zdtm: POSIX timers migration test

This test set up two posix timers with different clocks: REALTIME and
MONOTONIC.
Both send signals.
Signals are disabled before suspend. This makes overrun counters increasing.
After restore tests enables signals, and make sure, that:
1) signal handler for both timers was called with proper arguments
2) time displacement for both timers is not greater than specified (10% by
default).
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Vladimir Davydov <VDavydov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -66,6 +66,7 @@ TST_NOFILE	=				\
 		socket-ext			\
 		unhashed_proc			\
 		cow00				\
+		posix_timers			\
 #		jobctl00			\
 
 TST_FILE	=				\
@@ -193,6 +194,7 @@ pthread00:		override LDLIBS += -pthread
 shm:			override CFLAGS += -DNEW_IPC_NS
 msgque:			override CFLAGS += -DNEW_IPC_NS
 sem:			override CFLAGS += -DNEW_IPC_NS
+posix_timers:		override LDLIBS += -lrt
 
 $(LIB):	force
 	$(MAKE) -C $(LIBDIR)

test/zdtm/live/static/posix_timers.c

+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc ="Posix timers migration check";
+const char *test_author = "Kinsbursky Stanislav <skinsbursky@parallels.com>";
+
+struct timespec start;
+sigset_t mask;
+
+#define WRONG_SIGNAL		1
+#define WRONG_SI_PTR		2
+#define FAIL_OVERRUN		4
+
+#define MAX_TIMER_DISPLACEMENT	10
+
+static void realtime_handler(int sig, siginfo_t *si, void *uc);
+static void monotonic_handler(int sig, siginfo_t *si, void *uc);
+
+static struct posix_timers_info {
+	char clock;
+	char *name;
+	void (*handler)(int sig, siginfo_t *si, void *uc);
+	int sig;
+	int ms_int;
+	struct sigaction sa;
+	int handler_status;
+	int handler_cnt;
+	timer_t timerid;
+	int overrun;
+} posix_timers[] = {
+	[CLOCK_REALTIME] = {CLOCK_REALTIME, "REALTIME", realtime_handler, SIGALRM, 1},
+	[CLOCK_MONOTONIC] = {CLOCK_MONOTONIC, "MONOTONIC", monotonic_handler, SIGINT, 3},
+	{ }
+};
+
+static int check_handler_status(struct posix_timers_info *info, int ms_passed)
+{
+	int displacement;
+	int timer_ms;
+
+	if (!info->handler_cnt) {
+		fail("%s: Signal handler wasn't called\n", info->name);
+		return -EINVAL;
+	}
+
+	if (info->handler_status) {
+		if (info->handler_status & WRONG_SIGNAL)
+			fail("%s: Handler: wrong signal received\n", info->name);
+		if (info->handler_status & WRONG_SI_PTR)
+			fail("%s: Handler: wrong timer address\n", info->name);
+		if (info->handler_status & FAIL_OVERRUN)
+			fail("%s: Handler: failed to get overrun count\n", info->name);
+		return -1;
+	}
+
+	if (info->overrun + info->handler_cnt > ms_passed) {
+		fail("%s: Overrun (%d) is greater than time passed (%d). "
+			"Timers problems?\n", info->name, info->overrun + info->handler_cnt,
+			ms_passed);
+		return -E2BIG;
+	}
+
+	timer_ms = (info->overrun + info->handler_cnt) * info->ms_int;
+	displacement = (ms_passed - timer_ms) * 100 / ms_passed;
+
+	if (displacement > MAX_TIMER_DISPLACEMENT) {
+		test_msg("%s: Time passed (ms) : %d msec\n", info->name, ms_passed);
+		test_msg("%s: Timer results    : %d msec\n", info->name, timer_ms);
+		test_msg("%s: Handler count    : %d\n", info->name, info->handler_cnt);
+		fail("%s: Time displacement: %d%% (max alloved: %d%%)\n", info->name, displacement, MAX_TIMER_DISPLACEMENT);
+		return -EFAULT;
+	}
+	return 0;
+}
+
+static int check_timers(void)
+{
+	struct posix_timers_info *info = posix_timers;
+	struct timespec end;
+	int ms_passed;
+	int status = 0;
+
+	if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1) {
+		fail("Failed to unlock signal\n");
+		return -errno;
+	}
+
+       if (clock_gettime(CLOCK_REALTIME, &end) == -1) {
+		fail("Can't get end time\n");
+		return -errno;
+	}
+
+	ms_passed = (end.tv_sec - start.tv_sec) * 1000 + (end.tv_nsec - start.tv_nsec) / (1000 * 1000);
+
+	while (info->handler) {
+		if (timer_delete(info->timerid) == -1) {
+			fail("%s: Failed to delete timer\n", info->name);
+			return -errno;
+		}
+		if (check_handler_status(info, ms_passed))
+			status--;
+		info++;
+	}
+	return status;
+}
+
+static void generic_handler(struct posix_timers_info *info,
+			    struct posix_timers_info *real, int sig)
+{
+	int overrun;
+
+	if (info != real) {
+		real->handler_status |= WRONG_SI_PTR;
+		return;
+	}
+
+	if (sig != info->sig)
+		info->handler_status |= WRONG_SIGNAL;
+
+	overrun = timer_getoverrun(info->timerid);
+	if (overrun == -1)
+		info->handler_status |= FAIL_OVERRUN;
+	else
+		info->overrun += overrun;
+	info->handler_cnt++;
+}
+
+static void monotonic_handler(int sig, siginfo_t *si, void *uc)
+{
+	generic_handler(si->si_value.sival_ptr, &posix_timers[CLOCK_MONOTONIC], sig);
+}
+
+static void realtime_handler(int sig, siginfo_t *si, void *uc)
+{
+	generic_handler(si->si_value.sival_ptr, &posix_timers[CLOCK_REALTIME], sig);
+}
+
+static int setup_timers(void)
+{
+	struct posix_timers_info *info = posix_timers;
+	struct sigevent sev;
+	struct itimerspec its;
+
+	if (clock_gettime(CLOCK_REALTIME, &start) == -1) {
+		err("Can't get start time\n");
+		return -errno;
+	}
+
+	sigemptyset(&mask);
+	while(info->handler) {
+		sigaddset(&mask, info->sig);
+		info++;
+	}
+
+	if (sigprocmask(SIG_SETMASK, &mask, NULL) == -1) {
+		err("Failed to unlock signal\n");
+		return -errno;
+	}
+
+	info = posix_timers;
+	while(info->handler) {
+		info->sa.sa_flags = SA_SIGINFO;
+		info->sa.sa_sigaction = info->handler;
+		sigemptyset(&info->sa.sa_mask);
+
+		if (sigaction(info->sig, &info->sa, NULL) == -1) {
+			err("Failed to set SIGALRM handler\n");
+			return -errno;
+		}
+
+		sev.sigev_notify = SIGEV_SIGNAL;
+		sev.sigev_signo = info->sig;
+		sev.sigev_value.sival_ptr = info;
+
+		if (timer_create(info->clock, &sev, &info->timerid) == -1) {
+			err("Can't create timer\n");
+			return -errno;
+		}
+
+		its.it_value.tv_sec = 0;
+		its.it_value.tv_nsec = info->ms_int * 1000 * 1000;
+		its.it_interval.tv_sec = its.it_value.tv_sec;
+		its.it_interval.tv_nsec = its.it_value.tv_nsec;
+
+		if (timer_settime(info->timerid, 0, &its, NULL) == -1) {
+			err("Can't set timer\n");
+			return -errno;
+		}
+		info++;
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int err;
+
+	test_init(argc, argv);
+
+	err = setup_timers();
+	if (err)
+		return err;
+
+	usleep(500 * 1000);
+
+	test_daemon();
+	test_waitsig();
+
+	err = check_timers();
+	if (err)
+		return err;
+
+	pass();
+	return 0;
+}