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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 nreclaims; /* number of reclaims from freeArenas */
74: uint32 nmallocs; /* number of malloc() calls */
75: uint32 ndeallocs; /* number of lifetime deallocations */
76: uint32 ngrows; /* number of JS_ARENA_GROW() calls */
77: uint32 ninplace; /* number of in-place growths */
78: uint32 nreallocs; /* number of arena grow extending reallocs */
79: uint32 nreleases; /* number of JS_ARENA_RELEASE() calls */
80: uint32 nfastrels; /* number of "fast path" releases */
81: size_t nbytes; /* total bytes allocated */
82: size_t maxalloc; /* maximum allocation size in bytes */
83: double variance; /* size variance accumulator */
84: };
85: #endif
86:
87: struct JSArenaPool {
88: JSArena first; /* first arena in pool list */
89: JSArena *current; /* arena from which to allocate space */
90: size_t arenasize; /* net exact size of a new arena */
91: jsuword mask; /* alignment mask (power-of-2 - 1) */
92: #ifdef JS_ARENAMETER
93: JSArenaStats stats;
94: #endif
95: };
96:
97: /*
98: * If the including .c file uses only one power-of-2 alignment, it may define
99: * JS_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions
100: * per ALLOCATE and GROW.
101: */
102: #ifdef JS_ARENA_CONST_ALIGN_MASK
103: #define JS_ARENA_ALIGN(pool, n) (((jsuword)(n) + JS_ARENA_CONST_ALIGN_MASK) \
104: & ~(jsuword)JS_ARENA_CONST_ALIGN_MASK)
105:
106: #define JS_INIT_ARENA_POOL(pool, name, size) \
107: JS_InitArenaPool(pool, name, size, JS_ARENA_CONST_ALIGN_MASK + 1)
108: #else
109: #define JS_ARENA_ALIGN(pool, n) (((jsuword)(n) + (pool)->mask) & ~(pool)->mask)
110: #endif
111:
112: #define JS_ARENA_ALLOCATE(p, pool, nb) \
113: JS_ARENA_ALLOCATE_CAST(p, void *, pool, nb)
114:
115: #define JS_ARENA_ALLOCATE_TYPE(p, type, pool) \
116: JS_ARENA_ALLOCATE_CAST(p, type *, pool, sizeof(type))
117:
118: #define JS_ARENA_ALLOCATE_CAST(p, type, pool, nb) \
119: JS_BEGIN_MACRO \
120: JSArena *_a = (pool)->current; \
121: size_t _nb = JS_ARENA_ALIGN(pool, nb); \
122: jsuword _p = _a->avail; \
123: jsuword _q = _p + _nb; \
124: JS_ASSERT(_q >= _p); \
125: if (_q > _a->limit) \
126: _p = (jsuword)JS_ArenaAllocate(pool, _nb); \
127: else \
128: _a->avail = _q; \
129: p = (type) _p; \
130: JS_ArenaCountAllocation(pool, nb); \
131: JS_END_MACRO
132:
133: #define JS_ARENA_GROW(p, pool, size, incr) \
134: JS_ARENA_GROW_CAST(p, void *, pool, size, incr)
135:
136: #define JS_ARENA_GROW_CAST(p, type, pool, size, incr) \
137: JS_BEGIN_MACRO \
138: JSArena *_a = (pool)->current; \
139: if (_a->avail == (jsuword)(p) + JS_ARENA_ALIGN(pool, size)) { \
140: size_t _nb = (size) + (incr); \
141: jsuword _q = (jsuword)(p) + JS_ARENA_ALIGN(pool, _nb); \
142: if (_q <= _a->limit) { \
143: _a->avail = _q; \
144: JS_ArenaCountInplaceGrowth(pool, size, incr); \
145: } else if ((jsuword)(p) == _a->base) { \
146: p = (type) JS_ArenaRealloc(pool, p, size, incr); \
147: } else { \
148: p = (type) JS_ArenaGrow(pool, p, size, incr); \
149: } \
150: } else { \
151: p = (type) JS_ArenaGrow(pool, p, size, incr); \
152: } \
153: JS_ArenaCountGrowth(pool, size, incr); \
154: JS_END_MACRO
155:
156: #define JS_ARENA_MARK(pool) ((void *) (pool)->current->avail)
157: #define JS_UPTRDIFF(p,q) ((jsuword)(p) - (jsuword)(q))
158:
159: #ifdef DEBUG
160: #define JS_FREE_PATTERN 0xDA
161: #define JS_CLEAR_UNUSED(a) (JS_ASSERT((a)->avail <= (a)->limit), \
162: memset((void*)(a)->avail, JS_FREE_PATTERN, \
163: (a)->limit - (a)->avail))
164: #define JS_CLEAR_ARENA(a) memset((void*)(a), JS_FREE_PATTERN, \
165: (a)->limit - (jsuword)(a))
166: #else
167: #define JS_CLEAR_UNUSED(a) /* nothing */
168: #define JS_CLEAR_ARENA(a) /* nothing */
169: #endif
170:
171: #define JS_ARENA_RELEASE(pool, mark) \
172: JS_BEGIN_MACRO \
173: char *_m = (char *)(mark); \
174: JSArena *_a = (pool)->current; \
175: if (_a != &(pool)->first && \
176: JS_UPTRDIFF(_m, _a->base) <= JS_UPTRDIFF(_a->avail, _a->base)) { \
177: _a->avail = (jsuword)JS_ARENA_ALIGN(pool, _m); \
178: JS_ASSERT(_a->avail <= _a->limit); \
179: JS_CLEAR_UNUSED(_a); \
180: JS_ArenaCountRetract(pool, _m); \
181: } else { \
182: JS_ArenaRelease(pool, _m); \
183: } \
184: JS_ArenaCountRelease(pool, _m); \
185: JS_END_MACRO
186:
187: #ifdef JS_ARENAMETER
188: #define JS_COUNT_ARENA(pool,op) ((pool)->stats.narenas op)
189: #else
190: #define JS_COUNT_ARENA(pool,op)
191: #endif
192:
193: #define JS_ARENA_DESTROY(pool, a, pnext) \
194: JS_BEGIN_MACRO \
195: JS_COUNT_ARENA(pool,--); \
196: if ((pool)->current == (a)) (pool)->current = &(pool)->first; \
197: *(pnext) = (a)->next; \
198: JS_CLEAR_ARENA(a); \
199: free(a); \
200: (a) = NULL; \
201: JS_END_MACRO
202:
203: /*
204: * Initialize an arena pool with the given name for debugging and metering,
205: * with a minimum size per arena of size bytes.
206: */
207: extern JS_PUBLIC_API(void)
208: JS_InitArenaPool(JSArenaPool *pool, const char *name, size_t size,
209: size_t align);
210:
211: /*
212: * Free the arenas in pool. The user may continue to allocate from pool
213: * after calling this function. There is no need to call JS_InitArenaPool()
214: * again unless JS_FinishArenaPool(pool) has been called.
215: */
216: extern JS_PUBLIC_API(void)
217: JS_FreeArenaPool(JSArenaPool *pool);
218:
219: /*
220: * Free the arenas in pool and finish using it altogether.
221: */
222: extern JS_PUBLIC_API(void)
223: JS_FinishArenaPool(JSArenaPool *pool);
224:
225: /*
226: * Finish using arenas, freeing all memory associated with them except for
227: * any locks needed for thread safety.
228: */
229: extern JS_PUBLIC_API(void)
230: JS_ArenaFinish(void);
231:
232: /*
233: * Free any locks or other memory needed for thread safety, just before
234: * shutting down. At that point, we must be called by a single thread.
235: *
236: * After shutting down, the next thread to call JS_InitArenaPool must not
237: * race with any other thread. Once a pool has been initialized, threads
238: * may safely call jsarena.c functions on thread-local pools. The upshot
239: * is that pools are per-thread, but the underlying global freelist is
240: * thread-safe, provided that both the first pool initialization and the
241: * shut-down call are single-threaded.
242: */
243: extern JS_PUBLIC_API(void)
244: JS_ArenaShutDown(void);
245:
246: /*
247: * Friend functions used by the JS_ARENA_*() macros.
248: */
249: extern JS_PUBLIC_API(void *)
250: JS_ArenaAllocate(JSArenaPool *pool, size_t nb);
251:
252: extern JS_PUBLIC_API(void *)
253: JS_ArenaRealloc(JSArenaPool *pool, void *p, size_t size, size_t incr);
254:
255: extern JS_PUBLIC_API(void *)
256: JS_ArenaGrow(JSArenaPool *pool, void *p, size_t size, size_t incr);
257:
258: extern JS_PUBLIC_API(void)
259: JS_ArenaRelease(JSArenaPool *pool, char *mark);
260:
261: /*
262: * Function to be used directly when an allocation has likely grown to consume
263: * an entire JSArena, in which case the arena is returned to the malloc heap.
264: */
265: extern JS_PUBLIC_API(void)
266: JS_ArenaFreeAllocation(JSArenaPool *pool, void *p, size_t size);
267:
268: #ifdef JS_ARENAMETER
269:
270: #include <stdio.h>
271:
272: extern JS_PUBLIC_API(void)
273: JS_ArenaCountAllocation(JSArenaPool *pool, size_t nb);
274:
275: extern JS_PUBLIC_API(void)
276: JS_ArenaCountInplaceGrowth(JSArenaPool *pool, size_t size, size_t incr);
277:
278: extern JS_PUBLIC_API(void)
279: JS_ArenaCountGrowth(JSArenaPool *pool, size_t size, size_t incr);
280:
281: extern JS_PUBLIC_API(void)
282: JS_ArenaCountRelease(JSArenaPool *pool, char *mark);
283:
284: extern JS_PUBLIC_API(void)
285: JS_ArenaCountRetract(JSArenaPool *pool, char *mark);
286:
287: extern JS_PUBLIC_API(void)
288: JS_DumpArenaStats(FILE *fp);
289:
290: #else /* !JS_ARENAMETER */
291:
292: #define JS_ArenaCountAllocation(ap, nb) /* nothing */
293: #define JS_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */
294: #define JS_ArenaCountGrowth(ap, size, incr) /* nothing */
295: #define JS_ArenaCountRelease(ap, mark) /* nothing */
296: #define JS_ArenaCountRetract(ap, mark) /* nothing */
297:
298: #endif /* !JS_ARENAMETER */
299:
300: JS_END_EXTERN_C
301:
302: #endif /* jsarena_h___ */
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