diff options
| -rw-r--r-- | runtime/mirror/object.cc | 47 |
1 files changed, 37 insertions, 10 deletions
diff --git a/runtime/mirror/object.cc b/runtime/mirror/object.cc index fbb7c96b58..8e497431ba 100644 --- a/runtime/mirror/object.cc +++ b/runtime/mirror/object.cc @@ -72,18 +72,45 @@ class CopyReferenceFieldsWithReadBarrierVisitor { Object* const dest_obj_; }; -Object* Object::CopyObject(Thread* self, mirror::Object* dest, mirror::Object* src, +Object* Object::CopyObject(Thread* self, + mirror::Object* dest, + mirror::Object* src, size_t num_bytes) { - // Copy instance data. We assume memcpy copies by words. - // TODO: expose and use move32. - uint8_t* src_bytes = reinterpret_cast<uint8_t*>(src); - uint8_t* dst_bytes = reinterpret_cast<uint8_t*>(dest); - size_t offset = sizeof(Object); - memcpy(dst_bytes + offset, src_bytes + offset, num_bytes - offset); + // Copy instance data. Don't assume memcpy copies by words (b/32012820). + { + const size_t offset = sizeof(Object); + uint8_t* src_bytes = reinterpret_cast<uint8_t*>(src) + offset; + uint8_t* dst_bytes = reinterpret_cast<uint8_t*>(dest) + offset; + num_bytes -= offset; + DCHECK_ALIGNED(src_bytes, sizeof(uintptr_t)); + DCHECK_ALIGNED(dst_bytes, sizeof(uintptr_t)); + // Use word sized copies to begin. + while (num_bytes >= sizeof(uintptr_t)) { + *reinterpret_cast<uintptr_t*>(dst_bytes) = *reinterpret_cast<uintptr_t*>(src_bytes); + src_bytes += sizeof(uintptr_t); + dst_bytes += sizeof(uintptr_t); + num_bytes -= sizeof(uintptr_t); + } + // Copy possible 32 bit word. + if (sizeof(uintptr_t) != sizeof(uint32_t) && num_bytes >= sizeof(uint32_t)) { + *reinterpret_cast<uint32_t*>(dst_bytes) = *reinterpret_cast<uint32_t*>(src_bytes); + src_bytes += sizeof(uint32_t); + dst_bytes += sizeof(uint32_t); + num_bytes -= sizeof(uint32_t); + } + // Copy remaining bytes, avoid going past the end of num_bytes since there may be a redzone + // there. + while (num_bytes > 0) { + *reinterpret_cast<uint8_t*>(dst_bytes) = *reinterpret_cast<uint8_t*>(src_bytes); + src_bytes += sizeof(uint8_t); + dst_bytes += sizeof(uint8_t); + num_bytes -= sizeof(uint8_t); + } + } + if (kUseReadBarrier) { - // We need a RB here. After the memcpy that covers the whole - // object above, copy references fields one by one again with a - // RB. TODO: Optimize this later? + // We need a RB here. After copying the whole object above, copy references fields one by one + // again with a RB to make sure there are no from space refs. TODO: Optimize this later? CopyReferenceFieldsWithReadBarrierVisitor visitor(dest); src->VisitReferences(visitor, visitor); } |