printf(" -N n Create n children each iteration\n");
- printf(" -v Verbose mode\n");
+ ret = read(fd, &buf, 1);
+ if (ret == 0)
+ tst_res(TPASS, "read the end of file correctly");
+ else
+ tst_res(TFAIL, "read() returns %d, expected 0", ret);
}
static void setup(void)
{
- tst_sig(FORK, DEF_HANDLER, cleanup);
- umask(0);
- TEST_PAUSE;
- tst_tmpdir();
-
- strcpy(fnamebuf, "fork07.");
- sprintf(pbuf, "%d", getpid());
- strcat(fnamebuf, pbuf);
+ tst_fill_file(TESTFILE, 'a', NFORKS, 1);
}
static void cleanup(void)
{
- int waitstatus;
-
- /* collect our zombies */
- while (wait(&waitstatus) > 0) ;
-
- unlink(fnamebuf);
- tst_rmdir();
+ if (fd > 0)
+ SAFE_CLOSE(fd);
}
+
+static struct tst_test test = {
+ .forks_child = 1,
+ .needs_tmpdir = 1,
+ .cleanup = cleanup,
+ .setup = setup,
+ .test_all = run,
+};
--
2.17.1
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