src/hotspot/share/oops/oop.cpp - toolchain/jdk/jdk21 - Git at Google

 /*
  * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #include "precompiled.hpp"
 #include "classfile/altHashing.hpp"
 #include "classfile/javaClasses.inline.hpp"
 #include "gc/shared/collectedHeap.inline.hpp"
 #include "gc/shared/gc_globals.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
 #include "oops/access.inline.hpp"
 #include "oops/compressedOops.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/verifyOopClosure.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/javaThread.hpp"
 #include "runtime/synchronizer.hpp"
 #include "utilities/macros.hpp"

 void oopDesc::print_on(outputStream* st) const {
   if (*((juint*)this) == badHeapWordVal) {
     st->print_cr("BAD WORD");
   } else if (*((juint*)this) == badMetaWordVal) {
     st->print_cr("BAD META WORD");
   } else {
     klass()->oop_print_on(cast_to_oop(this), st);
   }
 }

 void oopDesc::print_address_on(outputStream* st) const {
   st->print("{" PTR_FORMAT "}", p2i(this));

 }

 void oopDesc::print_name_on(outputStream* st) const {
   if (*((juint*)this) == badHeapWordVal) {
     st->print_cr("BAD WORD");
   } else if (*((juint*)this) == badMetaWordVal) {
     st->print_cr("BAD META WORD");
   } else {
     st->print_cr("%s", klass()->external_name());
   }
 }

 void oopDesc::print()         { print_on(tty);         }

 void oopDesc::print_address() { print_address_on(tty); }

 char* oopDesc::print_string() {
   stringStream st;
   print_on(&st);
   return st.as_string();
 }

 void oopDesc::print_value() {
   print_value_on(tty);
 }

 char* oopDesc::print_value_string() {
   char buf[100];
   stringStream st(buf, sizeof(buf));
   print_value_on(&st);
   return st.as_string();
 }

 void oopDesc::print_value_on(outputStream* st) const {
   oop obj = const_cast<oopDesc*>(this);
   if (java_lang_String::is_instance(obj)) {
     java_lang_String::print(obj, st);
     print_address_on(st);
   } else {
     klass()->oop_print_value_on(obj, st);
   }
 }


 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
   if (oop_desc != nullptr) {
     oop_desc->klass()->oop_verify_on(oop_desc, st);
   }
 }


 void oopDesc::verify(oopDesc* oop_desc) {
   verify_on(tty, oop_desc);
 }

 intptr_t oopDesc::slow_identity_hash() {
   // slow case; we have to acquire the micro lock in order to locate the header
   Thread* current = Thread::current();
   return ObjectSynchronizer::FastHashCode(current, this);
 }

 // used only for asserts and guarantees
 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
   if (!Universe::heap()->is_oop(obj)) {
     return false;
   }

   // Header verification: the mark is typically non-zero. If we're
   // at a safepoint, it must not be zero, except when using the new lightweight locking.
   // Outside of a safepoint, the header could be changing (for example,
   // another thread could be inflating a lock on this object).
   if (ignore_mark_word) {
     return true;
   }
   if (obj->mark().value() != 0) {
     return true;
   }
   return LockingMode == LM_LIGHTWEIGHT || !SafepointSynchronize::is_at_safepoint();
 }

 // used only for asserts and guarantees
 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
   return obj == nullptr ? true : is_oop(obj, ignore_mark_word);
 }

 VerifyOopClosure VerifyOopClosure::verify_oop;

 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
   oop obj = RawAccess<>::oop_load(p);
   guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
 }

 void VerifyOopClosure::do_oop(oop* p)       { VerifyOopClosure::do_oop_work(p); }
 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }

 // type test operations that doesn't require inclusion of oop.inline.hpp.
 bool oopDesc::is_instance_noinline()    const { return is_instance();    }
 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
 bool oopDesc::is_stackChunk_noinline()  const { return is_stackChunk();  }
 bool oopDesc::is_array_noinline()       const { return is_array();       }
 bool oopDesc::is_objArray_noinline()    const { return is_objArray();    }
 bool oopDesc::is_typeArray_noinline()   const { return is_typeArray();   }

 bool oopDesc::has_klass_gap() {
   // Only has a klass gap when compressed class pointers are used.
   return UseCompressedClassPointers;
 }

 #if INCLUDE_CDS_JAVA_HEAP
 void oopDesc::set_narrow_klass(narrowKlass nk) {
   assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!");
   assert(UseCompressedClassPointers, "must be");
   _metadata._compressed_klass = nk;
 }
 #endif

 void* oopDesc::load_klass_raw(oop obj) {
   if (UseCompressedClassPointers) {
     narrowKlass narrow_klass = obj->_metadata._compressed_klass;
     if (narrow_klass == 0) return nullptr;
     return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
   } else {
     return obj->_metadata._klass;
   }
 }

 void* oopDesc::load_oop_raw(oop obj, int offset) {
   uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
   if (UseCompressedOops) {
     narrowOop narrow_oop = *(narrowOop*)addr;
     if (CompressedOops::is_null(narrow_oop)) return nullptr;
     return (void*)CompressedOops::decode_raw(narrow_oop);
   } else {
     return *(void**)addr;
   }
 }

 oop oopDesc::obj_field_acquire(int offset) const                      { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }

 void oopDesc::obj_field_put_raw(int offset, oop value)                { assert(!(UseZGC && ZGenerational), "Generational ZGC must use store barriers");
                                                                         RawAccess<>::oop_store_at(as_oop(), offset, value); }
 void oopDesc::release_obj_field_put(int offset, oop value)            { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
 void oopDesc::obj_field_put_volatile(int offset, oop value)           { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }

 address oopDesc::address_field(int offset) const                      { return *field_addr<address>(offset); }
 address oopDesc::address_field_acquire(int offset) const              { return Atomic::load_acquire(field_addr<address>(offset)); }

 void oopDesc::address_field_put(int offset, address value)            { *field_addr<address>(offset) = value; }
 void oopDesc::release_address_field_put(int offset, address value)    { Atomic::release_store(field_addr<address>(offset), value); }

 Metadata* oopDesc::metadata_field(int offset) const                   { return *field_addr<Metadata*>(offset); }
 void oopDesc::metadata_field_put(int offset, Metadata* value)         { *field_addr<Metadata*>(offset) = value; }

 Metadata* oopDesc::metadata_field_acquire(int offset) const           { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }

 jbyte oopDesc::byte_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
 void oopDesc::release_byte_field_put(int offset, jbyte value)         { Atomic::release_store(field_addr<jbyte>(offset), value); }

 jchar oopDesc::char_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jchar>(offset)); }
 void oopDesc::release_char_field_put(int offset, jchar value)         { Atomic::release_store(field_addr<jchar>(offset), value); }

 jboolean oopDesc::bool_field_acquire(int offset) const                { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
 void oopDesc::release_bool_field_put(int offset, jboolean value)      { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }

 jint oopDesc::int_field_acquire(int offset) const                     { return Atomic::load_acquire(field_addr<jint>(offset)); }
 void oopDesc::release_int_field_put(int offset, jint value)           { Atomic::release_store(field_addr<jint>(offset), value); }

 jshort oopDesc::short_field_acquire(int offset) const                 { return Atomic::load_acquire(field_addr<jshort>(offset)); }
 void oopDesc::release_short_field_put(int offset, jshort value)       { Atomic::release_store(field_addr<jshort>(offset), value); }

 jlong oopDesc::long_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jlong>(offset)); }
 void oopDesc::release_long_field_put(int offset, jlong value)         { Atomic::release_store(field_addr<jlong>(offset), value); }

 jfloat oopDesc::float_field_acquire(int offset) const                 { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
 void oopDesc::release_float_field_put(int offset, jfloat value)       { Atomic::release_store(field_addr<jfloat>(offset), value); }

 jdouble oopDesc::double_field_acquire(int offset) const               { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
 void oopDesc::release_double_field_put(int offset, jdouble value)     { Atomic::release_store(field_addr<jdouble>(offset), value); }

 #ifdef ASSERT
 bool oopDesc::size_might_change() {
   // UseParallelGC and UseG1GC can change the length field
   // of an "old copy" of an object array in the young gen so it indicates
   // the grey portion of an already copied array. This will cause the first
   // disjunct below to fail if the two comparands are computed across such
   // a concurrent change.
   return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
 }
 #endif
	/*
	* Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#include "precompiled.hpp"
	#include "classfile/altHashing.hpp"
	#include "classfile/javaClasses.inline.hpp"
	#include "gc/shared/collectedHeap.inline.hpp"
	#include "gc/shared/gc_globals.hpp"
	#include "memory/resourceArea.hpp"
	#include "memory/universe.hpp"
	#include "oops/access.inline.hpp"
	#include "oops/compressedOops.inline.hpp"
	#include "oops/oop.inline.hpp"
	#include "oops/verifyOopClosure.hpp"
	#include "runtime/handles.inline.hpp"
	#include "runtime/javaThread.hpp"
	#include "runtime/synchronizer.hpp"
	#include "utilities/macros.hpp"

	void oopDesc::print_on(outputStream* st) const {
	if (((juint)this) == badHeapWordVal) {
	st->print_cr("BAD WORD");
	} else if (((juint)this) == badMetaWordVal) {
	st->print_cr("BAD META WORD");
	} else {
	klass()->oop_print_on(cast_to_oop(this), st);
	}
	}

	void oopDesc::print_address_on(outputStream* st) const {
	st->print("{" PTR_FORMAT "}", p2i(this));

	}

	void oopDesc::print_name_on(outputStream* st) const {
	if (((juint)this) == badHeapWordVal) {
	st->print_cr("BAD WORD");
	} else if (((juint)this) == badMetaWordVal) {
	st->print_cr("BAD META WORD");
	} else {
	st->print_cr("%s", klass()->external_name());
	}
	}

	void oopDesc::print() { print_on(tty); }

	void oopDesc::print_address() { print_address_on(tty); }

	char* oopDesc::print_string() {
	stringStream st;
	print_on(&st);
	return st.as_string();
	}

	void oopDesc::print_value() {
	print_value_on(tty);
	}

	char* oopDesc::print_value_string() {
	char buf[100];
	stringStream st(buf, sizeof(buf));
	print_value_on(&st);
	return st.as_string();
	}

	void oopDesc::print_value_on(outputStream* st) const {
	oop obj = const_cast<oopDesc*>(this);
	if (java_lang_String::is_instance(obj)) {
	java_lang_String::print(obj, st);
	print_address_on(st);
	} else {
	klass()->oop_print_value_on(obj, st);
	}
	}


	void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
	if (oop_desc != nullptr) {
	oop_desc->klass()->oop_verify_on(oop_desc, st);
	}
	}


	void oopDesc::verify(oopDesc* oop_desc) {
	verify_on(tty, oop_desc);
	}

	intptr_t oopDesc::slow_identity_hash() {
	// slow case; we have to acquire the micro lock in order to locate the header
	Thread* current = Thread::current();
	return ObjectSynchronizer::FastHashCode(current, this);
	}

	// used only for asserts and guarantees
	bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
	if (!Universe::heap()->is_oop(obj)) {
	return false;
	}

	// Header verification: the mark is typically non-zero. If we're
	// at a safepoint, it must not be zero, except when using the new lightweight locking.
	// Outside of a safepoint, the header could be changing (for example,
	// another thread could be inflating a lock on this object).
	if (ignore_mark_word) {
	return true;
	}
	if (obj->mark().value() != 0) {
	return true;
	}
	return LockingMode == LM_LIGHTWEIGHT \|\| !SafepointSynchronize::is_at_safepoint();
	}

	// used only for asserts and guarantees
	bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
	return obj == nullptr ? true : is_oop(obj, ignore_mark_word);
	}

	VerifyOopClosure VerifyOopClosure::verify_oop;

	template <class T> void VerifyOopClosure::do_oop_work(T* p) {
	oop obj = RawAccess<>::oop_load(p);
	guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
	}

	void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); }
	void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }

	// type test operations that doesn't require inclusion of oop.inline.hpp.
	bool oopDesc::is_instance_noinline() const { return is_instance(); }
	bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
	bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); }
	bool oopDesc::is_array_noinline() const { return is_array(); }
	bool oopDesc::is_objArray_noinline() const { return is_objArray(); }
	bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); }

	bool oopDesc::has_klass_gap() {
	// Only has a klass gap when compressed class pointers are used.
	return UseCompressedClassPointers;
	}

	#if INCLUDE_CDS_JAVA_HEAP
	void oopDesc::set_narrow_klass(narrowKlass nk) {
	assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!");
	assert(UseCompressedClassPointers, "must be");
	_metadata._compressed_klass = nk;
	}
	#endif

	void* oopDesc::load_klass_raw(oop obj) {
	if (UseCompressedClassPointers) {
	narrowKlass narrow_klass = obj->_metadata._compressed_klass;
	if (narrow_klass == 0) return nullptr;
	return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
	} else {
	return obj->_metadata._klass;
	}
	}

	void* oopDesc::load_oop_raw(oop obj, int offset) {
	uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
	if (UseCompressedOops) {
	narrowOop narrow_oop = (narrowOop)addr;
	if (CompressedOops::is_null(narrow_oop)) return nullptr;
	return (void*)CompressedOops::decode_raw(narrow_oop);
	} else {
	return (void*)addr;
	}
	}

	oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }

	void oopDesc::obj_field_put_raw(int offset, oop value) { assert(!(UseZGC && ZGenerational), "Generational ZGC must use store barriers");
	RawAccess<>::oop_store_at(as_oop(), offset, value); }
	void oopDesc::release_obj_field_put(int offset, oop value) { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
	void oopDesc::obj_field_put_volatile(int offset, oop value) { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }

	address oopDesc::address_field(int offset) const { return *field_addr<address>(offset); }
	address oopDesc::address_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<address>(offset)); }

	void oopDesc::address_field_put(int offset, address value) { *field_addr<address>(offset) = value; }
	void oopDesc::release_address_field_put(int offset, address value) { Atomic::release_store(field_addr<address>(offset), value); }

	Metadata* oopDesc::metadata_field(int offset) const { return field_addr<Metadata>(offset); }
	void oopDesc::metadata_field_put(int offset, Metadata* value) { field_addr<Metadata>(offset) = value; }

	Metadata* oopDesc::metadata_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
	void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }

	jbyte oopDesc::byte_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
	void oopDesc::release_byte_field_put(int offset, jbyte value) { Atomic::release_store(field_addr<jbyte>(offset), value); }

	jchar oopDesc::char_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jchar>(offset)); }
	void oopDesc::release_char_field_put(int offset, jchar value) { Atomic::release_store(field_addr<jchar>(offset), value); }

	jboolean oopDesc::bool_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
	void oopDesc::release_bool_field_put(int offset, jboolean value) { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }

	jint oopDesc::int_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jint>(offset)); }
	void oopDesc::release_int_field_put(int offset, jint value) { Atomic::release_store(field_addr<jint>(offset), value); }

	jshort oopDesc::short_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jshort>(offset)); }
	void oopDesc::release_short_field_put(int offset, jshort value) { Atomic::release_store(field_addr<jshort>(offset), value); }

	jlong oopDesc::long_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jlong>(offset)); }
	void oopDesc::release_long_field_put(int offset, jlong value) { Atomic::release_store(field_addr<jlong>(offset), value); }

	jfloat oopDesc::float_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
	void oopDesc::release_float_field_put(int offset, jfloat value) { Atomic::release_store(field_addr<jfloat>(offset), value); }

	jdouble oopDesc::double_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
	void oopDesc::release_double_field_put(int offset, jdouble value) { Atomic::release_store(field_addr<jdouble>(offset), value); }

	#ifdef ASSERT
	bool oopDesc::size_might_change() {
	// UseParallelGC and UseG1GC can change the length field
	// of an "old copy" of an object array in the young gen so it indicates
	// the grey portion of an already copied array. This will cause the first
	// disjunct below to fail if the two comparands are computed across such
	// a concurrent change.
	return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC \|\| UseG1GC);
	}
	#endif