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