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 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 (!atomic_load_b(&mutex->locked, ATOMIC_RELAXED) 70 && !malloc_mutex_trylock_final(mutex)) { 71 data->n_spin_acquired++; 72 return; 73 } 74 } while (cnt++ < max_cnt); 75 76 if (!config_stats) { 77 /* Only spin is useful when stats is off. */ 78 malloc_mutex_lock_final(mutex); 79 return; 80 } 81 label_spin_done: 82 nstime_update(&before); 83 /* Copy before to after to avoid clock skews. */ 84 nstime_t after; 85 nstime_copy(&after, &before); 86 uint32_t n_thds = atomic_fetch_add_u32(&data->n_waiting_thds, 1, 87 ATOMIC_RELAXED) + 1; 88 /* One last try as above two calls may take quite some cycles. */ 89 if (!malloc_mutex_trylock_final(mutex)) { 90 atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); 91 data->n_spin_acquired++; 92 return; 93 } 94 95 /* True slow path. */ 96 malloc_mutex_lock_final(mutex); 97 /* Update more slow-path only counters. */ 98 atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); 99 nstime_update(&after); 100 101 nstime_t delta; 102 nstime_copy(&delta, &after); 103 nstime_subtract(&delta, &before); 104 105 data->n_wait_times++; 106 nstime_add(&data->tot_wait_time, &delta); 107 if (nstime_compare(&data->max_wait_time, &delta) < 0) { 108 nstime_copy(&data->max_wait_time, &delta); 109 } 110 if (n_thds > data->max_n_thds) { 111 data->max_n_thds = n_thds; 112 } 113 } 114 115 static void 116 mutex_prof_data_init(mutex_prof_data_t *data) { 117 memset(data, 0, sizeof(mutex_prof_data_t)); 118 nstime_init(&data->max_wait_time, 0); 119 nstime_init(&data->tot_wait_time, 0); 120 data->prev_owner = NULL; 121 } 122 123 void 124 malloc_mutex_prof_data_reset(tsdn_t *tsdn, malloc_mutex_t *mutex) { 125 malloc_mutex_assert_owner(tsdn, mutex); 126 mutex_prof_data_init(&mutex->prof_data); 127 } 128 129 static int 130 mutex_addr_comp(const witness_t *witness1, void *mutex1, 131 const witness_t *witness2, void *mutex2) { 132 assert(mutex1 != NULL); 133 assert(mutex2 != NULL); 134 uintptr_t mu1int = (uintptr_t)mutex1; 135 uintptr_t mu2int = (uintptr_t)mutex2; 136 if (mu1int < mu2int) { 137 return -1; 138 } else if (mu1int == mu2int) { 139 return 0; 140 } else { 141 return 1; 142 } 143 } 144 145 bool 146 malloc_mutex_first_thread(void) { 147 148 #ifndef JEMALLOC_MUTEX_INIT_CB 149 return (malloc_mutex_first_thread()); 150 #else 151 return (false); 152 #endif 153 } 154 155 bool 156 malloc_mutex_init(malloc_mutex_t *mutex, const char *name, 157 witness_rank_t rank, malloc_mutex_lock_order_t lock_order) { 158 mutex_prof_data_init(&mutex->prof_data); 159 #ifdef _WIN32 160 # if _WIN32_WINNT >= 0x0600 161 InitializeSRWLock(&mutex->lock); 162 # else 163 if (!InitializeCriticalSectionAndSpinCount(&mutex->lock, 164 _CRT_SPINCOUNT)) { 165 return true; 166 } 167 # endif 168 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK)) 169 mutex->lock = OS_UNFAIR_LOCK_INIT; 170 #elif (defined(JEMALLOC_MUTEX_INIT_CB)) 171 if (postpone_init) { 172 mutex->postponed_next = postponed_mutexes; 173 postponed_mutexes = mutex; 174 } else { 175 if (_pthread_mutex_init_calloc_cb(&mutex->lock, 176 bootstrap_calloc) != 0) { 177 return true; 178 } 179 } 180 #else 181 pthread_mutexattr_t attr; 182 183 if (pthread_mutexattr_init(&attr) != 0) { 184 return true; 185 } 186 pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE); 187 if (pthread_mutex_init(&mutex->lock, &attr) != 0) { 188 pthread_mutexattr_destroy(&attr); 189 return true; 190 } 191 pthread_mutexattr_destroy(&attr); 192 #endif 193 if (config_debug) { 194 mutex->lock_order = lock_order; 195 if (lock_order == malloc_mutex_address_ordered) { 196 witness_init(&mutex->witness, name, rank, 197 mutex_addr_comp, mutex); 198 } else { 199 witness_init(&mutex->witness, name, rank, NULL, NULL); 200 } 201 } 202 return false; 203 } 204 205 void 206 malloc_mutex_prefork(tsdn_t *tsdn, malloc_mutex_t *mutex) { 207 malloc_mutex_lock(tsdn, mutex); 208 } 209 210 void 211 malloc_mutex_postfork_parent(tsdn_t *tsdn, malloc_mutex_t *mutex) { 212 malloc_mutex_unlock(tsdn, mutex); 213 } 214 215 void 216 malloc_mutex_postfork_child(tsdn_t *tsdn, malloc_mutex_t *mutex) { 217 #ifdef JEMALLOC_MUTEX_INIT_CB 218 malloc_mutex_unlock(tsdn, mutex); 219 #else 220 if (malloc_mutex_init(mutex, mutex->witness.name, 221 mutex->witness.rank, mutex->lock_order)) { 222 malloc_printf("<jemalloc>: Error re-initializing mutex in " 223 "child\n"); 224 if (opt_abort) { 225 abort(); 226 } 227 } 228 #endif 229 } 230 231 bool 232 malloc_mutex_boot(void) { 233 #ifdef JEMALLOC_MUTEX_INIT_CB 234 postpone_init = false; 235 while (postponed_mutexes != NULL) { 236 if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock, 237 bootstrap_calloc) != 0) { 238 return true; 239 } 240 postponed_mutexes = postponed_mutexes->postponed_next; 241 } 242 #endif 243 return false; 244 } 245