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8305755: [JVMCI] missing barriers in CompilerToVM.readFieldValue for Reference.referent

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Reviewed-by: eosterlund, dnsimon
This commit is contained in:
Tom Rodriguez 2023-04-17 16:45:56 +00:00
parent 4ed933cf77
commit 497f9e760d
2 changed files with 12 additions and 8 deletions
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16
src/hotspot/share/jvmci/jvmciCompilerToVM.cpp
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@ -2050,14 +2050,14 @@ static jobject read_field_value(Handle obj, long displacement, jchar type_char,
// folding Unsafe.get* methods with volatile semantics.
switch (basic_type) {
case T_BOOLEAN: value = obj->bool_field_acquire(displacement); break;
case T_BYTE: value = obj->byte_field_acquire(displacement); break;
case T_SHORT: value = obj->short_field_acquire(displacement); break;
case T_CHAR: value = obj->char_field_acquire(displacement); break;
case T_BOOLEAN: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jboolean>(displacement)); break;
case T_BYTE: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jbyte>(displacement)); break;
case T_SHORT: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jshort>(displacement)); break;
case T_CHAR: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jchar>(displacement)); break;
case T_FLOAT:
case T_INT: value = obj->int_field_acquire(displacement); break;
case T_INT: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jint>(displacement)); break;
case T_DOUBLE:
case T_LONG: value = obj->long_field_acquire(displacement); break;
case T_LONG: value = HeapAccess<MO_SEQ_CST>::load(obj->field_addr<jlong>(displacement)); break;
case T_OBJECT: {
if (displacement == java_lang_Class::component_mirror_offset() && java_lang_Class::is_instance(obj()) &&
@ -2067,7 +2067,9 @@ static jobject read_field_value(Handle obj, long displacement, jchar type_char,
return JVMCIENV->get_jobject(JVMCIENV->get_JavaConstant_NULL_POINTER());
}
oop value = obj->obj_field_acquire(displacement);
// Perform the read including any barriers required to make the reference strongly reachable
// since it will be wrapped as a JavaConstant.
oop value = obj->obj_field_access<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>(displacement);
if (value == nullptr) {
return JVMCIENV->get_jobject(JVMCIENV->get_JavaConstant_NULL_POINTER());

4
src/hotspot/share/jvmci/jvmciRuntime.cpp
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@ -939,7 +939,9 @@ int JVMCIRuntime::release_cleared_oop_handles() {
// Example: to_release: 2
// Bulk release the handles with a null referent
object_handles()->release(_oop_handles.adr_at(num_alive), to_release);
if (to_release != 0) {
object_handles()->release(_oop_handles.adr_at(num_alive), to_release);
}
// Truncate oop handles to only those with a non-null referent
JVMCI_event_1("compacted oop handles in JVMCI runtime %d from %d to %d", _id, _oop_handles.length(), num_alive);