2024-04-10 22:46:39

by Thomas Gleixner

[permalink] [raw]
Subject: [patch V2 01/50] selftests/timers/posix_timers: Simplify error handling

No point in returning to main() on fatal errors. Just exit right away.

Signed-off-by: Thomas Gleixner <[email protected]>
---
tools/testing/selftests/timers/posix_timers.c | 151 ++++++++------------------
1 file changed, 52 insertions(+), 99 deletions(-)

--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -10,6 +10,7 @@
#include <sys/time.h>
#include <stdio.h>
#include <signal.h>
+#include <string.h>
#include <unistd.h>
#include <time.h>
#include <pthread.h>
@@ -19,6 +20,20 @@
#define DELAY 2
#define USECS_PER_SEC 1000000

+static void __fatal_error(const char *test, const char *name, const char *what)
+{
+ char buf[64];
+
+ strerror_r(errno, buf, sizeof(buf));
+
+ if (name && strlen(name))
+ ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, buf);
+ else
+ ksft_exit_fail_msg("%s %s %s\n", test, what, buf);
+}
+
+#define fatal_error(name, what) __fatal_error(__func__, name, what)
+
static volatile int done;

/* Busy loop in userspace to elapse ITIMER_VIRTUAL */
@@ -74,24 +89,13 @@ static int check_diff(struct timeval sta
return 0;
}

-static int check_itimer(int which)
+static void check_itimer(int which, const char *name)
{
- const char *name;
- int err;
struct timeval start, end;
struct itimerval val = {
.it_value.tv_sec = DELAY,
};

- if (which == ITIMER_VIRTUAL)
- name = "ITIMER_VIRTUAL";
- else if (which == ITIMER_PROF)
- name = "ITIMER_PROF";
- else if (which == ITIMER_REAL)
- name = "ITIMER_REAL";
- else
- return -1;
-
done = 0;

if (which == ITIMER_VIRTUAL)
@@ -101,17 +105,11 @@ static int check_itimer(int which)
else if (which == ITIMER_REAL)
signal(SIGALRM, sig_handler);

- err = gettimeofday(&start, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (gettimeofday(&start, NULL) < 0)
+ fatal_error(name, "gettimeofday()");

- err = setitimer(which, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ if (setitimer(which, &val, NULL) < 0)
+ fatal_error(name, "setitimer()");

if (which == ITIMER_VIRTUAL)
user_loop();
@@ -120,68 +118,41 @@ static int check_itimer(int which)
else if (which == ITIMER_REAL)
idle_loop();

- err = gettimeofday(&end, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (gettimeofday(&end, NULL) < 0)
+ fatal_error(name, "gettimeofday()");

ksft_test_result(check_diff(start, end) == 0, "%s\n", name);
-
- return 0;
}

-static int check_timer_create(int which)
+static void check_timer_create(int which, const char *name)
{
- const char *type;
- int err;
- timer_t id;
struct timeval start, end;
struct itimerspec val = {
.it_value.tv_sec = DELAY,
};
-
- if (which == CLOCK_THREAD_CPUTIME_ID) {
- type = "thread";
- } else if (which == CLOCK_PROCESS_CPUTIME_ID) {
- type = "process";
- } else {
- ksft_print_msg("Unknown timer_create() type %d\n", which);
- return -1;
- }
+ timer_t id;

done = 0;
- err = timer_create(which, NULL, &id);
- if (err < 0) {
- ksft_perror("Can't create timer");
- return -1;
- }
- signal(SIGALRM, sig_handler);

- err = gettimeofday(&start, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (timer_create(which, NULL, &id) < 0)
+ fatal_error(name, "timer_create()");

- err = timer_settime(id, 0, &val, NULL);
- if (err < 0) {
- ksft_perror("Can't set timer");
- return -1;
- }
+ if (signal(SIGALRM, sig_handler) == SIG_ERR)
+ fatal_error(name, "signal()");
+
+ if (gettimeofday(&start, NULL) < 0)
+ fatal_error(name, "gettimeofday()");
+
+ if (timer_settime(id, 0, &val, NULL) < 0)
+ fatal_error(name, "timer_settime()");

user_loop();

- err = gettimeofday(&end, NULL);
- if (err < 0) {
- ksft_perror("Can't call gettimeofday()");
- return -1;
- }
+ if (gettimeofday(&end, NULL) < 0)
+ fatal_error(name, "gettimeofday()");

ksft_test_result(check_diff(start, end) == 0,
- "timer_create() per %s\n", type);
-
- return 0;
+ "timer_create() per %s\n", name);
}

static pthread_t ctd_thread;
@@ -209,15 +180,14 @@ static void *ctd_thread_func(void *arg)

ctd_count = 100;
if (timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id))
- return "Can't create timer\n";
+ fatal_error(NULL, "timer_create()");
if (timer_settime(id, 0, &val, NULL))
- return "Can't set timer\n";
-
+ fatal_error(NULL, "timer_settime()");
while (ctd_count > 0 && !ctd_failed)
;

if (timer_delete(id))
- return "Can't delete timer\n";
+ fatal_error(NULL, "timer_delete()");

return NULL;
}
@@ -225,19 +195,16 @@ static void *ctd_thread_func(void *arg)
/*
* Test that only the running thread receives the timer signal.
*/
-static int check_timer_distribution(void)
+static void check_timer_distribution(void)
{
- const char *errmsg;
-
- signal(SIGALRM, ctd_sighandler);
+ if (signal(SIGALRM, ctd_sighandler) == SIG_ERR)
+ fatal_error(NULL, "signal()");

- errmsg = "Can't create thread\n";
if (pthread_create(&ctd_thread, NULL, ctd_thread_func, NULL))
- goto err;
+ fatal_error(NULL, "pthread_create()");

- errmsg = "Can't join thread\n";
- if (pthread_join(ctd_thread, (void **)&errmsg) || errmsg)
- goto err;
+ if (pthread_join(ctd_thread, NULL))
+ fatal_error(NULL, "pthread_join()");

if (!ctd_failed)
ksft_test_result_pass("check signal distribution\n");
@@ -245,10 +212,6 @@ static int check_timer_distribution(void
ksft_test_result_fail("check signal distribution\n");
else
ksft_test_result_skip("check signal distribution (old kernel)\n");
- return 0;
-err:
- ksft_print_msg(errmsg);
- return -1;
}

int main(int argc, char **argv)
@@ -259,17 +222,10 @@ int main(int argc, char **argv)
ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
ksft_print_msg("based timers if other threads run on the CPU...\n");

- if (check_itimer(ITIMER_VIRTUAL) < 0)
- return ksft_exit_fail();
-
- if (check_itimer(ITIMER_PROF) < 0)
- return ksft_exit_fail();
-
- if (check_itimer(ITIMER_REAL) < 0)
- return ksft_exit_fail();
-
- if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0)
- return ksft_exit_fail();
+ check_itimer(ITIMER_VIRTUAL, "ITIMER_VIRTUAL");
+ check_itimer(ITIMER_PROF, "ITIMER_PROF");
+ check_itimer(ITIMER_REAL, "ITIMER_REAL");
+ check_timer_create(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");

/*
* It's unfortunately hard to reliably test a timer expiration
@@ -280,11 +236,8 @@ int main(int argc, char **argv)
* to ensure true parallelism. So test only one thread until we
* find a better solution.
*/
- if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0)
- return ksft_exit_fail();
-
- if (check_timer_distribution() < 0)
- return ksft_exit_fail();
+ check_timer_create(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+ check_timer_distribution();

ksft_finished();
}



2024-04-12 07:35:14

by Anna-Maria Behnsen

[permalink] [raw]
Subject: Re: [patch V2 01/50] selftests/timers/posix_timers: Simplify error handling

Thomas Gleixner <[email protected]> writes:

> No point in returning to main() on fatal errors. Just exit right away.
>
> Signed-off-by: Thomas Gleixner <[email protected]>

Reviewed-by: Anna-Maria Behnsen <[email protected]>