1 #include "jemalloc/internal/jemalloc_internal.h"
2 #ifndef JEMALLOC_ZONE
3 #  error "This source file is for zones on Darwin (OS X)."
4 #endif
5 
6 /*
7  * The malloc_default_purgeable_zone function is only available on >= 10.6.
8  * We need to check whether it is present at runtime, thus the weak_import.
9  */
10 extern malloc_zone_t *malloc_default_purgeable_zone(void)
11 JEMALLOC_ATTR(weak_import);
12 
13 /******************************************************************************/
14 /* Data. */
15 
16 static malloc_zone_t zone;
17 static struct malloc_introspection_t zone_introspect;
18 
19 /******************************************************************************/
20 /* Function prototypes for non-inline static functions. */
21 
22 static size_t	zone_size(malloc_zone_t *zone, void *ptr);
23 static void	*zone_malloc(malloc_zone_t *zone, size_t size);
24 static void	*zone_calloc(malloc_zone_t *zone, size_t num, size_t size);
25 static void	*zone_valloc(malloc_zone_t *zone, size_t size);
26 static void	zone_free(malloc_zone_t *zone, void *ptr);
27 static void	*zone_realloc(malloc_zone_t *zone, void *ptr, size_t size);
28 #if (JEMALLOC_ZONE_VERSION >= 5)
29 static void	*zone_memalign(malloc_zone_t *zone, size_t alignment,
30 #endif
31 #if (JEMALLOC_ZONE_VERSION >= 6)
32     size_t size);
33 static void	zone_free_definite_size(malloc_zone_t *zone, void *ptr,
34     size_t size);
35 #endif
36 static void	*zone_destroy(malloc_zone_t *zone);
37 static size_t	zone_good_size(malloc_zone_t *zone, size_t size);
38 static void	zone_force_lock(malloc_zone_t *zone);
39 static void	zone_force_unlock(malloc_zone_t *zone);
40 
41 /******************************************************************************/
42 /*
43  * Functions.
44  */
45 
46 static size_t
zone_size(malloc_zone_t * zone,void * ptr)47 zone_size(malloc_zone_t *zone, void *ptr)
48 {
49 
50 	/*
51 	 * There appear to be places within Darwin (such as setenv(3)) that
52 	 * cause calls to this function with pointers that *no* zone owns.  If
53 	 * we knew that all pointers were owned by *some* zone, we could split
54 	 * our zone into two parts, and use one as the default allocator and
55 	 * the other as the default deallocator/reallocator.  Since that will
56 	 * not work in practice, we must check all pointers to assure that they
57 	 * reside within a mapped chunk before determining size.
58 	 */
59 	return (ivsalloc(ptr, config_prof));
60 }
61 
62 static void *
zone_malloc(malloc_zone_t * zone,size_t size)63 zone_malloc(malloc_zone_t *zone, size_t size)
64 {
65 
66 	return (je_malloc(size));
67 }
68 
69 static void *
zone_calloc(malloc_zone_t * zone,size_t num,size_t size)70 zone_calloc(malloc_zone_t *zone, size_t num, size_t size)
71 {
72 
73 	return (je_calloc(num, size));
74 }
75 
76 static void *
zone_valloc(malloc_zone_t * zone,size_t size)77 zone_valloc(malloc_zone_t *zone, size_t size)
78 {
79 	void *ret = NULL; /* Assignment avoids useless compiler warning. */
80 
81 	je_posix_memalign(&ret, PAGE, size);
82 
83 	return (ret);
84 }
85 
86 static void
zone_free(malloc_zone_t * zone,void * ptr)87 zone_free(malloc_zone_t *zone, void *ptr)
88 {
89 
90 	if (ivsalloc(ptr, config_prof) != 0) {
91 		je_free(ptr);
92 		return;
93 	}
94 
95 	free(ptr);
96 }
97 
98 static void *
zone_realloc(malloc_zone_t * zone,void * ptr,size_t size)99 zone_realloc(malloc_zone_t *zone, void *ptr, size_t size)
100 {
101 
102 	if (ivsalloc(ptr, config_prof) != 0)
103 		return (je_realloc(ptr, size));
104 
105 	return (realloc(ptr, size));
106 }
107 
108 #if (JEMALLOC_ZONE_VERSION >= 5)
109 static void *
zone_memalign(malloc_zone_t * zone,size_t alignment,size_t size)110 zone_memalign(malloc_zone_t *zone, size_t alignment, size_t size)
111 {
112 	void *ret = NULL; /* Assignment avoids useless compiler warning. */
113 
114 	je_posix_memalign(&ret, alignment, size);
115 
116 	return (ret);
117 }
118 #endif
119 
120 #if (JEMALLOC_ZONE_VERSION >= 6)
121 static void
zone_free_definite_size(malloc_zone_t * zone,void * ptr,size_t size)122 zone_free_definite_size(malloc_zone_t *zone, void *ptr, size_t size)
123 {
124 
125 	if (ivsalloc(ptr, config_prof) != 0) {
126 		assert(ivsalloc(ptr, config_prof) == size);
127 		je_free(ptr);
128 		return;
129 	}
130 
131 	free(ptr);
132 }
133 #endif
134 
135 static void *
zone_destroy(malloc_zone_t * zone)136 zone_destroy(malloc_zone_t *zone)
137 {
138 
139 	/* This function should never be called. */
140 	not_reached();
141 	return (NULL);
142 }
143 
144 static size_t
zone_good_size(malloc_zone_t * zone,size_t size)145 zone_good_size(malloc_zone_t *zone, size_t size)
146 {
147 
148 	if (size == 0)
149 		size = 1;
150 	return (s2u(size));
151 }
152 
153 static void
zone_force_lock(malloc_zone_t * zone)154 zone_force_lock(malloc_zone_t *zone)
155 {
156 
157 	if (isthreaded)
158 		jemalloc_prefork();
159 }
160 
161 static void
zone_force_unlock(malloc_zone_t * zone)162 zone_force_unlock(malloc_zone_t *zone)
163 {
164 
165 	if (isthreaded)
166 		jemalloc_postfork_parent();
167 }
168 
JEMALLOC_ATTR(constructor)169 JEMALLOC_ATTR(constructor)
170 void
171 register_zone(void)
172 {
173 
174 	/*
175 	 * If something else replaced the system default zone allocator, don't
176 	 * register jemalloc's.
177 	 */
178 	malloc_zone_t *default_zone = malloc_default_zone();
179 	malloc_zone_t *purgeable_zone = NULL;
180 	if (!default_zone->zone_name ||
181 	    strcmp(default_zone->zone_name, "DefaultMallocZone") != 0) {
182 		return;
183 	}
184 
185 	zone.size = (void *)zone_size;
186 	zone.malloc = (void *)zone_malloc;
187 	zone.calloc = (void *)zone_calloc;
188 	zone.valloc = (void *)zone_valloc;
189 	zone.free = (void *)zone_free;
190 	zone.realloc = (void *)zone_realloc;
191 	zone.destroy = (void *)zone_destroy;
192 	zone.zone_name = "jemalloc_zone";
193 	zone.batch_malloc = NULL;
194 	zone.batch_free = NULL;
195 	zone.introspect = &zone_introspect;
196 	zone.version = JEMALLOC_ZONE_VERSION;
197 #if (JEMALLOC_ZONE_VERSION >= 5)
198 	zone.memalign = zone_memalign;
199 #endif
200 #if (JEMALLOC_ZONE_VERSION >= 6)
201 	zone.free_definite_size = zone_free_definite_size;
202 #endif
203 #if (JEMALLOC_ZONE_VERSION >= 8)
204 	zone.pressure_relief = NULL;
205 #endif
206 
207 	zone_introspect.enumerator = NULL;
208 	zone_introspect.good_size = (void *)zone_good_size;
209 	zone_introspect.check = NULL;
210 	zone_introspect.print = NULL;
211 	zone_introspect.log = NULL;
212 	zone_introspect.force_lock = (void *)zone_force_lock;
213 	zone_introspect.force_unlock = (void *)zone_force_unlock;
214 	zone_introspect.statistics = NULL;
215 #if (JEMALLOC_ZONE_VERSION >= 6)
216 	zone_introspect.zone_locked = NULL;
217 #endif
218 #if (JEMALLOC_ZONE_VERSION >= 7)
219 	zone_introspect.enable_discharge_checking = NULL;
220 	zone_introspect.disable_discharge_checking = NULL;
221 	zone_introspect.discharge = NULL;
222 #ifdef __BLOCKS__
223 	zone_introspect.enumerate_discharged_pointers = NULL;
224 #else
225 	zone_introspect.enumerate_unavailable_without_blocks = NULL;
226 #endif
227 #endif
228 
229 	/*
230 	 * The default purgeable zone is created lazily by OSX's libc.  It uses
231 	 * the default zone when it is created for "small" allocations
232 	 * (< 15 KiB), but assumes the default zone is a scalable_zone.  This
233 	 * obviously fails when the default zone is the jemalloc zone, so
234 	 * malloc_default_purgeable_zone is called beforehand so that the
235 	 * default purgeable zone is created when the default zone is still
236 	 * a scalable_zone.  As purgeable zones only exist on >= 10.6, we need
237 	 * to check for the existence of malloc_default_purgeable_zone() at
238 	 * run time.
239 	 */
240 	if (malloc_default_purgeable_zone != NULL)
241 		purgeable_zone = malloc_default_purgeable_zone();
242 
243 	/* Register the custom zone.  At this point it won't be the default. */
244 	malloc_zone_register(&zone);
245 
246 	do {
247 		default_zone = malloc_default_zone();
248 		/*
249 		 * Unregister and reregister the default zone.  On OSX >= 10.6,
250 		 * unregistering takes the last registered zone and places it
251 		 * at the location of the specified zone.  Unregistering the
252 		 * default zone thus makes the last registered one the default.
253 		 * On OSX < 10.6, unregistering shifts all registered zones.
254 		 * The first registered zone then becomes the default.
255 		 */
256 		malloc_zone_unregister(default_zone);
257 		malloc_zone_register(default_zone);
258 		/*
259 		 * On OSX 10.6, having the default purgeable zone appear before
260 		 * the default zone makes some things crash because it thinks it
261 		 * owns the default zone allocated pointers.  We thus
262 		 * unregister/re-register it in order to ensure it's always
263 		 * after the default zone.  On OSX < 10.6, there is no purgeable
264 		 * zone, so this does nothing.  On OSX >= 10.6, unregistering
265 		 * replaces the purgeable zone with the last registered zone
266 		 * above, i.e. the default zone.  Registering it again then puts
267 		 * it at the end, obviously after the default zone.
268 		 */
269 		if (purgeable_zone) {
270 			malloc_zone_unregister(purgeable_zone);
271 			malloc_zone_register(purgeable_zone);
272 		}
273 	} while (malloc_default_zone() != &zone);
274 }
275