xref: /freebsd/contrib/jemalloc/src/mutex.c (revision 23f6875a43f7ce365f2d52cf857da010c47fb03b)
1 #define	JEMALLOC_MUTEX_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
3 
4 #if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32)
5 #include <dlfcn.h>
6 #endif
7 
8 #ifndef _CRT_SPINCOUNT
9 #define	_CRT_SPINCOUNT 4000
10 #endif
11 
12 /******************************************************************************/
13 /* Data. */
14 
15 #ifdef JEMALLOC_LAZY_LOCK
16 bool isthreaded = false;
17 #endif
18 #ifdef JEMALLOC_MUTEX_INIT_CB
19 static bool		postpone_init = true;
20 static malloc_mutex_t	*postponed_mutexes = NULL;
21 #endif
22 
23 #if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32)
24 static void	pthread_create_once(void);
25 #endif
26 
27 /******************************************************************************/
28 /*
29  * We intercept pthread_create() calls in order to toggle isthreaded if the
30  * process goes multi-threaded.
31  */
32 
33 #if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32)
34 static int (*pthread_create_fptr)(pthread_t *__restrict, const pthread_attr_t *,
35     void *(*)(void *), void *__restrict);
36 
37 static void
38 pthread_create_once(void)
39 {
40 
41 	pthread_create_fptr = dlsym(RTLD_NEXT, "pthread_create");
42 	if (pthread_create_fptr == NULL) {
43 		malloc_write("<jemalloc>: Error in dlsym(RTLD_NEXT, "
44 		    "\"pthread_create\")\n");
45 		abort();
46 	}
47 
48 	isthreaded = true;
49 }
50 
51 JEMALLOC_EXPORT int
52 pthread_create(pthread_t *__restrict thread,
53     const pthread_attr_t *__restrict attr, void *(*start_routine)(void *),
54     void *__restrict arg)
55 {
56 	static pthread_once_t once_control = PTHREAD_ONCE_INIT;
57 
58 	pthread_once(&once_control, pthread_create_once);
59 
60 	return (pthread_create_fptr(thread, attr, start_routine, arg));
61 }
62 #endif
63 
64 /******************************************************************************/
65 
66 #ifdef JEMALLOC_MUTEX_INIT_CB
67 JEMALLOC_EXPORT int	_pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex,
68     void *(calloc_cb)(size_t, size_t));
69 
70 #pragma weak _pthread_mutex_init_calloc_cb
71 int
72 _pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex,
73     void *(calloc_cb)(size_t, size_t))
74 {
75 
76 	return (((int (*)(pthread_mutex_t *, void *(*)(size_t, size_t)))
77 	    __libc_interposing[INTERPOS__pthread_mutex_init_calloc_cb])(mutex,
78 	    calloc_cb));
79 }
80 #endif
81 
82 bool
83 malloc_mutex_init(malloc_mutex_t *mutex, const char *name, witness_rank_t rank)
84 {
85 
86 #ifdef _WIN32
87 #  if _WIN32_WINNT >= 0x0600
88 	InitializeSRWLock(&mutex->lock);
89 #  else
90 	if (!InitializeCriticalSectionAndSpinCount(&mutex->lock,
91 	    _CRT_SPINCOUNT))
92 		return (true);
93 #  endif
94 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
95 	mutex->lock = OS_UNFAIR_LOCK_INIT;
96 #elif (defined(JEMALLOC_OSSPIN))
97 	mutex->lock = 0;
98 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
99 	if (postpone_init) {
100 		mutex->postponed_next = postponed_mutexes;
101 		postponed_mutexes = mutex;
102 	} else {
103 		if (_pthread_mutex_init_calloc_cb(&mutex->lock,
104 		    bootstrap_calloc) != 0)
105 			return (true);
106 	}
107 #else
108 	pthread_mutexattr_t attr;
109 
110 	if (pthread_mutexattr_init(&attr) != 0)
111 		return (true);
112 	pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE);
113 	if (pthread_mutex_init(&mutex->lock, &attr) != 0) {
114 		pthread_mutexattr_destroy(&attr);
115 		return (true);
116 	}
117 	pthread_mutexattr_destroy(&attr);
118 #endif
119 	if (config_debug)
120 		witness_init(&mutex->witness, name, rank, NULL);
121 	return (false);
122 }
123 
124 void
125 malloc_mutex_prefork(tsdn_t *tsdn, malloc_mutex_t *mutex)
126 {
127 
128 	malloc_mutex_lock(tsdn, mutex);
129 }
130 
131 void
132 malloc_mutex_postfork_parent(tsdn_t *tsdn, malloc_mutex_t *mutex)
133 {
134 
135 	malloc_mutex_unlock(tsdn, mutex);
136 }
137 
138 void
139 malloc_mutex_postfork_child(tsdn_t *tsdn, malloc_mutex_t *mutex)
140 {
141 
142 #ifdef JEMALLOC_MUTEX_INIT_CB
143 	malloc_mutex_unlock(tsdn, mutex);
144 #else
145 	if (malloc_mutex_init(mutex, mutex->witness.name,
146 	    mutex->witness.rank)) {
147 		malloc_printf("<jemalloc>: Error re-initializing mutex in "
148 		    "child\n");
149 		if (opt_abort)
150 			abort();
151 	}
152 #endif
153 }
154 
155 bool
156 malloc_mutex_first_thread(void)
157 {
158 
159 #ifdef JEMALLOC_MUTEX_INIT_CB
160 	postpone_init = false;
161 	while (postponed_mutexes != NULL) {
162 		if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock,
163 		    bootstrap_calloc) != 0)
164 			return (true);
165 		postponed_mutexes = postponed_mutexes->postponed_next;
166 	}
167 #endif
168 	return (false);
169 }
170 
171 bool
172 malloc_mutex_boot(void)
173 {
174 
175 #ifndef JEMALLOC_MUTEX_INIT_CB
176 	return (malloc_mutex_first_thread());
177 #else
178 	return (false);
179 #endif
180 }
181