200 lines
7.8 KiB
C++
200 lines
7.8 KiB
C++
/*
|
|
* Copyright (c) 1998, 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_RUNTIME_JNIHANDLES_HPP
|
|
#define SHARE_VM_RUNTIME_JNIHANDLES_HPP
|
|
|
|
#include "memory/allocation.hpp"
|
|
#include "runtime/handles.hpp"
|
|
|
|
class OopStorage;
|
|
|
|
// Interface for creating and resolving local/global JNI handles
|
|
|
|
class JNIHandles : AllStatic {
|
|
friend class VMStructs;
|
|
private:
|
|
static OopStorage* _global_handles;
|
|
static OopStorage* _weak_global_handles;
|
|
|
|
inline static bool is_jweak(jobject handle);
|
|
inline static oop* jobject_ptr(jobject handle); // NOT jweak!
|
|
inline static oop* jweak_ptr(jobject handle);
|
|
|
|
template<bool external_guard> inline static oop resolve_impl(jobject handle);
|
|
static oop resolve_jweak(jweak handle);
|
|
|
|
// This method is not inlined in order to avoid circular includes between
|
|
// this header file and thread.hpp.
|
|
static bool current_thread_in_native();
|
|
|
|
public:
|
|
// Low tag bit in jobject used to distinguish a jweak. jweak is
|
|
// type equivalent to jobject, but there are places where we need to
|
|
// be able to distinguish jweak values from other jobjects, and
|
|
// is_weak_global_handle is unsuitable for performance reasons. To
|
|
// provide such a test we add weak_tag_value to the (aligned) byte
|
|
// address designated by the jobject to produce the corresponding
|
|
// jweak. Accessing the value of a jobject must account for it
|
|
// being a possibly offset jweak.
|
|
static const uintptr_t weak_tag_size = 1;
|
|
static const uintptr_t weak_tag_alignment = (1u << weak_tag_size);
|
|
static const uintptr_t weak_tag_mask = weak_tag_alignment - 1;
|
|
static const int weak_tag_value = 1;
|
|
|
|
// Resolve handle into oop
|
|
inline static oop resolve(jobject handle);
|
|
// Resolve handle into oop, result guaranteed not to be null
|
|
inline static oop resolve_non_null(jobject handle);
|
|
// Resolve externally provided handle into oop with some guards
|
|
static oop resolve_external_guard(jobject handle);
|
|
|
|
// Local handles
|
|
static jobject make_local(oop obj);
|
|
static jobject make_local(JNIEnv* env, oop obj); // Fast version when env is known
|
|
static jobject make_local(Thread* thread, oop obj); // Even faster version when current thread is known
|
|
inline static void destroy_local(jobject handle);
|
|
|
|
// Global handles
|
|
static jobject make_global(Handle obj, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
|
|
static void destroy_global(jobject handle);
|
|
|
|
// Weak global handles
|
|
static jobject make_weak_global(Handle obj, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
|
|
static void destroy_weak_global(jobject handle);
|
|
static bool is_global_weak_cleared(jweak handle); // Test jweak without resolution
|
|
|
|
// Initialization
|
|
static void initialize();
|
|
|
|
// Debugging
|
|
static void print_on(outputStream* st);
|
|
static void print() { print_on(tty); }
|
|
static void verify();
|
|
// The category predicates all require handle != NULL.
|
|
static bool is_local_handle(Thread* thread, jobject handle);
|
|
static bool is_frame_handle(JavaThread* thread, jobject handle);
|
|
static bool is_global_handle(jobject handle);
|
|
static bool is_weak_global_handle(jobject handle);
|
|
static size_t global_handle_memory_usage();
|
|
static size_t weak_global_handle_memory_usage();
|
|
|
|
#ifndef PRODUCT
|
|
// Is handle from any local block of any thread?
|
|
static bool is_local_handle(jobject handle);
|
|
#endif
|
|
|
|
// precondition: handle != NULL.
|
|
static jobjectRefType handle_type(Thread* thread, jobject handle);
|
|
|
|
// Garbage collection support(global handles only, local handles are traversed from thread)
|
|
// Traversal of regular global handles
|
|
static void oops_do(OopClosure* f);
|
|
// Traversal of weak global handles. Unreachable oops are cleared.
|
|
static void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f);
|
|
// Traversal of weak global handles.
|
|
static void weak_oops_do(OopClosure* f);
|
|
};
|
|
|
|
|
|
|
|
// JNI handle blocks holding local/global JNI handles
|
|
|
|
class JNIHandleBlock : public CHeapObj<mtInternal> {
|
|
friend class VMStructs;
|
|
friend class CppInterpreter;
|
|
|
|
private:
|
|
enum SomeConstants {
|
|
block_size_in_oops = 32 // Number of handles per handle block
|
|
};
|
|
|
|
oop _handles[block_size_in_oops]; // The handles
|
|
int _top; // Index of next unused handle
|
|
JNIHandleBlock* _next; // Link to next block
|
|
|
|
// The following instance variables are only used by the first block in a chain.
|
|
// Having two types of blocks complicates the code and the space overhead in negligible.
|
|
JNIHandleBlock* _last; // Last block in use
|
|
JNIHandleBlock* _pop_frame_link; // Block to restore on PopLocalFrame call
|
|
oop* _free_list; // Handle free list
|
|
int _allocate_before_rebuild; // Number of blocks to allocate before rebuilding free list
|
|
|
|
// Check JNI, "planned capacity" for current frame (or push/ensure)
|
|
size_t _planned_capacity;
|
|
|
|
#ifndef PRODUCT
|
|
JNIHandleBlock* _block_list_link; // Link for list below
|
|
static JNIHandleBlock* _block_list; // List of all allocated blocks (for debugging only)
|
|
#endif
|
|
|
|
static JNIHandleBlock* _block_free_list; // Free list of currently unused blocks
|
|
static int _blocks_allocated; // For debugging/printing
|
|
|
|
// Fill block with bad_handle values
|
|
void zap() NOT_DEBUG_RETURN;
|
|
|
|
// Free list computation
|
|
void rebuild_free_list();
|
|
|
|
// No more handles in the both the current and following blocks
|
|
void clear() { _top = 0; }
|
|
|
|
public:
|
|
// Handle allocation
|
|
jobject allocate_handle(oop obj);
|
|
|
|
// Block allocation and block free list management
|
|
static JNIHandleBlock* allocate_block(Thread* thread = NULL);
|
|
static void release_block(JNIHandleBlock* block, Thread* thread = NULL);
|
|
|
|
// JNI PushLocalFrame/PopLocalFrame support
|
|
JNIHandleBlock* pop_frame_link() const { return _pop_frame_link; }
|
|
void set_pop_frame_link(JNIHandleBlock* block) { _pop_frame_link = block; }
|
|
|
|
// Stub generator support
|
|
static int top_offset_in_bytes() { return offset_of(JNIHandleBlock, _top); }
|
|
|
|
// Garbage collection support
|
|
// Traversal of handles
|
|
void oops_do(OopClosure* f);
|
|
|
|
// Checked JNI support
|
|
void set_planned_capacity(size_t planned_capacity) { _planned_capacity = planned_capacity; }
|
|
const size_t get_planned_capacity() { return _planned_capacity; }
|
|
const size_t get_number_of_live_handles();
|
|
|
|
// Debugging
|
|
bool chain_contains(jobject handle) const; // Does this block or following blocks contain handle
|
|
bool contains(jobject handle) const; // Does this block contain handle
|
|
size_t length() const; // Length of chain starting with this block
|
|
size_t memory_usage() const;
|
|
#ifndef PRODUCT
|
|
static bool any_contains(jobject handle); // Does any block currently in use contain handle
|
|
static void print_statistics();
|
|
#endif
|
|
};
|
|
|
|
#endif // SHARE_VM_RUNTIME_JNIHANDLES_HPP
|