1 /* $NetBSD: thread.c,v 1.3 2025/01/26 16:25:39 christos Exp $ */ 2 3 /* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 7 * 8 * This Source Code Form is subject to the terms of the Mozilla Public 9 * License, v. 2.0. If a copy of the MPL was not distributed with this 10 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11 * 12 * See the COPYRIGHT file distributed with this work for additional 13 * information regarding copyright ownership. 14 */ 15 16 /*! \file */ 17 18 #if defined(HAVE_SCHED_H) 19 #include <sched.h> 20 #endif /* if defined(HAVE_SCHED_H) */ 21 22 #if defined(HAVE_CPUSET_H) 23 #include <sys/cpuset.h> 24 #include <sys/param.h> 25 #endif /* if defined(HAVE_CPUSET_H) */ 26 27 #if defined(HAVE_SYS_PROCSET_H) 28 #include <sys/processor.h> 29 #include <sys/procset.h> 30 #include <sys/types.h> 31 #endif /* if defined(HAVE_SYS_PROCSET_H) */ 32 33 #include <stdlib.h> 34 35 #include <isc/atomic.h> 36 #include <isc/iterated_hash.h> 37 #include <isc/strerr.h> 38 #include <isc/thread.h> 39 #include <isc/tid.h> 40 #include <isc/urcu.h> 41 #include <isc/util.h> 42 43 #ifndef THREAD_MINSTACKSIZE 44 #define THREAD_MINSTACKSIZE (1024U * 1024) 45 #endif /* ifndef THREAD_MINSTACKSIZE */ 46 47 /* 48 * We can't use isc_mem API here, because it's called too early and the 49 * isc_mem_debugging flags can be changed later causing mismatch between flags 50 * used for isc_mem_get() and isc_mem_put(). 51 */ 52 53 struct thread_wrap { 54 struct rcu_head rcu_head; 55 isc_threadfunc_t func; 56 void *arg; 57 }; 58 59 static struct thread_wrap * 60 thread_wrap(isc_threadfunc_t func, void *arg) { 61 struct thread_wrap *wrap = malloc(sizeof(*wrap)); 62 RUNTIME_CHECK(wrap != NULL); 63 *wrap = (struct thread_wrap){ 64 .func = func, 65 .arg = arg, 66 }; 67 return wrap; 68 } 69 70 static void * 71 thread_body(struct thread_wrap *wrap) { 72 isc_threadfunc_t func = wrap->func; 73 void *arg = wrap->arg; 74 void *ret = NULL; 75 76 /* 77 * Every thread starts with a malloc() call to prevent memory bloat 78 * caused by a jemalloc quirk. We use CMM_ACCESS_ONCE() To stop an 79 * optimizing compiler from stripping out free(malloc(1)). 80 */ 81 void *jemalloc_enforce_init = NULL; 82 CMM_ACCESS_ONCE(jemalloc_enforce_init) = malloc(1); 83 free(jemalloc_enforce_init); 84 85 free(wrap); 86 87 ret = func(arg); 88 89 return ret; 90 } 91 92 static void * 93 thread_run(void *wrap) { 94 /* 95 * Get a thread-local digest context only in new threads. 96 * The main thread is handled by isc__initialize(). 97 */ 98 isc__iterated_hash_initialize(); 99 100 rcu_register_thread(); 101 102 void *ret = thread_body(wrap); 103 104 isc__iterated_hash_shutdown(); 105 106 rcu_unregister_thread(); 107 108 return ret; 109 } 110 111 void 112 isc_thread_main(isc_threadfunc_t func, void *arg) { 113 /* 114 * Either this thread has not yet been started, so it can become the 115 * main thread, or it has already been annointed as the chosen zero 116 */ 117 REQUIRE(isc_tid() == ISC_TID_UNKNOWN || isc_tid() == 0); 118 thread_body(thread_wrap(func, arg)); 119 } 120 121 void 122 isc_thread_create(isc_threadfunc_t func, void *arg, isc_thread_t *thread) { 123 int ret; 124 pthread_attr_t attr; 125 126 pthread_attr_init(&attr); 127 128 #if defined(HAVE_PTHREAD_ATTR_GETSTACKSIZE) && \ 129 defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE) 130 size_t stacksize; 131 ret = pthread_attr_getstacksize(&attr, &stacksize); 132 PTHREADS_RUNTIME_CHECK(pthread_attr_getstacksize, ret); 133 134 if (stacksize < THREAD_MINSTACKSIZE) { 135 ret = pthread_attr_setstacksize(&attr, THREAD_MINSTACKSIZE); 136 PTHREADS_RUNTIME_CHECK(pthread_attr_setstacksize, ret); 137 } 138 #endif /* if defined(HAVE_PTHREAD_ATTR_GETSTACKSIZE) && \ 139 * defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE) */ 140 141 ret = pthread_create(thread, &attr, thread_run, thread_wrap(func, arg)); 142 PTHREADS_RUNTIME_CHECK(pthread_create, ret); 143 144 pthread_attr_destroy(&attr); 145 } 146 147 void 148 isc_thread_join(isc_thread_t thread, void **resultp) { 149 int ret = pthread_join(thread, resultp); 150 151 PTHREADS_RUNTIME_CHECK(pthread_join, ret); 152 } 153 154 void 155 isc_thread_setname(isc_thread_t thread, const char *name) { 156 #if defined(HAVE_PTHREAD_SETNAME_NP) && !defined(__APPLE__) 157 /* 158 * macOS has pthread_setname_np but only works on the 159 * current thread so it's not used here 160 */ 161 #if defined(__NetBSD__) 162 (void)pthread_setname_np(thread, name, NULL); 163 #else /* if defined(__NetBSD__) */ 164 (void)pthread_setname_np(thread, name); 165 #endif /* if defined(__NetBSD__) */ 166 #elif defined(HAVE_PTHREAD_SET_NAME_NP) 167 (void)pthread_set_name_np(thread, name); 168 #else /* if defined(HAVE_PTHREAD_SETNAME_NP) && !defined(__APPLE__) */ 169 UNUSED(thread); 170 UNUSED(name); 171 #endif /* if defined(HAVE_PTHREAD_SETNAME_NP) && !defined(__APPLE__) */ 172 } 173 174 void 175 isc_thread_yield(void) { 176 #if defined(HAVE_SCHED_YIELD) 177 sched_yield(); 178 #elif defined(HAVE_PTHREAD_YIELD) 179 pthread_yield(); 180 #elif defined(HAVE_PTHREAD_YIELD_NP) 181 pthread_yield_np(); 182 #endif /* if defined(HAVE_SCHED_YIELD) */ 183 } 184