diff options
| -rw-r--r-- | src/qml/jsruntime/qv4arraydata.cpp | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/src/qml/jsruntime/qv4arraydata.cpp b/src/qml/jsruntime/qv4arraydata.cpp index 6d1fb62e0a..dac899e23f 100644 --- a/src/qml/jsruntime/qv4arraydata.cpp +++ b/src/qml/jsruntime/qv4arraydata.cpp @@ -235,18 +235,39 @@ void ArrayData::ensureAttributes(Object *o) ArrayData::realloc(o, Heap::ArrayData::Simple, 0, true); } +// Note: This function, and the calls from SimpleArrayData::markObjects, is a partial backport +// of the functionality of ValueArray in 5.11. It prevents huge arrays to overflow the JS stack +// during the mark phase by draining it while marking the array contents. +static void drainMarkStack(QV4::ExecutionEngine *engine, Value *markBase) +{ + while (engine->jsStackTop > markBase) { + Heap::Base *h = engine->popForGC(); + Q_ASSERT(h); // at this point we should only have Heap::Base objects in this area on the stack. If not, weird things might happen. + Q_ASSERT (h->vtable()->markObjects); + h->vtable()->markObjects(h, engine); + } +} void SimpleArrayData::markObjects(Heap::Base *d, ExecutionEngine *e) { + Value *markBase = e->jsStackTop; + const auto *maxMarkStack = markBase + 32 * 1024; + Heap::SimpleArrayData *dd = static_cast<Heap::SimpleArrayData *>(d); uint end = dd->offset + dd->len; if (end > dd->alloc) { - for (uint i = 0; i < end - dd->alloc; ++i) + for (uint i = 0; i < end - dd->alloc; ++i) { + if (e->jsStackTop > maxMarkStack) + drainMarkStack(e, markBase); dd->arrayData[i].mark(e); + } end = dd->alloc; } - for (uint i = dd->offset; i < end; ++i) + for (uint i = dd->offset; i < end; ++i) { + if (e->jsStackTop > maxMarkStack) + drainMarkStack(e, markBase); dd->arrayData[i].mark(e); + } } ReturnedValue SimpleArrayData::get(const Heap::ArrayData *d, uint index) |