src/hotspot/share/gc/shared/barrierSet.hpp - platform/libcore - Git at Google

 /*
  * Copyright (c) 2000, 2018, 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.
  *
  */

 #ifndef SHARE_VM_GC_SHARED_BARRIERSET_HPP
 #define SHARE_VM_GC_SHARED_BARRIERSET_HPP

 #include "gc/shared/barrierSetConfig.hpp"
 #include "memory/memRegion.hpp"
 #include "oops/access.hpp"
 #include "oops/accessBackend.hpp"
 #include "oops/oopsHierarchy.hpp"
 #include "utilities/fakeRttiSupport.hpp"

 class JavaThread;

 // This class provides the interface between a barrier implementation and
 // the rest of the system.

 class BarrierSet: public CHeapObj<mtGC> {
   friend class VMStructs;

   static BarrierSet* _bs;

 public:
   enum Name {
 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
     FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
 #undef BARRIER_SET_DECLARE_BS_ENUM
     UnknownBS
   };

   static BarrierSet* barrier_set() { return _bs; }

 protected:
   // Fake RTTI support.  For a derived class T to participate
   // - T must have a corresponding Name entry.
   // - GetName<T> must be specialized to return the corresponding Name
   //   entry.
   // - If T is a base class, the constructor must have a FakeRtti
   //   parameter and pass it up to its base class, with the tag set
   //   augmented with the corresponding Name entry.
   // - If T is a concrete class, the constructor must create a
   //   FakeRtti object whose tag set includes the corresponding Name
   //   entry, and pass it up to its base class.
   typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;

 private:
   FakeRtti _fake_rtti;

 public:
   // Metafunction mapping a class derived from BarrierSet to the
   // corresponding Name enum tag.
   template<typename T> struct GetName;

   // Metafunction mapping a Name enum type to the corresponding
   // lass derived from BarrierSet.
   template<BarrierSet::Name T> struct GetType;

   // Note: This is not presently the Name corresponding to the
   // concrete class of this object.
   BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }

   // Test whether this object is of the type corresponding to bsn.
   bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }

   // End of fake RTTI support.

 protected:
   BarrierSet(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti) { }
   ~BarrierSet() { }

 public:
   // Operations on arrays, or general regions (e.g., for "clone") may be
   // optimized by some barriers.

   // Below length is the # array elements being written
   virtual void write_ref_array_pre(oop* dst, int length,
                                    bool dest_uninitialized = false) {}
   virtual void write_ref_array_pre(narrowOop* dst, int length,
                                    bool dest_uninitialized = false) {}
   // Below count is the # array elements being written, starting
   // at the address "start", which may not necessarily be HeapWord-aligned
   inline void write_ref_array(HeapWord* start, size_t count);

   // Static versions, suitable for calling from generated code;
   // count is # array elements being written, starting with "start",
   // which may not necessarily be HeapWord-aligned.
   static void static_write_ref_array_pre(HeapWord* start, size_t count);
   static void static_write_ref_array_post(HeapWord* start, size_t count);

   // Support for optimizing compilers to call the barrier set on slow path allocations
   // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
   // The allocation is safe to use iff it returns true. If not, the slow-path allocation
   // is redone until it succeeds. This can e.g. prevent allocations from the slow path
   // to be in old.
   virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
   virtual void on_thread_attach(JavaThread* thread) {}
   virtual void on_thread_detach(JavaThread* thread) {}
   virtual void make_parsable(JavaThread* thread) {}

 protected:
   virtual void write_ref_array_work(MemRegion mr) = 0;

 public:
   // Inform the BarrierSet that the the covered heap region that starts
   // with "base" has been changed to have the given size (possibly from 0,
   // for initialization.)
   virtual void resize_covered_region(MemRegion new_region) = 0;

   // If the barrier set imposes any alignment restrictions on boundaries
   // within the heap, this function tells whether they are met.
   virtual bool is_aligned(HeapWord* addr) = 0;

   // Print a description of the memory for the barrier set
   virtual void print_on(outputStream* st) const = 0;

   static void set_bs(BarrierSet* bs) { _bs = bs; }

   // The AccessBarrier of a BarrierSet subclass is called by the Access API
   // (cf. oops/access.hpp) to perform decorated accesses. GC implementations
   // may override these default access operations by declaring an
   // AccessBarrier class in its BarrierSet. Its accessors will then be
   // automatically resolved at runtime.
   //
   // In order to register a new FooBarrierSet::AccessBarrier with the Access API,
   // the following steps should be taken:
   // 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
   // 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
   // 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
   template <DecoratorSet decorators, typename BarrierSetT>
   class AccessBarrier: protected RawAccessBarrier<decorators> {
   private:
     typedef RawAccessBarrier<decorators> Raw;

   public:
     // Primitive heap accesses. These accessors get resolved when
     // IN_HEAP is set (e.g. when using the HeapAccess API), it is
     // not an oop_* overload, and the barrier strength is AS_NORMAL.
     template <typename T>
     static T load_in_heap(T* addr) {
       return Raw::template load<T>(addr);
     }

     template <typename T>
     static T load_in_heap_at(oop base, ptrdiff_t offset) {
       return Raw::template load_at<T>(base, offset);
     }

     template <typename T>
     static void store_in_heap(T* addr, T value) {
       Raw::store(addr, value);
     }

     template <typename T>
     static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
       Raw::store_at(base, offset, value);
     }

     template <typename T>
     static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
       return Raw::atomic_cmpxchg(new_value, addr, compare_value);
     }

     template <typename T>
     static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
       return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
     }

     template <typename T>
     static T atomic_xchg_in_heap(T new_value, T* addr) {
       return Raw::atomic_xchg(new_value, addr);
     }

     template <typename T>
     static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
       return Raw::atomic_xchg_at(new_value, base, offset);
     }

     template <typename T>
     static bool arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
       return Raw::arraycopy(src_obj, dst_obj, src, dst, length);
     }

     // Heap oop accesses. These accessors get resolved when
     // IN_HEAP is set (e.g. when using the HeapAccess API), it is
     // an oop_* overload, and the barrier strength is AS_NORMAL.
     template <typename T>
     static oop oop_load_in_heap(T* addr) {
       return Raw::template oop_load<oop>(addr);
     }

     static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
       return Raw::template oop_load_at<oop>(base, offset);
     }

     template <typename T>
     static void oop_store_in_heap(T* addr, oop value) {
       Raw::oop_store(addr, value);
     }

     static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
       Raw::oop_store_at(base, offset, value);
     }

     template <typename T>
     static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
       return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
     }

     static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
       return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
     }

     template <typename T>
     static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
       return Raw::oop_atomic_xchg(new_value, addr);
     }

     static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
       return Raw::oop_atomic_xchg_at(new_value, base, offset);
     }

     template <typename T>
     static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
       return Raw::oop_arraycopy(src_obj, dst_obj, src, dst, length);
     }

     // Off-heap oop accesses. These accessors get resolved when
     // IN_HEAP is not set (e.g. when using the RootAccess API), it is
     // an oop* overload, and the barrier strength is AS_NORMAL.
     template <typename T>
     static oop oop_load_not_in_heap(T* addr) {
       return Raw::template oop_load<oop>(addr);
     }

     template <typename T>
     static void oop_store_not_in_heap(T* addr, oop value) {
       Raw::oop_store(addr, value);
     }

     template <typename T>
     static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
       return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
     }

     template <typename T>
     static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
       return Raw::oop_atomic_xchg(new_value, addr);
     }

     // Clone barrier support
     static void clone_in_heap(oop src, oop dst, size_t size) {
       Raw::clone(src, dst, size);
     }

     static oop resolve(oop obj) {
       return Raw::resolve(obj);
     }
   };
 };

 template<typename T>
 inline T* barrier_set_cast(BarrierSet* bs) {
   assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
   return static_cast<T*>(bs);
 }

 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP
	/*
	* Copyright (c) 2000, 2018, 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.
	*
	*/

	#ifndef SHARE_VM_GC_SHARED_BARRIERSET_HPP
	#define SHARE_VM_GC_SHARED_BARRIERSET_HPP

	#include "gc/shared/barrierSetConfig.hpp"
	#include "memory/memRegion.hpp"
	#include "oops/access.hpp"
	#include "oops/accessBackend.hpp"
	#include "oops/oopsHierarchy.hpp"
	#include "utilities/fakeRttiSupport.hpp"

	class JavaThread;

	// This class provides the interface between a barrier implementation and
	// the rest of the system.

	class BarrierSet: public CHeapObj<mtGC> {
	friend class VMStructs;

	static BarrierSet* _bs;

	public:
	enum Name {
	#define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
	FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
	#undef BARRIER_SET_DECLARE_BS_ENUM
	UnknownBS
	};

	static BarrierSet* barrier_set() { return _bs; }

	protected:
	// Fake RTTI support. For a derived class T to participate
	// - T must have a corresponding Name entry.
	// - GetName<T> must be specialized to return the corresponding Name
	// entry.
	// - If T is a base class, the constructor must have a FakeRtti
	// parameter and pass it up to its base class, with the tag set
	// augmented with the corresponding Name entry.
	// - If T is a concrete class, the constructor must create a
	// FakeRtti object whose tag set includes the corresponding Name
	// entry, and pass it up to its base class.
	typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;

	private:
	FakeRtti _fake_rtti;

	public:
	// Metafunction mapping a class derived from BarrierSet to the
	// corresponding Name enum tag.
	template<typename T> struct GetName;

	// Metafunction mapping a Name enum type to the corresponding
	// lass derived from BarrierSet.
	template<BarrierSet::Name T> struct GetType;

	// Note: This is not presently the Name corresponding to the
	// concrete class of this object.
	BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }

	// Test whether this object is of the type corresponding to bsn.
	bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }

	// End of fake RTTI support.

	protected:
	BarrierSet(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti) { }
	~BarrierSet() { }

	public:
	// Operations on arrays, or general regions (e.g., for "clone") may be
	// optimized by some barriers.

	// Below length is the # array elements being written
	virtual void write_ref_array_pre(oop* dst, int length,
	bool dest_uninitialized = false) {}
	virtual void write_ref_array_pre(narrowOop* dst, int length,
	bool dest_uninitialized = false) {}
	// Below count is the # array elements being written, starting
	// at the address "start", which may not necessarily be HeapWord-aligned
	inline void write_ref_array(HeapWord* start, size_t count);

	// Static versions, suitable for calling from generated code;
	// count is # array elements being written, starting with "start",
	// which may not necessarily be HeapWord-aligned.
	static void static_write_ref_array_pre(HeapWord* start, size_t count);
	static void static_write_ref_array_post(HeapWord* start, size_t count);

	// Support for optimizing compilers to call the barrier set on slow path allocations
	// that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks.
	// The allocation is safe to use iff it returns true. If not, the slow-path allocation
	// is redone until it succeeds. This can e.g. prevent allocations from the slow path
	// to be in old.
	virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj) {}
	virtual void on_thread_attach(JavaThread* thread) {}
	virtual void on_thread_detach(JavaThread* thread) {}
	virtual void make_parsable(JavaThread* thread) {}

	protected:
	virtual void write_ref_array_work(MemRegion mr) = 0;

	public:
	// Inform the BarrierSet that the the covered heap region that starts
	// with "base" has been changed to have the given size (possibly from 0,
	// for initialization.)
	virtual void resize_covered_region(MemRegion new_region) = 0;

	// If the barrier set imposes any alignment restrictions on boundaries
	// within the heap, this function tells whether they are met.
	virtual bool is_aligned(HeapWord* addr) = 0;

	// Print a description of the memory for the barrier set
	virtual void print_on(outputStream* st) const = 0;

	static void set_bs(BarrierSet* bs) { _bs = bs; }

	// The AccessBarrier of a BarrierSet subclass is called by the Access API
	// (cf. oops/access.hpp) to perform decorated accesses. GC implementations
	// may override these default access operations by declaring an
	// AccessBarrier class in its BarrierSet. Its accessors will then be
	// automatically resolved at runtime.
	//
	// In order to register a new FooBarrierSet::AccessBarrier with the Access API,
	// the following steps should be taken:
	// 1) Provide an enum "name" for the BarrierSet in barrierSetConfig.hpp
	// 2) Make sure the barrier set headers are included from barrierSetConfig.inline.hpp
	// 3) Provide specializations for BarrierSet::GetName and BarrierSet::GetType.
	template <DecoratorSet decorators, typename BarrierSetT>
	class AccessBarrier: protected RawAccessBarrier<decorators> {
	private:
	typedef RawAccessBarrier<decorators> Raw;

	public:
	// Primitive heap accesses. These accessors get resolved when
	// IN_HEAP is set (e.g. when using the HeapAccess API), it is
	// not an oop_* overload, and the barrier strength is AS_NORMAL.
	template <typename T>
	static T load_in_heap(T* addr) {
	return Raw::template load<T>(addr);
	}

	template <typename T>
	static T load_in_heap_at(oop base, ptrdiff_t offset) {
	return Raw::template load_at<T>(base, offset);
	}

	template <typename T>
	static void store_in_heap(T* addr, T value) {
	Raw::store(addr, value);
	}

	template <typename T>
	static void store_in_heap_at(oop base, ptrdiff_t offset, T value) {
	Raw::store_at(base, offset, value);
	}

	template <typename T>
	static T atomic_cmpxchg_in_heap(T new_value, T* addr, T compare_value) {
	return Raw::atomic_cmpxchg(new_value, addr, compare_value);
	}

	template <typename T>
	static T atomic_cmpxchg_in_heap_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
	return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
	}

	template <typename T>
	static T atomic_xchg_in_heap(T new_value, T* addr) {
	return Raw::atomic_xchg(new_value, addr);
	}

	template <typename T>
	static T atomic_xchg_in_heap_at(T new_value, oop base, ptrdiff_t offset) {
	return Raw::atomic_xchg_at(new_value, base, offset);
	}

	template <typename T>
	static bool arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
	return Raw::arraycopy(src_obj, dst_obj, src, dst, length);
	}

	// Heap oop accesses. These accessors get resolved when
	// IN_HEAP is set (e.g. when using the HeapAccess API), it is
	// an oop_* overload, and the barrier strength is AS_NORMAL.
	template <typename T>
	static oop oop_load_in_heap(T* addr) {
	return Raw::template oop_load<oop>(addr);
	}

	static oop oop_load_in_heap_at(oop base, ptrdiff_t offset) {
	return Raw::template oop_load_at<oop>(base, offset);
	}

	template <typename T>
	static void oop_store_in_heap(T* addr, oop value) {
	Raw::oop_store(addr, value);
	}

	static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
	Raw::oop_store_at(base, offset, value);
	}

	template <typename T>
	static oop oop_atomic_cmpxchg_in_heap(oop new_value, T* addr, oop compare_value) {
	return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
	}

	static oop oop_atomic_cmpxchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
	return Raw::oop_atomic_cmpxchg_at(new_value, base, offset, compare_value);
	}

	template <typename T>
	static oop oop_atomic_xchg_in_heap(oop new_value, T* addr) {
	return Raw::oop_atomic_xchg(new_value, addr);
	}

	static oop oop_atomic_xchg_in_heap_at(oop new_value, oop base, ptrdiff_t offset) {
	return Raw::oop_atomic_xchg_at(new_value, base, offset);
	}

	template <typename T>
	static bool oop_arraycopy_in_heap(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
	return Raw::oop_arraycopy(src_obj, dst_obj, src, dst, length);
	}

	// Off-heap oop accesses. These accessors get resolved when
	// IN_HEAP is not set (e.g. when using the RootAccess API), it is
	// an oop* overload, and the barrier strength is AS_NORMAL.
	template <typename T>
	static oop oop_load_not_in_heap(T* addr) {
	return Raw::template oop_load<oop>(addr);
	}

	template <typename T>
	static void oop_store_not_in_heap(T* addr, oop value) {
	Raw::oop_store(addr, value);
	}

	template <typename T>
	static oop oop_atomic_cmpxchg_not_in_heap(oop new_value, T* addr, oop compare_value) {
	return Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);
	}

	template <typename T>
	static oop oop_atomic_xchg_not_in_heap(oop new_value, T* addr) {
	return Raw::oop_atomic_xchg(new_value, addr);
	}

	// Clone barrier support
	static void clone_in_heap(oop src, oop dst, size_t size) {
	Raw::clone(src, dst, size);
	}

	static oop resolve(oop obj) {
	return Raw::resolve(obj);
	}
	};
	};

	template<typename T>
	inline T* barrier_set_cast(BarrierSet* bs) {
	assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
	return static_cast<T*>(bs);
	}

	#endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP