/*
* Copyright (c) 1997, 2011, 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
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*/
#ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
#define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
#include "oops/arrayOop.hpp"
#include "oops/cpCacheOop.hpp"
#include "oops/symbol.hpp"
#include "oops/typeArrayOop.hpp"
#include "utilities/constantTag.hpp"
#ifdef TARGET_ARCH_x86
# include "bytes_x86.hpp"
#endif
#ifdef TARGET_ARCH_sparc
# include "bytes_sparc.hpp"
#endif
#ifdef TARGET_ARCH_zero
# include "bytes_zero.hpp"
#endif
#ifdef TARGET_ARCH_arm
# include "bytes_arm.hpp"
#endif
#ifdef TARGET_ARCH_ppc
# include "bytes_ppc.hpp"
#endif
// A constantPool is an array containing class constants as described in the
// class file.
//
// Most of the constant pool entries are written during class parsing, which
// is safe. For klass and string types, the constant pool entry is
// modified when the entry is resolved. If a klass or string constant pool
// entry is read without a lock, only the resolved state guarantees that
// the entry in the constant pool is a klass or String object and
// not a Symbol*.
class SymbolHashMap;
class CPSlot VALUE_OBJ_CLASS_SPEC {
intptr_t _ptr;
public:
CPSlot(intptr_t ptr): _ptr(ptr) {}
CPSlot(void* ptr): _ptr((intptr_t)ptr) {}
CPSlot(oop ptr): _ptr((intptr_t)ptr) {}
CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {}
intptr_t value() { return _ptr; }
bool is_oop() { return (_ptr & 1) == 0; }
bool is_metadata() { return (_ptr & 1) == 1; }
oop get_oop() {
assert(is_oop(), "bad call");
return oop(_ptr);
}
Symbol* get_symbol() {
assert(is_metadata(), "bad call");
return (Symbol*)(_ptr & ~1);
}
};
class constantPoolOopDesc : public oopDesc {
friend class VMStructs;
friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
private:
typeArrayOop _tags; // the tag array describing the constant pool's contents
constantPoolCacheOop _cache; // the cache holding interpreter runtime information
klassOop _pool_holder; // the corresponding class
typeArrayOop _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
int _flags; // a few header bits to describe contents for GC
int _length; // number of elements in the array
volatile bool _is_conc_safe; // if true, safe for concurrent
// GC processing
// only set to non-zero if constant pool is merged by RedefineClasses
int _orig_length;
void set_tags(typeArrayOop tags) { oop_store_without_check((oop*)&_tags, tags); }
void tag_at_put(int which, jbyte t) { tags()->byte_at_put(which, t); }
void release_tag_at_put(int which, jbyte t) { tags()->release_byte_at_put(which, t); }
void set_operands(typeArrayOop operands) { oop_store_without_check((oop*)&_operands, operands); }
enum FlagBit {
FB_has_invokedynamic = 1,
FB_has_pseudo_string = 2
};
int flags() const { return _flags; }
void set_flags(int f) { _flags = f; }
bool flag_at(FlagBit fb) const { return (_flags & (1 << (int)fb)) != 0; }
void set_flag_at(FlagBit fb);
// no clear_flag_at function; they only increase
private:
intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(constantPoolOopDesc)); }
oop* tags_addr() { return (oop*)&_tags; }
oop* cache_addr() { return (oop*)&_cache; }
oop* operands_addr() { return (oop*)&_operands; }
CPSlot slot_at(int which) {
assert(is_within_bounds(which), "index out of bounds");
// There's a transitional value of zero when converting from
// Symbol->0->Klass for G1 when resolving classes and strings.
// wait for the value to be non-zero (this is temporary)
volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
if (adr == 0 && which != 0) {
constantTag t = tag_at(which);
if (t.is_unresolved_klass() || t.is_klass() ||
t.is_unresolved_string() || t.is_string()) {
while ((adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))) == 0);
}
}
return CPSlot(adr);
}
void slot_at_put(int which, CPSlot s) const {
assert(is_within_bounds(which), "index out of bounds");
*(intptr_t*)&base()[which] = s.value();
}
oop* obj_at_addr_raw(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (oop*) &base()[which];
}
void obj_at_put_without_check(int which, oop o) {
assert(is_within_bounds(which), "index out of bounds");
oop_store_without_check((volatile oop *)obj_at_addr_raw(which), o);
}
void obj_at_put(int which, oop o) const {
assert(is_within_bounds(which), "index out of bounds");
oop_store((volatile oop*)obj_at_addr_raw(which), o);
}
jint* int_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jint*) &base()[which];
}
jlong* long_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jlong*) &base()[which];
}
jfloat* float_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jfloat*) &base()[which];
}
jdouble* double_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jdouble*) &base()[which];
}
public:
typeArrayOop tags() const { return _tags; }
typeArrayOop operands() const { return _operands; }
bool has_pseudo_string() const { return flag_at(FB_has_pseudo_string); }
bool has_invokedynamic() const { return flag_at(FB_has_invokedynamic); }
void set_pseudo_string() { set_flag_at(FB_has_pseudo_string); }
void set_invokedynamic() { set_flag_at(FB_has_invokedynamic); }
// Klass holding pool
klassOop pool_holder() const { return _pool_holder; }
void set_pool_holder(klassOop k) { oop_store_without_check((oop*)&_pool_holder, (oop) k); }
oop* pool_holder_addr() { return (oop*)&_pool_holder; }
// Interpreter runtime support
constantPoolCacheOop cache() const { return _cache; }
void set_cache(constantPoolCacheOop cache){ oop_store((oop*)&_cache, cache); }
// Assembly code support
static int tags_offset_in_bytes() { return offset_of(constantPoolOopDesc, _tags); }
static int cache_offset_in_bytes() { return offset_of(constantPoolOopDesc, _cache); }
static int operands_offset_in_bytes() { return offset_of(constantPoolOopDesc, _operands); }
static int pool_holder_offset_in_bytes() { return offset_of(constantPoolOopDesc, _pool_holder); }
// Storing constants
void klass_at_put(int which, klassOop k) {
// Overwrite the old index with a GC friendly value so
// that if G1 looks during the transition during oop_store it won't
// assert the symbol is not an oop.
*obj_at_addr_raw(which) = NULL;
assert(k != NULL, "resolved class shouldn't be null");
obj_at_put_without_check(which, k);
// The interpreter assumes when the tag is stored, the klass is resolved
// and the klassOop is a klass rather than a Symbol*, so we need
// hardware store ordering here.
release_tag_at_put(which, JVM_CONSTANT_Class);
if (UseConcMarkSweepGC) {
// In case the earlier card-mark was consumed by a concurrent
// marking thread before the tag was updated, redirty the card.
obj_at_put_without_check(which, k);
}
}
// For temporary use while constructing constant pool
void klass_index_at_put(int which, int name_index) {
tag_at_put(which, JVM_CONSTANT_ClassIndex);
*int_at_addr(which) = name_index;
}
// Temporary until actual use
void unresolved_klass_at_put(int which, Symbol* s) {
release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
slot_at_put(which, s);
}
void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
tag_at_put(which, JVM_CONSTANT_MethodHandle);
*int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
}
void method_type_index_at_put(int which, int ref_index) {
tag_at_put(which, JVM_CONSTANT_MethodType);
*int_at_addr(which) = ref_index;
}
void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
}
// Temporary until actual use
void unresolved_string_at_put(int which, Symbol* s) {
release_tag_at_put(which, JVM_CONSTANT_UnresolvedString);
slot_at_put(which, s);
}
void int_at_put(int which, jint i) {
tag_at_put(which, JVM_CONSTANT_Integer);
*int_at_addr(which) = i;
}
void long_at_put(int which, jlong l) {
tag_at_put(which, JVM_CONSTANT_Long);
// *long_at_addr(which) = l;
Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
}
void float_at_put(int which, jfloat f) {
tag_at_put(which, JVM_CONSTANT_Float);
*float_at_addr(which) = f;
}
void double_at_put(int which, jdouble d) {
tag_at_put(which, JVM_CONSTANT_Double);
// *double_at_addr(which) = d;
// u8 temp = *(u8*) &d;
Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
}
Symbol** symbol_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (Symbol**) &base()[which];
}
void symbol_at_put(int which, Symbol* s) {
assert(s->refcount() != 0, "should have nonzero refcount");
tag_at_put(which, JVM_CONSTANT_Utf8);
slot_at_put(which, s);
}
void string_at_put(int which, oop str) {
// Overwrite the old index with a GC friendly value so
// that if G1 looks during the transition during oop_store it won't
// assert the symbol is not an oop.
*obj_at_addr_raw(which) = NULL;
assert(str != NULL, "resolved string shouldn't be null");
obj_at_put(which, str);
release_tag_at_put(which, JVM_CONSTANT_String);
if (UseConcMarkSweepGC) {
// In case the earlier card-mark was consumed by a concurrent
// marking thread before the tag was updated, redirty the card.
obj_at_put_without_check(which, str);
}
}
void object_at_put(int which, oop str) {
obj_at_put(which, str);
release_tag_at_put(which, JVM_CONSTANT_Object);
if (UseConcMarkSweepGC) {
// In case the earlier card-mark was consumed by a concurrent
// marking thread before the tag was updated, redirty the card.
obj_at_put_without_check(which, str);
}
}
// For temporary use while constructing constant pool
void string_index_at_put(int which, int string_index) {
tag_at_put(which, JVM_CONSTANT_StringIndex);
*int_at_addr(which) = string_index;
}
void field_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_Fieldref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
}
void method_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_Methodref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
}
void interface_method_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
}
void name_and_type_at_put(int which, int name_index, int signature_index) {
tag_at_put(which, JVM_CONSTANT_NameAndType);
*int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
}
// Tag query
constantTag tag_at(int which) const { return (constantTag)tags()->byte_at_acquire(which); }
// Whether the entry is a pointer that must be GC'd.
bool is_pointer_entry(int which) {
constantTag tag = tag_at(which);
return tag.is_klass() ||
tag.is_string() ||
tag.is_object();
}
// Whether the entry points to an object for ldc (resolved or not)
bool is_object_entry(int which) {
constantTag tag = tag_at(which);
return is_pointer_entry(which) ||
tag.is_unresolved_klass() ||
tag.is_unresolved_string() ||
tag.is_symbol();
}
// Fetching constants
klassOop klass_at(int which, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return klass_at_impl(h_this, which, CHECK_NULL);
}
Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
klassOop resolved_klass_at(int which) { // Used by Compiler
guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
// Must do an acquire here in case another thread resolved the klass
// behind our back, lest we later load stale values thru the oop.
return klassOop(CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_oop());
}
// This method should only be used with a cpool lock or during parsing or gc
Symbol* unresolved_klass_at(int which) { // Temporary until actual use
Symbol* s = CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
// check that the klass is still unresolved.
assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
return s;
}
// RedefineClasses() API support:
Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
jint int_at(int which) {
assert(tag_at(which).is_int(), "Corrupted constant pool");
return *int_at_addr(which);
}
jlong long_at(int which) {
assert(tag_at(which).is_long(), "Corrupted constant pool");
// return *long_at_addr(which);
u8 tmp = Bytes::get_native_u8((address)&base()[which]);
return *((jlong*)&tmp);
}
jfloat float_at(int which) {
assert(tag_at(which).is_float(), "Corrupted constant pool");
return *float_at_addr(which);
}
jdouble double_at(int which) {
assert(tag_at(which).is_double(), "Corrupted constant pool");
u8 tmp = Bytes::get_native_u8((address)&base()[which]);
return *((jdouble*)&tmp);
}
Symbol* symbol_at(int which) {
assert(tag_at(which).is_utf8(), "Corrupted constant pool");
return slot_at(which).get_symbol();
}
oop string_at(int which, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return string_at_impl(h_this, which, CHECK_NULL);
}
oop object_at(int which) {
assert(tag_at(which).is_object(), "Corrupted constant pool");
return slot_at(which).get_oop();
}
// A "pseudo-string" is an non-string oop that has found is way into
// a String entry.
// Under EnableInvokeDynamic this can happen if the user patches a live
// object into a CONSTANT_String entry of an anonymous class.
// Method oops internally created for method handles may also
// use pseudo-strings to link themselves to related metaobjects.
bool is_pseudo_string_at(int which);
oop pseudo_string_at(int which) {
assert(tag_at(which).is_string(), "Corrupted constant pool");
return slot_at(which).get_oop();
}
void pseudo_string_at_put(int which, oop x) {
assert(EnableInvokeDynamic, "");
set_pseudo_string(); // mark header
assert(tag_at(which).is_string() || tag_at(which).is_unresolved_string(), "Corrupted constant pool");
string_at_put(which, x); // this works just fine
}
// only called when we are sure a string entry is already resolved (via an
// earlier string_at call.
oop resolved_string_at(int which) {
assert(tag_at(which).is_string(), "Corrupted constant pool");
// Must do an acquire here in case another thread resolved the klass
// behind our back, lest we later load stale values thru the oop.
return CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_oop();
}
// This method should only be used with a cpool lock or during parsing or gc
Symbol* unresolved_string_at(int which) { // Temporary until actual use
Symbol* s = CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
// check that the string is still unresolved.
assert(tag_at(which).is_unresolved_string(), "Corrupted constant pool");
return s;
}
// Returns an UTF8 for a CONSTANT_String entry at a given index.
// UTF8 char* representation was chosen to avoid conversion of
// java_lang_Strings at resolved entries into Symbol*s
// or vice versa.
// Caller is responsible for checking for pseudo-strings.
char* string_at_noresolve(int which);
jint name_and_type_at(int which) {
assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
return *int_at_addr(which);
}
int method_handle_ref_kind_at(int which) {
assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
}
int method_handle_index_at(int which) {
assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
}
int method_type_index_at(int which) {
assert(tag_at(which).is_method_type(), "Corrupted constant pool");
return *int_at_addr(which);
}
// Derived queries:
Symbol* method_handle_name_ref_at(int which) {
int member = method_handle_index_at(which);
return impl_name_ref_at(member, true);
}
Symbol* method_handle_signature_ref_at(int which) {
int member = method_handle_index_at(which);
return impl_signature_ref_at(member, true);
}
int method_handle_klass_index_at(int which) {
int member = method_handle_index_at(which);
return impl_klass_ref_index_at(member, true);
}
Symbol* method_type_signature_at(int which) {
int sym = method_type_index_at(which);
return symbol_at(sym);
}
int invoke_dynamic_name_and_type_ref_index_at(int which) {
assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
return extract_high_short_from_int(*int_at_addr(which));
}
int invoke_dynamic_bootstrap_specifier_index(int which) {
assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
return extract_low_short_from_int(*int_at_addr(which));
}
int invoke_dynamic_operand_base(int which) {
int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
return operand_offset_at(operands(), bootstrap_specifier_index);
}
// The first part of the operands array consists of an index into the second part.
// Extract a 32-bit index value from the first part.
static int operand_offset_at(typeArrayOop operands, int bootstrap_specifier_index) {
int n = (bootstrap_specifier_index * 2);
assert(n >= 0 && n+2 <= operands->length(), "oob");
// The first 32-bit index points to the beginning of the second part
// of the operands array. Make sure this index is in the first part.
DEBUG_ONLY(int second_part = build_int_from_shorts(operands->short_at(0),
operands->short_at(1)));
assert(second_part == 0 || n+2 <= second_part, "oob (2)");
int offset = build_int_from_shorts(operands->short_at(n+0),
operands->short_at(n+1));
// The offset itself must point into the second part of the array.
assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
return offset;
}
static void operand_offset_at_put(typeArrayOop operands, int bootstrap_specifier_index, int offset) {
int n = bootstrap_specifier_index * 2;
assert(n >= 0 && n+2 <= operands->length(), "oob");
operands->short_at_put(n+0, extract_low_short_from_int(offset));
operands->short_at_put(n+1, extract_high_short_from_int(offset));
}
static int operand_array_length(typeArrayOop operands) {
if (operands == NULL || operands->length() == 0) return 0;
int second_part = operand_offset_at(operands, 0);
return (second_part / 2);
}
#ifdef ASSERT
// operand tuples fit together exactly, end to end
static int operand_limit_at(typeArrayOop operands, int bootstrap_specifier_index) {
int nextidx = bootstrap_specifier_index + 1;
if (nextidx == operand_array_length(operands))
return operands->length();
else
return operand_offset_at(operands, nextidx);
}
int invoke_dynamic_operand_limit(int which) {
int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
return operand_limit_at(operands(), bootstrap_specifier_index);
}
#endif //ASSERT
// layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
enum {
_indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
_indy_argc_offset = 1, // u2 argc
_indy_argv_offset = 2 // u2 argv[argc]
};
int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
int op_base = invoke_dynamic_operand_base(which);
return operands()->short_at(op_base + _indy_bsm_offset);
}
int invoke_dynamic_argument_count_at(int which) {
assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
int op_base = invoke_dynamic_operand_base(which);
int argc = operands()->short_at(op_base + _indy_argc_offset);
DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
int next_offset = invoke_dynamic_operand_limit(which));
assert(end_offset == next_offset, "matched ending");
return argc;
}
int invoke_dynamic_argument_index_at(int which, int j) {
int op_base = invoke_dynamic_operand_base(which);
DEBUG_ONLY(int argc = operands()->short_at(op_base + _indy_argc_offset));
assert((uint)j < (uint)argc, "oob");
return operands()->short_at(op_base + _indy_argv_offset + j);
}
// The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
// name_and_type_ref_index_at) all expect to be passed indices obtained
// directly from the bytecode.
// If the indices are meant to refer to fields or methods, they are
// actually rewritten constant pool cache indices.
// The routine remap_instruction_operand_from_cache manages the adjustment
// of these values back to constant pool indices.
// There are also "uncached" versions which do not adjust the operand index; see below.
// FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
// In a few cases (the verifier) there are uses before a cpcache has been built,
// which are handled by a dynamic check in remap_instruction_operand_from_cache.
// FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
// Lookup for entries consisting of (klass_index, name_and_type index)
klassOop klass_ref_at(int which, TRAPS);
Symbol* klass_ref_at_noresolve(int which);
Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
// Lookup for entries consisting of (name_index, signature_index)
int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
BasicType basic_type_for_signature_at(int which);
// Resolve string constants (to prevent allocation during compilation)
void resolve_string_constants(TRAPS) {
constantPoolHandle h_this(THREAD, this);
resolve_string_constants_impl(h_this, CHECK);
}
private:
enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
public:
// Resolve late bound constants.
oop resolve_constant_at(int index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
}
oop resolve_cached_constant_at(int cache_index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
}
oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
}
// Klass name matches name at offset
bool klass_name_at_matches(instanceKlassHandle k, int which);
// Sizing
int length() const { return _length; }
void set_length(int length) { _length = length; }
// Tells whether index is within bounds.
bool is_within_bounds(int index) const {
return 0 <= index && index < length();
}
static int header_size() { return sizeof(constantPoolOopDesc)/HeapWordSize; }
static int object_size(int length) { return align_object_size(header_size() + length); }
int object_size() { return object_size(length()); }
bool is_conc_safe() { return _is_conc_safe; }
void set_is_conc_safe(bool v) { _is_conc_safe = v; }
friend class constantPoolKlass;
friend class ClassFileParser;
friend class SystemDictionary;
// Used by compiler to prevent classloading.
static klassOop klass_at_if_loaded (constantPoolHandle this_oop, int which);
static klassOop klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
// Same as above - but does LinkResolving.
static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
// Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
// future by other Java code. These take constant pool indices rather than
// constant pool cache indices as do the peer methods above.
Symbol* uncached_klass_ref_at_noresolve(int which);
Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
// Sharing
int pre_resolve_shared_klasses(TRAPS);
void shared_symbols_iterate(SymbolClosure* closure0);
void shared_tags_iterate(OopClosure* closure0);
void shared_strings_iterate(OopClosure* closure0);
// Debugging
const char* printable_name_at(int which) PRODUCT_RETURN0;
#ifdef ASSERT
enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
#else
enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
#endif //ASSERT
private:
Symbol* impl_name_ref_at(int which, bool uncached);
Symbol* impl_signature_ref_at(int which, bool uncached);
int impl_klass_ref_index_at(int which, bool uncached);
int impl_name_and_type_ref_index_at(int which, bool uncached);
int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
// Used while constructing constant pool (only by ClassFileParser)
jint klass_index_at(int which) {
assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
return *int_at_addr(which);
}
jint string_index_at(int which) {
assert(tag_at(which).is_string_index(), "Corrupted constant pool");
return *int_at_addr(which);
}
// Performs the LinkResolver checks
static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
// Implementation of methods that needs an exposed 'this' pointer, in order to
// handle GC while executing the method
static klassOop klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
static oop string_at_impl(constantPoolHandle this_oop, int which, TRAPS);
// Resolve string constants (to prevent allocation during compilation)
static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
public:
// Merging constantPoolOop support:
bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
constantPoolHandle h_this(THREAD, this);
copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
}
static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
int orig_length() const { return _orig_length; }
void set_orig_length(int orig_length) { _orig_length = orig_length; }
// Decrease ref counts of symbols that are in the constant pool
// when the holder class is unloaded
void unreference_symbols();
// JVMTI accesss - GetConstantPool, RetransformClasses, ...
friend class JvmtiConstantPoolReconstituter;
private:
jint cpool_entry_size(jint idx);
jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
// Copy cpool bytes into byte array.
// Returns:
// int > 0, count of the raw cpool bytes that have been copied
// 0, OutOfMemory error
// -1, Internal error
int copy_cpool_bytes(int cpool_size,
SymbolHashMap* tbl,
unsigned char *bytes);
};
class SymbolHashMapEntry : public CHeapObj {
private:
unsigned int _hash; // 32-bit hash for item
SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
Symbol* _symbol; // 1-st part of the mapping: symbol => value
u2 _value; // 2-nd part of the mapping: symbol => value
public:
unsigned int hash() const { return _hash; }
void set_hash(unsigned int hash) { _hash = hash; }
SymbolHashMapEntry* next() const { return _next; }
void set_next(SymbolHashMapEntry* next) { _next = next; }
Symbol* symbol() const { return _symbol; }
void set_symbol(Symbol* sym) { _symbol = sym; }
u2 value() const { return _value; }
void set_value(u2 value) { _value = value; }
SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
: _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
}; // End SymbolHashMapEntry class
class SymbolHashMapBucket : public CHeapObj {
private:
SymbolHashMapEntry* _entry;
public:
SymbolHashMapEntry* entry() const { return _entry; }
void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
void clear() { _entry = NULL; }
}; // End SymbolHashMapBucket class
class SymbolHashMap: public CHeapObj {
private:
// Default number of entries in the table
enum SymbolHashMap_Constants {
_Def_HashMap_Size = 256
};
int _table_size;
SymbolHashMapBucket* _buckets;
void initialize_table(int table_size) {
_table_size = table_size;
_buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size);
for (int index = 0; index < table_size; index++) {
_buckets[index].clear();
}
}
public:
int table_size() const { return _table_size; }
SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
SymbolHashMap(int table_size) { initialize_table(table_size); }
// hash P(31) from Kernighan & Ritchie
static unsigned int compute_hash(const char* str, int len) {
unsigned int hash = 0;
while (len-- > 0) {
hash = 31*hash + (unsigned) *str;
str++;
}
return hash;
}
SymbolHashMapEntry* bucket(int i) {
return _buckets[i].entry();
}
void add_entry(Symbol* sym, u2 value);
SymbolHashMapEntry* find_entry(Symbol* sym);
u2 symbol_to_value(Symbol* sym) {
SymbolHashMapEntry *entry = find_entry(sym);
return (entry == NULL) ? 0 : entry->value();
}
~SymbolHashMap() {
SymbolHashMapEntry* next;
for (int i = 0; i < _table_size; i++) {
for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
next = cur->next();
delete(cur);
}
}
delete _buckets;
}
}; // End SymbolHashMap class
#endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP