WIP FPC-III support
[linux/fpc-iii.git] / tools / testing / selftests / rseq / param_test.c
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1 // SPDX-License-Identifier: LGPL-2.1
2 #define _GNU_SOURCE
3 #include <assert.h>
4 #include <linux/membarrier.h>
5 #include <pthread.h>
6 #include <sched.h>
7 #include <stdatomic.h>
8 #include <stdint.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <syscall.h>
13 #include <unistd.h>
14 #include <poll.h>
15 #include <sys/types.h>
16 #include <signal.h>
17 #include <errno.h>
18 #include <stddef.h>
20 static inline pid_t rseq_gettid(void)
22 return syscall(__NR_gettid);
25 #define NR_INJECT 9
26 static int loop_cnt[NR_INJECT + 1];
28 static int loop_cnt_1 asm("asm_loop_cnt_1") __attribute__((used));
29 static int loop_cnt_2 asm("asm_loop_cnt_2") __attribute__((used));
30 static int loop_cnt_3 asm("asm_loop_cnt_3") __attribute__((used));
31 static int loop_cnt_4 asm("asm_loop_cnt_4") __attribute__((used));
32 static int loop_cnt_5 asm("asm_loop_cnt_5") __attribute__((used));
33 static int loop_cnt_6 asm("asm_loop_cnt_6") __attribute__((used));
35 static int opt_modulo, verbose;
37 static int opt_yield, opt_signal, opt_sleep,
38 opt_disable_rseq, opt_threads = 200,
39 opt_disable_mod = 0, opt_test = 's', opt_mb = 0;
41 #ifndef RSEQ_SKIP_FASTPATH
42 static long long opt_reps = 5000;
43 #else
44 static long long opt_reps = 100;
45 #endif
47 static __thread __attribute__((tls_model("initial-exec")))
48 unsigned int signals_delivered;
50 #ifndef BENCHMARK
52 static __thread __attribute__((tls_model("initial-exec"), unused))
53 unsigned int yield_mod_cnt, nr_abort;
55 #define printf_verbose(fmt, ...) \
56 do { \
57 if (verbose) \
58 printf(fmt, ## __VA_ARGS__); \
59 } while (0)
61 #ifdef __i386__
63 #define INJECT_ASM_REG "eax"
65 #define RSEQ_INJECT_CLOBBER \
66 , INJECT_ASM_REG
68 #define RSEQ_INJECT_ASM(n) \
69 "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
70 "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
71 "jz 333f\n\t" \
72 "222:\n\t" \
73 "dec %%" INJECT_ASM_REG "\n\t" \
74 "jnz 222b\n\t" \
75 "333:\n\t"
77 #elif defined(__x86_64__)
79 #define INJECT_ASM_REG_P "rax"
80 #define INJECT_ASM_REG "eax"
82 #define RSEQ_INJECT_CLOBBER \
83 , INJECT_ASM_REG_P \
84 , INJECT_ASM_REG
86 #define RSEQ_INJECT_ASM(n) \
87 "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
88 "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
89 "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
90 "jz 333f\n\t" \
91 "222:\n\t" \
92 "dec %%" INJECT_ASM_REG "\n\t" \
93 "jnz 222b\n\t" \
94 "333:\n\t"
96 #elif defined(__s390__)
98 #define RSEQ_INJECT_INPUT \
99 , [loop_cnt_1]"m"(loop_cnt[1]) \
100 , [loop_cnt_2]"m"(loop_cnt[2]) \
101 , [loop_cnt_3]"m"(loop_cnt[3]) \
102 , [loop_cnt_4]"m"(loop_cnt[4]) \
103 , [loop_cnt_5]"m"(loop_cnt[5]) \
104 , [loop_cnt_6]"m"(loop_cnt[6])
106 #define INJECT_ASM_REG "r12"
108 #define RSEQ_INJECT_CLOBBER \
109 , INJECT_ASM_REG
111 #define RSEQ_INJECT_ASM(n) \
112 "l %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
113 "ltr %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG "\n\t" \
114 "je 333f\n\t" \
115 "222:\n\t" \
116 "ahi %%" INJECT_ASM_REG ", -1\n\t" \
117 "jnz 222b\n\t" \
118 "333:\n\t"
120 #elif defined(__ARMEL__)
122 #define RSEQ_INJECT_INPUT \
123 , [loop_cnt_1]"m"(loop_cnt[1]) \
124 , [loop_cnt_2]"m"(loop_cnt[2]) \
125 , [loop_cnt_3]"m"(loop_cnt[3]) \
126 , [loop_cnt_4]"m"(loop_cnt[4]) \
127 , [loop_cnt_5]"m"(loop_cnt[5]) \
128 , [loop_cnt_6]"m"(loop_cnt[6])
130 #define INJECT_ASM_REG "r4"
132 #define RSEQ_INJECT_CLOBBER \
133 , INJECT_ASM_REG
135 #define RSEQ_INJECT_ASM(n) \
136 "ldr " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
137 "cmp " INJECT_ASM_REG ", #0\n\t" \
138 "beq 333f\n\t" \
139 "222:\n\t" \
140 "subs " INJECT_ASM_REG ", #1\n\t" \
141 "bne 222b\n\t" \
142 "333:\n\t"
144 #elif defined(__AARCH64EL__)
146 #define RSEQ_INJECT_INPUT \
147 , [loop_cnt_1] "Qo" (loop_cnt[1]) \
148 , [loop_cnt_2] "Qo" (loop_cnt[2]) \
149 , [loop_cnt_3] "Qo" (loop_cnt[3]) \
150 , [loop_cnt_4] "Qo" (loop_cnt[4]) \
151 , [loop_cnt_5] "Qo" (loop_cnt[5]) \
152 , [loop_cnt_6] "Qo" (loop_cnt[6])
154 #define INJECT_ASM_REG RSEQ_ASM_TMP_REG32
156 #define RSEQ_INJECT_ASM(n) \
157 " ldr " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n" \
158 " cbz " INJECT_ASM_REG ", 333f\n" \
159 "222:\n" \
160 " sub " INJECT_ASM_REG ", " INJECT_ASM_REG ", #1\n" \
161 " cbnz " INJECT_ASM_REG ", 222b\n" \
162 "333:\n"
164 #elif __PPC__
166 #define RSEQ_INJECT_INPUT \
167 , [loop_cnt_1]"m"(loop_cnt[1]) \
168 , [loop_cnt_2]"m"(loop_cnt[2]) \
169 , [loop_cnt_3]"m"(loop_cnt[3]) \
170 , [loop_cnt_4]"m"(loop_cnt[4]) \
171 , [loop_cnt_5]"m"(loop_cnt[5]) \
172 , [loop_cnt_6]"m"(loop_cnt[6])
174 #define INJECT_ASM_REG "r18"
176 #define RSEQ_INJECT_CLOBBER \
177 , INJECT_ASM_REG
179 #define RSEQ_INJECT_ASM(n) \
180 "lwz %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
181 "cmpwi %%" INJECT_ASM_REG ", 0\n\t" \
182 "beq 333f\n\t" \
183 "222:\n\t" \
184 "subic. %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG ", 1\n\t" \
185 "bne 222b\n\t" \
186 "333:\n\t"
188 #elif defined(__mips__)
190 #define RSEQ_INJECT_INPUT \
191 , [loop_cnt_1]"m"(loop_cnt[1]) \
192 , [loop_cnt_2]"m"(loop_cnt[2]) \
193 , [loop_cnt_3]"m"(loop_cnt[3]) \
194 , [loop_cnt_4]"m"(loop_cnt[4]) \
195 , [loop_cnt_5]"m"(loop_cnt[5]) \
196 , [loop_cnt_6]"m"(loop_cnt[6])
198 #define INJECT_ASM_REG "$5"
200 #define RSEQ_INJECT_CLOBBER \
201 , INJECT_ASM_REG
203 #define RSEQ_INJECT_ASM(n) \
204 "lw " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
205 "beqz " INJECT_ASM_REG ", 333f\n\t" \
206 "222:\n\t" \
207 "addiu " INJECT_ASM_REG ", -1\n\t" \
208 "bnez " INJECT_ASM_REG ", 222b\n\t" \
209 "333:\n\t"
211 #else
212 #error unsupported target
213 #endif
215 #define RSEQ_INJECT_FAILED \
216 nr_abort++;
218 #define RSEQ_INJECT_C(n) \
220 int loc_i, loc_nr_loops = loop_cnt[n]; \
222 for (loc_i = 0; loc_i < loc_nr_loops; loc_i++) { \
223 rseq_barrier(); \
225 if (loc_nr_loops == -1 && opt_modulo) { \
226 if (yield_mod_cnt == opt_modulo - 1) { \
227 if (opt_sleep > 0) \
228 poll(NULL, 0, opt_sleep); \
229 if (opt_yield) \
230 sched_yield(); \
231 if (opt_signal) \
232 raise(SIGUSR1); \
233 yield_mod_cnt = 0; \
234 } else { \
235 yield_mod_cnt++; \
240 #else
242 #define printf_verbose(fmt, ...)
244 #endif /* BENCHMARK */
246 #include "rseq.h"
248 struct percpu_lock_entry {
249 intptr_t v;
250 } __attribute__((aligned(128)));
252 struct percpu_lock {
253 struct percpu_lock_entry c[CPU_SETSIZE];
256 struct test_data_entry {
257 intptr_t count;
258 } __attribute__((aligned(128)));
260 struct spinlock_test_data {
261 struct percpu_lock lock;
262 struct test_data_entry c[CPU_SETSIZE];
265 struct spinlock_thread_test_data {
266 struct spinlock_test_data *data;
267 long long reps;
268 int reg;
271 struct inc_test_data {
272 struct test_data_entry c[CPU_SETSIZE];
275 struct inc_thread_test_data {
276 struct inc_test_data *data;
277 long long reps;
278 int reg;
281 struct percpu_list_node {
282 intptr_t data;
283 struct percpu_list_node *next;
286 struct percpu_list_entry {
287 struct percpu_list_node *head;
288 } __attribute__((aligned(128)));
290 struct percpu_list {
291 struct percpu_list_entry c[CPU_SETSIZE];
294 #define BUFFER_ITEM_PER_CPU 100
296 struct percpu_buffer_node {
297 intptr_t data;
300 struct percpu_buffer_entry {
301 intptr_t offset;
302 intptr_t buflen;
303 struct percpu_buffer_node **array;
304 } __attribute__((aligned(128)));
306 struct percpu_buffer {
307 struct percpu_buffer_entry c[CPU_SETSIZE];
310 #define MEMCPY_BUFFER_ITEM_PER_CPU 100
312 struct percpu_memcpy_buffer_node {
313 intptr_t data1;
314 uint64_t data2;
317 struct percpu_memcpy_buffer_entry {
318 intptr_t offset;
319 intptr_t buflen;
320 struct percpu_memcpy_buffer_node *array;
321 } __attribute__((aligned(128)));
323 struct percpu_memcpy_buffer {
324 struct percpu_memcpy_buffer_entry c[CPU_SETSIZE];
327 /* A simple percpu spinlock. Grabs lock on current cpu. */
328 static int rseq_this_cpu_lock(struct percpu_lock *lock)
330 int cpu;
332 for (;;) {
333 int ret;
335 cpu = rseq_cpu_start();
336 ret = rseq_cmpeqv_storev(&lock->c[cpu].v,
337 0, 1, cpu);
338 if (rseq_likely(!ret))
339 break;
340 /* Retry if comparison fails or rseq aborts. */
343 * Acquire semantic when taking lock after control dependency.
344 * Matches rseq_smp_store_release().
346 rseq_smp_acquire__after_ctrl_dep();
347 return cpu;
350 static void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
352 assert(lock->c[cpu].v == 1);
354 * Release lock, with release semantic. Matches
355 * rseq_smp_acquire__after_ctrl_dep().
357 rseq_smp_store_release(&lock->c[cpu].v, 0);
360 void *test_percpu_spinlock_thread(void *arg)
362 struct spinlock_thread_test_data *thread_data = arg;
363 struct spinlock_test_data *data = thread_data->data;
364 long long i, reps;
366 if (!opt_disable_rseq && thread_data->reg &&
367 rseq_register_current_thread())
368 abort();
369 reps = thread_data->reps;
370 for (i = 0; i < reps; i++) {
371 int cpu = rseq_cpu_start();
373 cpu = rseq_this_cpu_lock(&data->lock);
374 data->c[cpu].count++;
375 rseq_percpu_unlock(&data->lock, cpu);
376 #ifndef BENCHMARK
377 if (i != 0 && !(i % (reps / 10)))
378 printf_verbose("tid %d: count %lld\n",
379 (int) rseq_gettid(), i);
380 #endif
382 printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
383 (int) rseq_gettid(), nr_abort, signals_delivered);
384 if (!opt_disable_rseq && thread_data->reg &&
385 rseq_unregister_current_thread())
386 abort();
387 return NULL;
391 * A simple test which implements a sharded counter using a per-cpu
392 * lock. Obviously real applications might prefer to simply use a
393 * per-cpu increment; however, this is reasonable for a test and the
394 * lock can be extended to synchronize more complicated operations.
396 void test_percpu_spinlock(void)
398 const int num_threads = opt_threads;
399 int i, ret;
400 uint64_t sum;
401 pthread_t test_threads[num_threads];
402 struct spinlock_test_data data;
403 struct spinlock_thread_test_data thread_data[num_threads];
405 memset(&data, 0, sizeof(data));
406 for (i = 0; i < num_threads; i++) {
407 thread_data[i].reps = opt_reps;
408 if (opt_disable_mod <= 0 || (i % opt_disable_mod))
409 thread_data[i].reg = 1;
410 else
411 thread_data[i].reg = 0;
412 thread_data[i].data = &data;
413 ret = pthread_create(&test_threads[i], NULL,
414 test_percpu_spinlock_thread,
415 &thread_data[i]);
416 if (ret) {
417 errno = ret;
418 perror("pthread_create");
419 abort();
423 for (i = 0; i < num_threads; i++) {
424 ret = pthread_join(test_threads[i], NULL);
425 if (ret) {
426 errno = ret;
427 perror("pthread_join");
428 abort();
432 sum = 0;
433 for (i = 0; i < CPU_SETSIZE; i++)
434 sum += data.c[i].count;
436 assert(sum == (uint64_t)opt_reps * num_threads);
439 void *test_percpu_inc_thread(void *arg)
441 struct inc_thread_test_data *thread_data = arg;
442 struct inc_test_data *data = thread_data->data;
443 long long i, reps;
445 if (!opt_disable_rseq && thread_data->reg &&
446 rseq_register_current_thread())
447 abort();
448 reps = thread_data->reps;
449 for (i = 0; i < reps; i++) {
450 int ret;
452 do {
453 int cpu;
455 cpu = rseq_cpu_start();
456 ret = rseq_addv(&data->c[cpu].count, 1, cpu);
457 } while (rseq_unlikely(ret));
458 #ifndef BENCHMARK
459 if (i != 0 && !(i % (reps / 10)))
460 printf_verbose("tid %d: count %lld\n",
461 (int) rseq_gettid(), i);
462 #endif
464 printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
465 (int) rseq_gettid(), nr_abort, signals_delivered);
466 if (!opt_disable_rseq && thread_data->reg &&
467 rseq_unregister_current_thread())
468 abort();
469 return NULL;
472 void test_percpu_inc(void)
474 const int num_threads = opt_threads;
475 int i, ret;
476 uint64_t sum;
477 pthread_t test_threads[num_threads];
478 struct inc_test_data data;
479 struct inc_thread_test_data thread_data[num_threads];
481 memset(&data, 0, sizeof(data));
482 for (i = 0; i < num_threads; i++) {
483 thread_data[i].reps = opt_reps;
484 if (opt_disable_mod <= 0 || (i % opt_disable_mod))
485 thread_data[i].reg = 1;
486 else
487 thread_data[i].reg = 0;
488 thread_data[i].data = &data;
489 ret = pthread_create(&test_threads[i], NULL,
490 test_percpu_inc_thread,
491 &thread_data[i]);
492 if (ret) {
493 errno = ret;
494 perror("pthread_create");
495 abort();
499 for (i = 0; i < num_threads; i++) {
500 ret = pthread_join(test_threads[i], NULL);
501 if (ret) {
502 errno = ret;
503 perror("pthread_join");
504 abort();
508 sum = 0;
509 for (i = 0; i < CPU_SETSIZE; i++)
510 sum += data.c[i].count;
512 assert(sum == (uint64_t)opt_reps * num_threads);
515 void this_cpu_list_push(struct percpu_list *list,
516 struct percpu_list_node *node,
517 int *_cpu)
519 int cpu;
521 for (;;) {
522 intptr_t *targetptr, newval, expect;
523 int ret;
525 cpu = rseq_cpu_start();
526 /* Load list->c[cpu].head with single-copy atomicity. */
527 expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
528 newval = (intptr_t)node;
529 targetptr = (intptr_t *)&list->c[cpu].head;
530 node->next = (struct percpu_list_node *)expect;
531 ret = rseq_cmpeqv_storev(targetptr, expect, newval, cpu);
532 if (rseq_likely(!ret))
533 break;
534 /* Retry if comparison fails or rseq aborts. */
536 if (_cpu)
537 *_cpu = cpu;
541 * Unlike a traditional lock-less linked list; the availability of a
542 * rseq primitive allows us to implement pop without concerns over
543 * ABA-type races.
545 struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
546 int *_cpu)
548 struct percpu_list_node *node = NULL;
549 int cpu;
551 for (;;) {
552 struct percpu_list_node *head;
553 intptr_t *targetptr, expectnot, *load;
554 off_t offset;
555 int ret;
557 cpu = rseq_cpu_start();
558 targetptr = (intptr_t *)&list->c[cpu].head;
559 expectnot = (intptr_t)NULL;
560 offset = offsetof(struct percpu_list_node, next);
561 load = (intptr_t *)&head;
562 ret = rseq_cmpnev_storeoffp_load(targetptr, expectnot,
563 offset, load, cpu);
564 if (rseq_likely(!ret)) {
565 node = head;
566 break;
568 if (ret > 0)
569 break;
570 /* Retry if rseq aborts. */
572 if (_cpu)
573 *_cpu = cpu;
574 return node;
578 * __percpu_list_pop is not safe against concurrent accesses. Should
579 * only be used on lists that are not concurrently modified.
581 struct percpu_list_node *__percpu_list_pop(struct percpu_list *list, int cpu)
583 struct percpu_list_node *node;
585 node = list->c[cpu].head;
586 if (!node)
587 return NULL;
588 list->c[cpu].head = node->next;
589 return node;
592 void *test_percpu_list_thread(void *arg)
594 long long i, reps;
595 struct percpu_list *list = (struct percpu_list *)arg;
597 if (!opt_disable_rseq && rseq_register_current_thread())
598 abort();
600 reps = opt_reps;
601 for (i = 0; i < reps; i++) {
602 struct percpu_list_node *node;
604 node = this_cpu_list_pop(list, NULL);
605 if (opt_yield)
606 sched_yield(); /* encourage shuffling */
607 if (node)
608 this_cpu_list_push(list, node, NULL);
611 printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
612 (int) rseq_gettid(), nr_abort, signals_delivered);
613 if (!opt_disable_rseq && rseq_unregister_current_thread())
614 abort();
616 return NULL;
619 /* Simultaneous modification to a per-cpu linked list from many threads. */
620 void test_percpu_list(void)
622 const int num_threads = opt_threads;
623 int i, j, ret;
624 uint64_t sum = 0, expected_sum = 0;
625 struct percpu_list list;
626 pthread_t test_threads[num_threads];
627 cpu_set_t allowed_cpus;
629 memset(&list, 0, sizeof(list));
631 /* Generate list entries for every usable cpu. */
632 sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
633 for (i = 0; i < CPU_SETSIZE; i++) {
634 if (!CPU_ISSET(i, &allowed_cpus))
635 continue;
636 for (j = 1; j <= 100; j++) {
637 struct percpu_list_node *node;
639 expected_sum += j;
641 node = malloc(sizeof(*node));
642 assert(node);
643 node->data = j;
644 node->next = list.c[i].head;
645 list.c[i].head = node;
649 for (i = 0; i < num_threads; i++) {
650 ret = pthread_create(&test_threads[i], NULL,
651 test_percpu_list_thread, &list);
652 if (ret) {
653 errno = ret;
654 perror("pthread_create");
655 abort();
659 for (i = 0; i < num_threads; i++) {
660 ret = pthread_join(test_threads[i], NULL);
661 if (ret) {
662 errno = ret;
663 perror("pthread_join");
664 abort();
668 for (i = 0; i < CPU_SETSIZE; i++) {
669 struct percpu_list_node *node;
671 if (!CPU_ISSET(i, &allowed_cpus))
672 continue;
674 while ((node = __percpu_list_pop(&list, i))) {
675 sum += node->data;
676 free(node);
681 * All entries should now be accounted for (unless some external
682 * actor is interfering with our allowed affinity while this
683 * test is running).
685 assert(sum == expected_sum);
688 bool this_cpu_buffer_push(struct percpu_buffer *buffer,
689 struct percpu_buffer_node *node,
690 int *_cpu)
692 bool result = false;
693 int cpu;
695 for (;;) {
696 intptr_t *targetptr_spec, newval_spec;
697 intptr_t *targetptr_final, newval_final;
698 intptr_t offset;
699 int ret;
701 cpu = rseq_cpu_start();
702 offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
703 if (offset == buffer->c[cpu].buflen)
704 break;
705 newval_spec = (intptr_t)node;
706 targetptr_spec = (intptr_t *)&buffer->c[cpu].array[offset];
707 newval_final = offset + 1;
708 targetptr_final = &buffer->c[cpu].offset;
709 if (opt_mb)
710 ret = rseq_cmpeqv_trystorev_storev_release(
711 targetptr_final, offset, targetptr_spec,
712 newval_spec, newval_final, cpu);
713 else
714 ret = rseq_cmpeqv_trystorev_storev(targetptr_final,
715 offset, targetptr_spec, newval_spec,
716 newval_final, cpu);
717 if (rseq_likely(!ret)) {
718 result = true;
719 break;
721 /* Retry if comparison fails or rseq aborts. */
723 if (_cpu)
724 *_cpu = cpu;
725 return result;
728 struct percpu_buffer_node *this_cpu_buffer_pop(struct percpu_buffer *buffer,
729 int *_cpu)
731 struct percpu_buffer_node *head;
732 int cpu;
734 for (;;) {
735 intptr_t *targetptr, newval;
736 intptr_t offset;
737 int ret;
739 cpu = rseq_cpu_start();
740 /* Load offset with single-copy atomicity. */
741 offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
742 if (offset == 0) {
743 head = NULL;
744 break;
746 head = RSEQ_READ_ONCE(buffer->c[cpu].array[offset - 1]);
747 newval = offset - 1;
748 targetptr = (intptr_t *)&buffer->c[cpu].offset;
749 ret = rseq_cmpeqv_cmpeqv_storev(targetptr, offset,
750 (intptr_t *)&buffer->c[cpu].array[offset - 1],
751 (intptr_t)head, newval, cpu);
752 if (rseq_likely(!ret))
753 break;
754 /* Retry if comparison fails or rseq aborts. */
756 if (_cpu)
757 *_cpu = cpu;
758 return head;
762 * __percpu_buffer_pop is not safe against concurrent accesses. Should
763 * only be used on buffers that are not concurrently modified.
765 struct percpu_buffer_node *__percpu_buffer_pop(struct percpu_buffer *buffer,
766 int cpu)
768 struct percpu_buffer_node *head;
769 intptr_t offset;
771 offset = buffer->c[cpu].offset;
772 if (offset == 0)
773 return NULL;
774 head = buffer->c[cpu].array[offset - 1];
775 buffer->c[cpu].offset = offset - 1;
776 return head;
779 void *test_percpu_buffer_thread(void *arg)
781 long long i, reps;
782 struct percpu_buffer *buffer = (struct percpu_buffer *)arg;
784 if (!opt_disable_rseq && rseq_register_current_thread())
785 abort();
787 reps = opt_reps;
788 for (i = 0; i < reps; i++) {
789 struct percpu_buffer_node *node;
791 node = this_cpu_buffer_pop(buffer, NULL);
792 if (opt_yield)
793 sched_yield(); /* encourage shuffling */
794 if (node) {
795 if (!this_cpu_buffer_push(buffer, node, NULL)) {
796 /* Should increase buffer size. */
797 abort();
802 printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
803 (int) rseq_gettid(), nr_abort, signals_delivered);
804 if (!opt_disable_rseq && rseq_unregister_current_thread())
805 abort();
807 return NULL;
810 /* Simultaneous modification to a per-cpu buffer from many threads. */
811 void test_percpu_buffer(void)
813 const int num_threads = opt_threads;
814 int i, j, ret;
815 uint64_t sum = 0, expected_sum = 0;
816 struct percpu_buffer buffer;
817 pthread_t test_threads[num_threads];
818 cpu_set_t allowed_cpus;
820 memset(&buffer, 0, sizeof(buffer));
822 /* Generate list entries for every usable cpu. */
823 sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
824 for (i = 0; i < CPU_SETSIZE; i++) {
825 if (!CPU_ISSET(i, &allowed_cpus))
826 continue;
827 /* Worse-case is every item in same CPU. */
828 buffer.c[i].array =
829 malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
830 BUFFER_ITEM_PER_CPU);
831 assert(buffer.c[i].array);
832 buffer.c[i].buflen = CPU_SETSIZE * BUFFER_ITEM_PER_CPU;
833 for (j = 1; j <= BUFFER_ITEM_PER_CPU; j++) {
834 struct percpu_buffer_node *node;
836 expected_sum += j;
839 * We could theoretically put the word-sized
840 * "data" directly in the buffer. However, we
841 * want to model objects that would not fit
842 * within a single word, so allocate an object
843 * for each node.
845 node = malloc(sizeof(*node));
846 assert(node);
847 node->data = j;
848 buffer.c[i].array[j - 1] = node;
849 buffer.c[i].offset++;
853 for (i = 0; i < num_threads; i++) {
854 ret = pthread_create(&test_threads[i], NULL,
855 test_percpu_buffer_thread, &buffer);
856 if (ret) {
857 errno = ret;
858 perror("pthread_create");
859 abort();
863 for (i = 0; i < num_threads; i++) {
864 ret = pthread_join(test_threads[i], NULL);
865 if (ret) {
866 errno = ret;
867 perror("pthread_join");
868 abort();
872 for (i = 0; i < CPU_SETSIZE; i++) {
873 struct percpu_buffer_node *node;
875 if (!CPU_ISSET(i, &allowed_cpus))
876 continue;
878 while ((node = __percpu_buffer_pop(&buffer, i))) {
879 sum += node->data;
880 free(node);
882 free(buffer.c[i].array);
886 * All entries should now be accounted for (unless some external
887 * actor is interfering with our allowed affinity while this
888 * test is running).
890 assert(sum == expected_sum);
893 bool this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
894 struct percpu_memcpy_buffer_node item,
895 int *_cpu)
897 bool result = false;
898 int cpu;
900 for (;;) {
901 intptr_t *targetptr_final, newval_final, offset;
902 char *destptr, *srcptr;
903 size_t copylen;
904 int ret;
906 cpu = rseq_cpu_start();
907 /* Load offset with single-copy atomicity. */
908 offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
909 if (offset == buffer->c[cpu].buflen)
910 break;
911 destptr = (char *)&buffer->c[cpu].array[offset];
912 srcptr = (char *)&item;
913 /* copylen must be <= 4kB. */
914 copylen = sizeof(item);
915 newval_final = offset + 1;
916 targetptr_final = &buffer->c[cpu].offset;
917 if (opt_mb)
918 ret = rseq_cmpeqv_trymemcpy_storev_release(
919 targetptr_final, offset,
920 destptr, srcptr, copylen,
921 newval_final, cpu);
922 else
923 ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
924 offset, destptr, srcptr, copylen,
925 newval_final, cpu);
926 if (rseq_likely(!ret)) {
927 result = true;
928 break;
930 /* Retry if comparison fails or rseq aborts. */
932 if (_cpu)
933 *_cpu = cpu;
934 return result;
937 bool this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
938 struct percpu_memcpy_buffer_node *item,
939 int *_cpu)
941 bool result = false;
942 int cpu;
944 for (;;) {
945 intptr_t *targetptr_final, newval_final, offset;
946 char *destptr, *srcptr;
947 size_t copylen;
948 int ret;
950 cpu = rseq_cpu_start();
951 /* Load offset with single-copy atomicity. */
952 offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
953 if (offset == 0)
954 break;
955 destptr = (char *)item;
956 srcptr = (char *)&buffer->c[cpu].array[offset - 1];
957 /* copylen must be <= 4kB. */
958 copylen = sizeof(*item);
959 newval_final = offset - 1;
960 targetptr_final = &buffer->c[cpu].offset;
961 ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
962 offset, destptr, srcptr, copylen,
963 newval_final, cpu);
964 if (rseq_likely(!ret)) {
965 result = true;
966 break;
968 /* Retry if comparison fails or rseq aborts. */
970 if (_cpu)
971 *_cpu = cpu;
972 return result;
976 * __percpu_memcpy_buffer_pop is not safe against concurrent accesses. Should
977 * only be used on buffers that are not concurrently modified.
979 bool __percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
980 struct percpu_memcpy_buffer_node *item,
981 int cpu)
983 intptr_t offset;
985 offset = buffer->c[cpu].offset;
986 if (offset == 0)
987 return false;
988 memcpy(item, &buffer->c[cpu].array[offset - 1], sizeof(*item));
989 buffer->c[cpu].offset = offset - 1;
990 return true;
993 void *test_percpu_memcpy_buffer_thread(void *arg)
995 long long i, reps;
996 struct percpu_memcpy_buffer *buffer = (struct percpu_memcpy_buffer *)arg;
998 if (!opt_disable_rseq && rseq_register_current_thread())
999 abort();
1001 reps = opt_reps;
1002 for (i = 0; i < reps; i++) {
1003 struct percpu_memcpy_buffer_node item;
1004 bool result;
1006 result = this_cpu_memcpy_buffer_pop(buffer, &item, NULL);
1007 if (opt_yield)
1008 sched_yield(); /* encourage shuffling */
1009 if (result) {
1010 if (!this_cpu_memcpy_buffer_push(buffer, item, NULL)) {
1011 /* Should increase buffer size. */
1012 abort();
1017 printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
1018 (int) rseq_gettid(), nr_abort, signals_delivered);
1019 if (!opt_disable_rseq && rseq_unregister_current_thread())
1020 abort();
1022 return NULL;
1025 /* Simultaneous modification to a per-cpu buffer from many threads. */
1026 void test_percpu_memcpy_buffer(void)
1028 const int num_threads = opt_threads;
1029 int i, j, ret;
1030 uint64_t sum = 0, expected_sum = 0;
1031 struct percpu_memcpy_buffer buffer;
1032 pthread_t test_threads[num_threads];
1033 cpu_set_t allowed_cpus;
1035 memset(&buffer, 0, sizeof(buffer));
1037 /* Generate list entries for every usable cpu. */
1038 sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
1039 for (i = 0; i < CPU_SETSIZE; i++) {
1040 if (!CPU_ISSET(i, &allowed_cpus))
1041 continue;
1042 /* Worse-case is every item in same CPU. */
1043 buffer.c[i].array =
1044 malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
1045 MEMCPY_BUFFER_ITEM_PER_CPU);
1046 assert(buffer.c[i].array);
1047 buffer.c[i].buflen = CPU_SETSIZE * MEMCPY_BUFFER_ITEM_PER_CPU;
1048 for (j = 1; j <= MEMCPY_BUFFER_ITEM_PER_CPU; j++) {
1049 expected_sum += 2 * j + 1;
1052 * We could theoretically put the word-sized
1053 * "data" directly in the buffer. However, we
1054 * want to model objects that would not fit
1055 * within a single word, so allocate an object
1056 * for each node.
1058 buffer.c[i].array[j - 1].data1 = j;
1059 buffer.c[i].array[j - 1].data2 = j + 1;
1060 buffer.c[i].offset++;
1064 for (i = 0; i < num_threads; i++) {
1065 ret = pthread_create(&test_threads[i], NULL,
1066 test_percpu_memcpy_buffer_thread,
1067 &buffer);
1068 if (ret) {
1069 errno = ret;
1070 perror("pthread_create");
1071 abort();
1075 for (i = 0; i < num_threads; i++) {
1076 ret = pthread_join(test_threads[i], NULL);
1077 if (ret) {
1078 errno = ret;
1079 perror("pthread_join");
1080 abort();
1084 for (i = 0; i < CPU_SETSIZE; i++) {
1085 struct percpu_memcpy_buffer_node item;
1087 if (!CPU_ISSET(i, &allowed_cpus))
1088 continue;
1090 while (__percpu_memcpy_buffer_pop(&buffer, &item, i)) {
1091 sum += item.data1;
1092 sum += item.data2;
1094 free(buffer.c[i].array);
1098 * All entries should now be accounted for (unless some external
1099 * actor is interfering with our allowed affinity while this
1100 * test is running).
1102 assert(sum == expected_sum);
1105 static void test_signal_interrupt_handler(int signo)
1107 signals_delivered++;
1110 static int set_signal_handler(void)
1112 int ret = 0;
1113 struct sigaction sa;
1114 sigset_t sigset;
1116 ret = sigemptyset(&sigset);
1117 if (ret < 0) {
1118 perror("sigemptyset");
1119 return ret;
1122 sa.sa_handler = test_signal_interrupt_handler;
1123 sa.sa_mask = sigset;
1124 sa.sa_flags = 0;
1125 ret = sigaction(SIGUSR1, &sa, NULL);
1126 if (ret < 0) {
1127 perror("sigaction");
1128 return ret;
1131 printf_verbose("Signal handler set for SIGUSR1\n");
1133 return ret;
1136 /* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
1137 #ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
1138 struct test_membarrier_thread_args {
1139 int stop;
1140 intptr_t percpu_list_ptr;
1143 /* Worker threads modify data in their "active" percpu lists. */
1144 void *test_membarrier_worker_thread(void *arg)
1146 struct test_membarrier_thread_args *args =
1147 (struct test_membarrier_thread_args *)arg;
1148 const int iters = opt_reps;
1149 int i;
1151 if (rseq_register_current_thread()) {
1152 fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1153 errno, strerror(errno));
1154 abort();
1157 /* Wait for initialization. */
1158 while (!atomic_load(&args->percpu_list_ptr)) {}
1160 for (i = 0; i < iters; ++i) {
1161 int ret;
1163 do {
1164 int cpu = rseq_cpu_start();
1166 ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
1167 sizeof(struct percpu_list_entry) * cpu, 1, cpu);
1168 } while (rseq_unlikely(ret));
1171 if (rseq_unregister_current_thread()) {
1172 fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1173 errno, strerror(errno));
1174 abort();
1176 return NULL;
1179 void test_membarrier_init_percpu_list(struct percpu_list *list)
1181 int i;
1183 memset(list, 0, sizeof(*list));
1184 for (i = 0; i < CPU_SETSIZE; i++) {
1185 struct percpu_list_node *node;
1187 node = malloc(sizeof(*node));
1188 assert(node);
1189 node->data = 0;
1190 node->next = NULL;
1191 list->c[i].head = node;
1195 void test_membarrier_free_percpu_list(struct percpu_list *list)
1197 int i;
1199 for (i = 0; i < CPU_SETSIZE; i++)
1200 free(list->c[i].head);
1203 static int sys_membarrier(int cmd, int flags, int cpu_id)
1205 return syscall(__NR_membarrier, cmd, flags, cpu_id);
1209 * The manager thread swaps per-cpu lists that worker threads see,
1210 * and validates that there are no unexpected modifications.
1212 void *test_membarrier_manager_thread(void *arg)
1214 struct test_membarrier_thread_args *args =
1215 (struct test_membarrier_thread_args *)arg;
1216 struct percpu_list list_a, list_b;
1217 intptr_t expect_a = 0, expect_b = 0;
1218 int cpu_a = 0, cpu_b = 0;
1220 if (rseq_register_current_thread()) {
1221 fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1222 errno, strerror(errno));
1223 abort();
1226 /* Init lists. */
1227 test_membarrier_init_percpu_list(&list_a);
1228 test_membarrier_init_percpu_list(&list_b);
1230 atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1232 while (!atomic_load(&args->stop)) {
1233 /* list_a is "active". */
1234 cpu_a = rand() % CPU_SETSIZE;
1236 * As list_b is "inactive", we should never see changes
1237 * to list_b.
1239 if (expect_b != atomic_load(&list_b.c[cpu_b].head->data)) {
1240 fprintf(stderr, "Membarrier test failed\n");
1241 abort();
1244 /* Make list_b "active". */
1245 atomic_store(&args->percpu_list_ptr, (intptr_t)&list_b);
1246 if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1247 MEMBARRIER_CMD_FLAG_CPU, cpu_a) &&
1248 errno != ENXIO /* missing CPU */) {
1249 perror("sys_membarrier");
1250 abort();
1253 * Cpu A should now only modify list_b, so the values
1254 * in list_a should be stable.
1256 expect_a = atomic_load(&list_a.c[cpu_a].head->data);
1258 cpu_b = rand() % CPU_SETSIZE;
1260 * As list_a is "inactive", we should never see changes
1261 * to list_a.
1263 if (expect_a != atomic_load(&list_a.c[cpu_a].head->data)) {
1264 fprintf(stderr, "Membarrier test failed\n");
1265 abort();
1268 /* Make list_a "active". */
1269 atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1270 if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1271 MEMBARRIER_CMD_FLAG_CPU, cpu_b) &&
1272 errno != ENXIO /* missing CPU*/) {
1273 perror("sys_membarrier");
1274 abort();
1276 /* Remember a value from list_b. */
1277 expect_b = atomic_load(&list_b.c[cpu_b].head->data);
1280 test_membarrier_free_percpu_list(&list_a);
1281 test_membarrier_free_percpu_list(&list_b);
1283 if (rseq_unregister_current_thread()) {
1284 fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1285 errno, strerror(errno));
1286 abort();
1288 return NULL;
1291 void test_membarrier(void)
1293 const int num_threads = opt_threads;
1294 struct test_membarrier_thread_args thread_args;
1295 pthread_t worker_threads[num_threads];
1296 pthread_t manager_thread;
1297 int i, ret;
1299 if (sys_membarrier(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ, 0, 0)) {
1300 perror("sys_membarrier");
1301 abort();
1304 thread_args.stop = 0;
1305 thread_args.percpu_list_ptr = 0;
1306 ret = pthread_create(&manager_thread, NULL,
1307 test_membarrier_manager_thread, &thread_args);
1308 if (ret) {
1309 errno = ret;
1310 perror("pthread_create");
1311 abort();
1314 for (i = 0; i < num_threads; i++) {
1315 ret = pthread_create(&worker_threads[i], NULL,
1316 test_membarrier_worker_thread, &thread_args);
1317 if (ret) {
1318 errno = ret;
1319 perror("pthread_create");
1320 abort();
1325 for (i = 0; i < num_threads; i++) {
1326 ret = pthread_join(worker_threads[i], NULL);
1327 if (ret) {
1328 errno = ret;
1329 perror("pthread_join");
1330 abort();
1334 atomic_store(&thread_args.stop, 1);
1335 ret = pthread_join(manager_thread, NULL);
1336 if (ret) {
1337 errno = ret;
1338 perror("pthread_join");
1339 abort();
1342 #else /* RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV */
1343 void test_membarrier(void)
1345 fprintf(stderr, "rseq_offset_deref_addv is not implemented on this architecture. "
1346 "Skipping membarrier test.\n");
1348 #endif
1350 static void show_usage(int argc, char **argv)
1352 printf("Usage : %s <OPTIONS>\n",
1353 argv[0]);
1354 printf("OPTIONS:\n");
1355 printf(" [-1 loops] Number of loops for delay injection 1\n");
1356 printf(" [-2 loops] Number of loops for delay injection 2\n");
1357 printf(" [-3 loops] Number of loops for delay injection 3\n");
1358 printf(" [-4 loops] Number of loops for delay injection 4\n");
1359 printf(" [-5 loops] Number of loops for delay injection 5\n");
1360 printf(" [-6 loops] Number of loops for delay injection 6\n");
1361 printf(" [-7 loops] Number of loops for delay injection 7 (-1 to enable -m)\n");
1362 printf(" [-8 loops] Number of loops for delay injection 8 (-1 to enable -m)\n");
1363 printf(" [-9 loops] Number of loops for delay injection 9 (-1 to enable -m)\n");
1364 printf(" [-m N] Yield/sleep/kill every modulo N (default 0: disabled) (>= 0)\n");
1365 printf(" [-y] Yield\n");
1366 printf(" [-k] Kill thread with signal\n");
1367 printf(" [-s S] S: =0: disabled (default), >0: sleep time (ms)\n");
1368 printf(" [-t N] Number of threads (default 200)\n");
1369 printf(" [-r N] Number of repetitions per thread (default 5000)\n");
1370 printf(" [-d] Disable rseq system call (no initialization)\n");
1371 printf(" [-D M] Disable rseq for each M threads\n");
1372 printf(" [-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement, membarrie(r)\n");
1373 printf(" [-M] Push into buffer and memcpy buffer with memory barriers.\n");
1374 printf(" [-v] Verbose output.\n");
1375 printf(" [-h] Show this help.\n");
1376 printf("\n");
1379 int main(int argc, char **argv)
1381 int i;
1383 for (i = 1; i < argc; i++) {
1384 if (argv[i][0] != '-')
1385 continue;
1386 switch (argv[i][1]) {
1387 case '1':
1388 case '2':
1389 case '3':
1390 case '4':
1391 case '5':
1392 case '6':
1393 case '7':
1394 case '8':
1395 case '9':
1396 if (argc < i + 2) {
1397 show_usage(argc, argv);
1398 goto error;
1400 loop_cnt[argv[i][1] - '0'] = atol(argv[i + 1]);
1401 i++;
1402 break;
1403 case 'm':
1404 if (argc < i + 2) {
1405 show_usage(argc, argv);
1406 goto error;
1408 opt_modulo = atol(argv[i + 1]);
1409 if (opt_modulo < 0) {
1410 show_usage(argc, argv);
1411 goto error;
1413 i++;
1414 break;
1415 case 's':
1416 if (argc < i + 2) {
1417 show_usage(argc, argv);
1418 goto error;
1420 opt_sleep = atol(argv[i + 1]);
1421 if (opt_sleep < 0) {
1422 show_usage(argc, argv);
1423 goto error;
1425 i++;
1426 break;
1427 case 'y':
1428 opt_yield = 1;
1429 break;
1430 case 'k':
1431 opt_signal = 1;
1432 break;
1433 case 'd':
1434 opt_disable_rseq = 1;
1435 break;
1436 case 'D':
1437 if (argc < i + 2) {
1438 show_usage(argc, argv);
1439 goto error;
1441 opt_disable_mod = atol(argv[i + 1]);
1442 if (opt_disable_mod < 0) {
1443 show_usage(argc, argv);
1444 goto error;
1446 i++;
1447 break;
1448 case 't':
1449 if (argc < i + 2) {
1450 show_usage(argc, argv);
1451 goto error;
1453 opt_threads = atol(argv[i + 1]);
1454 if (opt_threads < 0) {
1455 show_usage(argc, argv);
1456 goto error;
1458 i++;
1459 break;
1460 case 'r':
1461 if (argc < i + 2) {
1462 show_usage(argc, argv);
1463 goto error;
1465 opt_reps = atoll(argv[i + 1]);
1466 if (opt_reps < 0) {
1467 show_usage(argc, argv);
1468 goto error;
1470 i++;
1471 break;
1472 case 'h':
1473 show_usage(argc, argv);
1474 goto end;
1475 case 'T':
1476 if (argc < i + 2) {
1477 show_usage(argc, argv);
1478 goto error;
1480 opt_test = *argv[i + 1];
1481 switch (opt_test) {
1482 case 's':
1483 case 'l':
1484 case 'i':
1485 case 'b':
1486 case 'm':
1487 case 'r':
1488 break;
1489 default:
1490 show_usage(argc, argv);
1491 goto error;
1493 i++;
1494 break;
1495 case 'v':
1496 verbose = 1;
1497 break;
1498 case 'M':
1499 opt_mb = 1;
1500 break;
1501 default:
1502 show_usage(argc, argv);
1503 goto error;
1507 loop_cnt_1 = loop_cnt[1];
1508 loop_cnt_2 = loop_cnt[2];
1509 loop_cnt_3 = loop_cnt[3];
1510 loop_cnt_4 = loop_cnt[4];
1511 loop_cnt_5 = loop_cnt[5];
1512 loop_cnt_6 = loop_cnt[6];
1514 if (set_signal_handler())
1515 goto error;
1517 if (!opt_disable_rseq && rseq_register_current_thread())
1518 goto error;
1519 switch (opt_test) {
1520 case 's':
1521 printf_verbose("spinlock\n");
1522 test_percpu_spinlock();
1523 break;
1524 case 'l':
1525 printf_verbose("linked list\n");
1526 test_percpu_list();
1527 break;
1528 case 'b':
1529 printf_verbose("buffer\n");
1530 test_percpu_buffer();
1531 break;
1532 case 'm':
1533 printf_verbose("memcpy buffer\n");
1534 test_percpu_memcpy_buffer();
1535 break;
1536 case 'i':
1537 printf_verbose("counter increment\n");
1538 test_percpu_inc();
1539 break;
1540 case 'r':
1541 printf_verbose("membarrier\n");
1542 test_membarrier();
1543 break;
1545 if (!opt_disable_rseq && rseq_unregister_current_thread())
1546 abort();
1547 end:
1548 return 0;
1550 error:
1551 return -1;