1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright 2018 Joyent, Inc. 14 */ 15 16 /* 17 * All we're doing is constantly modifying a thread name while DTrace is 18 * watching us, making sure we don't break. 19 */ 20 21 #include <sys/fcntl.h> 22 #include <pthread.h> 23 #include <stdlib.h> 24 #include <stdio.h> 25 26 #define NR_THREADS (100) 27 #define RUNTIME (30) /* seconds */ 28 29 static void 30 random_ascii(char *buf, size_t bufsize) 31 { 32 char table[] = "abcdefghijklmnopqrstuvwxyz" 33 "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 ,.-#'?!"; 34 size_t len = rand() % bufsize; 35 36 bzero(buf, bufsize); 37 38 for (size_t i = 0; i < len; i++) { 39 buf[i] = table[rand() % (sizeof (table) - 1)]; 40 } 41 } 42 43 static void 44 busy() 45 { 46 struct timeval tv1; 47 struct timeval tv2; 48 49 if (gettimeofday(&tv1, NULL) != 0) 50 abort(); 51 52 for (;;) { 53 static volatile int i; 54 for (i = 0; i < 2000000; i++) 55 ; 56 57 if (gettimeofday(&tv2, NULL) != 0) 58 abort(); 59 60 /* janky, but we don't care */ 61 if (tv2.tv_sec != tv1.tv_sec) 62 return; 63 } 64 } 65 66 static void * 67 thread(void *arg) 68 { 69 char name[PTHREAD_MAX_NAMELEN_NP]; 70 71 for (size_t i = 0; ; i++) { 72 random_ascii(name, sizeof (name)); 73 74 if ((i % 100) == 0) { 75 if (pthread_setname_np(pthread_self(), NULL) != 0) 76 abort(); 77 } else { 78 (void) pthread_setname_np(pthread_self(), name); 79 } 80 81 busy(); 82 } 83 84 return (NULL); 85 } 86 87 int 88 main(int argc, char **argv) 89 { 90 pthread_t tids[NR_THREADS]; 91 92 for (size_t i = 0; i < NR_THREADS; i++) { 93 if (pthread_create(&tids[i], NULL, thread, NULL) != 0) 94 exit(EXIT_FAILURE); 95 } 96 97 sleep(RUNTIME); 98 exit(EXIT_SUCCESS); 99 } 100