qemu/test-coroutine.c
Stefan Hajnoczi 5e3840ce24 coroutine: add test-coroutine --benchmark-lifecycle
Add a microbenchmark for coroutine create, enter, and return (aka
lifecycle).  This is a useful benchmark because users are expected to
create many coroutines, one per I/O request for example, and we
therefore need to provide good performance in that scenario.

To run:

  make test-coroutine
  ./test-coroutine --benchmark-lifecycle 20000000

This will do 20,000,000 coroutine create, enter, return iterations and
print the resulting time.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-08-02 15:53:40 +02:00

193 lines
4.1 KiB
C

/*
* Coroutine tests
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include <glib.h>
#include "qemu-coroutine.h"
/*
* Check that qemu_in_coroutine() works
*/
static void coroutine_fn verify_in_coroutine(void *opaque)
{
g_assert(qemu_in_coroutine());
}
static void test_in_coroutine(void)
{
Coroutine *coroutine;
g_assert(!qemu_in_coroutine());
coroutine = qemu_coroutine_create(verify_in_coroutine);
qemu_coroutine_enter(coroutine, NULL);
}
/*
* Check that qemu_coroutine_self() works
*/
static void coroutine_fn verify_self(void *opaque)
{
g_assert(qemu_coroutine_self() == opaque);
}
static void test_self(void)
{
Coroutine *coroutine;
coroutine = qemu_coroutine_create(verify_self);
qemu_coroutine_enter(coroutine, coroutine);
}
/*
* Check that coroutines may nest multiple levels
*/
typedef struct {
unsigned int n_enter; /* num coroutines entered */
unsigned int n_return; /* num coroutines returned */
unsigned int max; /* maximum level of nesting */
} NestData;
static void coroutine_fn nest(void *opaque)
{
NestData *nd = opaque;
nd->n_enter++;
if (nd->n_enter < nd->max) {
Coroutine *child;
child = qemu_coroutine_create(nest);
qemu_coroutine_enter(child, nd);
}
nd->n_return++;
}
static void test_nesting(void)
{
Coroutine *root;
NestData nd = {
.n_enter = 0,
.n_return = 0,
.max = 128,
};
root = qemu_coroutine_create(nest);
qemu_coroutine_enter(root, &nd);
/* Must enter and return from max nesting level */
g_assert_cmpint(nd.n_enter, ==, nd.max);
g_assert_cmpint(nd.n_return, ==, nd.max);
}
/*
* Check that yield/enter transfer control correctly
*/
static void coroutine_fn yield_5_times(void *opaque)
{
bool *done = opaque;
int i;
for (i = 0; i < 5; i++) {
qemu_coroutine_yield();
}
*done = true;
}
static void test_yield(void)
{
Coroutine *coroutine;
bool done = false;
int i = -1; /* one extra time to return from coroutine */
coroutine = qemu_coroutine_create(yield_5_times);
while (!done) {
qemu_coroutine_enter(coroutine, &done);
i++;
}
g_assert_cmpint(i, ==, 5); /* coroutine must yield 5 times */
}
/*
* Check that creation, enter, and return work
*/
static void coroutine_fn set_and_exit(void *opaque)
{
bool *done = opaque;
*done = true;
}
static void test_lifecycle(void)
{
Coroutine *coroutine;
bool done = false;
/* Create, enter, and return from coroutine */
coroutine = qemu_coroutine_create(set_and_exit);
qemu_coroutine_enter(coroutine, &done);
g_assert(done); /* expect done to be true (first time) */
/* Repeat to check that no state affects this test */
done = false;
coroutine = qemu_coroutine_create(set_and_exit);
qemu_coroutine_enter(coroutine, &done);
g_assert(done); /* expect done to be true (second time) */
}
/*
* Lifecycle benchmark
*/
static void coroutine_fn empty_coroutine(void *opaque)
{
/* Do nothing */
}
static void perf_lifecycle(void)
{
Coroutine *coroutine;
unsigned int i, max;
double duration;
max = 1000000;
g_test_timer_start();
for (i = 0; i < max; i++) {
coroutine = qemu_coroutine_create(empty_coroutine);
qemu_coroutine_enter(coroutine, NULL);
}
duration = g_test_timer_elapsed();
g_test_message("Lifecycle %u iterations: %f s\n", max, duration);
}
int main(int argc, char **argv)
{
g_test_init(&argc, &argv, NULL);
g_test_add_func("/basic/lifecycle", test_lifecycle);
g_test_add_func("/basic/yield", test_yield);
g_test_add_func("/basic/nesting", test_nesting);
g_test_add_func("/basic/self", test_self);
g_test_add_func("/basic/in_coroutine", test_in_coroutine);
if (g_test_perf()) {
g_test_add_func("/perf/lifecycle", perf_lifecycle);
}
return g_test_run();
}