Mercurial > hg > graal-jvmci-8
view src/share/vm/runtime/signature.hpp @ 1716:be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam
author | ysr |
---|---|
date | Mon, 16 Aug 2010 15:58:42 -0700 |
parents | 126ea7725993 |
children | f95d63e2154a |
line wrap: on
line source
/* * Copyright (c) 1997, 2006, 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. * */ // SignatureIterators iterate over a Java signature (or parts of it). // (Syntax according to: "The Java Virtual Machine Specification" by // Tim Lindholm & Frank Yellin; section 4.3 Descriptors; p. 89ff.) // // Example: Iterating over ([Lfoo;D)I using // 0123456789 // // iterate_parameters() calls: do_array(2, 7); do_double(); // iterate_returntype() calls: do_int(); // iterate() calls: do_array(2, 7); do_double(); do_int(); // // is_return_type() is: false ; false ; true // // NOTE: The new optimizer has an alternate, for-loop based signature // iterator implemented in opto/type.cpp, TypeTuple::make(). class SignatureIterator: public ResourceObj { protected: symbolHandle _signature; // the signature to iterate over int _index; // the current character index (only valid during iteration) int _parameter_index; // the current parameter index (0 outside iteration phase) BasicType _return_type; void expect(char c); void skip_optional_size(); int parse_type(); // returns the parameter size in words (0 for void) void check_signature_end(); public: // Definitions used in generating and iterating the // bit field form of the signature generated by the // Fingerprinter. enum { static_feature_size = 1, result_feature_size = 4, result_feature_mask = 0xF, parameter_feature_size = 4, parameter_feature_mask = 0xF, bool_parm = 1, byte_parm = 2, char_parm = 3, short_parm = 4, int_parm = 5, long_parm = 6, float_parm = 7, double_parm = 8, obj_parm = 9, done_parm = 10, // marker for end of parameters // max parameters is wordsize minus // The sign bit, termination field, the result and static bit fields max_size_of_parameters = (BitsPerLong-1 - result_feature_size - parameter_feature_size - static_feature_size) / parameter_feature_size }; // Constructors SignatureIterator(symbolOop signature); SignatureIterator(Thread *thread, symbolOop signature); SignatureIterator(symbolHandle signature); // Iteration void dispatch_field(); // dispatches once for field signatures void iterate_parameters(); // iterates over parameters only void iterate_parameters( uint64_t fingerprint ); void iterate_returntype(); // iterates over returntype only void iterate(); // iterates over whole signature // Returns the word index of the current parameter; int parameter_index() const { return _parameter_index; } bool is_return_type() const { return parameter_index() < 0; } BasicType get_ret_type() const { return _return_type; } // Basic types virtual void do_bool () = 0; virtual void do_char () = 0; virtual void do_float () = 0; virtual void do_double() = 0; virtual void do_byte () = 0; virtual void do_short () = 0; virtual void do_int () = 0; virtual void do_long () = 0; virtual void do_void () = 0; // Object types (begin indexes the first character of the entry, end indexes the first character after the entry) virtual void do_object(int begin, int end) = 0; virtual void do_array (int begin, int end) = 0; }; // Specialized SignatureIterators: Used to compute signature specific values. class SignatureTypeNames : public SignatureIterator { protected: virtual void type_name(const char* name) = 0; void do_bool() { type_name("jboolean"); } void do_char() { type_name("jchar" ); } void do_float() { type_name("jfloat" ); } void do_double() { type_name("jdouble" ); } void do_byte() { type_name("jbyte" ); } void do_short() { type_name("jshort" ); } void do_int() { type_name("jint" ); } void do_long() { type_name("jlong" ); } void do_void() { type_name("void" ); } void do_object(int begin, int end) { type_name("jobject" ); } void do_array (int begin, int end) { type_name("jobject" ); } public: SignatureTypeNames(symbolHandle signature) : SignatureIterator(signature) {} }; class SignatureInfo: public SignatureIterator { protected: bool _has_iterated; // need this because iterate cannot be called in constructor (set is virtual!) bool _has_iterated_return; int _size; void lazy_iterate_parameters() { if (!_has_iterated) { iterate_parameters(); _has_iterated = true; } } void lazy_iterate_return() { if (!_has_iterated_return) { iterate_returntype(); _has_iterated_return = true; } } virtual void set(int size, BasicType type) = 0; void do_bool () { set(T_BOOLEAN_size, T_BOOLEAN); } void do_char () { set(T_CHAR_size , T_CHAR ); } void do_float () { set(T_FLOAT_size , T_FLOAT ); } void do_double() { set(T_DOUBLE_size , T_DOUBLE ); } void do_byte () { set(T_BYTE_size , T_BYTE ); } void do_short () { set(T_SHORT_size , T_SHORT ); } void do_int () { set(T_INT_size , T_INT ); } void do_long () { set(T_LONG_size , T_LONG ); } void do_void () { set(T_VOID_size , T_VOID ); } void do_object(int begin, int end) { set(T_OBJECT_size , T_OBJECT ); } void do_array (int begin, int end) { set(T_ARRAY_size , T_ARRAY ); } public: SignatureInfo(symbolHandle signature) : SignatureIterator(signature) { _has_iterated = _has_iterated_return = false; _size = 0; _return_type = T_ILLEGAL; } }; // Specialized SignatureIterator: Used to compute the argument size. class ArgumentSizeComputer: public SignatureInfo { private: void set(int size, BasicType type) { _size += size; } public: ArgumentSizeComputer(symbolHandle signature) : SignatureInfo(signature) {} int size() { lazy_iterate_parameters(); return _size; } }; class ArgumentCount: public SignatureInfo { private: void set(int size, BasicType type) { _size ++; } public: ArgumentCount(symbolHandle signature) : SignatureInfo(signature) {} int size() { lazy_iterate_parameters(); return _size; } }; // Specialized SignatureIterator: Used to compute the result type. class ResultTypeFinder: public SignatureInfo { private: void set(int size, BasicType type) { _return_type = type; } public: BasicType type() { lazy_iterate_return(); return _return_type; } ResultTypeFinder(symbolHandle signature) : SignatureInfo(signature) {} }; // Fingerprinter computes a unique ID for a given method. The ID // is a bitvector characterizing the methods signature (incl. the receiver). class Fingerprinter: public SignatureIterator { private: uint64_t _fingerprint; int _shift_count; methodHandle mh; public: void do_bool() { _fingerprint |= (((uint64_t)bool_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_char() { _fingerprint |= (((uint64_t)char_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_byte() { _fingerprint |= (((uint64_t)byte_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_short() { _fingerprint |= (((uint64_t)short_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_int() { _fingerprint |= (((uint64_t)int_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_long() { _fingerprint |= (((uint64_t)long_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_float() { _fingerprint |= (((uint64_t)float_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_double() { _fingerprint |= (((uint64_t)double_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_object(int begin, int end) { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_array (int begin, int end) { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; } void do_void() { ShouldNotReachHere(); } Fingerprinter(methodHandle method) : SignatureIterator(method->signature()) { mh = method; _fingerprint = 0; } Fingerprinter(Thread *thread, methodHandle method) : SignatureIterator(thread, method->signature()) { mh = method; _fingerprint = 0; } uint64_t fingerprint() { // See if we fingerprinted this method already if (mh->constMethod()->fingerprint() != CONST64(0)) { return mh->constMethod()->fingerprint(); } if (mh->size_of_parameters() > max_size_of_parameters ) { _fingerprint = UCONST64(-1); mh->constMethod()->set_fingerprint(_fingerprint); return _fingerprint; } assert( (int)mh->result_type() <= (int)result_feature_mask, "bad result type"); _fingerprint = mh->result_type(); _fingerprint <<= static_feature_size; if (mh->is_static()) _fingerprint |= 1; _shift_count = result_feature_size + static_feature_size; iterate_parameters(); _fingerprint |= ((uint64_t)done_parm) << _shift_count;// mark end of sig mh->constMethod()->set_fingerprint(_fingerprint); return _fingerprint; } }; // Specialized SignatureIterator: Used for native call purposes class NativeSignatureIterator: public SignatureIterator { private: methodHandle _method; // We need separate JNI and Java offset values because in 64 bit mode, // the argument offsets are not in sync with the Java stack. // For example a long takes up 1 "C" stack entry but 2 Java stack entries. int _offset; // The java stack offset int _prepended; // number of prepended JNI parameters (1 JNIEnv, plus 1 mirror if static) int _jni_offset; // the current parameter offset, starting with 0 void do_bool () { pass_int(); _jni_offset++; _offset++; } void do_char () { pass_int(); _jni_offset++; _offset++; } void do_float () { pass_float(); _jni_offset++; _offset++; } #ifdef _LP64 void do_double() { pass_double(); _jni_offset++; _offset += 2; } #else void do_double() { pass_double(); _jni_offset += 2; _offset += 2; } #endif void do_byte () { pass_int(); _jni_offset++; _offset++; } void do_short () { pass_int(); _jni_offset++; _offset++; } void do_int () { pass_int(); _jni_offset++; _offset++; } #ifdef _LP64 void do_long () { pass_long(); _jni_offset++; _offset += 2; } #else void do_long () { pass_long(); _jni_offset += 2; _offset += 2; } #endif void do_void () { ShouldNotReachHere(); } void do_object(int begin, int end) { pass_object(); _jni_offset++; _offset++; } void do_array (int begin, int end) { pass_object(); _jni_offset++; _offset++; } public: methodHandle method() const { return _method; } int offset() const { return _offset; } int jni_offset() const { return _jni_offset + _prepended; } // int java_offset() const { return method()->size_of_parameters() - _offset - 1; } bool is_static() const { return method()->is_static(); } virtual void pass_int() = 0; virtual void pass_long() = 0; virtual void pass_object() = 0; virtual void pass_float() = 0; #ifdef _LP64 virtual void pass_double() = 0; #else virtual void pass_double() { pass_long(); } // may be same as long #endif NativeSignatureIterator(methodHandle method) : SignatureIterator(method->signature()) { _method = method; _offset = 0; _jni_offset = 0; const int JNIEnv_words = 1; const int mirror_words = 1; _prepended = !is_static() ? JNIEnv_words : JNIEnv_words + mirror_words; } // iterate() calles the 2 virtual methods according to the following invocation syntax: // // {pass_int | pass_long | pass_object} // // Arguments are handled from left to right (receiver first, if any). // The offset() values refer to the Java stack offsets but are 0 based and increasing. // The java_offset() values count down to 0, and refer to the Java TOS. // The jni_offset() values increase from 1 or 2, and refer to C arguments. void iterate() { iterate(Fingerprinter(method()).fingerprint()); } // Optimized path if we have the bitvector form of signature void iterate( uint64_t fingerprint ) { if (!is_static()) { // handle receiver (not handled by iterate because not in signature) pass_object(); _jni_offset++; _offset++; } SignatureIterator::iterate_parameters( fingerprint ); } }; // Handy stream for iterating over signature class SignatureStream : public StackObj { private: symbolHandle _signature; int _begin; int _end; BasicType _type; bool _at_return_type; public: bool at_return_type() const { return _at_return_type; } bool is_done() const; void next_non_primitive(int t); void next() { symbolOop sig = _signature(); int len = sig->utf8_length(); if (_end >= len) { _end = len + 1; return; } _begin = _end; int t = sig->byte_at(_begin); switch (t) { case 'B': _type = T_BYTE; break; case 'C': _type = T_CHAR; break; case 'D': _type = T_DOUBLE; break; case 'F': _type = T_FLOAT; break; case 'I': _type = T_INT; break; case 'J': _type = T_LONG; break; case 'S': _type = T_SHORT; break; case 'Z': _type = T_BOOLEAN; break; case 'V': _type = T_VOID; break; default : next_non_primitive(t); return; } _end++; } SignatureStream(symbolHandle signature, bool is_method = true) : _signature(signature), _at_return_type(false) { _begin = _end = (is_method ? 1 : 0); // skip first '(' in method signatures next(); } bool is_object() const; // True if this argument is an object bool is_array() const; // True if this argument is an array BasicType type() const { return _type; } symbolOop as_symbol(TRAPS); enum FailureMode { ReturnNull, CNFException, NCDFError }; klassOop as_klass(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS); oop as_java_mirror(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS); // return same as_symbol except allocation of new symbols is avoided. symbolOop as_symbol_or_null(); }; class SignatureVerifier : public StackObj { public: // Returns true if the symbol is valid method or type signature static bool is_valid_signature(symbolHandle sig); static bool is_valid_method_signature(symbolHandle sig); static bool is_valid_type_signature(symbolHandle sig); private: static ssize_t is_valid_type(const char*, ssize_t); static bool invalid_name_char(char); };