xref: /openbmc/qemu/tests/unit/test-coroutine.c (revision 835fde4a) 
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 }
513