Initial commit of upstream NSPR (4.7.3) and NSS3 (3.12).

third_party/nspr/mozilla/nsprpub/lib/ds/plarena.h

Index: third_party/nspr/mozilla/nsprpub/lib/ds/plarena.h
diff --git a/third_party/nspr/mozilla/nsprpub/lib/ds/plarena.h b/third_party/nspr/mozilla/nsprpub/lib/ds/plarena.h
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index 0000000000000000000000000000000000000000..38f3e3990a58fe98820fd053521ccd57aa13973f
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ * 
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are 
+ * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
+ * Rights Reserved.
+ * 
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK *****
+ */
+
+#ifndef plarena_h___
+#define plarena_h___
+/*
+ * Lifetime-based fast allocation, inspired by much prior art, including
+ * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes"
+ * David R. Hanson, Software -- Practice and Experience, Vol. 20(1).
+ *
+ * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE).
+ */
+#include "prtypes.h"
+#include "plarenas.h"
+
+PR_BEGIN_EXTERN_C
+
+typedef struct PLArena          PLArena;
+
+struct PLArena {
+    PLArena     *next;          /* next arena for this lifetime */
+    PRUword     base;           /* aligned base address, follows this header */
+    PRUword     limit;          /* one beyond last byte in arena */
+    PRUword     avail;          /* points to next available byte */
+};
+
+#ifdef PL_ARENAMETER
+typedef struct PLArenaStats PLArenaStats;
+
+struct PLArenaStats {
+    PLArenaStats  *next;        /* next in arenaStats list */
+    char          *name;        /* name for debugging */
+    PRUint32      narenas;      /* number of arenas in pool */
+    PRUint32      nallocs;      /* number of PL_ARENA_ALLOCATE() calls */
+    PRUint32      nreclaims;    /* number of reclaims from freeArenas */
+    PRUint32      nmallocs;     /* number of malloc() calls */
+    PRUint32      ndeallocs;    /* number of lifetime deallocations */
+    PRUint32      ngrows;       /* number of PL_ARENA_GROW() calls */
+    PRUint32      ninplace;     /* number of in-place growths */
+    PRUint32      nreleases;    /* number of PL_ARENA_RELEASE() calls */
+    PRUint32      nfastrels;    /* number of "fast path" releases */
+    PRUint32      nbytes;       /* total bytes allocated */
+    PRUint32      maxalloc;     /* maximum allocation size in bytes */
+    PRFloat64     variance;     /* size variance accumulator */
+};
+#endif
+
+struct PLArenaPool {
+    PLArena     first;          /* first arena in pool list */
+    PLArena     *current;       /* arena from which to allocate space */
+    PRUint32    arenasize;      /* net exact size of a new arena */
+    PRUword     mask;           /* alignment mask (power-of-2 - 1) */
+#ifdef PL_ARENAMETER
+    PLArenaStats stats;
+#endif
+};
+
+/*
+ * If the including .c file uses only one power-of-2 alignment, it may define
+ * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions
+ * per ALLOCATE and GROW.
+ */
+#ifdef PL_ARENA_CONST_ALIGN_MASK
+#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \
+                                & ~PL_ARENA_CONST_ALIGN_MASK)
+
+#define PL_INIT_ARENA_POOL(pool, name, size) \
+        PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1)
+#else
+#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + (pool)->mask) & ~(pool)->mask)
+#endif
+
+#define PL_ARENA_ALLOCATE(p, pool, nb) \
+    PR_BEGIN_MACRO \
+        PLArena *_a = (pool)->current; \
+        PRUint32 _nb = PL_ARENA_ALIGN(pool, nb); \
+        PRUword _p = _a->avail; \
+        PRUword _q = _p + _nb; \
+        if (_q > _a->limit) \
+            _p = (PRUword)PL_ArenaAllocate(pool, _nb); \
+        else \
+            _a->avail = _q; \
+        p = (void *)_p; \
+        PL_ArenaCountAllocation(pool, nb); \
+    PR_END_MACRO
+
+#define PL_ARENA_GROW(p, pool, size, incr) \
+    PR_BEGIN_MACRO \
+        PLArena *_a = (pool)->current; \
+        PRUint32 _incr = PL_ARENA_ALIGN(pool, incr); \
+        PRUword _p = _a->avail; \
+        PRUword _q = _p + _incr; \
+        if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \
+            _q <= _a->limit) { \
+            _a->avail = _q; \
+            PL_ArenaCountInplaceGrowth(pool, size, incr); \
+        } else { \
+            p = PL_ArenaGrow(pool, p, size, incr); \
+        } \
+        PL_ArenaCountGrowth(pool, size, incr); \
+    PR_END_MACRO
+
+#define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail)
+#define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q))
+
+#ifdef DEBUG
+#define PL_FREE_PATTERN 0xDA
+#define PL_CLEAR_UNUSED(a) (PR_ASSERT((a)->avail <= (a)->limit), \
+                           memset((void*)(a)->avail, PL_FREE_PATTERN, \
+                           (a)->limit - (a)->avail))
+#define PL_CLEAR_ARENA(a)  memset((void*)(a), PL_FREE_PATTERN, \
+                           (a)->limit - (PRUword)(a))
+#else
+#define PL_CLEAR_UNUSED(a)
+#define PL_CLEAR_ARENA(a)
+#endif
+
+#define PL_ARENA_RELEASE(pool, mark) \
+    PR_BEGIN_MACRO \
+        char *_m = (char *)(mark); \
+        PLArena *_a = (pool)->current; \
+        if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \
+            _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \
+            PL_CLEAR_UNUSED(_a); \
+            PL_ArenaCountRetract(pool, _m); \
+        } else { \
+            PL_ArenaRelease(pool, _m); \
+        } \
+        PL_ArenaCountRelease(pool, _m); \
+    PR_END_MACRO
+
+#ifdef PL_ARENAMETER
+#define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op)
+#else
+#define PL_COUNT_ARENA(pool,op)
+#endif
+
+#define PL_ARENA_DESTROY(pool, a, pnext) \
+    PR_BEGIN_MACRO \
+        PL_COUNT_ARENA(pool,--); \
+        if ((pool)->current == (a)) (pool)->current = &(pool)->first; \
+        *(pnext) = (a)->next; \
+        PL_CLEAR_ARENA(a); \
+        free(a); \
+        (a) = 0; \
+    PR_END_MACRO
+
+#ifdef PL_ARENAMETER
+
+#include <stdio.h>
+
+PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb);
+
+PR_EXTERN(void) PL_ArenaCountInplaceGrowth(
+    PLArenaPool *pool, PRUint32 size, PRUint32 incr);
+
+PR_EXTERN(void) PL_ArenaCountGrowth(
+    PLArenaPool *pool, PRUint32 size, PRUint32 incr);
+
+PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark);
+
+PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark);
+
+PR_EXTERN(void) PL_DumpArenaStats(FILE *fp);
+
+#else  /* !PL_ARENAMETER */
+
+#define PL_ArenaCountAllocation(ap, nb)                 /* nothing */
+#define PL_ArenaCountInplaceGrowth(ap, size, incr)      /* nothing */
+#define PL_ArenaCountGrowth(ap, size, incr)             /* nothing */
+#define PL_ArenaCountRelease(ap, mark)                  /* nothing */
+#define PL_ArenaCountRetract(ap, mark)                  /* nothing */
+
+#endif /* !PL_ARENAMETER */
+
+PR_END_EXTERN_C
+
+#endif /* plarena_h___ */