1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /****************************************************************************** 3 * 4 * Copyright © International Business Machines Corp., 2009 5 * 6 * DESCRIPTION 7 * Block on a futex and wait for timeout. 8 * 9 * AUTHOR 10 * Darren Hart <dvhart@linux.intel.com> 11 * 12 * HISTORY 13 * 2009-Nov-6: Initial version by Darren Hart <dvhart@linux.intel.com> 14 * 2021-Apr-26: More test cases by André Almeida <andrealmeid@collabora.com> 15 * 16 *****************************************************************************/ 17 18 #include <pthread.h> 19 #include "futextest.h" 20 #include "futex2test.h" 21 #include "logging.h" 22 23 #define TEST_NAME "futex-wait-timeout" 24 25 static long timeout_ns = 100000; /* 100us default timeout */ 26 static futex_t futex_pi; 27 static pthread_barrier_t barrier; 28 29 void usage(char *prog) 30 { 31 printf("Usage: %s\n", prog); 32 printf(" -c Use color\n"); 33 printf(" -h Display this help message\n"); 34 printf(" -t N Timeout in nanoseconds (default: 100,000)\n"); 35 printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", 36 VQUIET, VCRITICAL, VINFO); 37 } 38 39 /* 40 * Get a PI lock and hold it forever, so the main thread lock_pi will block 41 * and we can test the timeout 42 */ 43 void *get_pi_lock(void *arg) 44 { 45 int ret; 46 volatile futex_t lock = 0; 47 48 ret = futex_lock_pi(&futex_pi, NULL, 0, 0); 49 if (ret != 0) 50 error("futex_lock_pi failed\n", ret); 51 52 pthread_barrier_wait(&barrier); 53 54 /* Blocks forever */ 55 ret = futex_wait(&lock, 0, NULL, 0); 56 error("futex_wait failed\n", ret); 57 58 return NULL; 59 } 60 61 /* 62 * Check if the function returned the expected error 63 */ 64 static void test_timeout(int res, int *ret, char *test_name, int err) 65 { 66 if (!res || errno != err) { 67 ksft_test_result_fail("%s returned %d\n", test_name, 68 res < 0 ? errno : res); 69 *ret = RET_FAIL; 70 } else { 71 ksft_test_result_pass("%s succeeds\n", test_name); 72 } 73 } 74 75 /* 76 * Calculate absolute timeout and correct overflow 77 */ 78 static int futex_get_abs_timeout(clockid_t clockid, struct timespec *to, 79 long timeout_ns) 80 { 81 if (clock_gettime(clockid, to)) { 82 error("clock_gettime failed\n", errno); 83 return errno; 84 } 85 86 to->tv_nsec += timeout_ns; 87 88 if (to->tv_nsec >= 1000000000) { 89 to->tv_sec++; 90 to->tv_nsec -= 1000000000; 91 } 92 93 return 0; 94 } 95 96 int main(int argc, char *argv[]) 97 { 98 futex_t f1 = FUTEX_INITIALIZER; 99 int res, ret = RET_PASS; 100 struct timespec to; 101 pthread_t thread; 102 int c; 103 struct futex_waitv waitv = { 104 .uaddr = (uintptr_t)&f1, 105 .val = f1, 106 .flags = FUTEX_32, 107 .__reserved = 0 108 }; 109 110 while ((c = getopt(argc, argv, "cht:v:")) != -1) { 111 switch (c) { 112 case 'c': 113 log_color(1); 114 break; 115 case 'h': 116 usage(basename(argv[0])); 117 exit(0); 118 case 't': 119 timeout_ns = atoi(optarg); 120 break; 121 case 'v': 122 log_verbosity(atoi(optarg)); 123 break; 124 default: 125 usage(basename(argv[0])); 126 exit(1); 127 } 128 } 129 130 ksft_print_header(); 131 ksft_set_plan(9); 132 ksft_print_msg("%s: Block on a futex and wait for timeout\n", 133 basename(argv[0])); 134 ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns); 135 136 pthread_barrier_init(&barrier, NULL, 2); 137 pthread_create(&thread, NULL, get_pi_lock, NULL); 138 139 /* initialize relative timeout */ 140 to.tv_sec = 0; 141 to.tv_nsec = timeout_ns; 142 143 res = futex_wait(&f1, f1, &to, 0); 144 test_timeout(res, &ret, "futex_wait relative", ETIMEDOUT); 145 146 /* FUTEX_WAIT_BITSET with CLOCK_REALTIME */ 147 if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) 148 return RET_FAIL; 149 res = futex_wait_bitset(&f1, f1, &to, 1, FUTEX_CLOCK_REALTIME); 150 test_timeout(res, &ret, "futex_wait_bitset realtime", ETIMEDOUT); 151 152 /* FUTEX_WAIT_BITSET with CLOCK_MONOTONIC */ 153 if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns)) 154 return RET_FAIL; 155 res = futex_wait_bitset(&f1, f1, &to, 1, 0); 156 test_timeout(res, &ret, "futex_wait_bitset monotonic", ETIMEDOUT); 157 158 /* FUTEX_WAIT_REQUEUE_PI with CLOCK_REALTIME */ 159 if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) 160 return RET_FAIL; 161 res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, FUTEX_CLOCK_REALTIME); 162 test_timeout(res, &ret, "futex_wait_requeue_pi realtime", ETIMEDOUT); 163 164 /* FUTEX_WAIT_REQUEUE_PI with CLOCK_MONOTONIC */ 165 if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns)) 166 return RET_FAIL; 167 res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, 0); 168 test_timeout(res, &ret, "futex_wait_requeue_pi monotonic", ETIMEDOUT); 169 170 /* Wait until the other thread calls futex_lock_pi() */ 171 pthread_barrier_wait(&barrier); 172 pthread_barrier_destroy(&barrier); 173 /* 174 * FUTEX_LOCK_PI with CLOCK_REALTIME 175 * Due to historical reasons, FUTEX_LOCK_PI supports only realtime 176 * clock, but requires the caller to not set CLOCK_REALTIME flag. 177 * 178 * If you call FUTEX_LOCK_PI with a monotonic clock, it'll be 179 * interpreted as a realtime clock, and (unless you mess your machine's 180 * time or your time machine) the monotonic clock value is always 181 * smaller than realtime and the syscall will timeout immediately. 182 */ 183 if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) 184 return RET_FAIL; 185 res = futex_lock_pi(&futex_pi, &to, 0, 0); 186 test_timeout(res, &ret, "futex_lock_pi realtime", ETIMEDOUT); 187 188 /* Test operations that don't support FUTEX_CLOCK_REALTIME */ 189 res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME); 190 test_timeout(res, &ret, "futex_lock_pi invalid timeout flag", ENOSYS); 191 192 /* futex_waitv with CLOCK_MONOTONIC */ 193 if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns)) 194 return RET_FAIL; 195 res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC); 196 test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT); 197 198 /* futex_waitv with CLOCK_REALTIME */ 199 if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) 200 return RET_FAIL; 201 res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME); 202 test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT); 203 204 ksft_print_cnts(); 205 return ret; 206 } 207