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/*

 * 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 "block/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) */

}

#define RECORD_SIZE 10 /* Leave some room for expansion */

struct coroutine_position {

    int func;

    int state;

};

static struct coroutine_position records[RECORD_SIZE];

static unsigned record_pos;

static void record_push(int func, int state)

{

    struct coroutine_position *cp = &records[record_pos++];

    g_assert_cmpint(record_pos, <, RECORD_SIZE);

    cp->func = func;

    cp->state = state;

}

static void coroutine_fn co_order_test(void *opaque)

{

    record_push(2, 1);

    g_assert(qemu_in_coroutine());

    qemu_coroutine_yield();

    record_push(2, 2);

    g_assert(qemu_in_coroutine());

}

static void do_order_test(void)

{

    Coroutine *co;

    co = qemu_coroutine_create(co_order_test);

    record_push(1, 1);

    qemu_coroutine_enter(co, NULL);

    record_push(1, 2);

    g_assert(!qemu_in_coroutine());

    qemu_coroutine_enter(co, NULL);

    record_push(1, 3);

    g_assert(!qemu_in_coroutine());

}

static void test_order(void)

{

    int i;

    const struct coroutine_position expected_pos[] = {

        {1, 1,}, {2, 1}, {1, 2}, {2, 2}, {1, 3}

    };

    do_order_test();

    g_assert_cmpint(record_pos, ==, 5);

    for (i = 0; i < record_pos; i++) {

        g_assert_cmpint(records[i].func , ==, expected_pos[i].func );

        g_assert_cmpint(records[i].state, ==, expected_pos[i].state);

    }

}

/*

 * 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);

}

static void perf_nesting(void)

{

    unsigned int i, maxcycles, maxnesting;

    double duration;

    maxcycles = 10000;

    maxnesting = 1000;

    Coroutine *root;

    g_test_timer_start();

    for (i = 0; i < maxcycles; i++) {

        NestData nd = {

            .n_enter  = 0,

            .n_return = 0,

            .max      = maxnesting,

        };

        root = qemu_coroutine_create(nest);

        qemu_coroutine_enter(root, &nd);

    }

    duration = g_test_timer_elapsed();

    g_test_message("Nesting %u iterations of %u depth each: %f s\n",

        maxcycles, maxnesting, duration);

}

/*

 * Yield benchmark

 */

static void coroutine_fn yield_loop(void *opaque)

{

    unsigned int *counter = opaque;

    while ((*counter) > 0) {

        (*counter)--;

        qemu_coroutine_yield();

    }

}

static void perf_yield(void)

{

    unsigned int i, maxcycles;

    double duration;

    maxcycles = 100000000;

    i = maxcycles;

    Coroutine *coroutine = qemu_coroutine_create(yield_loop);

    g_test_timer_start();

    while (i > 0) {

        qemu_coroutine_enter(coroutine, &i);

    }

    duration = g_test_timer_elapsed();

    g_test_message("Yield %u iterations: %f s\n",

        maxcycles, 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);

    g_test_add_func("/basic/order", test_order);

    if (g_test_perf()) {

        g_test_add_func("/perf/lifecycle", perf_lifecycle);

        g_test_add_func("/perf/nesting", perf_nesting);

        g_test_add_func("/perf/yield", perf_yield);

    }

    return g_test_run();

}