mutex.c revision 277317 
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
16bool isthreaded = false;
17#endif
18#ifdef JEMALLOC_MUTEX_INIT_CB
19static bool		postpone_init = true;
20static malloc_mutex_t	*postponed_mutexes = NULL;
21#endif
22
23#if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32)
24static 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)
34static int (*pthread_create_fptr)(pthread_t *__restrict, const pthread_attr_t *,
35    void *(*)(void *), void *__restrict);
36
37static void
38pthread_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
51JEMALLOC_EXPORT int
52pthread_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
67JEMALLOC_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
71int
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])(
78	   mutex, calloc_cb));
79}
80#endif
81
82bool
83malloc_mutex_init(malloc_mutex_t *mutex)
84{
85
86#ifdef _WIN32
87	if (!InitializeCriticalSectionAndSpinCount(&mutex->lock,
88	    _CRT_SPINCOUNT))
89		return (true);
90#elif (defined(JEMALLOC_OSSPIN))
91	mutex->lock = 0;
92#elif (defined(JEMALLOC_MUTEX_INIT_CB))
93	if (postpone_init) {
94		mutex->postponed_next = postponed_mutexes;
95		postponed_mutexes = mutex;
96	} else {
97		if (_pthread_mutex_init_calloc_cb(&mutex->lock, base_calloc) !=
98		    0)
99			return (true);
100	}
101#else
102	pthread_mutexattr_t attr;
103
104	if (pthread_mutexattr_init(&attr) != 0)
105		return (true);
106	pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE);
107	if (pthread_mutex_init(&mutex->lock, &attr) != 0) {
108		pthread_mutexattr_destroy(&attr);
109		return (true);
110	}
111	pthread_mutexattr_destroy(&attr);
112#endif
113	return (false);
114}
115
116void
117malloc_mutex_prefork(malloc_mutex_t *mutex)
118{
119
120	malloc_mutex_lock(mutex);
121}
122
123void
124malloc_mutex_postfork_parent(malloc_mutex_t *mutex)
125{
126
127	malloc_mutex_unlock(mutex);
128}
129
130void
131malloc_mutex_postfork_child(malloc_mutex_t *mutex)
132{
133
134#ifdef JEMALLOC_MUTEX_INIT_CB
135	malloc_mutex_unlock(mutex);
136#else
137	if (malloc_mutex_init(mutex)) {
138		malloc_printf("<jemalloc>: Error re-initializing mutex in "
139		    "child\n");
140		if (opt_abort)
141			abort();
142	}
143#endif
144}
145
146bool
147malloc_mutex_first_thread(void)
148{
149
150#ifdef JEMALLOC_MUTEX_INIT_CB
151	postpone_init = false;
152	while (postponed_mutexes != NULL) {
153		if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock,
154		    base_calloc) != 0)
155			return (true);
156		postponed_mutexes = postponed_mutexes->postponed_next;
157	}
158#endif
159	return (false);
160}
161
162bool
163mutex_boot(void)
164{
165
166#ifndef JEMALLOC_MUTEX_INIT_CB
167	return (malloc_mutex_first_thread());
168#else
169	return (false);
170#endif
171}
172