mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-10 03:45:46 +00:00
287 lines
11 KiB
C++
287 lines
11 KiB
C++
/* -*- 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"
|
|
|
|
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>.
|
|
*/
|
|
|
|
/* Property cache value capabilities. */
|
|
enum {
|
|
PCVCAP_PROTOBITS = 4,
|
|
PCVCAP_PROTOSIZE = JS_BIT(PCVCAP_PROTOBITS),
|
|
PCVCAP_PROTOMASK = JS_BITMASK(PCVCAP_PROTOBITS),
|
|
|
|
PCVCAP_SCOPEBITS = 4,
|
|
PCVCAP_SCOPESIZE = JS_BIT(PCVCAP_SCOPEBITS),
|
|
PCVCAP_SCOPEMASK = JS_BITMASK(PCVCAP_SCOPEBITS),
|
|
|
|
PCVCAP_TAGBITS = PCVCAP_PROTOBITS + PCVCAP_SCOPEBITS,
|
|
PCVCAP_TAGMASK = JS_BITMASK(PCVCAP_TAGBITS)
|
|
};
|
|
|
|
const uint32 SHAPE_OVERFLOW_BIT = JS_BIT(32 - PCVCAP_TAGBITS);
|
|
|
|
/*
|
|
* Property cache value. This is simply a tagged union:
|
|
* PCVal = (JSObject * | uint32 | js::Shape *).
|
|
* It is the type of PropertyCacheEntry::vword and combines with the tag bits
|
|
* of PropertyCacheEntry::vcap to tell how to get or set the property, once a
|
|
* property cache hit is validated.
|
|
*
|
|
* PropertyCache::purge depends on the bit-pattern of a null PCVal being 0.
|
|
*/
|
|
class PCVal
|
|
{
|
|
private:
|
|
enum {
|
|
OBJECT = 0,
|
|
SLOT = 1,
|
|
SHAPE = 2,
|
|
TAG = 3
|
|
};
|
|
|
|
jsuword v;
|
|
|
|
public:
|
|
bool isNull() const { return v == 0; }
|
|
void setNull() { v = 0; }
|
|
|
|
bool isFunObj() const { return (v & TAG) == OBJECT; }
|
|
JSObject &toFunObj() const {
|
|
JS_ASSERT(isFunObj());
|
|
return *reinterpret_cast<JSObject *>(v);
|
|
}
|
|
void setFunObj(JSObject &obj) {
|
|
v = reinterpret_cast<jsuword>(&obj);
|
|
}
|
|
|
|
bool isSlot() const { return v & SLOT; }
|
|
uint32 toSlot() const { JS_ASSERT(isSlot()); return uint32(v) >> 1; }
|
|
void setSlot(uint32 slot) { v = (jsuword(slot) << 1) | SLOT; }
|
|
|
|
bool isShape() const { return (v & TAG) == SHAPE; }
|
|
const js::Shape *toShape() const {
|
|
JS_ASSERT(isShape());
|
|
return reinterpret_cast<js::Shape *>(v & ~TAG);
|
|
}
|
|
void setShape(const js::Shape *shape) {
|
|
JS_ASSERT(shape);
|
|
v = reinterpret_cast<jsuword>(shape) | SHAPE;
|
|
}
|
|
};
|
|
|
|
struct PropertyCacheEntry
|
|
{
|
|
jsbytecode *kpc; /* pc of cache-testing bytecode */
|
|
jsuword kshape; /* shape of direct (key) object */
|
|
jsuword vcap; /* value capability, see above */
|
|
PCVal vword; /* value word, see PCVal above */
|
|
|
|
bool adding() const { return vcapTag() == 0 && kshape != vshape(); }
|
|
bool directHit() const { return vcapTag() == 0 && kshape == vshape(); }
|
|
|
|
jsuword vcapTag() const { return vcap & PCVCAP_TAGMASK; }
|
|
uint32 vshape() const { return uint32(vcap >> PCVCAP_TAGBITS); }
|
|
jsuword scopeIndex() const { return (vcap >> PCVCAP_PROTOBITS) & PCVCAP_SCOPEMASK; }
|
|
jsuword protoIndex() const { return vcap & PCVCAP_PROTOMASK; }
|
|
|
|
void assign(jsbytecode *kpc, jsuword kshape, jsuword vshape,
|
|
uintN scopeIndex, uintN protoIndex, PCVal vword) {
|
|
JS_ASSERT(kshape < SHAPE_OVERFLOW_BIT);
|
|
JS_ASSERT(vshape < SHAPE_OVERFLOW_BIT);
|
|
JS_ASSERT(scopeIndex <= PCVCAP_SCOPEMASK);
|
|
JS_ASSERT(protoIndex <= PCVCAP_PROTOMASK);
|
|
|
|
this->kpc = kpc;
|
|
this->kshape = kshape;
|
|
this->vcap = (vshape << PCVCAP_TAGBITS) | (scopeIndex << PCVCAP_PROTOBITS) | protoIndex;
|
|
this->vword = vword;
|
|
}
|
|
};
|
|
|
|
/*
|
|
* 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 fills; /* number of cache entry fills */
|
|
uint32 nofills; /* couldn't fill (e.g. default get) */
|
|
uint32 rofills; /* set on read-only prop can't fill */
|
|
uint32 disfills; /* fill attempts on disabled cache */
|
|
uint32 oddfills; /* fill attempt after setter deleted */
|
|
uint32 add2dictfills; /* fill attempt on dictionary object */
|
|
uint32 modfills; /* fill that rehashed to a new entry */
|
|
uint32 brandfills; /* scope brandings to type structural
|
|
method fills */
|
|
uint32 noprotos; /* resolve-returned non-proto pobj */
|
|
uint32 longchains; /* overlong scope and/or proto chain */
|
|
uint32 recycles; /* cache entries recycled by fills */
|
|
uint32 tests; /* cache probes */
|
|
uint32 pchits; /* fast-path polymorphic op hits */
|
|
uint32 protopchits; /* pchits hitting immediate prototype */
|
|
uint32 initests; /* cache probes from JSOP_INITPROP */
|
|
uint32 inipchits; /* init'ing next property pchit case */
|
|
uint32 inipcmisses; /* init'ing next property pc misses */
|
|
uint32 settests; /* cache probes from JOF_SET opcodes */
|
|
uint32 addpchits; /* adding next property pchit case */
|
|
uint32 setpchits; /* setting existing property pchit */
|
|
uint32 setpcmisses; /* setting/adding property pc misses */
|
|
uint32 setmisses; /* JSOP_SET{NAME,PROP} total misses */
|
|
uint32 kpcmisses; /* slow-path key id == atom misses */
|
|
uint32 kshapemisses; /* slow-path key object misses */
|
|
uint32 vcapmisses; /* value capability misses */
|
|
uint32 misses; /* cache misses */
|
|
uint32 flushes; /* cache flushes */
|
|
uint32 pcpurges; /* shadowing purges on proto chain */
|
|
|
|
# define PCMETER(x) x
|
|
#else
|
|
# define PCMETER(x) ((void)0)
|
|
#endif
|
|
|
|
PropertyCache() {
|
|
PodZero(this);
|
|
}
|
|
|
|
private:
|
|
/*
|
|
* Add kshape rather than xor it to avoid collisions between nearby bytecode
|
|
* that are evolving an object by setting successive properties, incrementing
|
|
* the object's shape on each set.
|
|
*/
|
|
static inline jsuword
|
|
hash(jsbytecode *pc, jsuword kshape)
|
|
{
|
|
return ((((jsuword(pc) >> SIZE_LOG2) ^ jsuword(pc)) + kshape) & MASK);
|
|
}
|
|
|
|
static inline bool matchShape(JSContext *cx, JSObject *obj, uint32 shape);
|
|
|
|
JS_REQUIRES_STACK JSAtom *fullTest(JSContext *cx, jsbytecode *pc, JSObject **objp,
|
|
JSObject **pobjp, PropertyCacheEntry *entry);
|
|
|
|
#ifdef DEBUG
|
|
void assertEmpty();
|
|
#else
|
|
inline void assertEmpty() {}
|
|
#endif
|
|
|
|
public:
|
|
JS_ALWAYS_INLINE JS_REQUIRES_STACK void test(JSContext *cx, jsbytecode *pc,
|
|
JSObject *&obj, JSObject *&pobj,
|
|
PropertyCacheEntry *&entry, JSAtom *&atom);
|
|
|
|
/*
|
|
* 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 *atomp 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,
|
|
JSAtom **atomp);
|
|
|
|
/*
|
|
* Test for cached information about creating a new own data property on obj at pc.
|
|
*
|
|
* On a hit, set *shapep to an shape from the property tree describing the
|
|
* new property as well as all existing properties on obj and return
|
|
* true. Otherwise return false.
|
|
*
|
|
* Hit or miss, *entryp receives a pointer to the property cache entry.
|
|
*/
|
|
JS_ALWAYS_INLINE bool testForInit(JSRuntime *rt, jsbytecode *pc, JSObject *obj,
|
|
const js::Shape **shapep, PropertyCacheEntry **entryp);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
JS_REQUIRES_STACK PropertyCacheEntry *fill(JSContext *cx, JSObject *obj, uintN scopeIndex,
|
|
JSObject *pobj, const js::Shape *shape,
|
|
JSBool adding = false);
|
|
|
|
void purge(JSContext *cx);
|
|
void purgeForScript(JSContext *cx, JSScript *script);
|
|
|
|
/* Restore an entry that may have been purged during a GC. */
|
|
void restore(PropertyCacheEntry *entry);
|
|
};
|
|
|
|
} /* namespace js */
|
|
|
|
#endif /* jspropertycache_h___ */
|