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8022853: add ability to load uncompressed object and Klass references in a compressed environment to Unsafe

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Reviewed-by: coleenp, jrose, kvn
This commit is contained in:
Christian Thalinger 2015-04-27 09:02:41 -07:00
parent 021adf731b
commit 8cb760c280
3 changed files with 133 additions and 13 deletions
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44
hotspot/src/share/vm/prims/unsafe.cpp
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@ -172,18 +172,6 @@ jint Unsafe_invocation_key_to_method_slot(jint key) {
oop p = JNIHandles::resolve(obj); \
OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x);
// Macros for oops that check UseCompressedOops
#define GET_OOP_FIELD(obj, offset, v) \
oop p = JNIHandles::resolve(obj); \
oop v; \
if (UseCompressedOops) { \
narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \
v = oopDesc::decode_heap_oop(n); \
} else { \
v = *(oop*)index_oop_from_field_offset_long(p, offset); \
}
// Get/SetObject must be special-cased, since it works with handles.
@ -192,7 +180,14 @@ jint Unsafe_invocation_key_to_method_slot(jint key) {
// That is, it should be in the range [0, MAX_OBJECT_SIZE].
UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
UnsafeWrapper("Unsafe_GetObject");
GET_OOP_FIELD(obj, offset, v)
oop p = JNIHandles::resolve(obj);
oop v;
if (UseCompressedOops) {
narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
v = oopDesc::decode_heap_oop(n);
} else {
v = *(oop*)index_oop_from_field_offset_long(p, offset);
}
jobject ret = JNIHandles::make_local(env, v);
#if INCLUDE_ALL_GCS
// We could be accessing the referent field in a reference
@ -261,6 +256,25 @@ UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject
OrderAccess::fence();
UNSAFE_END
UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr))
UnsafeWrapper("Unsafe_GetUncompressedObject");
oop v = *(oop*) (address) addr;
return JNIHandles::make_local(env, v);
UNSAFE_END
UNSAFE_ENTRY(jclass, Unsafe_GetJavaMirror(JNIEnv *env, jobject unsafe, jlong metaspace_klass))
UnsafeWrapper("Unsafe_GetJavaMirror");
Klass* klass = (Klass*) (address) metaspace_klass;
return (jclass) JNIHandles::make_local(klass->java_mirror());
UNSAFE_END
UNSAFE_ENTRY(jlong, Unsafe_GetKlassPointer(JNIEnv *env, jobject unsafe, jobject obj))
UnsafeWrapper("Unsafe_GetKlassPointer");
oop o = JNIHandles::resolve(obj);
jlong klass = (jlong) (address) o->klass();
return klass;
UNSAFE_END
#ifndef SUPPORTS_NATIVE_CX8
// VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
@ -1222,6 +1236,10 @@ static JNINativeMethod methods[] = {
{CC"getObjectVolatile",CC"("OBJ"J)"OBJ"", FN_PTR(Unsafe_GetObjectVolatile)},
{CC"putObjectVolatile",CC"("OBJ"J"OBJ")V", FN_PTR(Unsafe_SetObjectVolatile)},
{CC"getUncompressedObject", CC"("ADR")"OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
{CC"getJavaMirror", CC"("ADR")"CLS, FN_PTR(Unsafe_GetJavaMirror)},
{CC"getKlassPointer", CC"("OBJ")"ADR, FN_PTR(Unsafe_GetKlassPointer)},
DECLARE_GETPUTOOP(Boolean, Z),
DECLARE_GETPUTOOP(Byte, B),
DECLARE_GETPUTOOP(Short, S),