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libvirt/tests/commandhelper.c
Peter Krempa 6ae53a1509 tests: commandtest: Make 'test4' checking daemonization more reliable
The 'commandhelper' checks effectively whether the parent process is
still around to report whether it was daemonized or not.

This creates a unlikely race condition in cases when we do actually
daemonize the process as the intermediate process used for the
daemonization might not have terminated yet which would report wrong
result leading to test failure.

For now there's just 'test4' which actually daemonizes the process.

Add an argument '--check-daemonize' which asks for retries of the
daemonization check in cases where we expect that the commandhelper is
going to be daemonized and use it in 'test4' to make the test more
reliable.

I've observed the test failure sporadically when my box is under load
e.g. while building two trees at once.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-07-27 15:44:38 +02:00

255 lines
6.5 KiB
C

/*
* commandhelper.c: Auxiliary program for commandtest
*
* Copyright (C) 2010-2014 Red Hat, Inc.
*
* This 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.
*
* This 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 this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#define VIR_NO_GLIB_STDIO /* This file intentionally does not link to libvirt/glib */
#include "testutils.h"
#ifndef WIN32
# include <poll.h>
/* Some UNIX lack it in headers & it doesn't hurt to redeclare */
extern char **environ;
# define VIR_FROM_THIS VIR_FROM_NONE
static int envsort(const void *a, const void *b)
{
const char *const*astrptr = a;
const char *const*bstrptr = b;
const char *astr = *astrptr;
const char *bstr = *bstrptr;
char *aeq = strchr(astr, '=');
char *beq = strchr(bstr, '=');
char *akey;
char *bkey;
int ret;
if (!(akey = strndup(astr, aeq - astr)))
abort();
if (!(bkey = strndup(bstr, beq - bstr)))
abort();
ret = strcmp(akey, bkey);
free(akey);
free(bkey);
return ret;
}
int main(int argc, char **argv) {
size_t i, n;
int open_max;
char **origenv;
char **newenv = NULL;
char *cwd;
FILE *log = fopen(abs_builddir "/commandhelper.log", "w");
int ret = EXIT_FAILURE;
int readfds[3] = { STDIN_FILENO, };
int numreadfds = 1;
struct pollfd fds[3];
int numpollfds = 0;
char *buffers[3] = {NULL, NULL, NULL};
size_t buflen[3] = {0, 0, 0};
char c;
bool daemonize_check = false;
size_t daemonize_retries = 3;
if (!log)
return ret;
for (i = 1; i < argc; i++) {
fprintf(log, "ARG:%s\n", argv[i]);
if (STREQ(argv[i - 1], "--readfd") &&
sscanf(argv[i], "%u%c", &readfds[numreadfds++], &c) != 1) {
printf("Could not parse fd %s\n", argv[i]);
goto cleanup;
} else if (STREQ(argv[i], "--check-daemonize")) {
daemonize_check = true;
}
}
origenv = environ;
n = 0;
while (*origenv != NULL) {
n++;
origenv++;
}
if (!(newenv = malloc(sizeof(*newenv) * n)))
abort();
origenv = environ;
n = i = 0;
while (*origenv != NULL) {
newenv[i++] = *origenv;
n++;
origenv++;
}
qsort(newenv, n, sizeof(newenv[0]), envsort);
for (i = 0; i < n; i++) {
/* Ignore the variables used to instruct the loader into
* behaving differently, as they could throw the tests off. */
if (!STRPREFIX(newenv[i], "LD_"))
fprintf(log, "ENV:%s\n", newenv[i]);
}
open_max = sysconf(_SC_OPEN_MAX);
if (open_max < 0)
goto cleanup;
for (i = 0; i < open_max; i++) {
int f;
int closed;
if (i == fileno(log))
continue;
closed = fcntl(i, F_GETFD, &f) == -1 &&
errno == EBADF;
if (!closed)
fprintf(log, "FD:%zu\n", i);
}
while (true) {
bool daemonized = getpgrp() != getppid();
if (daemonize_check && !daemonized && daemonize_retries-- > 0) {
usleep(100*1000);
continue;
}
fprintf(log, "DAEMON:%s\n", daemonized ? "yes" : "no");
break;
}
if (!(cwd = getcwd(NULL, 0)))
goto cleanup;
if (strlen(cwd) > strlen(".../commanddata") &&
STREQ(cwd + strlen(cwd) - strlen("/commanddata"), "/commanddata"))
strcpy(cwd, ".../commanddata");
# ifdef __APPLE__
char *noprivateprefix = NULL;
if (strstr(cwd, "/private"))
noprivateprefix = cwd + strlen("/private");
else
noprivateprefix = cwd;
fprintf(log, "CWD:%s\n", noprivateprefix);
# else
fprintf(log, "CWD:%s\n", cwd);
# endif
free(cwd);
fprintf(log, "UMASK:%04o\n", umask(0));
if (argc > 1 && STREQ(argv[1], "--close-stdin")) {
if (freopen("/dev/null", "r", stdin) != stdin)
goto cleanup;
usleep(100*1000);
}
char buf[1024];
ssize_t got;
fprintf(stdout, "BEGIN STDOUT\n");
fflush(stdout);
fprintf(stderr, "BEGIN STDERR\n");
fflush(stderr);
for (i = 0; i < numreadfds; i++) {
fds[numpollfds].fd = readfds[i];
fds[numpollfds].events = POLLIN;
fds[numpollfds].revents = 0;
numpollfds++;
}
for (;;) {
unsigned ctr = 0;
if (poll(fds, numpollfds, -1) < 0) {
printf("poll failed: %s\n", strerror(errno));
goto cleanup;
}
for (i = 0; i < numpollfds; i++) {
if (fds[i].revents & (POLLIN | POLLHUP | POLLERR)) {
fds[i].revents = 0;
got = read(fds[i].fd, buf, sizeof(buf));
if (got < 0)
goto cleanup;
if (got == 0) {
/* do not want to hear from this fd anymore */
fds[i].events = 0;
} else {
buffers[i] = realloc(buffers[i], buflen[i] + got);
if (!buf[i]) {
fprintf(stdout, "Out of memory!\n");
goto cleanup;
}
memcpy(buffers[i] + buflen[i], buf, got);
buflen[i] += got;
}
}
}
for (i = 0; i < numpollfds; i++) {
if (fds[i].events) {
ctr++;
break;
}
}
if (ctr == 0)
break;
}
for (i = 0; i < numpollfds; i++) {
if (write(STDOUT_FILENO, buffers[i], buflen[i]) != buflen[i])
goto cleanup;
if (write(STDERR_FILENO, buffers[i], buflen[i]) != buflen[i])
goto cleanup;
}
fprintf(stdout, "END STDOUT\n");
fflush(stdout);
fprintf(stderr, "END STDERR\n");
fflush(stderr);
ret = EXIT_SUCCESS;
cleanup:
for (i = 0; i < G_N_ELEMENTS(buffers); i++)
free(buffers[i]);
fclose(log);
free(newenv);
return ret;
}
#else
int
main(void)
{
return EXIT_AM_SKIP;
}
#endif