/*
* 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.
*/
/*
* java.lang.Class
*/
#include "Dalvik.h"
#include "native/InternalNativePriv.h"
/*
* Call the appropriate copy function given the circumstances.
*/
static void copy(void *dest, const void *src, size_t n, bool sameArray,
size_t elemSize)
{
if (sameArray) {
/* Might overlap. */
if (elemSize == sizeof(Object*)) {
/*
* In addition to handling overlap properly, bcopy()
* guarantees atomic treatment of words. This is needed so
* that concurrent threads never see half-formed pointers
* or ints. The former is required for proper gc behavior,
* and the latter is also required for proper high-level
* language support.
*
* Note: bcopy()'s argument order is different than memcpy().
*/
bcopy(src, dest, n);
} else {
memmove(dest, src, n);
}
} else {
memcpy(dest, src, n); /* Can't overlap; use faster function. */
}
}
/*
* public static void arraycopy(Object src, int srcPos, Object dest,
* int destPos, int length)
*
* The description of this function is long, and describes a multitude
* of checks and exceptions.
*/
static void Dalvik_java_lang_System_arraycopy(const u4* args, JValue* pResult)
{
ArrayObject* srcArray;
ArrayObject* dstArray;
ClassObject* srcClass;
ClassObject* dstClass;
int srcPos, dstPos, length;
char srcType, dstType;
bool srcPrim, dstPrim;
bool sameArray;
srcArray = (ArrayObject*) args[0];
srcPos = args[1];
dstArray = (ArrayObject*) args[2];
dstPos = args[3];
length = args[4];
sameArray = (srcArray == dstArray);
/* check for null or bad pointer */
if (!dvmValidateObject((Object*)srcArray) ||
!dvmValidateObject((Object*)dstArray))
{
assert(dvmCheckException(dvmThreadSelf()));
RETURN_VOID();
}
/* make sure it's an array */
if (!dvmIsArray(srcArray) || !dvmIsArray(dstArray)) {
dvmThrowExceptionFmt("Ljava/lang/ArrayStoreException;",
"source and destination must be arrays, but were %s and %s",
((Object*)srcArray)->clazz->descriptor,
((Object*)dstArray)->clazz->descriptor);
RETURN_VOID();
}
// avoid int overflow
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > (int) srcArray->length - length ||
dstPos > (int) dstArray->length - length)
{
dvmThrowExceptionFmt("Ljava/lang/ArrayIndexOutOfBoundsException;",
"src.length=%d srcPos=%d dst.length=%d dstPos=%d length=%d",
srcArray->length, srcPos, dstArray->length, dstPos, length);
RETURN_VOID();
}
srcClass = srcArray->obj.clazz;
dstClass = dstArray->obj.clazz;
srcType = srcClass->descriptor[1];
dstType = dstClass->descriptor[1];
/*
* If one of the arrays holds a primitive type, the other array must
* hold the same type.
*/
srcPrim = (srcType != '[' && srcType != 'L');
dstPrim = (dstType != '[' && dstType != 'L');
if (srcPrim || dstPrim) {
int width;
if (srcPrim != dstPrim || srcType != dstType) {
dvmThrowExceptionFmt("Ljava/lang/ArrayStoreException;",
"source and destination arrays are incompatible: %s and %s",
srcClass->descriptor, dstClass->descriptor);
RETURN_VOID();
}
switch (srcClass->descriptor[1]) {
case 'B':
case 'Z':
width = 1;
break;
case 'C':
case 'S':
width = 2;
break;
case 'F':
case 'I':
width = 4;
break;
case 'D':
case 'J':
width = 8;
break;
default: /* 'V' or something weird */
LOGE("Weird array type '%s'\n", srcClass->descriptor);
assert(false);
width = 0;
break;
}
if (false) LOGVV("arraycopy prim dst=%p %d src=%p %d len=%d\n",
dstArray->contents, dstPos * width,
srcArray->contents, srcPos * width,
length * width);
copy((u1*)dstArray->contents + dstPos * width,
(const u1*)srcArray->contents + srcPos * width,
length * width,
sameArray, width);
} else {
/*
* Neither class is primitive. See if elements in "src" are instances
* of elements in "dst" (e.g. copy String to String or String to
* Object).
*/
int width = sizeof(Object*);
if (srcClass->arrayDim == dstClass->arrayDim &&
dvmInstanceof(srcClass, dstClass))
{
/*
* "dst" can hold "src"; copy the whole thing.
*/
if (false) LOGVV("arraycopy ref dst=%p %d src=%p %d len=%d\n",
dstArray->contents, dstPos * width,
srcArray->contents, srcPos * width,
length * width);
copy((u1*)dstArray->contents + dstPos * width,
(const u1*)srcArray->contents + srcPos * width,
length * width,
sameArray, width);
dvmWriteBarrierArray(dstArray, dstPos, dstPos+length);
} else {
/*
* The arrays are not fundamentally compatible. However, we may
* still be able to do this if the destination object is compatible
* (e.g. copy Object to String, but the Object being copied is
* actually a String). We need to copy elements one by one until
* something goes wrong.
*
* Because of overlapping moves, what we really want to do is
* compare the types and count up how many we can move, then call
* memmove() to shift the actual data. If we just start from the
* front we could do a smear rather than a move.
*/
Object** srcObj;
Object** dstObj;
int copyCount;
ClassObject* clazz = NULL;
srcObj = ((Object**) srcArray->contents) + srcPos;
dstObj = ((Object**) dstArray->contents) + dstPos;
if (length > 0 && srcObj[0] != NULL)
{
clazz = srcObj[0]->clazz;
if (!dvmCanPutArrayElement(clazz, dstClass))
clazz = NULL;
}
for (copyCount = 0; copyCount < length; copyCount++)
{
if (srcObj[copyCount] != NULL &&
srcObj[copyCount]->clazz != clazz &&
!dvmCanPutArrayElement(srcObj[copyCount]->clazz, dstClass))
{
/* can't put this element into the array */
break;
}
}
if (false) LOGVV("arraycopy iref dst=%p %d src=%p %d count=%d of %d\n",
dstArray->contents, dstPos * width,
srcArray->contents, srcPos * width,
copyCount, length);
copy((u1*)dstArray->contents + dstPos * width,
(const u1*)srcArray->contents + srcPos * width,
copyCount * width,
sameArray, width);
dvmWriteBarrierArray(dstArray, 0, copyCount);
if (copyCount != length) {
dvmThrowExceptionFmt("Ljava/lang/ArrayStoreException;",
"source[%d] of type %s cannot be stored in destination array of type %s",
copyCount, srcObj[copyCount]->clazz->descriptor,
dstClass->descriptor);
RETURN_VOID();
}
}
}
RETURN_VOID();
}
/*
* static long currentTimeMillis()
*
* Current time, in miliseconds. This doesn't need to be internal to the
* VM, but we're already handling java.lang.System here.
*/
static void Dalvik_java_lang_System_currentTimeMillis(const u4* args,
JValue* pResult)
{
struct timeval tv;
UNUSED_PARAMETER(args);
gettimeofday(&tv, (struct timezone *) NULL);
long long when = tv.tv_sec * 1000LL + tv.tv_usec / 1000;
RETURN_LONG(when);
}
/*
* static long nanoTime()
*
* Current monotonically-increasing time, in nanoseconds. This doesn't
* need to be internal to the VM, but we're already handling
* java.lang.System here.
*/
static void Dalvik_java_lang_System_nanoTime(const u4* args, JValue* pResult)
{
UNUSED_PARAMETER(args);
u8 when = dvmGetRelativeTimeNsec();
RETURN_LONG(when);
}
/*
* static int identityHashCode(Object x)
*
* Returns that hash code that the default hashCode()
* method would return for "x", even if "x"s class
* overrides hashCode().
*/
static void Dalvik_java_lang_System_identityHashCode(const u4* args,
JValue* pResult)
{
Object* thisPtr = (Object*) args[0];
RETURN_INT(dvmIdentityHashCode(thisPtr));
}
/*
* public static String mapLibraryName(String libname)
*/
static void Dalvik_java_lang_System_mapLibraryName(const u4* args,
JValue* pResult)
{
StringObject* nameObj = (StringObject*) args[0];
StringObject* result = NULL;
char* name;
char* mappedName;
if (nameObj == NULL) {
dvmThrowException("Ljava/lang/NullPointerException;", NULL);
RETURN_VOID();
}
name = dvmCreateCstrFromString(nameObj);
mappedName = dvmCreateSystemLibraryName(name);
if (mappedName != NULL) {
result = dvmCreateStringFromCstr(mappedName);
dvmReleaseTrackedAlloc((Object*) result, NULL);
}
free(name);
free(mappedName);
RETURN_PTR(result);
}
const DalvikNativeMethod dvm_java_lang_System[] = {
{ "arraycopy", "(Ljava/lang/Object;ILjava/lang/Object;II)V",
Dalvik_java_lang_System_arraycopy },
{ "currentTimeMillis", "()J",
Dalvik_java_lang_System_currentTimeMillis },
{ "nanoTime", "()J",
Dalvik_java_lang_System_nanoTime },
{ "identityHashCode", "(Ljava/lang/Object;)I",
Dalvik_java_lang_System_identityHashCode },
{ "mapLibraryName", "(Ljava/lang/String;)Ljava/lang/String;",
Dalvik_java_lang_System_mapLibraryName },
{ NULL, NULL, NULL },
};