Created attachment 582396 [details] [diff] [review] v1: barriers on slots and elements. This adds an "after(.*)RangeOverwritten" to match the existing "prepare(.*)RangeForOverwrite" methods and adds calls to them where needed in the object implementation to properly trigger post-write barriers. Ironically, this undoes the changes to copyDenseArrayElements I made yesterday: this is a more general solution, applicable in more places (and probably faster as well). This also removes the void* parameter to HeapValue::writeBarrierPost. Unlike with the HeapPtr, HeapValue needs to know that addr has Value* type in order to deref it safely. Because of this, we can't use the addr parameter in HeapValue::writeBarrierPost. I added it to this patch because this is the first place we use the function directly and not through operator=.
Created attachment 583027 [details] [diff] [review] v2: Uses loops everywhere. This is quite a bit clearer.
Comment on attachment 583027 [details] [diff] [review] v2: Uses loops everywhere. Review of attachment 583027 [details] [diff] [review]: ----------------------------------------------------------------- ::: js/src/jsobj.cpp @@ +4509,5 @@ > ps, fs, static_ps, static_fs, ctorp, ctorKind); > } > > void > +JSObject::initSlotRange(size_t start, const Value *vector, size_t length) How about adding a getSlotRange method? It would use the current branching logic to generate four things: fixedStart, fixedEnd, slotsStart, slotsEnd These would be returned as HeapValue** parameters. Then the code for initSlotRange would be: getSlotRange(&fixedStart, &fixedEnd, &slotsStart, &slotsEnd); for (HeapValue *vp = fixedStart; vp != fixedEnd; vp++) vp->init(comp, *vector++); for (HeapValue *vp = slotsStart; vp != slotsEnd; vp++) vp->init(comp, *vector++); And the code for copySlotRange would be similar, except that it would use set instead of init. ::: js/src/jsobj.h @@ +702,5 @@ > inline void prepareElementRangeForOverwrite(size_t start, size_t end); > > /* > + * Initialize a flat array of slots to this object at a start slot. The > + * caller must ensure that are enough slots. Let's rewrite this. How about: "Initialize the slots in the range [start, start+length) to values from vector. The caller must ensure that there are enough slots."
Created attachment 584639 [details] [diff] [review] v3: With review feedback. For posterity, since there was a bit of reworking needed.