qemu-patch-raspberry4/tests/test-thread-pool.c
Chrysostomos Nanakos 2f78e491d7 async: aio_context_new(): Handle event_notifier_init failure
On a system with a low limit of open files the initialization
of the event notifier could fail and QEMU exits without printing any
error information to the user.

The problem can be easily reproduced by enforcing a low limit of open
files and start QEMU with enough I/O threads to hit this limit.

The same problem raises, without the creation of I/O threads, while
QEMU initializes the main event loop by enforcing an even lower limit of
open files.

This commit adds an error message on failure:

 # qemu [...] -object iothread,id=iothread0 -object iothread,id=iothread1
 qemu: Failed to initialize event notifier: Too many open files in system

Signed-off-by: Chrysostomos Nanakos <cnanakos@grnet.gr>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-22 11:39:48 +01:00

252 lines
6.2 KiB
C

#include <glib.h>
#include "qemu-common.h"
#include "block/aio.h"
#include "block/thread-pool.h"
#include "block/block.h"
#include "qemu/timer.h"
#include "qemu/error-report.h"
static AioContext *ctx;
static ThreadPool *pool;
static int active;
typedef struct {
BlockDriverAIOCB *aiocb;
int n;
int ret;
} WorkerTestData;
static int worker_cb(void *opaque)
{
WorkerTestData *data = opaque;
return atomic_fetch_inc(&data->n);
}
static int long_cb(void *opaque)
{
WorkerTestData *data = opaque;
atomic_inc(&data->n);
g_usleep(2000000);
atomic_inc(&data->n);
return 0;
}
static void done_cb(void *opaque, int ret)
{
WorkerTestData *data = opaque;
g_assert(data->ret == -EINPROGRESS || data->ret == -ECANCELED);
data->ret = ret;
data->aiocb = NULL;
/* Callbacks are serialized, so no need to use atomic ops. */
active--;
}
static void test_submit(void)
{
WorkerTestData data = { .n = 0 };
thread_pool_submit(pool, worker_cb, &data);
while (data.n == 0) {
aio_poll(ctx, true);
}
g_assert_cmpint(data.n, ==, 1);
}
static void test_submit_aio(void)
{
WorkerTestData data = { .n = 0, .ret = -EINPROGRESS };
data.aiocb = thread_pool_submit_aio(pool, worker_cb, &data,
done_cb, &data);
/* The callbacks are not called until after the first wait. */
active = 1;
g_assert_cmpint(data.ret, ==, -EINPROGRESS);
while (data.ret == -EINPROGRESS) {
aio_poll(ctx, true);
}
g_assert_cmpint(active, ==, 0);
g_assert_cmpint(data.n, ==, 1);
g_assert_cmpint(data.ret, ==, 0);
}
static void co_test_cb(void *opaque)
{
WorkerTestData *data = opaque;
active = 1;
data->n = 0;
data->ret = -EINPROGRESS;
thread_pool_submit_co(pool, worker_cb, data);
/* The test continues in test_submit_co, after qemu_coroutine_enter... */
g_assert_cmpint(data->n, ==, 1);
data->ret = 0;
active--;
/* The test continues in test_submit_co, after aio_poll... */
}
static void test_submit_co(void)
{
WorkerTestData data;
Coroutine *co = qemu_coroutine_create(co_test_cb);
qemu_coroutine_enter(co, &data);
/* Back here once the worker has started. */
g_assert_cmpint(active, ==, 1);
g_assert_cmpint(data.ret, ==, -EINPROGRESS);
/* aio_poll will execute the rest of the coroutine. */
while (data.ret == -EINPROGRESS) {
aio_poll(ctx, true);
}
/* Back here after the coroutine has finished. */
g_assert_cmpint(active, ==, 0);
g_assert_cmpint(data.ret, ==, 0);
}
static void test_submit_many(void)
{
WorkerTestData data[100];
int i;
/* Start more work items than there will be threads. */
for (i = 0; i < 100; i++) {
data[i].n = 0;
data[i].ret = -EINPROGRESS;
thread_pool_submit_aio(pool, worker_cb, &data[i], done_cb, &data[i]);
}
active = 100;
while (active > 0) {
aio_poll(ctx, true);
}
for (i = 0; i < 100; i++) {
g_assert_cmpint(data[i].n, ==, 1);
g_assert_cmpint(data[i].ret, ==, 0);
}
}
static void do_test_cancel(bool sync)
{
WorkerTestData data[100];
int num_canceled;
int i;
/* Start more work items than there will be threads, to ensure
* the pool is full.
*/
test_submit_many();
/* Start long running jobs, to ensure we can cancel some. */
for (i = 0; i < 100; i++) {
data[i].n = 0;
data[i].ret = -EINPROGRESS;
data[i].aiocb = thread_pool_submit_aio(pool, long_cb, &data[i],
done_cb, &data[i]);
}
/* Starting the threads may be left to a bottom half. Let it
* run, but do not waste too much time...
*/
active = 100;
aio_notify(ctx);
aio_poll(ctx, false);
/* Wait some time for the threads to start, with some sanity
* testing on the behavior of the scheduler...
*/
g_assert_cmpint(active, ==, 100);
g_usleep(1000000);
g_assert_cmpint(active, >, 50);
/* Cancel the jobs that haven't been started yet. */
num_canceled = 0;
for (i = 0; i < 100; i++) {
if (atomic_cmpxchg(&data[i].n, 0, 3) == 0) {
data[i].ret = -ECANCELED;
if (sync) {
bdrv_aio_cancel(data[i].aiocb);
} else {
bdrv_aio_cancel_async(data[i].aiocb);
}
num_canceled++;
}
}
g_assert_cmpint(active, >, 0);
g_assert_cmpint(num_canceled, <, 100);
for (i = 0; i < 100; i++) {
if (data[i].aiocb && data[i].n != 3) {
if (sync) {
/* Canceling the others will be a blocking operation. */
bdrv_aio_cancel(data[i].aiocb);
} else {
bdrv_aio_cancel_async(data[i].aiocb);
}
}
}
/* Finish execution and execute any remaining callbacks. */
while (active > 0) {
aio_poll(ctx, true);
}
g_assert_cmpint(active, ==, 0);
for (i = 0; i < 100; i++) {
if (data[i].n == 3) {
g_assert_cmpint(data[i].ret, ==, -ECANCELED);
g_assert(data[i].aiocb == NULL);
} else {
g_assert_cmpint(data[i].n, ==, 2);
g_assert(data[i].ret == 0 || data[i].ret == -ECANCELED);
g_assert(data[i].aiocb == NULL);
}
}
}
static void test_cancel(void)
{
do_test_cancel(true);
}
static void test_cancel_async(void)
{
do_test_cancel(false);
}
int main(int argc, char **argv)
{
int ret;
Error *local_error = NULL;
init_clocks();
ctx = aio_context_new(&local_error);
if (!ctx) {
error_report("Failed to create AIO Context: '%s'",
error_get_pretty(local_error));
error_free(local_error);
exit(1);
}
pool = aio_get_thread_pool(ctx);
g_test_init(&argc, &argv, NULL);
g_test_add_func("/thread-pool/submit", test_submit);
g_test_add_func("/thread-pool/submit-aio", test_submit_aio);
g_test_add_func("/thread-pool/submit-co", test_submit_co);
g_test_add_func("/thread-pool/submit-many", test_submit_many);
g_test_add_func("/thread-pool/cancel", test_cancel);
g_test_add_func("/thread-pool/cancel-async", test_cancel_async);
ret = g_test_run();
aio_context_unref(ctx);
return ret;
}