1 #define JEMALLOC_MUTEX_C_ 2 #include "jemalloc/internal/jemalloc_preamble.h" 3 #include "jemalloc/internal/jemalloc_internal_includes.h" 4 5 #include "jemalloc/internal/assert.h" 6 #include "jemalloc/internal/malloc_io.h" 7 #include "jemalloc/internal/spin.h" 8 9 #ifndef _CRT_SPINCOUNT 10 #define _CRT_SPINCOUNT 4000 11 #endif 12 13 /******************************************************************************/ 14 /* Data. */ 15 16 #ifdef JEMALLOC_LAZY_LOCK 17 bool isthreaded = false; 18 #endif 19 #ifdef JEMALLOC_MUTEX_INIT_CB 20 static bool postpone_init = true; 21 static malloc_mutex_t *postponed_mutexes = NULL; 22 #endif 23 24 /******************************************************************************/ 25 /* 26 * We intercept pthread_create() calls in order to toggle isthreaded if the 27 * process goes multi-threaded. 28 */ 29 30 #if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32) 31 JEMALLOC_EXPORT int 32 pthread_create(pthread_t *__restrict thread, 33 const pthread_attr_t *__restrict attr, void *(*start_routine)(void *), 34 void *__restrict arg) { 35 return pthread_create_wrapper(thread, attr, start_routine, arg); 36 } 37 #endif 38 39 /******************************************************************************/ 40 41 #ifdef JEMALLOC_MUTEX_INIT_CB 42 JEMALLOC_EXPORT int _pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex, 43 void *(calloc_cb)(size_t, size_t)); 44 45 #pragma weak _pthread_mutex_init_calloc_cb 46 int 47 _pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex, 48 void *(calloc_cb)(size_t, size_t)) 49 { 50 51 return (((int (*)(pthread_mutex_t *, void *(*)(size_t, size_t))) 52 __libc_interposing[INTERPOS__pthread_mutex_init_calloc_cb])(mutex, 53 calloc_cb)); 54 } 55 #endif 56 57 void 58 malloc_mutex_lock_slow(malloc_mutex_t *mutex) { 59 mutex_prof_data_t *data = &mutex->prof_data; 60 UNUSED nstime_t before = NSTIME_ZERO_INITIALIZER; 61 62 if (ncpus == 1) { 63 goto label_spin_done; 64 } 65 66 int cnt = 0, max_cnt = MALLOC_MUTEX_MAX_SPIN; 67 do { 68 spin_cpu_spinwait(); 69 if (!malloc_mutex_trylock_final(mutex)) { 70 data->n_spin_acquired++; 71 return; 72 } 73 } while (cnt++ < max_cnt); 74 75 if (!config_stats) { 76 /* Only spin is useful when stats is off. */ 77 malloc_mutex_lock_final(mutex); 78 return; 79 } 80 label_spin_done: 81 nstime_update(&before); 82 /* Copy before to after to avoid clock skews. */ 83 nstime_t after; 84 nstime_copy(&after, &before); 85 uint32_t n_thds = atomic_fetch_add_u32(&data->n_waiting_thds, 1, 86 ATOMIC_RELAXED) + 1; 87 /* One last try as above two calls may take quite some cycles. */ 88 if (!malloc_mutex_trylock_final(mutex)) { 89 atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); 90 data->n_spin_acquired++; 91 return; 92 } 93 94 /* True slow path. */ 95 malloc_mutex_lock_final(mutex); 96 /* Update more slow-path only counters. */ 97 atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); 98 nstime_update(&after); 99 100 nstime_t delta; 101 nstime_copy(&delta, &after); 102 nstime_subtract(&delta, &before); 103 104 data->n_wait_times++; 105 nstime_add(&data->tot_wait_time, &delta); 106 if (nstime_compare(&data->max_wait_time, &delta) < 0) { 107 nstime_copy(&data->max_wait_time, &delta); 108 } 109 if (n_thds > data->max_n_thds) { 110 data->max_n_thds = n_thds; 111 } 112 } 113 114 static void 115 mutex_prof_data_init(mutex_prof_data_t *data) { 116 memset(data, 0, sizeof(mutex_prof_data_t)); 117 nstime_init(&data->max_wait_time, 0); 118 nstime_init(&data->tot_wait_time, 0); 119 data->prev_owner = NULL; 120 } 121 122 void 123 malloc_mutex_prof_data_reset(tsdn_t *tsdn, malloc_mutex_t *mutex) { 124 malloc_mutex_assert_owner(tsdn, mutex); 125 mutex_prof_data_init(&mutex->prof_data); 126 } 127 128 static int 129 mutex_addr_comp(const witness_t *witness1, void *mutex1, 130 const witness_t *witness2, void *mutex2) { 131 assert(mutex1 != NULL); 132 assert(mutex2 != NULL); 133 uintptr_t mu1int = (uintptr_t)mutex1; 134 uintptr_t mu2int = (uintptr_t)mutex2; 135 if (mu1int < mu2int) { 136 return -1; 137 } else if (mu1int == mu2int) { 138 return 0; 139 } else { 140 return 1; 141 } 142 } 143 144 bool 145 malloc_mutex_first_thread(void) { 146 147 #ifndef JEMALLOC_MUTEX_INIT_CB 148 return (malloc_mutex_first_thread()); 149 #else 150 return (false); 151 #endif 152 } 153 154 bool 155 malloc_mutex_init(malloc_mutex_t *mutex, const char *name, 156 witness_rank_t rank, malloc_mutex_lock_order_t lock_order) { 157 mutex_prof_data_init(&mutex->prof_data); 158 #ifdef _WIN32 159 # if _WIN32_WINNT >= 0x0600 160 InitializeSRWLock(&mutex->lock); 161 # else 162 if (!InitializeCriticalSectionAndSpinCount(&mutex->lock, 163 _CRT_SPINCOUNT)) { 164 return true; 165 } 166 # endif 167 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK)) 168 mutex->lock = OS_UNFAIR_LOCK_INIT; 169 #elif (defined(JEMALLOC_OSSPIN)) 170 mutex->lock = 0; 171 #elif (defined(JEMALLOC_MUTEX_INIT_CB)) 172 if (postpone_init) { 173 mutex->postponed_next = postponed_mutexes; 174 postponed_mutexes = mutex; 175 } else { 176 if (_pthread_mutex_init_calloc_cb(&mutex->lock, 177 bootstrap_calloc) != 0) { 178 return true; 179 } 180 } 181 #else 182 pthread_mutexattr_t attr; 183 184 if (pthread_mutexattr_init(&attr) != 0) { 185 return true; 186 } 187 pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE); 188 if (pthread_mutex_init(&mutex->lock, &attr) != 0) { 189 pthread_mutexattr_destroy(&attr); 190 return true; 191 } 192 pthread_mutexattr_destroy(&attr); 193 #endif 194 if (config_debug) { 195 mutex->lock_order = lock_order; 196 if (lock_order == malloc_mutex_address_ordered) { 197 witness_init(&mutex->witness, name, rank, 198 mutex_addr_comp, mutex); 199 } else { 200 witness_init(&mutex->witness, name, rank, NULL, NULL); 201 } 202 } 203 return false; 204 } 205 206 void 207 malloc_mutex_prefork(tsdn_t *tsdn, malloc_mutex_t *mutex) { 208 malloc_mutex_lock(tsdn, mutex); 209 } 210 211 void 212 malloc_mutex_postfork_parent(tsdn_t *tsdn, malloc_mutex_t *mutex) { 213 malloc_mutex_unlock(tsdn, mutex); 214 } 215 216 void 217 malloc_mutex_postfork_child(tsdn_t *tsdn, malloc_mutex_t *mutex) { 218 #ifdef JEMALLOC_MUTEX_INIT_CB 219 malloc_mutex_unlock(tsdn, mutex); 220 #else 221 if (malloc_mutex_init(mutex, mutex->witness.name, 222 mutex->witness.rank, mutex->lock_order)) { 223 malloc_printf("<jemalloc>: Error re-initializing mutex in " 224 "child\n"); 225 if (opt_abort) { 226 abort(); 227 } 228 } 229 #endif 230 } 231 232 bool 233 malloc_mutex_boot(void) { 234 #ifdef JEMALLOC_MUTEX_INIT_CB 235 postpone_init = false; 236 while (postponed_mutexes != NULL) { 237 if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock, 238 bootstrap_calloc) != 0) { 239 return true; 240 } 241 postponed_mutexes = postponed_mutexes->postponed_next; 242 } 243 #endif 244 return false; 245 } 246