blob: 23bc6cf8db6839d0cab30e06c16b3abb44262972 [file] [log] [blame]
// Copyright 2011 Google Inc. All Rights Reserved.
#include "image_writer.h"
#include <sys/mman.h>
#include <vector>
#include "UniquePtr.h"
#include "class_linker.h"
#include "class_loader.h"
#include "dex_cache.h"
#include "file.h"
#include "globals.h"
#include "heap.h"
#include "image.h"
#include "intern_table.h"
#include "logging.h"
#include "object.h"
#include "runtime.h"
#include "space.h"
#include "utils.h"
namespace art {
bool ImageWriter::Write(const char* filename, uintptr_t image_base) {
CHECK_NE(image_base, 0U);
image_base_ = reinterpret_cast<byte*>(image_base);
const std::vector<Space*>& spaces = Heap::GetSpaces();
// currently just write the last space, assuming it is the space that was being used for allocation
CHECK_GE(spaces.size(), 1U);
source_space_ = spaces[spaces.size()-1];
if (!Init()) {
return false;
}
Heap::CollectGarbage();
CalculateNewObjectOffsets();
CopyAndFixupObjects();
UniquePtr<File> file(OS::OpenFile(filename, true));
if (file.get() == NULL) {
return false;
}
return file->WriteFully(image_->GetAddress(), image_top_);
}
bool ImageWriter::Init() {
size_t size = source_space_->Size();
int prot = PROT_READ | PROT_WRITE;
size_t length = RoundUp(size, kPageSize);
image_.reset(MemMap::Map(length, prot));
if (image_.get() == NULL) {
return false;
}
return true;
}
void ImageWriter::CalculateNewObjectOffsetsCallback(Object* obj, void* arg) {
DCHECK(obj != NULL);
DCHECK(arg != NULL);
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (!image_writer->InSourceSpace(obj)) {
return;
}
// if it is a string, we want to intern it if its not interned.
if (obj->IsString()) {
// we must be an interned string that was forward referenced and already assigned
if (IsImageOffsetAssigned(obj)) {
DCHECK_EQ(obj, obj->AsString()->Intern());
return;
}
String* interned = obj->AsString()->Intern();
if (obj != interned) {
if (!IsImageOffsetAssigned(interned)) {
// interned obj is after us, allocate its location early
image_writer->AssignImageOffset(interned);
}
// point those looking for this object to the interned version.
SetImageOffset(obj, GetImageOffset(interned));
return;
}
// else (obj == interned), nothing to do but fall through to the normal case
}
image_writer->AssignImageOffset(obj);
// sniff out the DexCaches on this pass for use on the next pass
if (obj->IsClass()) {
Class* klass = obj->AsClass();
DexCache* dex_cache = klass->GetDexCache();
if (dex_cache != NULL) {
image_writer->dex_caches_.insert(dex_cache);
} else {
DCHECK(klass->IsArrayClass() || klass->IsPrimitive());
}
}
}
ObjectArray<Object>* CreateImageRoots() {
// build a Object[] of the roots needed to restore the runtime
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
Class* object_array_class = class_linker->FindSystemClass("[Ljava/lang/Object;");
ObjectArray<Object>* image_roots = ObjectArray<Object>::Alloc(object_array_class,
ImageHeader::kImageRootsMax);
image_roots->Set(ImageHeader::kJniStubArray, runtime->GetJniStubArray());
image_roots->Set(ImageHeader::kCalleeSaveMethod, runtime->GetCalleeSaveMethod());
return image_roots;
}
void ImageWriter::CalculateNewObjectOffsets() {
ObjectArray<Object>* image_roots = CreateImageRoots();
HeapBitmap* heap_bitmap = Heap::GetLiveBits();
DCHECK(heap_bitmap != NULL);
DCHECK_EQ(0U, image_top_);
// leave space for the header, but do not write it yet, we need to
// know where image_roots is going to end up
image_top_ += RoundUp(sizeof(ImageHeader), 8); // 64-bit-alignment
heap_bitmap->Walk(CalculateNewObjectOffsetsCallback, this); // TODO: add Space-limited Walk
DCHECK_LT(image_top_, image_->GetLength());
// return to write header at start of image with future location of image_roots
ImageHeader image_header(reinterpret_cast<uint32_t>(image_base_),
reinterpret_cast<uint32_t>(GetImageAddress(image_roots)));
memcpy(image_->GetAddress(), &image_header, sizeof(image_header));
// Note that top_ is left at end of used space
}
void ImageWriter::CopyAndFixupObjects() {
HeapBitmap* heap_bitmap = Heap::GetLiveBits();
DCHECK(heap_bitmap != NULL);
// TODO: heap validation can't handle this fix up pass
Heap::DisableObjectValidation();
heap_bitmap->Walk(CopyAndFixupObjectsCallback, this); // TODO: add Space-limited Walk
FixupDexCaches();
}
void ImageWriter::CopyAndFixupObjectsCallback(Object* object, void* arg) {
DCHECK(object != NULL);
DCHECK(arg != NULL);
const Object* obj = object;
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (!image_writer->InSourceSpace(object)) {
return;
}
// see GetLocalAddress for similar computation
size_t offset = image_writer->GetImageOffset(obj);
byte* dst = image_writer->image_->GetAddress() + offset;
const byte* src = reinterpret_cast<const byte*>(obj);
size_t n = obj->SizeOf();
DCHECK_LT(offset + n, image_writer->image_->GetLength());
memcpy(dst, src, n);
Object* copy = reinterpret_cast<Object*>(dst);
ResetImageOffset(copy);
image_writer->FixupObject(obj, copy);
}
void ImageWriter::FixupObject(const Object* orig, Object* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
copy->SetClass(down_cast<Class*>(GetImageAddress(orig->GetClass())));
// TODO: special case init of pointers to malloc data (or removal of these pointers)
if (orig->IsClass()) {
FixupClass(orig->AsClass(), down_cast<Class*>(copy));
} else if (orig->IsObjectArray()) {
FixupObjectArray(orig->AsObjectArray<Object>(), down_cast<ObjectArray<Object>*>(copy));
} else if (orig->IsMethod()) {
FixupMethod(orig->AsMethod(), down_cast<Method*>(copy));
} else {
FixupInstanceFields(orig, copy);
}
}
void ImageWriter::FixupClass(const Class* orig, Class* copy) {
FixupInstanceFields(orig, copy);
FixupStaticFields(orig, copy);
}
const void* FixupCode(const ByteArray* copy_code_array, const void* orig_code) {
// TODO: change to DCHECK when all code compiling
if (copy_code_array == NULL) {
return NULL;
}
const void* copy_code = copy_code_array->GetData();
// TODO: remember InstructionSet with each code array so we know if we need to do thumb fixup?
if ((reinterpret_cast<uintptr_t>(orig_code) % 2) == 1) {
return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(copy_code) + 1);
}
return copy_code;
}
void ImageWriter::FixupMethod(const Method* orig, Method* copy) {
FixupInstanceFields(orig, copy);
copy->code_ = FixupCode(copy->code_array_, orig->code_);
copy->invoke_stub_ = reinterpret_cast<Method::InvokeStub*>(FixupCode(copy->invoke_stub_array_, reinterpret_cast<void*>(orig->invoke_stub_)));
if (orig->IsNative()) {
ByteArray* orig_jni_stub_array_ = Runtime::Current()->GetJniStubArray();
ByteArray* copy_jni_stub_array_ = down_cast<ByteArray*>(GetImageAddress(orig_jni_stub_array_));
copy->native_method_ = copy_jni_stub_array_->GetData();
} else {
DCHECK(copy->native_method_ == NULL);
}
}
void ImageWriter::FixupObjectArray(const ObjectArray<Object>* orig, ObjectArray<Object>* copy) {
for (int32_t i = 0; i < orig->GetLength(); ++i) {
const Object* element = orig->Get(i);
copy->SetWithoutChecks(i, GetImageAddress(element));
}
}
void ImageWriter::FixupInstanceFields(const Object* orig, Object* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
Class* klass = orig->GetClass();
DCHECK(klass != NULL);
FixupFields(orig,
copy,
klass->GetReferenceInstanceOffsets(),
false);
}
void ImageWriter::FixupStaticFields(const Class* orig, Class* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
FixupFields(orig,
copy,
orig->GetReferenceStaticOffsets(),
true);
}
void ImageWriter::FixupFields(const Object* orig,
Object* copy,
uint32_t ref_offsets,
bool is_static) {
if (ref_offsets != CLASS_WALK_SUPER) {
// Found a reference offset bitmap. Fixup the specified offsets.
while (ref_offsets != 0) {
size_t right_shift = CLZ(ref_offsets);
MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift);
const Object* ref = orig->GetFieldObject<const Object*>(byte_offset, false);
copy->SetFieldObject(byte_offset, GetImageAddress(ref), false);
ref_offsets &= ~(CLASS_HIGH_BIT >> right_shift);
}
} else {
// There is no reference offset bitmap. In the non-static case,
// walk up the class inheritance hierarchy and find reference
// offsets the hard way. In the static case, just consider this
// class.
for (const Class *klass = is_static ? orig->AsClass() : orig->GetClass();
klass != NULL;
klass = is_static ? NULL : klass->GetSuperClass()) {
size_t num_reference_fields = (is_static
? klass->NumReferenceStaticFields()
: klass->NumReferenceInstanceFields());
for (size_t i = 0; i < num_reference_fields; ++i) {
Field* field = (is_static
? klass->GetStaticField(i)
: klass->GetInstanceField(i));
MemberOffset field_offset = field->GetOffset();
const Object* ref = orig->GetFieldObject<const Object*>(field_offset, false);
copy->SetFieldObject(field_offset, GetImageAddress(ref), false);
}
}
}
}
void ImageWriter::FixupDexCaches() {
typedef Set::const_iterator It; // TODO: C++0x auto
for (It it = dex_caches_.begin(), end = dex_caches_.end(); it != end; ++it) {
DexCache* orig = *it;
DexCache* copy = down_cast<DexCache*>(GetLocalAddress(orig));
FixupDexCache(orig, copy);
}
}
void ImageWriter::FixupDexCache(const DexCache* orig, DexCache* copy) {
CHECK(orig != NULL);
CHECK(copy != NULL);
CodeAndDirectMethods* orig_cadms = orig->GetCodeAndDirectMethods();
CodeAndDirectMethods* copy_cadms = down_cast<CodeAndDirectMethods*>(GetLocalAddress(orig_cadms));
for (size_t i = 0; i < orig->NumResolvedMethods(); i++) {
Method* orig_method = orig->GetResolvedMethod(i);
// if it was resolved in the original, resolve it in the copy
if (orig_method != NULL
&& InSourceSpace(orig_method)
&& orig_method == orig_cadms->GetResolvedMethod(i)) {
Method* copy_method = down_cast<Method*>(GetLocalAddress(orig_method));
copy_cadms->Set(CodeAndDirectMethods::CodeIndex(i),
reinterpret_cast<int32_t>(copy_method->code_));
copy_cadms->Set(CodeAndDirectMethods::MethodIndex(i),
reinterpret_cast<int32_t>(GetImageAddress(orig_method)));
}
}
}
} // namespace art