Darren Hart | 2aa8470 | 2015-05-12 21:07:52 -0700 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Copyright © International Business Machines Corp., 2006-2008 |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * DESCRIPTION |
| 11 | * This test exercises the futex_wait_requeue_pi() signal handling both |
| 12 | * before and after the requeue. The first should be restarted by the |
| 13 | * kernel. The latter should return EWOULDBLOCK to the waiter. |
| 14 | * |
| 15 | * AUTHORS |
| 16 | * Darren Hart <dvhart@linux.intel.com> |
| 17 | * |
| 18 | * HISTORY |
| 19 | * 2008-May-5: Initial version by Darren Hart <dvhart@linux.intel.com> |
| 20 | * |
| 21 | *****************************************************************************/ |
| 22 | |
| 23 | #include <errno.h> |
| 24 | #include <getopt.h> |
| 25 | #include <limits.h> |
| 26 | #include <pthread.h> |
| 27 | #include <signal.h> |
| 28 | #include <stdio.h> |
| 29 | #include <stdlib.h> |
| 30 | #include <string.h> |
| 31 | #include "atomic.h" |
| 32 | #include "futextest.h" |
| 33 | #include "logging.h" |
| 34 | |
| 35 | #define DELAY_US 100 |
| 36 | |
| 37 | futex_t f1 = FUTEX_INITIALIZER; |
| 38 | futex_t f2 = FUTEX_INITIALIZER; |
| 39 | atomic_t requeued = ATOMIC_INITIALIZER; |
| 40 | |
| 41 | int waiter_ret = 0; |
| 42 | |
| 43 | void usage(char *prog) |
| 44 | { |
| 45 | printf("Usage: %s\n", prog); |
| 46 | printf(" -c Use color\n"); |
| 47 | printf(" -h Display this help message\n"); |
| 48 | printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", |
| 49 | VQUIET, VCRITICAL, VINFO); |
| 50 | } |
| 51 | |
| 52 | int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg, |
| 53 | int policy, int prio) |
| 54 | { |
| 55 | struct sched_param schedp; |
| 56 | pthread_attr_t attr; |
| 57 | int ret; |
| 58 | |
| 59 | pthread_attr_init(&attr); |
| 60 | memset(&schedp, 0, sizeof(schedp)); |
| 61 | |
| 62 | ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED); |
| 63 | if (ret) { |
| 64 | error("pthread_attr_setinheritsched\n", ret); |
| 65 | return -1; |
| 66 | } |
| 67 | |
| 68 | ret = pthread_attr_setschedpolicy(&attr, policy); |
| 69 | if (ret) { |
| 70 | error("pthread_attr_setschedpolicy\n", ret); |
| 71 | return -1; |
| 72 | } |
| 73 | |
| 74 | schedp.sched_priority = prio; |
| 75 | ret = pthread_attr_setschedparam(&attr, &schedp); |
| 76 | if (ret) { |
| 77 | error("pthread_attr_setschedparam\n", ret); |
| 78 | return -1; |
| 79 | } |
| 80 | |
| 81 | ret = pthread_create(pth, &attr, func, arg); |
| 82 | if (ret) { |
| 83 | error("pthread_create\n", ret); |
| 84 | return -1; |
| 85 | } |
| 86 | return 0; |
| 87 | } |
| 88 | |
| 89 | void handle_signal(int signo) |
| 90 | { |
| 91 | info("signal received %s requeue\n", |
| 92 | requeued.val ? "after" : "prior to"); |
| 93 | } |
| 94 | |
| 95 | void *waiterfn(void *arg) |
| 96 | { |
| 97 | unsigned int old_val; |
| 98 | int res; |
| 99 | |
| 100 | waiter_ret = RET_PASS; |
| 101 | |
| 102 | info("Waiter running\n"); |
| 103 | info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); |
| 104 | old_val = f1; |
| 105 | res = futex_wait_requeue_pi(&f1, old_val, &(f2), NULL, |
| 106 | FUTEX_PRIVATE_FLAG); |
| 107 | if (!requeued.val || errno != EWOULDBLOCK) { |
| 108 | fail("unexpected return from futex_wait_requeue_pi: %d (%s)\n", |
| 109 | res, strerror(errno)); |
| 110 | info("w2:futex: %x\n", f2); |
| 111 | if (!res) |
| 112 | futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); |
| 113 | waiter_ret = RET_FAIL; |
| 114 | } |
| 115 | |
| 116 | info("Waiter exiting with %d\n", waiter_ret); |
| 117 | pthread_exit(NULL); |
| 118 | } |
| 119 | |
| 120 | |
| 121 | int main(int argc, char *argv[]) |
| 122 | { |
| 123 | unsigned int old_val; |
| 124 | struct sigaction sa; |
| 125 | pthread_t waiter; |
| 126 | int c, res, ret = RET_PASS; |
| 127 | |
| 128 | while ((c = getopt(argc, argv, "chv:")) != -1) { |
| 129 | switch (c) { |
| 130 | case 'c': |
| 131 | log_color(1); |
| 132 | break; |
| 133 | case 'h': |
| 134 | usage(basename(argv[0])); |
| 135 | exit(0); |
| 136 | case 'v': |
| 137 | log_verbosity(atoi(optarg)); |
| 138 | break; |
| 139 | default: |
| 140 | usage(basename(argv[0])); |
| 141 | exit(1); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | printf("%s: Test signal handling during requeue_pi\n", |
| 146 | basename(argv[0])); |
| 147 | printf("\tArguments: <none>\n"); |
| 148 | |
| 149 | sa.sa_handler = handle_signal; |
| 150 | sigemptyset(&sa.sa_mask); |
| 151 | sa.sa_flags = 0; |
| 152 | if (sigaction(SIGUSR1, &sa, NULL)) { |
| 153 | error("sigaction\n", errno); |
| 154 | exit(1); |
| 155 | } |
| 156 | |
| 157 | info("m1:f2: %x\n", f2); |
| 158 | info("Creating waiter\n"); |
| 159 | res = create_rt_thread(&waiter, waiterfn, NULL, SCHED_FIFO, 1); |
| 160 | if (res) { |
| 161 | error("Creating waiting thread failed", res); |
| 162 | ret = RET_ERROR; |
| 163 | goto out; |
| 164 | } |
| 165 | |
| 166 | info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); |
| 167 | info("m2:f2: %x\n", f2); |
| 168 | futex_lock_pi(&f2, 0, 0, FUTEX_PRIVATE_FLAG); |
| 169 | info("m3:f2: %x\n", f2); |
| 170 | |
| 171 | while (1) { |
| 172 | /* |
| 173 | * signal the waiter before requeue, waiter should automatically |
| 174 | * restart futex_wait_requeue_pi() in the kernel. Wait for the |
| 175 | * waiter to block on f1 again. |
| 176 | */ |
| 177 | info("Issuing SIGUSR1 to waiter\n"); |
| 178 | pthread_kill(waiter, SIGUSR1); |
| 179 | usleep(DELAY_US); |
| 180 | |
| 181 | info("Requeueing waiter via FUTEX_CMP_REQUEUE_PI\n"); |
| 182 | old_val = f1; |
| 183 | res = futex_cmp_requeue_pi(&f1, old_val, &(f2), 1, 0, |
| 184 | FUTEX_PRIVATE_FLAG); |
| 185 | /* |
| 186 | * If res is non-zero, we either requeued the waiter or hit an |
| 187 | * error, break out and handle it. If it is zero, then the |
| 188 | * signal may have hit before the the waiter was blocked on f1. |
| 189 | * Try again. |
| 190 | */ |
| 191 | if (res > 0) { |
| 192 | atomic_set(&requeued, 1); |
| 193 | break; |
Darren Hart | fee50f3 | 2015-07-20 15:48:37 -0700 | [diff] [blame] | 194 | } else if (res < 0) { |
Darren Hart | 2aa8470 | 2015-05-12 21:07:52 -0700 | [diff] [blame] | 195 | error("FUTEX_CMP_REQUEUE_PI failed\n", errno); |
| 196 | ret = RET_ERROR; |
| 197 | break; |
| 198 | } |
| 199 | } |
| 200 | info("m4:f2: %x\n", f2); |
| 201 | |
| 202 | /* |
| 203 | * Signal the waiter after requeue, waiter should return from |
| 204 | * futex_wait_requeue_pi() with EWOULDBLOCK. Join the thread here so the |
| 205 | * futex_unlock_pi() can't happen before the signal wakeup is detected |
| 206 | * in the kernel. |
| 207 | */ |
| 208 | info("Issuing SIGUSR1 to waiter\n"); |
| 209 | pthread_kill(waiter, SIGUSR1); |
| 210 | info("Waiting for waiter to return\n"); |
| 211 | pthread_join(waiter, NULL); |
| 212 | |
| 213 | info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n", f2, &f2); |
| 214 | futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); |
| 215 | info("m5:f2: %x\n", f2); |
| 216 | |
| 217 | out: |
| 218 | if (ret == RET_PASS && waiter_ret) |
| 219 | ret = waiter_ret; |
| 220 | |
| 221 | print_result(ret); |
| 222 | return ret; |
| 223 | } |