/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "java_lang_System.h"
#include "common_throws.h"
#include "gc/accounting/card_table-inl.h"
#include "jni_internal.h"
#include "mirror/array.h"
#include "mirror/class.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "scoped_fast_native_object_access.h"
namespace art {
/*
* We make guarantees about the atomicity of accesses to primitive variables. These guarantees
* also apply to elements of arrays. In particular, 8-bit, 16-bit, and 32-bit accesses must not
* cause "word tearing". Accesses to 64-bit array elements may be two 32-bit operations.
* References are never torn regardless of the number of bits used to represent them.
*/
static void ThrowArrayStoreException_NotAnArray(const char* identifier, mirror::Object* array)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
std::string actualType(PrettyTypeOf(array));
Thread* self = Thread::Current();
self->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
"%s of type %s is not an array", identifier, actualType.c_str());
}
static void System_arraycopy(JNIEnv* env, jclass, jobject javaSrc, jint srcPos, jobject javaDst,
jint dstPos, jint length) {
// The API is defined in terms of length, but length is somewhat overloaded so we use count.
const jint count = length;
ScopedFastNativeObjectAccess soa(env);
// Null pointer checks.
if (UNLIKELY(javaSrc == nullptr)) {
ThrowNullPointerException("src == null");
return;
}
if (UNLIKELY(javaDst == nullptr)) {
ThrowNullPointerException("dst == null");
return;
}
// Make sure source and destination are both arrays.
mirror::Object* srcObject = soa.Decode<mirror::Object*>(javaSrc);
if (UNLIKELY(!srcObject->IsArrayInstance())) {
ThrowArrayStoreException_NotAnArray("source", srcObject);
return;
}
mirror::Object* dstObject = soa.Decode<mirror::Object*>(javaDst);
if (UNLIKELY(!dstObject->IsArrayInstance())) {
ThrowArrayStoreException_NotAnArray("destination", dstObject);
return;
}
mirror::Array* srcArray = srcObject->AsArray();
mirror::Array* dstArray = dstObject->AsArray();
// Bounds checking.
if (UNLIKELY(srcPos < 0) || UNLIKELY(dstPos < 0) || UNLIKELY(count < 0) ||
UNLIKELY(srcPos > srcArray->GetLength() - count) ||
UNLIKELY(dstPos > dstArray->GetLength() - count)) {
soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
"src.length=%d srcPos=%d dst.length=%d dstPos=%d length=%d",
srcArray->GetLength(), srcPos, dstArray->GetLength(), dstPos,
count);
return;
}
mirror::Class* dstComponentType = dstArray->GetClass()->GetComponentType();
mirror::Class* srcComponentType = srcArray->GetClass()->GetComponentType();
Primitive::Type dstComponentPrimitiveType = dstComponentType->GetPrimitiveType();
if (LIKELY(srcComponentType == dstComponentType)) {
// Trivial assignability.
switch (dstComponentPrimitiveType) {
case Primitive::kPrimVoid:
LOG(FATAL) << "Unreachable, cannot have arrays of type void";
UNREACHABLE();
case Primitive::kPrimBoolean:
case Primitive::kPrimByte:
DCHECK_EQ(Primitive::ComponentSize(dstComponentPrimitiveType), 1U);
dstArray->AsByteSizedArray()->Memmove(dstPos, srcArray->AsByteSizedArray(), srcPos, count);
return;
case Primitive::kPrimChar:
case Primitive::kPrimShort:
DCHECK_EQ(Primitive::ComponentSize(dstComponentPrimitiveType), 2U);
dstArray->AsShortSizedArray()->Memmove(dstPos, srcArray->AsShortSizedArray(), srcPos, count);
return;
case Primitive::kPrimInt:
case Primitive::kPrimFloat:
DCHECK_EQ(Primitive::ComponentSize(dstComponentPrimitiveType), 4U);
dstArray->AsIntArray()->Memmove(dstPos, srcArray->AsIntArray(), srcPos, count);
return;
case Primitive::kPrimLong:
case Primitive::kPrimDouble:
DCHECK_EQ(Primitive::ComponentSize(dstComponentPrimitiveType), 8U);
dstArray->AsLongArray()->Memmove(dstPos, srcArray->AsLongArray(), srcPos, count);
return;
case Primitive::kPrimNot: {
mirror::ObjectArray<mirror::Object>* dstObjArray = dstArray->AsObjectArray<mirror::Object>();
mirror::ObjectArray<mirror::Object>* srcObjArray = srcArray->AsObjectArray<mirror::Object>();
dstObjArray->AssignableMemmove(dstPos, srcObjArray, srcPos, count);
return;
}
default:
LOG(FATAL) << "Unknown array type: " << PrettyTypeOf(srcArray);
UNREACHABLE();
}
}
// If one of the arrays holds a primitive type the other array must hold the exact same type.
if (UNLIKELY((dstComponentPrimitiveType != Primitive::kPrimNot) ||
srcComponentType->IsPrimitive())) {
std::string srcType(PrettyTypeOf(srcArray));
std::string dstType(PrettyTypeOf(dstArray));
soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
"Incompatible types: src=%s, dst=%s",
srcType.c_str(), dstType.c_str());
return;
}
// Arrays hold distinct types and so therefore can't alias - use memcpy instead of memmove.
mirror::ObjectArray<mirror::Object>* dstObjArray = dstArray->AsObjectArray<mirror::Object>();
mirror::ObjectArray<mirror::Object>* srcObjArray = srcArray->AsObjectArray<mirror::Object>();
// If we're assigning into say Object[] then we don't need per element checks.
if (dstComponentType->IsAssignableFrom(srcComponentType)) {
dstObjArray->AssignableMemcpy(dstPos, srcObjArray, srcPos, count);
return;
}
dstObjArray->AssignableCheckingMemcpy(dstPos, srcObjArray, srcPos, count, true);
}
// Template to convert general array to that of its specific primitive type.
template <typename T>
inline T* AsPrimitiveArray(mirror::Array* array) {
return down_cast<T*>(array);
}
template <typename T, Primitive::Type kPrimType>
inline void System_arraycopyTUnchecked(JNIEnv* env, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
ScopedFastNativeObjectAccess soa(env);
mirror::Object* srcObject = soa.Decode<mirror::Object*>(javaSrc);
mirror::Object* dstObject = soa.Decode<mirror::Object*>(javaDst);
DCHECK(dstObject != nullptr);
mirror::Array* srcArray = srcObject->AsArray();
mirror::Array* dstArray = dstObject->AsArray();
DCHECK_GE(count, 0);
DCHECK_EQ(srcArray->GetClass(), dstArray->GetClass());
DCHECK_EQ(srcArray->GetClass()->GetComponentType()->GetPrimitiveType(), kPrimType);
AsPrimitiveArray<T>(dstArray)->Memmove(dstPos, AsPrimitiveArray<T>(srcArray), srcPos, count);
}
static void System_arraycopyCharUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::CharArray, Primitive::kPrimChar>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyByteUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::ByteArray, Primitive::kPrimByte>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyShortUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::ShortArray, Primitive::kPrimShort>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyIntUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::IntArray, Primitive::kPrimInt>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyLongUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::LongArray, Primitive::kPrimLong>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyFloatUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::FloatArray, Primitive::kPrimFloat>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyDoubleUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::DoubleArray, Primitive::kPrimDouble>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static void System_arraycopyBooleanUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
jobject javaDst, jint dstPos, jint count) {
System_arraycopyTUnchecked<mirror::BooleanArray, Primitive::kPrimBoolean>(env, javaSrc, srcPos,
javaDst, dstPos, count);
}
static jint System_identityHashCode(JNIEnv* env, jclass, jobject javaObject) {
if (UNLIKELY(javaObject == nullptr)) {
return 0;
}
ScopedFastNativeObjectAccess soa(env);
mirror::Object* o = soa.Decode<mirror::Object*>(javaObject);
return static_cast<jint>(o->IdentityHashCode());
}
static JNINativeMethod gMethods[] = {
NATIVE_METHOD(System, arraycopy, "!(Ljava/lang/Object;ILjava/lang/Object;II)V"),
NATIVE_METHOD(System, arraycopyCharUnchecked, "!([CI[CII)V"),
NATIVE_METHOD(System, arraycopyByteUnchecked, "!([BI[BII)V"),
NATIVE_METHOD(System, arraycopyShortUnchecked, "!([SI[SII)V"),
NATIVE_METHOD(System, arraycopyIntUnchecked, "!([II[III)V"),
NATIVE_METHOD(System, arraycopyLongUnchecked, "!([JI[JII)V"),
NATIVE_METHOD(System, arraycopyFloatUnchecked, "!([FI[FII)V"),
NATIVE_METHOD(System, arraycopyDoubleUnchecked, "!([DI[DII)V"),
NATIVE_METHOD(System, arraycopyBooleanUnchecked, "!([ZI[ZII)V"),
NATIVE_METHOD(System, identityHashCode, "!(Ljava/lang/Object;)I"),
};
void register_java_lang_System(JNIEnv* env) {
REGISTER_NATIVE_METHODS("java/lang/System");
}
} // namespace art