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Always allocate dslots for dense arrays (580877, r=njn).

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This commit is contained in:
Andreas Gal
2010-07-23 15:29:02 -07:00
parent e49d46bc24
commit 7256a2dfc2
5 changed files with 79 additions and 119 deletions
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174
js/src/jsarray.cpp
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@@ -309,21 +309,19 @@ BigIndexToId(JSContext *cx, JSObject *obj, jsuint index, JSBool createAtom,
}
bool
JSObject::resizeDenseArrayElements(JSContext *cx, uint32 oldcap, uint32 newcap,
bool initializeAllSlots)
JSObject::growDenseArrayElements(JSContext *cx, uint32 oldcap, uint32 newcap)
{
JS_ASSERT(isDenseArray());
if (newcap == 0) {
freeDenseArrayElements(cx);
return JS_TRUE;
}
JS_ASSERT(newcap >= ARRAY_CAPACITY_MIN);
JS_ASSERT(newcap >= oldcap);
if (newcap > MAX_DSLOTS_LENGTH32) {
js_ReportAllocationOverflow(cx);
if (!JS_ON_TRACE(cx))
js_ReportAllocationOverflow(cx);
return JS_FALSE;
}
/* dslots can be briefly NULL during array creation */
Value *slots = dslots ? dslots - 1 : NULL;
Value *newslots = (Value *) cx->realloc(slots, (size_t(newcap) + 1) * sizeof(Value));
if (!newslots)
@@ -332,17 +330,15 @@ JSObject::resizeDenseArrayElements(JSContext *cx, uint32 oldcap, uint32 newcap,
dslots = newslots + 1;
setDenseArrayCapacity(newcap);
if (initializeAllSlots) {
Value *base = addressOfDenseArrayElement(0);
for (Value *vp = base + oldcap, *end = base + newcap; vp < end; ++vp)
vp->setMagic(JS_ARRAY_HOLE);
}
Value *base = addressOfDenseArrayElement(0);
for (Value *vp = base + oldcap, *end = base + newcap; vp < end; ++vp)
vp->setMagic(JS_ARRAY_HOLE);
return true;
}
bool
JSObject::ensureDenseArrayElements(JSContext *cx, uint32 newcap, bool initializeAllSlots)
JSObject::ensureDenseArrayElements(JSContext *cx, uint32 newcap)
{
/*
* When a dense array with CAPACITY_DOUBLING_MAX or fewer slots needs to
@@ -359,7 +355,8 @@ JSObject::ensureDenseArrayElements(JSContext *cx, uint32 newcap, bool initialize
*/
static const size_t CAPACITY_CHUNK = 1024 * 1024 / sizeof(Value);
uint32 oldcap = getDenseArrayCapacity();
/* While creating arrays, dslots can be NULL. */
uint32 oldcap = dslots ? getDenseArrayCapacity() : 0;
if (newcap > oldcap) {
/*
@@ -382,21 +379,39 @@ JSObject::ensureDenseArrayElements(JSContext *cx, uint32 newcap, bool initialize
else if (actualCapacity < ARRAY_CAPACITY_MIN)
actualCapacity = ARRAY_CAPACITY_MIN;
if (!resizeDenseArrayElements(cx, oldcap, actualCapacity, initializeAllSlots))
if (!growDenseArrayElements(cx, oldcap, actualCapacity))
return false;
if (!initializeAllSlots) {
/*
* Initialize the slots caller didn't actually ask for.
*/
for (uint32 i = newcap; i < actualCapacity; i++) {
setDenseArrayElement(i, MagicValue(JS_ARRAY_HOLE));
}
}
}
return true;
}
bool
JSObject::shrinkDenseArrayElements(JSContext *cx, uint32 newcap)
{
JS_ASSERT(isDenseArray());
JS_ASSERT(newcap < getDenseArrayCapacity());
JS_ASSERT(dslots);
uint32 fill = newcap;
if (newcap < ARRAY_CAPACITY_MIN)
newcap = ARRAY_CAPACITY_MIN;
Value *newslots = (Value *) cx->realloc(dslots - 1, (size_t(newcap) + 1) * sizeof(Value));
if (!newslots)
return false;
dslots = newslots + 1;
setDenseArrayCapacity(newcap);
/* we refuse to shrink below a minimum value, so we have to clear the excess space */
Value *base = addressOfDenseArrayElement(0);
while (fill < newcap)
base[fill++].setMagic(JS_ARRAY_HOLE);
return true;
}
static bool
ReallyBigIndexToId(JSContext* cx, jsdouble index, jsid* idp)
{
@@ -635,8 +650,8 @@ array_length_setter(JSContext *cx, JSObject *obj, jsid id, Value *vp)
* right of newlen with JS_ARRAY_HOLE. This permits us to disregard
* length when reading from arrays as long we are within the capacity.
*/
jsuint capacity = obj->getDenseArrayCapacity();
if (capacity > newlen && !obj->resizeDenseArrayElements(cx, capacity, newlen))
jsuint oldcap = obj->getDenseArrayCapacity();
if (oldcap > newlen && !obj->shrinkDenseArrayElements(cx, newlen))
return false;
obj->setArrayLength(newlen);
} else if (oldlen - newlen < (1 << 24)) {
@@ -984,8 +999,10 @@ array_trace(JSTracer *trc, JSObject *obj)
JS_ASSERT(obj->isDenseArray());
obj->traceProtoAndParent(trc);
size_t holes = 0;
if (!obj->dslots)
return;
size_t holes = 0;
uint32 capacity = obj->getDenseArrayCapacity();
for (uint32 i = 0; i < capacity; i++) {
Value v = obj->getDenseArrayElement(i);
@@ -1075,7 +1092,8 @@ JSObject::makeDenseArraySlow(JSContext *cx)
if (!scope)
return JS_FALSE;
uint32 capacity = obj->getDenseArrayCapacity();
/* For a brief moment the class object has NULL dslots until we slowify it during construction. */
uint32 capacity = dslots ? obj->getDenseArrayCapacity() : 0;
if (capacity) {
scope->freeslot = obj->numSlots() + JS_INITIAL_NSLOTS;
// XXX: changing the capacity like this is awful. Bug 558263 will remove
@@ -1454,20 +1472,14 @@ InitArrayObject(JSContext *cx, JSObject *obj, jsuint length, const Value *vector
{
JS_ASSERT(obj->isArray());
if (vector) {
JS_ASSERT(obj->isDenseArray());
obj->setArrayLength(length);
if (!obj->ensureDenseArrayElements(cx, length))
return JS_FALSE;
memcpy(obj->getDenseArrayElements(), vector, length * sizeof(Value));
} else {
if (obj->isDenseArray()) {
obj->setArrayLength(length);
} else {
obj->setArrayLength(length);
}
}
return JS_TRUE;
JS_ASSERT(obj->isDenseArray());
obj->setArrayLength(length);
if (!vector || !length)
return obj->ensureDenseArrayElements(cx, ARRAY_CAPACITY_MIN);
if (!obj->ensureDenseArrayElements(cx, length))
return false;
memcpy(obj->getDenseArrayElements(), vector, length * sizeof(Value));
return true;
}
/*
@@ -2986,7 +2998,7 @@ js_Array(JSContext *cx, JSObject *obj, uintN argc, Value *argv, Value *rval)
}
JSObject* JS_FASTCALL
js_NewEmptyArray(JSContext* cx, JSObject* proto)
js_NewArrayWithSlots(JSContext* cx, JSObject* proto, uint32 len)
{
JS_ASSERT(proto->isArray());
@@ -2996,39 +3008,9 @@ js_NewEmptyArray(JSContext* cx, JSObject* proto)
/* Initialize all fields of JSObject. */
obj->map = const_cast<JSObjectMap *>(&SharedArrayMap);
obj->init(&js_ArrayClass, proto, proto->getParent(), NullValue());
obj->setArrayLength(0);
return obj;
}
#ifdef JS_TRACER
JS_DEFINE_CALLINFO_2(extern, OBJECT, js_NewEmptyArray, CONTEXT, OBJECT, 0, nanojit::ACC_STORE_ANY)
#endif
JSObject* JS_FASTCALL
js_NewEmptyArrayWithLength(JSContext* cx, JSObject* proto, int32 len)
{
if (len < 0)
return NULL;
JSObject *obj = js_NewEmptyArray(cx, proto);
if (!obj)
return NULL;
obj->setArrayLength(len);
return obj;
}
#ifdef JS_TRACER
JS_DEFINE_CALLINFO_3(extern, OBJECT, js_NewEmptyArrayWithLength, CONTEXT, OBJECT, INT32, 0,
nanojit::ACC_STORE_ANY)
#endif
JSObject* JS_FASTCALL
js_NewArrayWithSlots(JSContext* cx, JSObject* proto, uint32 len)
{
JSObject* obj = js_NewEmptyArray(cx, proto);
if (!obj)
return NULL;
obj->setArrayLength(len);
if (!obj->resizeDenseArrayElements(cx, 0, JS_MAX(len, ARRAY_CAPACITY_MIN)))
if (!obj->growDenseArrayElements(cx, 0, JS_MAX(len, ARRAY_CAPACITY_MIN)))
return NULL;
return obj;
}
@@ -3037,15 +3019,24 @@ JS_DEFINE_CALLINFO_3(extern, OBJECT, js_NewArrayWithSlots, CONTEXT, OBJECT, UINT
nanojit::ACC_STORE_ANY)
#endif
JSObject* JS_FASTCALL
js_NewEmptyArray(JSContext* cx, JSObject* proto)
{
return js_NewArrayWithSlots(cx, proto, 0);
}
#ifdef JS_TRACER
JS_DEFINE_CALLINFO_2(extern, OBJECT, js_NewEmptyArray, CONTEXT, OBJECT, 0, nanojit::ACC_STORE_ANY)
#endif
JSObject *
js_InitArrayClass(JSContext *cx, JSObject *obj)
{
JSObject *proto = js_InitClass(cx, obj, NULL, &js_ArrayClass, js_Array, 1,
NULL, array_methods, NULL, array_static_methods);
/* Initialize the Array prototype object so it gets a length property. */
if (!proto || !InitArrayObject(cx, proto, 0, NULL))
if (!proto)
return NULL;
proto->setArrayLength(0);
return proto;
}
@@ -3173,26 +3164,6 @@ js_CoerceArrayToCanvasImageData(JSObject *obj, jsuint offset, jsuint count,
return JS_TRUE;
}
JS_FRIEND_API(JSObject *)
js_NewArrayObjectWithCapacity(JSContext *cx, uint32_t capacity, jsval **vector)
{
JSObject *obj = js_NewArrayObject(cx, capacity, NULL);
if (!obj)
return NULL;
AutoObjectRooter tvr(cx, obj);
if (!obj->ensureDenseArrayElements(cx, capacity, JS_FALSE))
obj = NULL;
/* Set/clear newborn root, in case we lost it. */
cx->weakRoots.finalizableNewborns[FINALIZE_OBJECT] = obj;
if (!obj)
return NULL;
*vector = Jsvalify(obj->getDenseArrayElements());
return obj;
}
JS_FRIEND_API(JSBool)
js_IsDensePrimitiveArray(JSObject *obj)
{
@@ -3255,14 +3226,9 @@ js_CloneDensePrimitiveArray(JSContext *cx, JSObject *obj, JSObject **clone)
vector.append(val);
}
jsval *buffer;
*clone = js_NewArrayObjectWithCapacity(cx, jsvalCount, &buffer);
*clone = js_NewArrayObject(cx, jsvalCount, vector.begin());
if (!*clone)
return JS_FALSE;
AutoObjectRooter cloneRoot(cx, *clone);
memcpy(buffer, vector.begin(), jsvalCount * sizeof (jsval));
(*clone)->setArrayLength(length);
return JS_TRUE;