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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2021 Ahmad Fatoum, Pengutronix
*/
#include <bthread.h>
#include <errno.h>
#include <malloc.h>
#include <stdio.h>
#include <command.h>
#include <getopt.h>
#include <clock.h>
static int bthread_time(void)
{
uint64_t start = get_time_ns();
int i = 0;
/*
* How many background tasks can we have in one second?
*
* A low number here may point to problems with bthreads taking too
* much time.
*/
while (!is_timeout(start, SECOND))
i++;
return i;
}
static int bthread_infinite(void *data)
{
while (!bthread_should_stop())
;
return 0;
}
static int bthread_isolated_time(void)
{
uint64_t start = get_time_ns();
struct bthread *bthread;
int i = 0;
bthread = bthread_run(bthread_infinite, NULL, "infinite");
if (!bthread)
return -ENOMEM;
/* main thread is the first in the run queue. Newly created bthread
* is the last. So if main_thread explicitly schedules new bthread,
* it will schedule back to main_thread afterwards and we won't
* execute any other threads in-between.
*/
while (!is_timeout_non_interruptible(start, SECOND)) {
bthread_schedule(bthread);
i += 2;
}
bthread_stop(bthread);
bthread_free(bthread);
return i;
}
static int bthread_printer(void *arg)
{
volatile u64 start;
volatile unsigned long i = 0;
start = get_time_ns();
while (!bthread_should_stop()) {
if (!is_timeout_non_interruptible(start, 225 * MSECOND))
continue;
if ((unsigned long)arg == i++)
printf("%s yield #%lu\n", bthread_name(current), i);
start = get_time_ns();
}
return i;
}
static int yields;
static int bthread_spawner(void *arg)
{
struct bthread *bthread[4];
volatile u64 start;
volatile unsigned long i = 0;
int ret = 0;
int ecode;
start = get_time_ns();
for (i = 0; i < ARRAY_SIZE(bthread); i++) {
bthread[i] = bthread_run(bthread_printer, (void *)(long)i,
"%s-bthread%u", bthread_name(current), i+1);
if (!bthread[i]) {
ret = -ENOMEM;
goto cleanup;
}
}
while (!bthread_should_stop())
;
cleanup:
while (i--) {
ecode = bthread_stop(bthread[i]);
bthread_free(bthread[i]);
if (!ret && (ecode != 4 || yields < ecode))
ret = -EIO;
}
return ret;
}
struct spawn {
struct bthread *bthread;
struct list_head list;
};
static int do_bthread(int argc, char *argv[])
{
LIST_HEAD(spawners);
struct spawn *spawner, *tmp;
int ret = 0;
int ecode, opt, i = 0;
bool time = false;
while ((opt = getopt(argc, argv, "itcv")) > 0) {
switch (opt) {
case 'i':
bthread_info();
break;
case 'c':
yields = bthread_isolated_time();
printf("%d bthread context switches possible in 1s\n", yields);
break;
case 'v':
spawner = xzalloc(sizeof(*spawner));
spawner->bthread = bthread_run(bthread_spawner, NULL,
"spawner%u", ++i);
if (!spawner->bthread) {
free(spawner);
ret = -ENOMEM;
goto cleanup;
}
/* We create intermediate spawning threads to test thread
* creation and scheduling from non-main thread.
*/
list_add(&spawner->list, &spawners);
/* fallthrough */
case 't':
time = true;
}
}
if (time) {
yields = bthread_time();
printf("%d bthread yield calls in 1s\n", yields);
}
cleanup:
list_for_each_entry_safe(spawner, tmp, &spawners, list) {
ecode = bthread_stop(spawner->bthread);
bthread_free(spawner->bthread);
if (!ret && ecode)
ret = ecode;
free(spawner);
}
return ret;
}
BAREBOX_CMD_HELP_START(bthread)
BAREBOX_CMD_HELP_TEXT("print info about registered barebox threads")
BAREBOX_CMD_HELP_TEXT("")
BAREBOX_CMD_HELP_TEXT("Options:")
BAREBOX_CMD_HELP_OPT ("-i", "Print information about registered bthreads")
BAREBOX_CMD_HELP_OPT ("-t", "measure how many bthreads we currently run in 1s")
BAREBOX_CMD_HELP_OPT ("-c", "count maximum context switches in 1s")
BAREBOX_CMD_HELP_OPT ("-v", "verify correct bthread operation")
BAREBOX_CMD_HELP_END
BAREBOX_CMD_START(bthread)
.cmd = do_bthread,
BAREBOX_CMD_DESC("print info about registered bthreads")
BAREBOX_CMD_GROUP(CMD_GRP_MISC)
BAREBOX_CMD_HELP(cmd_bthread_help)
BAREBOX_CMD_END
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