1 | /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
2 | /* This Source Code Form is subject to the terms of the Mozilla Public |
3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
5 | |
6 | #ifndef plarena_h___ |
7 | #define plarena_h___ |
8 | /* |
9 | * Lifetime-based fast allocation, inspired by much prior art, including |
10 | * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes" |
11 | * David R. Hanson, Software -- Practice and Experience, Vol. 20(1). |
12 | * |
13 | * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE). |
14 | */ |
15 | #include "prtypes.h" |
16 | |
17 | PR_BEGIN_EXTERN_C |
18 | |
19 | typedef struct PLArena PLArena; |
20 | |
21 | struct PLArena { |
22 | PLArena *next; /* next arena for this lifetime */ |
23 | PRUword base; /* aligned base address, follows this header */ |
24 | PRUword limit; /* one beyond last byte in arena */ |
25 | PRUword avail; /* points to next available byte */ |
26 | }; |
27 | |
28 | #ifdef PL_ARENAMETER |
29 | typedef struct PLArenaStats PLArenaStats; |
30 | |
31 | struct PLArenaStats { |
32 | PLArenaStats *next; /* next in arenaStats list */ |
33 | char *name; /* name for debugging */ |
34 | PRUint32 narenas; /* number of arenas in pool */ |
35 | PRUint32 nallocs; /* number of PL_ARENA_ALLOCATE() calls */ |
36 | PRUint32 nreclaims; /* number of reclaims from freeArenas */ |
37 | PRUint32 nmallocs; /* number of malloc() calls */ |
38 | PRUint32 ndeallocs; /* number of lifetime deallocations */ |
39 | PRUint32 ngrows; /* number of PL_ARENA_GROW() calls */ |
40 | PRUint32 ninplace; /* number of in-place growths */ |
41 | PRUint32 nreleases; /* number of PL_ARENA_RELEASE() calls */ |
42 | PRUint32 nfastrels; /* number of "fast path" releases */ |
43 | PRUint32 nbytes; /* total bytes allocated */ |
44 | PRUint32 maxalloc; /* maximum allocation size in bytes */ |
45 | PRFloat64 variance; /* size variance accumulator */ |
46 | }; |
47 | #endif |
48 | |
49 | typedef struct PLArenaPool PLArenaPool; |
50 | |
51 | struct PLArenaPool { |
52 | PLArena first; /* first arena in pool list */ |
53 | PLArena *current; /* arena from which to allocate space */ |
54 | PRUint32 arenasize; /* net exact size of a new arena */ |
55 | PRUword mask; /* alignment mask (power-of-2 - 1) */ |
56 | #ifdef PL_ARENAMETER |
57 | PLArenaStats stats; |
58 | #endif |
59 | }; |
60 | |
61 | /* |
62 | * WARNING: The PL_MAKE_MEM_ macros are for internal use by NSPR. Do NOT use |
63 | * them in your code. |
64 | * |
65 | * NOTE: Valgrind support to be added. |
66 | * |
67 | * The PL_MAKE_MEM_ macros are modeled after the MOZ_MAKE_MEM_ macros in |
68 | * Mozilla's mfbt/MemoryChecking.h. Only AddressSanitizer is supported now. |
69 | * |
70 | * Provides a common interface to the ASan (AddressSanitizer) and Valgrind |
71 | * functions used to mark memory in certain ways. In detail, the following |
72 | * three macros are provided: |
73 | * |
74 | * PL_MAKE_MEM_NOACCESS - Mark memory as unsafe to access (e.g. freed) |
75 | * PL_MAKE_MEM_UNDEFINED - Mark memory as accessible, with content undefined |
76 | * PL_MAKE_MEM_DEFINED - Mark memory as accessible, with content defined |
77 | * |
78 | * With Valgrind in use, these directly map to the three respective Valgrind |
79 | * macros. With ASan in use, the NOACCESS macro maps to poisoning the memory, |
80 | * while the UNDEFINED/DEFINED macros unpoison memory. |
81 | * |
82 | * With no memory checker available, all macros expand to the empty statement. |
83 | */ |
84 | |
85 | /* WARNING: PL_SANITIZE_ADDRESS is for internal use by this header. Do NOT |
86 | * define or test this macro in your code. |
87 | */ |
88 | #if defined(__has_feature) |
89 | #if __has_feature(address_sanitizer) |
90 | #define PL_SANITIZE_ADDRESS 1 |
91 | #endif |
92 | #elif defined(__SANITIZE_ADDRESS__) |
93 | #define PL_SANITIZE_ADDRESS 1 |
94 | #endif |
95 | |
96 | #if defined(PL_SANITIZE_ADDRESS) |
97 | |
98 | #if defined(_MSC_VER) |
99 | /* We can't use dllimport due to DLL linkage mismatch with |
100 | * sanitizer/asan_interface.h. |
101 | */ |
102 | #define PL_ASAN_VISIBILITY(type_) type_ |
103 | #else |
104 | #define PL_ASAN_VISIBILITY(type_) PR_IMPORT(type_) |
105 | #endif |
106 | |
107 | /* These definitions are usually provided through the |
108 | * sanitizer/asan_interface.h header installed by ASan. |
109 | * See https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning |
110 | */ |
111 | |
112 | PL_ASAN_VISIBILITY(void) __asan_poison_memory_region( |
113 | void const volatile *addr, size_t size); |
114 | PL_ASAN_VISIBILITY(void) __asan_unpoison_memory_region( |
115 | void const volatile *addr, size_t size); |
116 | |
117 | #define PL_MAKE_MEM_NOACCESS(addr, size) \ |
118 | __asan_poison_memory_region((addr), (size)) |
119 | |
120 | #define PL_MAKE_MEM_UNDEFINED(addr, size) \ |
121 | __asan_unpoison_memory_region((addr), (size)) |
122 | |
123 | #define PL_MAKE_MEM_DEFINED(addr, size) \ |
124 | __asan_unpoison_memory_region((addr), (size)) |
125 | |
126 | #else |
127 | |
128 | #define PL_MAKE_MEM_NOACCESS(addr, size) |
129 | #define PL_MAKE_MEM_UNDEFINED(addr, size) |
130 | #define PL_MAKE_MEM_DEFINED(addr, size) |
131 | |
132 | #endif |
133 | |
134 | /* |
135 | * If the including .c file uses only one power-of-2 alignment, it may define |
136 | * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions |
137 | * per ALLOCATE and GROW. |
138 | */ |
139 | #ifdef PL_ARENA_CONST_ALIGN_MASK |
140 | #define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \ |
141 | & ~PL_ARENA_CONST_ALIGN_MASK) |
142 | |
143 | #define PL_INIT_ARENA_POOL(pool, name, size) \ |
144 | PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1) |
145 | #else |
146 | #define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + (pool)->mask) & ~(pool)->mask) |
147 | #endif |
148 | |
149 | #define PL_ARENA_ALLOCATE(p, pool, nb) \ |
150 | PR_BEGIN_MACRO \ |
151 | PLArena *_a = (pool)->current; \ |
152 | PRUint32 _nb = PL_ARENA_ALIGN(pool, (PRUint32)nb); \ |
153 | PRUword _p = _a->avail; \ |
154 | if (_nb < (PRUint32)nb) { \ |
155 | _p = 0; \ |
156 | } else if (_nb > (_a->limit - _a->avail)) { \ |
157 | _p = (PRUword)PL_ArenaAllocate(pool, _nb); \ |
158 | } else { \ |
159 | _a->avail += _nb; \ |
160 | } \ |
161 | p = (void *)_p; \ |
162 | if (p) { \ |
163 | PL_MAKE_MEM_UNDEFINED(p, (PRUint32)nb); \ |
164 | PL_ArenaCountAllocation(pool, (PRUint32)nb); \ |
165 | } \ |
166 | PR_END_MACRO |
167 | |
168 | #define PL_ARENA_GROW(p, pool, size, incr) \ |
169 | PR_BEGIN_MACRO \ |
170 | PLArena *_a = (pool)->current; \ |
171 | PRUint32 _incr = PL_ARENA_ALIGN(pool, (PRUint32)incr); \ |
172 | if (_incr < (PRUint32)incr) { \ |
173 | p = NULL; \ |
174 | } else if (_a->avail == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \ |
175 | _incr <= (_a->limit - _a->avail)) { \ |
176 | PL_MAKE_MEM_UNDEFINED((unsigned char *)(p) + size, (PRUint32)incr); \ |
177 | _a->avail += _incr; \ |
178 | PL_ArenaCountInplaceGrowth(pool, size, (PRUint32)incr); \ |
179 | } else { \ |
180 | p = PL_ArenaGrow(pool, p, size, (PRUint32)incr); \ |
181 | } \ |
182 | if (p) {\ |
183 | PL_ArenaCountGrowth(pool, size, (PRUint32)incr); \ |
184 | } \ |
185 | PR_END_MACRO |
186 | |
187 | #define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail) |
188 | #define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q)) |
189 | |
190 | #define PL_CLEAR_UNUSED_PATTERN(a, pattern) \ |
191 | PR_BEGIN_MACRO \ |
192 | PR_ASSERT((a)->avail <= (a)->limit); \ |
193 | PL_MAKE_MEM_UNDEFINED((void*)(a)->avail, (a)->limit - (a)->avail); \ |
194 | memset((void*)(a)->avail, (pattern), (a)->limit - (a)->avail); \ |
195 | PR_END_MACRO |
196 | #ifdef DEBUG |
197 | #define PL_FREE_PATTERN 0xDA |
198 | #define PL_CLEAR_UNUSED(a) PL_CLEAR_UNUSED_PATTERN((a), PL_FREE_PATTERN) |
199 | #define PL_CLEAR_ARENA(a) \ |
200 | PR_BEGIN_MACRO \ |
201 | PL_MAKE_MEM_UNDEFINED((void*)(a), (a)->limit - (PRUword)(a)); \ |
202 | memset((void*)(a), PL_FREE_PATTERN, (a)->limit - (PRUword)(a)); \ |
203 | PR_END_MACRO |
204 | #else |
205 | #define PL_CLEAR_UNUSED(a) |
206 | #define PL_CLEAR_ARENA(a) |
207 | #endif |
208 | |
209 | #define PL_ARENA_RELEASE(pool, mark) \ |
210 | PR_BEGIN_MACRO \ |
211 | char *_m = (char *)(mark); \ |
212 | PLArena *_a = (pool)->current; \ |
213 | if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \ |
214 | _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \ |
215 | PL_CLEAR_UNUSED(_a); \ |
216 | PL_MAKE_MEM_NOACCESS((void*)_a->avail, _a->limit - _a->avail); \ |
217 | PL_ArenaCountRetract(pool, _m); \ |
218 | } else { \ |
219 | PL_ArenaRelease(pool, _m); \ |
220 | } \ |
221 | PL_ArenaCountRelease(pool, _m); \ |
222 | PR_END_MACRO |
223 | |
224 | #ifdef PL_ARENAMETER |
225 | #define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op) |
226 | #else |
227 | #define PL_COUNT_ARENA(pool,op) |
228 | #endif |
229 | |
230 | #define PL_ARENA_DESTROY(pool, a, pnext) \ |
231 | PR_BEGIN_MACRO \ |
232 | PL_COUNT_ARENA(pool,--); \ |
233 | if ((pool)->current == (a)) (pool)->current = &(pool)->first; \ |
234 | *(pnext) = (a)->next; \ |
235 | PL_CLEAR_ARENA(a); \ |
236 | free(a); \ |
237 | (a) = 0; \ |
238 | PR_END_MACRO |
239 | |
240 | /* |
241 | ** Initialize an arena pool with the given name for debugging and metering, |
242 | ** with a minimum gross size per arena of size bytes. The net size per arena |
243 | ** is smaller than the gross size by a header of four pointers plus any |
244 | ** necessary padding for alignment. |
245 | ** |
246 | ** Note: choose a gross size that's a power of two to avoid the heap allocator |
247 | ** rounding the size up. |
248 | **/ |
249 | PR_EXTERN(void) PL_InitArenaPool( |
250 | PLArenaPool *pool, const char *name, PRUint32 size, PRUint32 align); |
251 | |
252 | /* |
253 | ** Finish using arenas, freeing all memory associated with them. |
254 | ** NOTE: this function is now a no-op. If you want to free a single |
255 | ** PLArenaPoolUse use PL_FreeArenaPool() or PL_FinishArenaPool(). |
256 | **/ |
257 | PR_EXTERN(void) PL_ArenaFinish(void); |
258 | |
259 | /* |
260 | ** Free the arenas in pool. The user may continue to allocate from pool |
261 | ** after calling this function. There is no need to call PL_InitArenaPool() |
262 | ** again unless PL_FinishArenaPool(pool) has been called. |
263 | **/ |
264 | PR_EXTERN(void) PL_FreeArenaPool(PLArenaPool *pool); |
265 | |
266 | /* |
267 | ** Free the arenas in pool and finish using it altogether. |
268 | **/ |
269 | PR_EXTERN(void) PL_FinishArenaPool(PLArenaPool *pool); |
270 | |
271 | /* |
272 | ** Compact all of the arenas in a pool so that no space is wasted. |
273 | ** NOT IMPLEMENTED. Do not use. |
274 | **/ |
275 | PR_EXTERN(void) PL_CompactArenaPool(PLArenaPool *pool); |
276 | |
277 | /* |
278 | ** Friend functions used by the PL_ARENA_*() macros. |
279 | ** |
280 | ** WARNING: do not call these functions directly. Always use the |
281 | ** PL_ARENA_*() macros. |
282 | **/ |
283 | PR_EXTERN(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb); |
284 | |
285 | PR_EXTERN(void *) PL_ArenaGrow( |
286 | PLArenaPool *pool, void *p, PRUint32 size, PRUint32 incr); |
287 | |
288 | PR_EXTERN(void) PL_ArenaRelease(PLArenaPool *pool, char *mark); |
289 | |
290 | /* |
291 | ** memset contents of all arenas in pool to pattern |
292 | */ |
293 | PR_EXTERN(void) PL_ClearArenaPool(PLArenaPool *pool, PRInt32 pattern); |
294 | |
295 | /* |
296 | ** A function like malloc_size() or malloc_usable_size() that measures the |
297 | ** size of a heap block. |
298 | */ |
299 | typedef size_t (*PLMallocSizeFn)(const void *ptr); |
300 | |
301 | /* |
302 | ** Measure all memory used by a PLArenaPool, excluding the PLArenaPool |
303 | ** structure. |
304 | */ |
305 | PR_EXTERN(size_t) PL_SizeOfArenaPoolExcludingPool( |
306 | const PLArenaPool *pool, PLMallocSizeFn mallocSizeOf); |
307 | |
308 | #ifdef PL_ARENAMETER |
309 | |
310 | #include <stdio.h> |
311 | |
312 | PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb); |
313 | |
314 | PR_EXTERN(void) PL_ArenaCountInplaceGrowth( |
315 | PLArenaPool *pool, PRUint32 size, PRUint32 incr); |
316 | |
317 | PR_EXTERN(void) PL_ArenaCountGrowth( |
318 | PLArenaPool *pool, PRUint32 size, PRUint32 incr); |
319 | |
320 | PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark); |
321 | |
322 | PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark); |
323 | |
324 | PR_EXTERN(void) PL_DumpArenaStats(FILE *fp); |
325 | |
326 | #else /* !PL_ARENAMETER */ |
327 | |
328 | #define PL_ArenaCountAllocation(ap, nb) /* nothing */ |
329 | #define PL_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */ |
330 | #define PL_ArenaCountGrowth(ap, size, incr) /* nothing */ |
331 | #define PL_ArenaCountRelease(ap, mark) /* nothing */ |
332 | #define PL_ArenaCountRetract(ap, mark) /* nothing */ |
333 | |
334 | #endif /* !PL_ARENAMETER */ |
335 | |
336 | PR_END_EXTERN_C |
337 | |
338 | #endif /* plarena_h___ */ |
339 | |