Hi,
I'm doing some profiling of pdf.js, and I would like to get the
allocation point for every object, either when it's allocated, and/or
when the JS memory reporter runs. This is for some ad hoc profiling --
I just want to dump the info to stderr so I can post-process it -- so
it doesn't need to be neat and tidy.
I have a patch that attempts the former (see below). It gives
semi-reasonable results, but I'm suspicious that they might just be
lies. In particular, the ExclusiveContext-to-JSContexts are highly
dubious. I also wonder if this misses objects created from jitted
code.
Suggestions on how to do this properly would be appreciated. The
object metadata stuff is probably a better way to proceed here...
Nick
diff --git a/js/src/jsarray.cpp b/js/src/jsarray.cpp
--- a/js/src/jsarray.cpp
+++ b/js/src/jsarray.cpp
@@ -3136,16 +3136,24 @@ template<bool allocateCapacity>
static MOZ_ALWAYS_INLINE ArrayObject *
NewArray(ExclusiveContext *cxArg, uint32_t length,
JSObject *protoArg, NewObjectKind newKind = GenericObject)
{
gc::AllocKind allocKind = GuessArrayGCKind(length);
JS_ASSERT(CanBeFinalizedInBackground(allocKind, &ArrayObject::class_));
allocKind = GetBackgroundAllocKind(allocKind);
+ // njn: temp
+ JS::Rooted<JSScript*> script(cxArg);
+ unsigned lineno;
+ if (JS_DescribeScriptedCaller((JSContext*)cxArg, &script, &lineno)) {
+ fprintf(stderr, "a: %s, %d, %u\n",
JS_GetScriptFilename((JSContext*)cxArg, script), lineno, length);
+ }
+
+
NewObjectCache::EntryIndex entry = -1;
if (JSContext *cx = cxArg->maybeJSContext()) {
NewObjectCache &cache = cx->runtime()->newObjectCache;
if (newKind == GenericObject &&
!cx->compartment()->hasObjectMetadataCallback() &&
cache.lookupGlobal(&ArrayObject::class_, cx->global(),
allocKind, &entry))
{
RootedObject obj(cx, cache.newObjectFromHit(cx, entry,
diff --git a/js/src/jsobj.cpp b/js/src/jsobj.cpp
--- a/js/src/jsobj.cpp
+++ b/js/src/jsobj.cpp
@@ -1245,16 +1245,23 @@ NewObject(ExclusiveContext *cx, types::T
{
const Class *clasp = type_->clasp();
JS_ASSERT(clasp != &ArrayObject::class_);
JS_ASSERT_IF(clasp == &JSFunction::class_,
kind == JSFunction::FinalizeKind || kind ==
JSFunction::ExtendedFinalizeKind);
JS_ASSERT_IF(parent, &parent->global() == cx->global());
+ // njn: temp
+ JS::Rooted<JSScript*> script(cx);
+ unsigned lineno;
+ if (JS_DescribeScriptedCaller((JSContext*)cx, &script, &lineno)) {
+ fprintf(stderr, "o: %s, %d\n",
JS_GetScriptFilename((JSContext*)cx, script), lineno);
+ }
+
RootedTypeObject type(cx, type_);
JSObject *metadata = nullptr;
if (!NewObjectMetadata(cx, &metadata))
return nullptr;
RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp,
type->proto(),
parent, metadata, kind));
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