xref: /freebsd/contrib/jemalloc/src/mutex.c (revision c9dbb1cc52b063bbd9ab078a7afc89a8696da659)
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)
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_OSSPIN))
95 	mutex->lock = 0;
96 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
97 	if (postpone_init) {
98 		mutex->postponed_next = postponed_mutexes;
99 		postponed_mutexes = mutex;
100 	} else {
101 		if (_pthread_mutex_init_calloc_cb(&mutex->lock,
102 		    bootstrap_calloc) != 0)
103 			return (true);
104 	}
105 #else
106 	pthread_mutexattr_t attr;
107 
108 	if (pthread_mutexattr_init(&attr) != 0)
109 		return (true);
110 	pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE);
111 	if (pthread_mutex_init(&mutex->lock, &attr) != 0) {
112 		pthread_mutexattr_destroy(&attr);
113 		return (true);
114 	}
115 	pthread_mutexattr_destroy(&attr);
116 #endif
117 	return (false);
118 }
119 
120 void
121 malloc_mutex_prefork(malloc_mutex_t *mutex)
122 {
123 
124 	malloc_mutex_lock(mutex);
125 }
126 
127 void
128 malloc_mutex_postfork_parent(malloc_mutex_t *mutex)
129 {
130 
131 	malloc_mutex_unlock(mutex);
132 }
133 
134 void
135 malloc_mutex_postfork_child(malloc_mutex_t *mutex)
136 {
137 
138 #ifdef JEMALLOC_MUTEX_INIT_CB
139 	malloc_mutex_unlock(mutex);
140 #else
141 	if (malloc_mutex_init(mutex)) {
142 		malloc_printf("<jemalloc>: Error re-initializing mutex in "
143 		    "child\n");
144 		if (opt_abort)
145 			abort();
146 	}
147 #endif
148 }
149 
150 bool
151 malloc_mutex_first_thread(void)
152 {
153 
154 #ifdef JEMALLOC_MUTEX_INIT_CB
155 	postpone_init = false;
156 	while (postponed_mutexes != NULL) {
157 		if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock,
158 		    bootstrap_calloc) != 0)
159 			return (true);
160 		postponed_mutexes = postponed_mutexes->postponed_next;
161 	}
162 #endif
163 	return (false);
164 }
165 
166 bool
167 mutex_boot(void)
168 {
169 
170 #ifndef JEMALLOC_MUTEX_INIT_CB
171 	return (malloc_mutex_first_thread());
172 #else
173 	return (false);
174 #endif
175 }
176