/*

* Copyright (C) 2013-2021 Canonical, Ltd.

* Copyright (C) 2022-2024 Colin Ian King.

*

* 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.

*

*/

#include "stress-ng.h"

#include "core-builtin.h"

#define MIN_TIMER_FREQ (1)

#define MAX_TIMER_FREQ (100000000)

#define DEFAULT_TIMER_FREQ (1000000)

static const stress_help_t help[] = {

{ "T N", "timer N", "start N workers producing timer events" },

{ NULL, "timer-freq F", "run timer(s) at F Hz, range 1 to 1000000000" },

{ NULL, "timer-ops N", "stop after N timer bogo events" },

{ NULL, "timer-rand", "enable random timer frequency" },

{ NULL, NULL, NULL }

};

#if defined(HAVE_LIB_RT) && \

defined(HAVE_TIMER_CREATE) && \

defined(HAVE_TIMER_DELETE) && \

defined(HAVE_TIMER_GETOVERRUN) && \

defined(HAVE_TIMER_SETTIME)

static volatile uint64_t timer_counter;

static volatile uint64_t timer_settime_failure;

static uint64_t timer_overruns;

static uint64_t max_ops;

static timer_t timerid;

static double rate_ns;

static double time_end;

static bool timer_rand;

#endif

/*

* stress_set_timer_freq()

* set timer frequency from given option

*/

static int stress_set_timer_freq(const char *opt)

{

uint64_t timer_freq;

timer_freq = stress_get_uint64(opt);

stress_check_range("timer-freq", timer_freq,

MIN_TIMER_FREQ, MAX_TIMER_FREQ);

return stress_set_setting("timer-freq", TYPE_ID_UINT64, &timer_freq);

}

static int stress_set_timer_rand(const char *opt)

{

return stress_set_setting_true("timer-rand", opt);

}

static const stress_opt_set_func_t opt_set_funcs[] = {

{ OPT_timer_freq, stress_set_timer_freq },

{ OPT_timer_rand, stress_set_timer_rand },

{ 0, NULL }

};

#if defined(HAVE_LIB_RT) && \

defined(HAVE_TIMER_CREATE) && \

defined(HAVE_TIMER_DELETE) && \

defined(HAVE_TIMER_GETOVERRUN) && \

defined(HAVE_TIMER_SETTIME)

/*

* stress_timer_set()

* set timer, ensure it is never zero

*/

static void OPTIMIZE3 stress_timer_set(struct itimerspec *timer)

{

double rate;

if (UNLIKELY(timer_rand)) {

/* Mix in some random variation */

const double r = ((double)stress_mwc32modn(10000) - 5000.0) / 40000.0;

rate = rate_ns + (rate_ns * r);

} else {

rate = rate_ns;

}

timer->it_value.tv_sec = (time_t)rate / STRESS_NANOSECOND;

timer->it_value.tv_nsec = (suseconds_t)rate % STRESS_NANOSECOND;

if (timer->it_value.tv_sec == 0 &&

timer->it_value.tv_nsec < 1)

timer->it_value.tv_nsec = 1;

timer->it_interval.tv_sec = timer->it_value.tv_sec;

timer->it_interval.tv_nsec = timer->it_value.tv_nsec;

}

/*

* stress_timer_stress_continue(args)

* returns true if we can keep on running a stressor

*/

static bool HOT OPTIMIZE3 stress_timer_stress_continue(void)

{

return (LIKELY(stress_continue_flag()) &&

LIKELY(!max_ops || (timer_counter < max_ops)));

}

/*

* stress_proc_self_timer_read()

* exercise read of /proc/self/timers, Linux only

*/

static inline void stress_proc_self_timer_read(void)

{

#if defined(__linux__)

char buf[1024];

VOID_RET(ssize_t, stress_system_read("/proc/self/timers", buf, sizeof(buf)));

#endif

}

/*

* stress_timer_handler()

* catch timer signal and cancel if no more runs flagged

*/

static void MLOCKED_TEXT OPTIMIZE3 stress_timer_handler(int sig)

{

struct itimerspec timer;

sigset_t mask;

(void)sig;

if (!stress_timer_stress_continue())

goto cancel;

timer_counter++;

if (sigpending(&mask) == 0)

if (sigismember(&mask, SIGINT))

goto cancel;

/* High freq timer, check periodically for timeout */

if (UNLIKELY((timer_counter & 65535) == 0)) {

if (stress_time_now() > time_end)

goto cancel;

stress_proc_self_timer_read();

}

if (LIKELY(stress_continue_flag())) {

const int ret = timer_getoverrun(timerid);

if (ret > 0)

timer_overruns += (uint64_t)ret;

stress_timer_set(&timer);

if (timer_settime(timerid, 0, &timer, NULL) < 0)

timer_settime_failure++;

return;

}

cancel:

stress_continue_set_flag(false);

/* Cancel timer if we detect no more runs */

(void)shim_memset(&timer, 0, sizeof(timer));

if (timer_settime(timerid, 0, &timer, NULL) < 0)

timer_settime_failure++;

}

/*

* stress_timer

* stress timers

*/

static int stress_timer(stress_args_t *args)

{

struct sigevent sev;

struct itimerspec timer;

sigset_t mask;

uint64_t timer_freq = DEFAULT_TIMER_FREQ;

int n = 0, rc = EXIT_SUCCESS;

time_end = args->time_end;

timer_counter = 0;

timer_settime_failure = 0;

timer_overruns = 0;

(void)sigemptyset(&mask);

(void)sigaddset(&mask, SIGINT);

(void)sigprocmask(SIG_SETMASK, &mask, NULL);

max_ops = args->max_ops;

timer_rand = false;

(void)stress_get_setting("timer-rand", &timer_rand);

if (!stress_get_setting("timer-freq", &timer_freq)) {

if (g_opt_flags & OPT_FLAGS_MAXIMIZE)

timer_freq = MAX_TIMER_FREQ;

if (g_opt_flags & OPT_FLAGS_MINIMIZE)

timer_freq = MIN_TIMER_FREQ;

}

rate_ns = timer_freq ? (double)STRESS_NANOSECOND / (double)timer_freq :

(double)STRESS_NANOSECOND;

if (stress_sighandler(args->name, SIGRTMIN, stress_timer_handler, NULL) < 0)

return EXIT_FAILURE;

(void)shim_memset(&sev, 0, sizeof(sev));

sev.sigev_notify = SIGEV_SIGNAL;

sev.sigev_signo = SIGRTMIN;

sev.sigev_value.sival_ptr = &timerid;

if (timer_create(CLOCK_REALTIME, &sev, &timerid) < 0) {

if ((errno == EAGAIN) || (errno == ENOMEM)) {

pr_inf_skip("%s: could not create timer, out of "

"resources, skipping stressor\n",

args->name);

return EXIT_NO_RESOURCE;

}

pr_fail("%s: timer_create failed, errno=%d (%s)\n",

args->name, errno, strerror(errno));

return EXIT_FAILURE;

}

stress_timer_set(&timer);

if (timer_settime(timerid, 0, &timer, NULL) < 0) {

pr_fail("%s: timer_settime failed, errno=%d (%s)\n",

args->name, errno, strerror(errno));

return EXIT_FAILURE;

}

stress_set_proc_state(args->name, STRESS_STATE_RUN);

do {

struct timespec req;

if (UNLIKELY(n++ >= 1024)) {

n = 0;

/* Exercise nanosleep on non-permitted timespec object values */

(void)shim_memset(&req, 0, sizeof(req));

req.tv_sec = -1;

VOID_RET(int, nanosleep(&req, NULL));

(void)shim_memset(&req, 0, sizeof(req));

req.tv_nsec = STRESS_NANOSECOND;

VOID_RET(int, nanosleep(&req, NULL));

}

req.tv_sec = 0;

req.tv_nsec = 10000000;

(void)nanosleep(&req, NULL);

stress_bogo_set(args, timer_counter);

} while (stress_continue(args));

/* stop timer */

(void)shim_memset(&timer, 0, sizeof(timer));

VOID_RET(int, timer_settime(timerid, 0, &timer, NULL));

if (timer_delete(timerid) < 0) {

pr_fail("%s: timer_delete failed, errno=%d (%s)\n",

args->name, errno, strerror(errno));

rc = EXIT_FAILURE;

}

pr_dbg("%s: %" PRIu64 " timer overruns (instance %" PRIu32 ")\n",

args->name, timer_overruns, args->instance);

if (timer_settime_failure) {

pr_fail("%s: %" PRIu64 " timer settime calls failed\n",

args->name, timer_settime_failure);

rc = EXIT_FAILURE;

}

stress_set_proc_state(args->name, STRESS_STATE_DEINIT);

#if defined(__linux__)

/* Some BSD flavours segfault on duplicated timer_delete calls */

{

/* Re-delete already deleted timer */

VOID_RET(int, timer_delete(timerid));

/*

* The manual states that EINVAL is returned when

* an invalid timerid is used, in practice this

* will most probably segfault librt, so ignore this

* test case for now.

*

VOID_RET(int, timer_delete((timer_t)stress_mwc32()));

*/

}

#endif

return rc;

}

stressor_info_t stress_timer_info = {

.stressor = stress_timer,

.class = CLASS_INTERRUPT | CLASS_OS,

.opt_set_funcs = opt_set_funcs,

.verify = VERIFY_ALWAYS,

.help = help

};

#else

stressor_info_t stress_timer_info = {

.stressor = stress_unimplemented,

.class = CLASS_INTERRUPT | CLASS_OS,

.opt_set_funcs = opt_set_funcs,

.verify = VERIFY_ALWAYS,

.help = help,

.unimplemented_reason = "built without librt, timer_create(), timer_delete(), timer_getoverrun() or timer_settime()"

};

#endif