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
pthread_create(pthread_t * __restrict thread,const pthread_attr_t * __restrict attr,void * (* start_routine)(void *),void * __restrict arg)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
_pthread_mutex_init_calloc_cb(pthread_mutex_t * mutex,void * (calloc_cb)(size_t,size_t))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
malloc_mutex_lock_slow(malloc_mutex_t * mutex)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
mutex_prof_data_init(mutex_prof_data_t * data)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
malloc_mutex_prof_data_reset(tsdn_t * tsdn,malloc_mutex_t * mutex)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
mutex_addr_comp(const witness_t * witness1,void * mutex1,const witness_t * witness2,void * mutex2)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
malloc_mutex_first_thread(void)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
malloc_mutex_init(malloc_mutex_t * mutex,const char * name,witness_rank_t rank,malloc_mutex_lock_order_t lock_order)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
malloc_mutex_prefork(tsdn_t * tsdn,malloc_mutex_t * mutex)207 malloc_mutex_prefork(tsdn_t *tsdn, malloc_mutex_t *mutex) {
208 malloc_mutex_lock(tsdn, mutex);
209 }
210
211 void
malloc_mutex_postfork_parent(tsdn_t * tsdn,malloc_mutex_t * mutex)212 malloc_mutex_postfork_parent(tsdn_t *tsdn, malloc_mutex_t *mutex) {
213 malloc_mutex_unlock(tsdn, mutex);
214 }
215
216 void
malloc_mutex_postfork_child(tsdn_t * tsdn,malloc_mutex_t * mutex)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
malloc_mutex_boot(void)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