tests/test-coroutine.c

   1 /*
   2  * Coroutine tests
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  10  * See the COPYING.LIB file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "qemu/coroutine.h"
  16 #include "qemu/coroutine_int.h"
  17 #include "qemu/lockable.h"
  18
  19 /*
  20  * Check that qemu_in_coroutine() works
  21  */
  22
  23 static void coroutine_fn verify_in_coroutine(void *opaque)
  24 {
  25     g_assert(qemu_in_coroutine());
  26 }
  27
  28 static void test_in_coroutine(void)
  29 {
  30     Coroutine *coroutine;
  31
  32     g_assert(!qemu_in_coroutine());
  33
  34     coroutine = qemu_coroutine_create(verify_in_coroutine, NULL);
  35     qemu_coroutine_enter(coroutine);
  36 }
  37
  38 /*
  39  * Check that qemu_coroutine_self() works
  40  */
  41
  42 static void coroutine_fn verify_self(void *opaque)
  43 {
  44     Coroutine **p_co = opaque;
  45     g_assert(qemu_coroutine_self() == *p_co);
  46 }
  47
  48 static void test_self(void)
  49 {
  50     Coroutine *coroutine;
  51
  52     coroutine = qemu_coroutine_create(verify_self, &coroutine);
  53     qemu_coroutine_enter(coroutine);
  54 }
  55
  56 /*
  57  * Check that qemu_coroutine_entered() works
  58  */
  59
  60 static void coroutine_fn verify_entered_step_2(void *opaque)
  61 {
  62     Coroutine *caller = (Coroutine *)opaque;
  63
  64     g_assert(qemu_coroutine_entered(caller));
  65     g_assert(qemu_coroutine_entered(qemu_coroutine_self()));
  66     qemu_coroutine_yield();
  67
  68     /* Once more to check it still works after yielding */
  69     g_assert(qemu_coroutine_entered(caller));
  70     g_assert(qemu_coroutine_entered(qemu_coroutine_self()));
  71 }
  72
  73 static void coroutine_fn verify_entered_step_1(void *opaque)
  74 {
  75     Coroutine *self = qemu_coroutine_self();
  76     Coroutine *coroutine;
  77
  78     g_assert(qemu_coroutine_entered(self));
  79
  80     coroutine = qemu_coroutine_create(verify_entered_step_2, self);
  81     g_assert(!qemu_coroutine_entered(coroutine));
  82     qemu_coroutine_enter(coroutine);
  83     g_assert(!qemu_coroutine_entered(coroutine));
  84     qemu_coroutine_enter(coroutine);
  85 }
  86
  87 static void test_entered(void)
  88 {
  89     Coroutine *coroutine;
  90
  91     coroutine = qemu_coroutine_create(verify_entered_step_1, NULL);
  92     g_assert(!qemu_coroutine_entered(coroutine));
  93     qemu_coroutine_enter(coroutine);
  94 }
  95
  96 /*
  97  * Check that coroutines may nest multiple levels
  98  */
  99
 100 typedef struct {
 101     unsigned int n_enter;   /* num coroutines entered */
 102     unsigned int n_return;  /* num coroutines returned */
 103     unsigned int max;       /* maximum level of nesting */
 104 } NestData;
 105
 106 static void coroutine_fn nest(void *opaque)
 107 {
 108     NestData *nd = opaque;
 109
 110     nd->n_enter++;
 111
 112     if (nd->n_enter < nd->max) {
 113         Coroutine *child;
 114
 115         child = qemu_coroutine_create(nest, nd);
 116         qemu_coroutine_enter(child);
 117     }
 118
 119     nd->n_return++;
 120 }
 121
 122 static void test_nesting(void)
 123 {
 124     Coroutine *root;
 125     NestData nd = {
 126         .n_enter  = 0,
 127         .n_return = 0,
 128         .max      = 128,
 129     };
 130
 131     root = qemu_coroutine_create(nest, &nd);
 132     qemu_coroutine_enter(root);
 133
 134     /* Must enter and return from max nesting level */
 135     g_assert_cmpint(nd.n_enter, ==, nd.max);
 136     g_assert_cmpint(nd.n_return, ==, nd.max);
 137 }
 138
 139 /*
 140  * Check that yield/enter transfer control correctly
 141  */
 142
 143 static void coroutine_fn yield_5_times(void *opaque)
 144 {
 145     bool *done = opaque;
 146     int i;
 147
 148     for (i = 0; i < 5; i++) {
 149         qemu_coroutine_yield();
 150     }
 151     *done = true;
 152 }
 153
 154 static void test_yield(void)
 155 {
 156     Coroutine *coroutine;
 157     bool done = false;
 158     int i = -1; /* one extra time to return from coroutine */
 159
 160     coroutine = qemu_coroutine_create(yield_5_times, &done);
 161     while (!done) {
 162         qemu_coroutine_enter(coroutine);
 163         i++;
 164     }
 165     g_assert_cmpint(i, ==, 5); /* coroutine must yield 5 times */
 166 }
 167
 168 static void coroutine_fn c2_fn(void *opaque)
 169 {
 170     qemu_coroutine_yield();
 171 }
 172
 173 static void coroutine_fn c1_fn(void *opaque)
 174 {
 175     Coroutine *c2 = opaque;
 176     qemu_coroutine_enter(c2);
 177 }
 178
 179 static void test_no_dangling_access(void)
 180 {
 181     Coroutine *c1;
 182     Coroutine *c2;
 183     Coroutine tmp;
 184
 185     c2 = qemu_coroutine_create(c2_fn, NULL);
 186     c1 = qemu_coroutine_create(c1_fn, c2);
 187
 188     qemu_coroutine_enter(c1);
 189
 190     /* c1 shouldn't be used any more now; make sure we segfault if it is */
 191     tmp = *c1;
 192     memset(c1, 0xff, sizeof(Coroutine));
 193     qemu_coroutine_enter(c2);
 194
 195     /* Must restore the coroutine now to avoid corrupted pool */
 196     *c1 = tmp;
 197 }
 198
 199 static bool locked;
 200 static int done;
 201
 202 static void coroutine_fn mutex_fn(void *opaque)
 203 {
 204     CoMutex *m = opaque;
 205     qemu_co_mutex_lock(m);
 206     assert(!locked);
 207     locked = true;
 208     qemu_coroutine_yield();
 209     locked = false;
 210     qemu_co_mutex_unlock(m);
 211     done++;
 212 }
 213
 214 static void coroutine_fn lockable_fn(void *opaque)
 215 {
 216     QemuLockable *x = opaque;
 217     qemu_lockable_lock(x);
 218     assert(!locked);
 219     locked = true;
 220     qemu_coroutine_yield();
 221     locked = false;
 222     qemu_lockable_unlock(x);
 223     done++;
 224 }
 225
 226 static void do_test_co_mutex(CoroutineEntry *entry, void *opaque)
 227 {
 228     Coroutine *c1 = qemu_coroutine_create(entry, opaque);
 229     Coroutine *c2 = qemu_coroutine_create(entry, opaque);
 230
 231     done = 0;
 232     qemu_coroutine_enter(c1);
 233     g_assert(locked);
 234     qemu_coroutine_enter(c2);
 235
 236     /* Unlock queues c2.  It is then started automatically when c1 yields or
 237      * terminates.
 238      */
 239     qemu_coroutine_enter(c1);
 240     g_assert_cmpint(done, ==, 1);
 241     g_assert(locked);
 242
 243     qemu_coroutine_enter(c2);
 244     g_assert_cmpint(done, ==, 2);
 245     g_assert(!locked);
 246 }
 247
 248 static void test_co_mutex(void)
 249 {
 250     CoMutex m;
 251
 252     qemu_co_mutex_init(&m);
 253     do_test_co_mutex(mutex_fn, &m);
 254 }
 255
 256 static void test_co_mutex_lockable(void)
 257 {
 258     CoMutex m;
 259     CoMutex *null_pointer = NULL;
 260
 261     qemu_co_mutex_init(&m);
 262     do_test_co_mutex(lockable_fn, QEMU_MAKE_LOCKABLE(&m));
 263
 264     g_assert(QEMU_MAKE_LOCKABLE(null_pointer) == NULL);
 265 }
 266
 267 /*
 268  * Check that creation, enter, and return work
 269  */
 270
 271 static void coroutine_fn set_and_exit(void *opaque)
 272 {
 273     bool *done = opaque;
 274
 275     *done = true;
 276 }
 277
 278 static void test_lifecycle(void)
 279 {
 280     Coroutine *coroutine;
 281     bool done = false;
 282
 283     /* Create, enter, and return from coroutine */
 284     coroutine = qemu_coroutine_create(set_and_exit, &done);
 285     qemu_coroutine_enter(coroutine);
 286     g_assert(done); /* expect done to be true (first time) */
 287
 288     /* Repeat to check that no state affects this test */
 289     done = false;
 290     coroutine = qemu_coroutine_create(set_and_exit, &done);
 291     qemu_coroutine_enter(coroutine);
 292     g_assert(done); /* expect done to be true (second time) */
 293 }
 294
 295
 296 #define RECORD_SIZE 10 /* Leave some room for expansion */
 297 struct coroutine_position {
 298     int func;
 299     int state;
 300 };
 301 static struct coroutine_position records[RECORD_SIZE];
 302 static unsigned record_pos;
 303
 304 static void record_push(int func, int state)
 305 {
 306     struct coroutine_position *cp = &records[record_pos++];
 307     g_assert_cmpint(record_pos, <, RECORD_SIZE);
 308     cp->func = func;
 309     cp->state = state;
 310 }
 311
 312 static void coroutine_fn co_order_test(void *opaque)
 313 {
 314     record_push(2, 1);
 315     g_assert(qemu_in_coroutine());
 316     qemu_coroutine_yield();
 317     record_push(2, 2);
 318     g_assert(qemu_in_coroutine());
 319 }
 320
 321 static void do_order_test(void)
 322 {
 323     Coroutine *co;
 324
 325     co = qemu_coroutine_create(co_order_test, NULL);
 326     record_push(1, 1);
 327     qemu_coroutine_enter(co);
 328     record_push(1, 2);
 329     g_assert(!qemu_in_coroutine());
 330     qemu_coroutine_enter(co);
 331     record_push(1, 3);
 332     g_assert(!qemu_in_coroutine());
 333 }
 334
 335 static void test_order(void)
 336 {
 337     int i;
 338     const struct coroutine_position expected_pos[] = {
 339         {1, 1,}, {2, 1}, {1, 2}, {2, 2}, {1, 3}
 340     };
 341     do_order_test();
 342     g_assert_cmpint(record_pos, ==, 5);
 343     for (i = 0; i < record_pos; i++) {
 344         g_assert_cmpint(records[i].func , ==, expected_pos[i].func );
 345         g_assert_cmpint(records[i].state, ==, expected_pos[i].state);
 346     }
 347 }
 348 /*
 349  * Lifecycle benchmark
 350  */
 351
 352 static void coroutine_fn empty_coroutine(void *opaque)
 353 {
 354     /* Do nothing */
 355 }
 356
 357 static void perf_lifecycle(void)
 358 {
 359     Coroutine *coroutine;
 360     unsigned int i, max;
 361     double duration;
 362
 363     max = 1000000;
 364
 365     g_test_timer_start();
 366     for (i = 0; i < max; i++) {
 367         coroutine = qemu_coroutine_create(empty_coroutine, NULL);
 368         qemu_coroutine_enter(coroutine);
 369     }
 370     duration = g_test_timer_elapsed();
 371
 372     g_test_message("Lifecycle %u iterations: %f s", max, duration);
 373 }
 374
 375 static void perf_nesting(void)
 376 {
 377     unsigned int i, maxcycles, maxnesting;
 378     double duration;
 379
 380     maxcycles = 10000;
 381     maxnesting = 1000;
 382     Coroutine *root;
 383
 384     g_test_timer_start();
 385     for (i = 0; i < maxcycles; i++) {
 386         NestData nd = {
 387             .n_enter  = 0,
 388             .n_return = 0,
 389             .max      = maxnesting,
 390         };
 391         root = qemu_coroutine_create(nest, &nd);
 392         qemu_coroutine_enter(root);
 393     }
 394     duration = g_test_timer_elapsed();
 395
 396     g_test_message("Nesting %u iterations of %u depth each: %f s",
 397         maxcycles, maxnesting, duration);
 398 }
 399
 400 /*
 401  * Yield benchmark
 402  */
 403
 404 static void coroutine_fn yield_loop(void *opaque)
 405 {
 406     unsigned int *counter = opaque;
 407
 408     while ((*counter) > 0) {
 409         (*counter)--;
 410         qemu_coroutine_yield();
 411     }
 412 }
 413
 414 static void perf_yield(void)
 415 {
 416     unsigned int i, maxcycles;
 417     double duration;
 418
 419     maxcycles = 100000000;
 420     i = maxcycles;
 421     Coroutine *coroutine = qemu_coroutine_create(yield_loop, &i);
 422
 423     g_test_timer_start();
 424     while (i > 0) {
 425         qemu_coroutine_enter(coroutine);
 426     }
 427     duration = g_test_timer_elapsed();
 428
 429     g_test_message("Yield %u iterations: %f s", maxcycles, duration);
 430 }
 431
 432 static __attribute__((noinline)) void dummy(unsigned *i)
 433 {
 434     (*i)--;
 435 }
 436
 437 static void perf_baseline(void)
 438 {
 439     unsigned int i, maxcycles;
 440     double duration;
 441
 442     maxcycles = 100000000;
 443     i = maxcycles;
 444
 445     g_test_timer_start();
 446     while (i > 0) {
 447         dummy(&i);
 448     }
 449     duration = g_test_timer_elapsed();
 450
 451     g_test_message("Function call %u iterations: %f s", maxcycles, duration);
 452 }
 453
 454 static __attribute__((noinline)) void perf_cost_func(void *opaque)
 455 {
 456     qemu_coroutine_yield();
 457 }
 458
 459 static void perf_cost(void)
 460 {
 461     const unsigned long maxcycles = 40000000;
 462     unsigned long i = 0;
 463     double duration;
 464     unsigned long ops;
 465     Coroutine *co;
 466
 467     g_test_timer_start();
 468     while (i++ < maxcycles) {
 469         co = qemu_coroutine_create(perf_cost_func, &i);
 470         qemu_coroutine_enter(co);
 471         qemu_coroutine_enter(co);
 472     }
 473     duration = g_test_timer_elapsed();
 474     ops = (long)(maxcycles / (duration * 1000));
 475
 476     g_test_message("Run operation %lu iterations %f s, %luK operations/s, "
 477                    "%luns per coroutine",
 478                    maxcycles,
 479                    duration, ops,
 480                    (unsigned long)(1000000000.0 * duration / maxcycles));
 481 }
 482
 483 int main(int argc, char **argv)
 484 {
 485     g_test_init(&argc, &argv, NULL);
 486
 487     /* This test assumes there is a freelist and marks freed coroutine memory
 488      * with a sentinel value.  If there is no freelist this would legitimately
 489      * crash, so skip it.
 490      */
 491     if (CONFIG_COROUTINE_POOL) {
 492         g_test_add_func("/basic/no-dangling-access", test_no_dangling_access);
 493     }
 494
 495     g_test_add_func("/basic/lifecycle", test_lifecycle);
 496     g_test_add_func("/basic/yield", test_yield);
 497     g_test_add_func("/basic/nesting", test_nesting);
 498     g_test_add_func("/basic/self", test_self);
 499     g_test_add_func("/basic/entered", test_entered);
 500     g_test_add_func("/basic/in_coroutine", test_in_coroutine);
 501     g_test_add_func("/basic/order", test_order);
 502     g_test_add_func("/locking/co-mutex", test_co_mutex);
 503     g_test_add_func("/locking/co-mutex/lockable", test_co_mutex_lockable);
 504     if (g_test_perf()) {
 505         g_test_add_func("/perf/lifecycle", perf_lifecycle);
 506         g_test_add_func("/perf/nesting", perf_nesting);
 507         g_test_add_func("/perf/yield", perf_yield);
 508         g_test_add_func("/perf/function-call", perf_baseline);
 509         g_test_add_func("/perf/cost", perf_cost);
 510     }
 511     return g_test_run();
 512 }