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Tip revision: cf84f2eafe2ad1dc4efeefef940acb095dedbe85 authored by ffxbld on 14 March 2012, 14:36:24 UTC
Added FIREFOX_12_0b1_RELEASE FIREFOX_12_0b1_BUILD1 tag(s) for changeset 249ecd7beaf3. DONTBUILD CLOSED TREE a=release
Added FIREFOX_12_0b1_RELEASE FIREFOX_12_0b1_BUILD1 tag(s) for changeset 249ecd7beaf3. DONTBUILD CLOSED TREE a=release
Tip revision: cf84f2e
jspropertycache.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=98:
*
* ***** 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 Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. 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 jspropertycache_h___
#define jspropertycache_h___
#include "jsapi.h"
#include "jsprvtd.h"
#include "jstypes.h"
#include "vm/String.h"
namespace js {
/*
* Property cache with structurally typed capabilities for invalidation, for
* polymorphic callsite method/get/set speedups. For details, see
* <https://developer.mozilla.org/en/SpiderMonkey/Internals/Property_cache>.
*/
class PropertyCache;
struct PropertyCacheEntry
{
jsbytecode *kpc; /* pc of cache-testing bytecode */
const Shape *kshape; /* shape of direct (key) object */
const Shape *pshape; /* shape of owning object */
const Shape *prop; /* shape of accessed property */
friend class PropertyCache;
private:
/* Index into scope chain; inapplicable to property lookup entries. */
uint8_t scopeIndex;
/* Index into the prototype chain from the object for this entry. */
uint8_t protoIndex;
public:
static const size_t MaxScopeIndex = 15;
static const size_t MaxProtoIndex = 15;
/*
* True iff the property lookup will find an own property on the object if
* the entry matches.
*
* This test is applicable only to property lookups, not to identifier
* lookups. It is meaningless to ask this question of an entry for an
* identifier lookup.
*/
bool isOwnPropertyHit() const { return scopeIndex == 0 && protoIndex == 0; }
/*
* True iff the property lookup will find the property on the prototype of
* the object if the entry matches.
*
* This test is applicable only to property lookups, not to identifier
* lookups. It is meaningless to ask this question of an entry for an
* identifier lookup.
*/
bool isPrototypePropertyHit() const { return scopeIndex == 0 && protoIndex == 1; }
void assign(jsbytecode *kpc, const Shape *kshape, const Shape *pshape,
const Shape *prop, uintN scopeIndex, uintN protoIndex) {
JS_ASSERT(scopeIndex <= MaxScopeIndex);
JS_ASSERT(protoIndex <= MaxProtoIndex);
this->kpc = kpc;
this->kshape = kshape;
this->pshape = pshape;
this->prop = prop;
this->scopeIndex = uint8_t(scopeIndex);
this->protoIndex = uint8_t(protoIndex);
}
};
/*
* Special value for functions returning PropertyCacheEntry * to distinguish
* between failure and no no-cache-fill cases.
*/
#define JS_NO_PROP_CACHE_FILL ((js::PropertyCacheEntry *) NULL + 1)
#if defined DEBUG_brendan || defined DEBUG_brendaneich
#define JS_PROPERTY_CACHE_METERING 1
#endif
class PropertyCache
{
private:
enum {
SIZE_LOG2 = 12,
SIZE = JS_BIT(SIZE_LOG2),
MASK = JS_BITMASK(SIZE_LOG2)
};
PropertyCacheEntry table[SIZE];
JSBool empty;
public:
#ifdef JS_PROPERTY_CACHE_METERING
PropertyCacheEntry *pctestentry; /* entry of the last PC-based test */
uint32_t fills; /* number of cache entry fills */
uint32_t nofills; /* couldn't fill (e.g. default get) */
uint32_t rofills; /* set on read-only prop can't fill */
uint32_t disfills; /* fill attempts on disabled cache */
uint32_t oddfills; /* fill attempt after setter deleted */
uint32_t add2dictfills; /* fill attempt on dictionary object */
uint32_t modfills; /* fill that rehashed to a new entry */
uint32_t brandfills; /* scope brandings to type structural
method fills */
uint32_t noprotos; /* resolve-returned non-proto pobj */
uint32_t longchains; /* overlong scope and/or proto chain */
uint32_t recycles; /* cache entries recycled by fills */
uint32_t tests; /* cache probes */
uint32_t pchits; /* fast-path polymorphic op hits */
uint32_t protopchits; /* pchits hitting immediate prototype */
uint32_t initests; /* cache probes from JSOP_INITPROP */
uint32_t inipchits; /* init'ing next property pchit case */
uint32_t inipcmisses; /* init'ing next property pc misses */
uint32_t settests; /* cache probes from JOF_SET opcodes */
uint32_t addpchits; /* adding next property pchit case */
uint32_t setpchits; /* setting existing property pchit */
uint32_t setpcmisses; /* setting/adding property pc misses */
uint32_t setmisses; /* JSOP_SET{NAME,PROP} total misses */
uint32_t kpcmisses; /* slow-path key id == atom misses */
uint32_t kshapemisses; /* slow-path key object misses */
uint32_t vcapmisses; /* value capability misses */
uint32_t misses; /* cache misses */
uint32_t flushes; /* cache flushes */
uint32_t pcpurges; /* shadowing purges on proto chain */
# define PCMETER(x) x
#else
# define PCMETER(x) ((void)0)
#endif
PropertyCache() {
PodZero(this);
}
private:
static inline uintptr_t
hash(jsbytecode *pc, const Shape *kshape)
{
return (((uintptr_t(pc) >> SIZE_LOG2) ^ uintptr_t(pc) ^ ((uintptr_t)kshape >> 3)) & MASK);
}
static inline bool matchShape(JSContext *cx, JSObject *obj, uint32_t shape);
PropertyName *
fullTest(JSContext *cx, jsbytecode *pc, JSObject **objp,
JSObject **pobjp, PropertyCacheEntry *entry);
#ifdef DEBUG
void assertEmpty();
#else
inline void assertEmpty() {}
#endif
public:
JS_ALWAYS_INLINE void test(JSContext *cx, jsbytecode *pc,
JSObject *&obj, JSObject *&pobj,
PropertyCacheEntry *&entry, PropertyName *&name);
/*
* Test for cached information about a property set on *objp at pc.
*
* On a hit, set *entryp to the entry and return true.
*
* On a miss, set *namep to the name of the property being set and return false.
*/
JS_ALWAYS_INLINE bool testForSet(JSContext *cx, jsbytecode *pc, JSObject *obj,
PropertyCacheEntry **entryp, JSObject **obj2p,
PropertyName **namep);
/*
* Fill property cache entry for key cx->fp->pc, optimized value word
* computed from obj and shape, and entry capability forged from 24-bit
* obj->shape(), 4-bit scopeIndex, and 4-bit protoIndex.
*
* Return the filled cache entry or JS_NO_PROP_CACHE_FILL if caching was
* not possible.
*/
PropertyCacheEntry *fill(JSContext *cx, JSObject *obj, uintN scopeIndex,
JSObject *pobj, const js::Shape *shape);
void purge(JSContext *cx);
/* Restore an entry that may have been purged during a GC. */
void restore(PropertyCacheEntry *entry);
};
} /* namespace js */
#endif /* jspropertycache_h___ */