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1.1 root 1: /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2: *
3: * ***** BEGIN LICENSE BLOCK *****
4: * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5: *
6: * The contents of this file are subject to the Mozilla Public License Version
7: * 1.1 (the "License"); you may not use this file except in compliance with
8: * the License. You may obtain a copy of the License at
9: * http://www.mozilla.org/MPL/
10: *
11: * Software distributed under the License is distributed on an "AS IS" basis,
12: * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13: * for the specific language governing rights and limitations under the
14: * License.
15: *
16: * The Original Code is Mozilla Communicator client code, released
17: * March 31, 1998.
18: *
19: * The Initial Developer of the Original Code is
20: * Netscape Communications Corporation.
21: * Portions created by the Initial Developer are Copyright (C) 1998
22: * the Initial Developer. All Rights Reserved.
23: *
24: * Contributor(s):
25: *
26: * Alternatively, the contents of this file may be used under the terms of
27: * either of the GNU General Public License Version 2 or later (the "GPL"),
28: * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29: * in which case the provisions of the GPL or the LGPL are applicable instead
30: * of those above. If you wish to allow use of your version of this file only
31: * under the terms of either the GPL or the LGPL, and not to allow others to
32: * use your version of this file under the terms of the MPL, indicate your
33: * decision by deleting the provisions above and replace them with the notice
34: * and other provisions required by the GPL or the LGPL. If you do not delete
35: * the provisions above, a recipient may use your version of this file under
36: * the terms of any one of the MPL, the GPL or the LGPL.
37: *
38: * ***** END LICENSE BLOCK ***** */
39:
40: #ifndef jsarena_h___
41: #define jsarena_h___
42: /*
43: * Lifetime-based fast allocation, inspired by much prior art, including
44: * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes"
45: * David R. Hanson, Software -- Practice and Experience, Vol. 20(1).
46: *
47: * Also supports LIFO allocation (JS_ARENA_MARK/JS_ARENA_RELEASE).
48: */
49: #include <stdlib.h>
50: #include "jstypes.h"
51: #include "jscompat.h"
52:
53: JS_BEGIN_EXTERN_C
54:
55: typedef struct JSArena JSArena;
56: typedef struct JSArenaPool JSArenaPool;
57:
58: struct JSArena {
59: JSArena *next; /* next arena for this lifetime */
60: jsuword base; /* aligned base address, follows this header */
61: jsuword limit; /* one beyond last byte in arena */
62: jsuword avail; /* points to next available byte */
63: };
64:
65: #ifdef JS_ARENAMETER
66: typedef struct JSArenaStats JSArenaStats;
67:
68: struct JSArenaStats {
69: JSArenaStats *next; /* next in arenaStats list */
70: char *name; /* name for debugging */
71: uint32 narenas; /* number of arenas in pool */
72: uint32 nallocs; /* number of JS_ARENA_ALLOCATE() calls */
73: uint32 nmallocs; /* number of malloc() calls */
74: uint32 ndeallocs; /* number of lifetime deallocations */
75: uint32 ngrows; /* number of JS_ARENA_GROW() calls */
76: uint32 ninplace; /* number of in-place growths */
77: uint32 nreallocs; /* number of arena grow extending reallocs */
78: uint32 nreleases; /* number of JS_ARENA_RELEASE() calls */
79: uint32 nfastrels; /* number of "fast path" releases */
80: size_t nbytes; /* total bytes allocated */
81: size_t maxalloc; /* maximum allocation size in bytes */
82: double variance; /* size variance accumulator */
83: };
84: #endif
85:
86: struct JSArenaPool {
87: JSArena first; /* first arena in pool list */
88: JSArena *current; /* arena from which to allocate space */
89: size_t arenasize; /* net exact size of a new arena */
90: jsuword mask; /* alignment mask (power-of-2 - 1) */
91: #ifdef JS_ARENAMETER
92: JSArenaStats stats;
93: #endif
94: };
95:
96: /*
97: * If the including .c file uses only one power-of-2 alignment, it may define
98: * JS_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions
99: * per ALLOCATE and GROW.
100: */
101: #ifdef JS_ARENA_CONST_ALIGN_MASK
102: #define JS_ARENA_ALIGN(pool, n) (((jsuword)(n) + JS_ARENA_CONST_ALIGN_MASK) \
103: & ~(jsuword)JS_ARENA_CONST_ALIGN_MASK)
104:
105: #define JS_INIT_ARENA_POOL(pool, name, size) \
106: JS_InitArenaPool(pool, name, size, JS_ARENA_CONST_ALIGN_MASK + 1)
107: #else
108: #define JS_ARENA_ALIGN(pool, n) (((jsuword)(n) + (pool)->mask) & ~(pool)->mask)
109: #endif
110:
111: #define JS_ARENA_ALLOCATE(p, pool, nb) \
112: JS_ARENA_ALLOCATE_CAST(p, void *, pool, nb)
113:
114: #define JS_ARENA_ALLOCATE_TYPE(p, type, pool) \
1.1.1.2 ! root 115: JS_ARENA_ALLOCATE_COMMON(p, type *, pool, sizeof(type), 0)
1.1 root 116:
117: #define JS_ARENA_ALLOCATE_CAST(p, type, pool, nb) \
1.1.1.2 ! root 118: JS_ARENA_ALLOCATE_COMMON(p, type, pool, nb, _nb > _a->limit)
! 119:
! 120: /*
! 121: * NB: In JS_ARENA_ALLOCATE_CAST and JS_ARENA_GROW_CAST, always subtract _nb
! 122: * from a->limit rather than adding _nb to _p, to avoid overflowing a 32-bit
! 123: * address space (possible when running a 32-bit program on a 64-bit system
! 124: * where the kernel maps the heap up against the top of the 32-bit address
! 125: * space).
! 126: *
! 127: * Thanks to Juergen Kreileder <[email protected]>, who brought this up in
! 128: * https://bugzilla.mozilla.org/show_bug.cgi?id=279273.
! 129: */
! 130: #define JS_ARENA_ALLOCATE_COMMON(p, type, pool, nb, guard) \
1.1 root 131: JS_BEGIN_MACRO \
132: JSArena *_a = (pool)->current; \
133: size_t _nb = JS_ARENA_ALIGN(pool, nb); \
134: jsuword _p = _a->avail; \
1.1.1.2 ! root 135: if ((guard) || _p > _a->limit - _nb) \
1.1 root 136: _p = (jsuword)JS_ArenaAllocate(pool, _nb); \
137: else \
1.1.1.2 ! root 138: _a->avail = _p + _nb; \
1.1 root 139: p = (type) _p; \
140: JS_ArenaCountAllocation(pool, nb); \
141: JS_END_MACRO
142:
143: #define JS_ARENA_GROW(p, pool, size, incr) \
144: JS_ARENA_GROW_CAST(p, void *, pool, size, incr)
145:
146: #define JS_ARENA_GROW_CAST(p, type, pool, size, incr) \
147: JS_BEGIN_MACRO \
148: JSArena *_a = (pool)->current; \
149: if (_a->avail == (jsuword)(p) + JS_ARENA_ALIGN(pool, size)) { \
150: size_t _nb = (size) + (incr); \
1.1.1.2 ! root 151: _nb = JS_ARENA_ALIGN(pool, _nb); \
! 152: if (_a->limit >= _nb && (jsuword)(p) <= _a->limit - _nb) { \
! 153: _a->avail = (jsuword)(p) + _nb; \
1.1 root 154: JS_ArenaCountInplaceGrowth(pool, size, incr); \
155: } else if ((jsuword)(p) == _a->base) { \
156: p = (type) JS_ArenaRealloc(pool, p, size, incr); \
157: } else { \
158: p = (type) JS_ArenaGrow(pool, p, size, incr); \
159: } \
160: } else { \
161: p = (type) JS_ArenaGrow(pool, p, size, incr); \
162: } \
163: JS_ArenaCountGrowth(pool, size, incr); \
164: JS_END_MACRO
165:
166: #define JS_ARENA_MARK(pool) ((void *) (pool)->current->avail)
167: #define JS_UPTRDIFF(p,q) ((jsuword)(p) - (jsuword)(q))
168:
169: #ifdef DEBUG
170: #define JS_FREE_PATTERN 0xDA
171: #define JS_CLEAR_UNUSED(a) (JS_ASSERT((a)->avail <= (a)->limit), \
172: memset((void*)(a)->avail, JS_FREE_PATTERN, \
173: (a)->limit - (a)->avail))
174: #define JS_CLEAR_ARENA(a) memset((void*)(a), JS_FREE_PATTERN, \
175: (a)->limit - (jsuword)(a))
176: #else
177: #define JS_CLEAR_UNUSED(a) /* nothing */
178: #define JS_CLEAR_ARENA(a) /* nothing */
179: #endif
180:
181: #define JS_ARENA_RELEASE(pool, mark) \
182: JS_BEGIN_MACRO \
183: char *_m = (char *)(mark); \
184: JSArena *_a = (pool)->current; \
185: if (_a != &(pool)->first && \
186: JS_UPTRDIFF(_m, _a->base) <= JS_UPTRDIFF(_a->avail, _a->base)) { \
187: _a->avail = (jsuword)JS_ARENA_ALIGN(pool, _m); \
188: JS_ASSERT(_a->avail <= _a->limit); \
189: JS_CLEAR_UNUSED(_a); \
190: JS_ArenaCountRetract(pool, _m); \
191: } else { \
192: JS_ArenaRelease(pool, _m); \
193: } \
194: JS_ArenaCountRelease(pool, _m); \
195: JS_END_MACRO
196:
197: #ifdef JS_ARENAMETER
198: #define JS_COUNT_ARENA(pool,op) ((pool)->stats.narenas op)
199: #else
200: #define JS_COUNT_ARENA(pool,op)
201: #endif
202:
203: #define JS_ARENA_DESTROY(pool, a, pnext) \
204: JS_BEGIN_MACRO \
205: JS_COUNT_ARENA(pool,--); \
206: if ((pool)->current == (a)) (pool)->current = &(pool)->first; \
207: *(pnext) = (a)->next; \
208: JS_CLEAR_ARENA(a); \
209: free(a); \
210: (a) = NULL; \
211: JS_END_MACRO
212:
213: /*
214: * Initialize an arena pool with the given name for debugging and metering,
215: * with a minimum size per arena of size bytes.
216: */
217: extern JS_PUBLIC_API(void)
218: JS_InitArenaPool(JSArenaPool *pool, const char *name, size_t size,
219: size_t align);
220:
221: /*
222: * Free the arenas in pool. The user may continue to allocate from pool
223: * after calling this function. There is no need to call JS_InitArenaPool()
224: * again unless JS_FinishArenaPool(pool) has been called.
225: */
226: extern JS_PUBLIC_API(void)
227: JS_FreeArenaPool(JSArenaPool *pool);
228:
229: /*
230: * Free the arenas in pool and finish using it altogether.
231: */
232: extern JS_PUBLIC_API(void)
233: JS_FinishArenaPool(JSArenaPool *pool);
234:
235: /*
1.1.1.2 ! root 236: * Deprecated do-nothing function.
1.1 root 237: */
238: extern JS_PUBLIC_API(void)
239: JS_ArenaFinish(void);
240:
241: /*
1.1.1.2 ! root 242: * Deprecated do-nothing function.
1.1 root 243: */
244: extern JS_PUBLIC_API(void)
245: JS_ArenaShutDown(void);
246:
247: /*
248: * Friend functions used by the JS_ARENA_*() macros.
249: */
250: extern JS_PUBLIC_API(void *)
251: JS_ArenaAllocate(JSArenaPool *pool, size_t nb);
252:
253: extern JS_PUBLIC_API(void *)
254: JS_ArenaRealloc(JSArenaPool *pool, void *p, size_t size, size_t incr);
255:
256: extern JS_PUBLIC_API(void *)
257: JS_ArenaGrow(JSArenaPool *pool, void *p, size_t size, size_t incr);
258:
259: extern JS_PUBLIC_API(void)
260: JS_ArenaRelease(JSArenaPool *pool, char *mark);
261:
262: /*
263: * Function to be used directly when an allocation has likely grown to consume
264: * an entire JSArena, in which case the arena is returned to the malloc heap.
265: */
266: extern JS_PUBLIC_API(void)
267: JS_ArenaFreeAllocation(JSArenaPool *pool, void *p, size_t size);
268:
269: #ifdef JS_ARENAMETER
270:
271: #include <stdio.h>
272:
273: extern JS_PUBLIC_API(void)
274: JS_ArenaCountAllocation(JSArenaPool *pool, size_t nb);
275:
276: extern JS_PUBLIC_API(void)
277: JS_ArenaCountInplaceGrowth(JSArenaPool *pool, size_t size, size_t incr);
278:
279: extern JS_PUBLIC_API(void)
280: JS_ArenaCountGrowth(JSArenaPool *pool, size_t size, size_t incr);
281:
282: extern JS_PUBLIC_API(void)
283: JS_ArenaCountRelease(JSArenaPool *pool, char *mark);
284:
285: extern JS_PUBLIC_API(void)
286: JS_ArenaCountRetract(JSArenaPool *pool, char *mark);
287:
288: extern JS_PUBLIC_API(void)
289: JS_DumpArenaStats(FILE *fp);
290:
291: #else /* !JS_ARENAMETER */
292:
293: #define JS_ArenaCountAllocation(ap, nb) /* nothing */
294: #define JS_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */
295: #define JS_ArenaCountGrowth(ap, size, incr) /* nothing */
296: #define JS_ArenaCountRelease(ap, mark) /* nothing */
297: #define JS_ArenaCountRetract(ap, mark) /* nothing */
298:
299: #endif /* !JS_ARENAMETER */
300:
301: JS_END_EXTERN_C
302:
303: #endif /* jsarena_h___ */
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