duke@435: /* coleenp@4037: * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #ifndef SHARE_VM_CODE_DEPENDENCIES_HPP stefank@2314: #define SHARE_VM_CODE_DEPENDENCIES_HPP stefank@2314: twisti@3050: #include "ci/ciCallSite.hpp" stefank@2314: #include "ci/ciKlass.hpp" twisti@3050: #include "ci/ciMethodHandle.hpp" twisti@3050: #include "classfile/systemDictionary.hpp" stefank@2314: #include "code/compressedStream.hpp" stefank@2314: #include "code/nmethod.hpp" stefank@2314: #include "utilities/growableArray.hpp" stefank@2314: duke@435: //** Dependencies represent assertions (approximate invariants) within twisti@3050: // the runtime system, e.g. class hierarchy changes. An example is an twisti@3050: // assertion that a given method is not overridden; another example is twisti@3050: // that a type has only one concrete subtype. Compiled code which twisti@3050: // relies on such assertions must be discarded if they are overturned twisti@3050: // by changes in the runtime system. We can think of these assertions twisti@3050: // as approximate invariants, because we expect them to be overturned duke@435: // very infrequently. We are willing to perform expensive recovery duke@435: // operations when they are overturned. The benefit, of course, is duke@435: // performing optimistic optimizations (!) on the object code. duke@435: // duke@435: // Changes in the class hierarchy due to dynamic linking or duke@435: // class evolution can violate dependencies. There is enough duke@435: // indexing between classes and nmethods to make dependency duke@435: // checking reasonably efficient. duke@435: duke@435: class ciEnv; duke@435: class nmethod; duke@435: class OopRecorder; duke@435: class xmlStream; duke@435: class CompileLog; duke@435: class DepChange; twisti@3050: class KlassDepChange; twisti@3050: class CallSiteDepChange; duke@435: class No_Safepoint_Verifier; duke@435: duke@435: class Dependencies: public ResourceObj { duke@435: public: duke@435: // Note: In the comments on dependency types, most uses of the terms duke@435: // subtype and supertype are used in a "non-strict" or "inclusive" duke@435: // sense, and are starred to remind the reader of this fact. duke@435: // Strict uses of the terms use the word "proper". duke@435: // duke@435: // Specifically, every class is its own subtype* and supertype*. duke@435: // (This trick is easier than continually saying things like "Y is a duke@435: // subtype of X or X itself".) duke@435: // duke@435: // Sometimes we write X > Y to mean X is a proper supertype of Y. duke@435: // The notation X > {Y, Z} means X has proper subtypes Y, Z. duke@435: // The notation X.m > Y means that Y inherits m from X, while duke@435: // X.m > Y.m means Y overrides X.m. A star denotes abstractness, duke@435: // as *I > A, meaning (abstract) interface I is a super type of A, duke@435: // or A.*m > B.m, meaning B.m implements abstract method A.m. duke@435: // duke@435: // In this module, the terms "subtype" and "supertype" refer to duke@435: // Java-level reference type conversions, as detected by duke@435: // "instanceof" and performed by "checkcast" operations. The method duke@435: // Klass::is_subtype_of tests these relations. Note that "subtype" duke@435: // is richer than "subclass" (as tested by Klass::is_subclass_of), duke@435: // since it takes account of relations involving interface and array duke@435: // types. duke@435: // duke@435: // To avoid needless complexity, dependencies involving array types duke@435: // are not accepted. If you need to make an assertion about an duke@435: // array type, make the assertion about its corresponding element duke@435: // types. Any assertion that might change about an array type can duke@435: // be converted to an assertion about its element type. duke@435: // duke@435: // Most dependencies are evaluated over a "context type" CX, which duke@435: // stands for the set Subtypes(CX) of every Java type that is a subtype* duke@435: // of CX. When the system loads a new class or interface N, it is duke@435: // responsible for re-evaluating changed dependencies whose context duke@435: // type now includes N, that is, all super types of N. duke@435: // duke@435: enum DepType { duke@435: end_marker = 0, duke@435: duke@435: // An 'evol' dependency simply notes that the contents of the duke@435: // method were used. If it evolves (is replaced), the nmethod duke@435: // must be recompiled. No other dependencies are implied. duke@435: evol_method, duke@435: FIRST_TYPE = evol_method, duke@435: duke@435: // A context type CX is a leaf it if has no proper subtype. duke@435: leaf_type, duke@435: duke@435: // An abstract class CX has exactly one concrete subtype CC. duke@435: abstract_with_unique_concrete_subtype, duke@435: duke@435: // The type CX is purely abstract, with no concrete subtype* at all. duke@435: abstract_with_no_concrete_subtype, duke@435: duke@435: // The concrete CX is free of concrete proper subtypes. duke@435: concrete_with_no_concrete_subtype, duke@435: duke@435: // Given a method M1 and a context class CX, the set MM(CX, M1) of duke@435: // "concrete matching methods" in CX of M1 is the set of every duke@435: // concrete M2 for which it is possible to create an invokevirtual duke@435: // or invokeinterface call site that can reach either M1 or M2. duke@435: // That is, M1 and M2 share a name, signature, and vtable index. duke@435: // We wish to notice when the set MM(CX, M1) is just {M1}, or duke@435: // perhaps a set of two {M1,M2}, and issue dependencies on this. duke@435: duke@435: // The set MM(CX, M1) can be computed by starting with any matching duke@435: // concrete M2 that is inherited into CX, and then walking the duke@435: // subtypes* of CX looking for concrete definitions. duke@435: duke@435: // The parameters to this dependency are the method M1 and the duke@435: // context class CX. M1 must be either inherited in CX or defined duke@435: // in a subtype* of CX. It asserts that MM(CX, M1) is no greater duke@435: // than {M1}. duke@435: unique_concrete_method, // one unique concrete method under CX duke@435: duke@435: // An "exclusive" assertion concerns two methods or subtypes, and duke@435: // declares that there are at most two (or perhaps later N>2) duke@435: // specific items that jointly satisfy the restriction. duke@435: // We list all items explicitly rather than just giving their duke@435: // count, for robustness in the face of complex schema changes. duke@435: duke@435: // A context class CX (which may be either abstract or concrete) duke@435: // has two exclusive concrete subtypes* C1, C2 if every concrete duke@435: // subtype* of CX is either C1 or C2. Note that if neither C1 or C2 duke@435: // are equal to CX, then CX itself must be abstract. But it is duke@435: // also possible (for example) that C1 is CX (a concrete class) duke@435: // and C2 is a proper subtype of C1. duke@435: abstract_with_exclusive_concrete_subtypes_2, duke@435: duke@435: // This dependency asserts that MM(CX, M1) is no greater than {M1,M2}. duke@435: exclusive_concrete_methods_2, duke@435: duke@435: // This dependency asserts that no instances of class or it's duke@435: // subclasses require finalization registration. duke@435: no_finalizable_subclasses, duke@435: twisti@3050: // This dependency asserts when the CallSite.target value changed. twisti@3050: call_site_target_value, twisti@3050: duke@435: TYPE_LIMIT duke@435: }; duke@435: enum { duke@435: LG2_TYPE_LIMIT = 4, // assert(TYPE_LIMIT <= (1<* _dep_seen; // (seen[h->ident] & (1<* _deps[TYPE_LIMIT]; duke@435: duke@435: static const char* _dep_name[TYPE_LIMIT]; duke@435: static int _dep_args[TYPE_LIMIT]; duke@435: duke@435: static bool dept_in_mask(DepType dept, int mask) { duke@435: return (int)dept >= 0 && dept < TYPE_LIMIT && ((1<ident(); duke@435: assert(_dep_seen != NULL, "deps must be writable"); duke@435: int seen = _dep_seen->at_grow(x_id, 0); duke@435: _dep_seen->at_put(x_id, seen | (1<* deps, duke@435: int ctxk_i, ciKlass* ctxk); duke@435: duke@435: void sort_all_deps(); duke@435: size_t estimate_size_in_bytes(); duke@435: duke@435: // Initialize _deps, etc. duke@435: void initialize(ciEnv* env); duke@435: duke@435: // State for making a new set of dependencies: duke@435: OopRecorder* _oop_recorder; duke@435: duke@435: // Logging support duke@435: CompileLog* _log; duke@435: duke@435: address _content_bytes; // everything but the oop references, encoded duke@435: size_t _size_in_bytes; duke@435: duke@435: public: duke@435: // Make a new empty dependencies set. duke@435: Dependencies(ciEnv* env) { duke@435: initialize(env); duke@435: } duke@435: duke@435: private: duke@435: // Check for a valid context type. duke@435: // Enforce the restriction against array types. duke@435: static void check_ctxk(ciKlass* ctxk) { duke@435: assert(ctxk->is_instance_klass(), "java types only"); duke@435: } duke@435: static void check_ctxk_concrete(ciKlass* ctxk) { duke@435: assert(is_concrete_klass(ctxk->as_instance_klass()), "must be concrete"); duke@435: } duke@435: static void check_ctxk_abstract(ciKlass* ctxk) { duke@435: check_ctxk(ctxk); duke@435: assert(!is_concrete_klass(ctxk->as_instance_klass()), "must be abstract"); duke@435: } duke@435: coleenp@4037: void assert_common_1(DepType dept, ciBaseObject* x); coleenp@4037: void assert_common_2(DepType dept, ciBaseObject* x0, ciBaseObject* x1); coleenp@4037: void assert_common_3(DepType dept, ciKlass* ctxk, ciBaseObject* x1, ciBaseObject* x2); duke@435: duke@435: public: duke@435: // Adding assertions to a new dependency set at compile time: duke@435: void assert_evol_method(ciMethod* m); duke@435: void assert_leaf_type(ciKlass* ctxk); duke@435: void assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck); duke@435: void assert_abstract_with_no_concrete_subtype(ciKlass* ctxk); duke@435: void assert_concrete_with_no_concrete_subtype(ciKlass* ctxk); duke@435: void assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm); duke@435: void assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2); duke@435: void assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2); duke@435: void assert_has_no_finalizable_subclasses(ciKlass* ctxk); twisti@3094: void assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle); duke@435: duke@435: // Define whether a given method or type is concrete. duke@435: // These methods define the term "concrete" as used in this module. duke@435: // For this module, an "abstract" class is one which is non-concrete. duke@435: // duke@435: // Future optimizations may allow some classes to remain duke@435: // non-concrete until their first instantiation, and allow some duke@435: // methods to remain non-concrete until their first invocation. duke@435: // In that case, there would be a middle ground between concrete duke@435: // and abstract (as defined by the Java language and VM). coleenp@4037: static bool is_concrete_klass(Klass* k); // k is instantiable coleenp@4037: static bool is_concrete_method(Method* m); // m is invocable duke@435: static Klass* find_finalizable_subclass(Klass* k); duke@435: duke@435: // These versions of the concreteness queries work through the CI. duke@435: // The CI versions are allowed to skew sometimes from the VM duke@435: // (oop-based) versions. The cost of such a difference is a duke@435: // (safely) aborted compilation, or a deoptimization, or a missed duke@435: // optimization opportunity. duke@435: // duke@435: // In order to prevent spurious assertions, query results must duke@435: // remain stable within any single ciEnv instance. (I.e., they must duke@435: // not go back into the VM to get their value; they must cache the duke@435: // bit in the CI, either eagerly or lazily.) duke@435: static bool is_concrete_klass(ciInstanceKlass* k); // k appears instantiable duke@435: static bool is_concrete_method(ciMethod* m); // m appears invocable duke@435: static bool has_finalizable_subclass(ciInstanceKlass* k); duke@435: duke@435: // As a general rule, it is OK to compile under the assumption that duke@435: // a given type or method is concrete, even if it at some future duke@435: // point becomes abstract. So dependency checking is one-sided, in duke@435: // that it permits supposedly concrete classes or methods to turn up duke@435: // as really abstract. (This shouldn't happen, except during class duke@435: // evolution, but that's the logic of the checking.) However, if a duke@435: // supposedly abstract class or method suddenly becomes concrete, a duke@435: // dependency on it must fail. duke@435: duke@435: // Checking old assertions at run-time (in the VM only): coleenp@4037: static Klass* check_evol_method(Method* m); coleenp@4037: static Klass* check_leaf_type(Klass* ctxk); coleenp@4037: static Klass* check_abstract_with_unique_concrete_subtype(Klass* ctxk, Klass* conck, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_abstract_with_no_concrete_subtype(Klass* ctxk, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_concrete_with_no_concrete_subtype(Klass* ctxk, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_unique_concrete_method(Klass* ctxk, Method* uniqm, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_abstract_with_exclusive_concrete_subtypes(Klass* ctxk, Klass* k1, Klass* k2, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_exclusive_concrete_methods(Klass* ctxk, Method* m1, Method* m2, twisti@3050: KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes = NULL); coleenp@4037: static Klass* check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes = NULL); coleenp@4037: // A returned Klass* is NULL if the dependency assertion is still coleenp@4037: // valid. A non-NULL Klass* is a 'witness' to the assertion duke@435: // failure, a point in the class hierarchy where the assertion has duke@435: // been proven false. For example, if check_leaf_type returns duke@435: // non-NULL, the value is a subtype of the supposed leaf type. This duke@435: // witness value may be useful for logging the dependency failure. duke@435: // Note that, when a dependency fails, there may be several possible duke@435: // witnesses to the failure. The value returned from the check_foo duke@435: // method is chosen arbitrarily. duke@435: duke@435: // The 'changes' value, if non-null, requests a limited spot-check duke@435: // near the indicated recent changes in the class hierarchy. duke@435: // It is used by DepStream::spot_check_dependency_at. duke@435: duke@435: // Detecting possible new assertions: coleenp@4037: static Klass* find_unique_concrete_subtype(Klass* ctxk); coleenp@4037: static Method* find_unique_concrete_method(Klass* ctxk, Method* m); coleenp@4037: static int find_exclusive_concrete_subtypes(Klass* ctxk, int klen, Klass* k[]); coleenp@4037: static int find_exclusive_concrete_methods(Klass* ctxk, int mlen, Method* m[]); duke@435: duke@435: // Create the encoding which will be stored in an nmethod. duke@435: void encode_content_bytes(); duke@435: duke@435: address content_bytes() { duke@435: assert(_content_bytes != NULL, "encode it first"); duke@435: return _content_bytes; duke@435: } duke@435: size_t size_in_bytes() { duke@435: assert(_content_bytes != NULL, "encode it first"); duke@435: return _size_in_bytes; duke@435: } duke@435: duke@435: OopRecorder* oop_recorder() { return _oop_recorder; } duke@435: CompileLog* log() { return _log; } duke@435: duke@435: void copy_to(nmethod* nm); duke@435: duke@435: void log_all_dependencies(); coleenp@4037: void log_dependency(DepType dept, int nargs, ciBaseObject* args[]) { duke@435: write_dependency_to(log(), dept, nargs, args); duke@435: } duke@435: void log_dependency(DepType dept, coleenp@4037: ciBaseObject* x0, coleenp@4037: ciBaseObject* x1 = NULL, coleenp@4037: ciBaseObject* x2 = NULL) { duke@435: if (log() == NULL) return; coleenp@4037: ciBaseObject* args[max_arg_count]; duke@435: args[0] = x0; duke@435: args[1] = x1; duke@435: args[2] = x2; duke@435: assert(2 < max_arg_count, ""); duke@435: log_dependency(dept, dep_args(dept), args); duke@435: } duke@435: coleenp@4037: class DepArgument : public ResourceObj { coleenp@4037: private: coleenp@4037: bool _is_oop; coleenp@4037: bool _valid; coleenp@4037: void* _value; coleenp@4037: public: coleenp@4037: DepArgument() : _is_oop(false), _value(NULL), _valid(false) {} coleenp@4037: DepArgument(oop v): _is_oop(true), _value(v), _valid(true) {} coleenp@4037: DepArgument(Metadata* v): _is_oop(false), _value(v), _valid(true) {} coleenp@4037: coleenp@4037: bool is_null() const { return _value == NULL; } coleenp@4037: bool is_oop() const { return _is_oop; } coleenp@4037: bool is_metadata() const { return !_is_oop; } coleenp@4037: bool is_klass() const { return is_metadata() && metadata_value()->is_klass(); } coleenp@4037: bool is_method() const { return is_metadata() && metadata_value()->is_method(); } coleenp@4037: coleenp@4037: oop oop_value() const { assert(_is_oop && _valid, "must be"); return (oop) _value; } coleenp@4037: Metadata* metadata_value() const { assert(!_is_oop && _valid, "must be"); return (Metadata*) _value; } coleenp@4037: }; coleenp@4037: duke@435: static void write_dependency_to(CompileLog* log, duke@435: DepType dept, coleenp@4037: int nargs, ciBaseObject* args[], coleenp@4037: Klass* witness = NULL); duke@435: static void write_dependency_to(CompileLog* log, duke@435: DepType dept, coleenp@4037: int nargs, DepArgument args[], coleenp@4037: Klass* witness = NULL); duke@435: static void write_dependency_to(xmlStream* xtty, duke@435: DepType dept, coleenp@4037: int nargs, DepArgument args[], coleenp@4037: Klass* witness = NULL); duke@435: static void print_dependency(DepType dept, coleenp@4037: int nargs, DepArgument args[], coleenp@4037: Klass* witness = NULL); duke@435: duke@435: private: duke@435: // helper for encoding common context types as zero: coleenp@4037: static ciKlass* ctxk_encoded_as_null(DepType dept, ciBaseObject* x); duke@435: coleenp@4037: static Klass* ctxk_encoded_as_null(DepType dept, Metadata* x); duke@435: duke@435: public: duke@435: // Use this to iterate over an nmethod's dependency set. duke@435: // Works on new and old dependency sets. duke@435: // Usage: duke@435: // duke@435: // ; duke@435: // Dependencies::DepType dept; duke@435: // for (Dependencies::DepStream deps(nm); deps.next(); ) { duke@435: // ... duke@435: // } duke@435: // duke@435: // The caller must be in the VM, since oops are not wrapped in handles. duke@435: class DepStream { duke@435: private: duke@435: nmethod* _code; // null if in a compiler thread duke@435: Dependencies* _deps; // null if not in a compiler thread duke@435: CompressedReadStream _bytes; duke@435: #ifdef ASSERT duke@435: size_t _byte_limit; duke@435: #endif duke@435: duke@435: // iteration variables: duke@435: DepType _type; duke@435: int _xi[max_arg_count+1]; duke@435: duke@435: void initial_asserts(size_t byte_limit) NOT_DEBUG({}); duke@435: coleenp@4037: inline Metadata* recorded_metadata_at(int i); duke@435: inline oop recorded_oop_at(int i); duke@435: coleenp@4037: Klass* check_klass_dependency(KlassDepChange* changes); coleenp@4037: Klass* check_call_site_dependency(CallSiteDepChange* changes); twisti@3050: coleenp@4037: void trace_and_log_witness(Klass* witness); duke@435: duke@435: public: duke@435: DepStream(Dependencies* deps) duke@435: : _deps(deps), duke@435: _code(NULL), duke@435: _bytes(deps->content_bytes()) duke@435: { duke@435: initial_asserts(deps->size_in_bytes()); duke@435: } duke@435: DepStream(nmethod* code) duke@435: : _deps(NULL), duke@435: _code(code), duke@435: _bytes(code->dependencies_begin()) duke@435: { duke@435: initial_asserts(code->dependencies_size()); duke@435: } duke@435: duke@435: bool next(); duke@435: duke@435: DepType type() { return _type; } duke@435: int argument_count() { return dep_args(type()); } duke@435: int argument_index(int i) { assert(0 <= i && i < argument_count(), "oob"); duke@435: return _xi[i]; } coleenp@4037: Metadata* argument(int i); // => recorded_oop_at(argument_index(i)) coleenp@4037: oop argument_oop(int i); // => recorded_oop_at(argument_index(i)) coleenp@4037: Klass* context_type(); duke@435: twisti@3094: bool is_klass_type() { return Dependencies::is_klass_type(type()); } twisti@3094: coleenp@4037: Method* method_argument(int i) { coleenp@4037: Metadata* x = argument(i); duke@435: assert(x->is_method(), "type"); coleenp@4037: return (Method*) x; duke@435: } coleenp@4037: Klass* type_argument(int i) { coleenp@4037: Metadata* x = argument(i); duke@435: assert(x->is_klass(), "type"); coleenp@4037: return (Klass*) x; duke@435: } duke@435: twisti@3050: // The point of the whole exercise: Is this dep still OK? coleenp@4037: Klass* check_dependency() { coleenp@4037: Klass* result = check_klass_dependency(NULL); twisti@3050: if (result != NULL) return result; twisti@3050: return check_call_site_dependency(NULL); duke@435: } twisti@3050: duke@435: // A lighter version: Checks only around recent changes in a class duke@435: // hierarchy. (See Universe::flush_dependents_on.) coleenp@4037: Klass* spot_check_dependency_at(DepChange& changes); duke@435: duke@435: // Log the current dependency to xtty or compilation log. coleenp@4037: void log_dependency(Klass* witness = NULL); duke@435: duke@435: // Print the current dependency to tty. coleenp@4037: void print_dependency(Klass* witness = NULL, bool verbose = false); duke@435: }; duke@435: friend class Dependencies::DepStream; duke@435: duke@435: static void print_statistics() PRODUCT_RETURN; duke@435: }; duke@435: twisti@3050: twisti@3050: // Every particular DepChange is a sub-class of this class. duke@435: class DepChange : public StackObj { phh@1558: public: twisti@3050: // What kind of DepChange is this? twisti@3050: virtual bool is_klass_change() const { return false; } twisti@3050: virtual bool is_call_site_change() const { return false; } twisti@3050: twisti@3050: // Subclass casting with assertions. twisti@3050: KlassDepChange* as_klass_change() { twisti@3050: assert(is_klass_change(), "bad cast"); twisti@3050: return (KlassDepChange*) this; twisti@3050: } twisti@3050: CallSiteDepChange* as_call_site_change() { twisti@3050: assert(is_call_site_change(), "bad cast"); twisti@3050: return (CallSiteDepChange*) this; twisti@3050: } twisti@3050: twisti@3050: void print(); twisti@3050: twisti@3050: public: duke@435: enum ChangeType { duke@435: NO_CHANGE = 0, // an uninvolved klass duke@435: Change_new_type, // a newly loaded type duke@435: Change_new_sub, // a super with a new subtype duke@435: Change_new_impl, // an interface with a new implementation duke@435: CHANGE_LIMIT, duke@435: Start_Klass = CHANGE_LIMIT // internal indicator for ContextStream duke@435: }; duke@435: duke@435: // Usage: duke@435: // for (DepChange::ContextStream str(changes); str.next(); ) { coleenp@4037: // Klass* k = str.klass(); duke@435: // switch (str.change_type()) { duke@435: // ... duke@435: // } duke@435: // } duke@435: class ContextStream : public StackObj { duke@435: private: phh@1558: DepChange& _changes; duke@435: friend class DepChange; duke@435: duke@435: // iteration variables: phh@1558: ChangeType _change_type; coleenp@4037: Klass* _klass; coleenp@4037: Array* _ti_base; // i.e., transitive_interfaces phh@1558: int _ti_index; phh@1558: int _ti_limit; duke@435: duke@435: // start at the beginning: twisti@3050: void start(); duke@435: phh@1558: public: duke@435: ContextStream(DepChange& changes) duke@435: : _changes(changes) duke@435: { start(); } duke@435: duke@435: ContextStream(DepChange& changes, No_Safepoint_Verifier& nsv) duke@435: : _changes(changes) duke@435: // the nsv argument makes it safe to hold oops like _klass duke@435: { start(); } duke@435: duke@435: bool next(); duke@435: phh@1558: ChangeType change_type() { return _change_type; } coleenp@4037: Klass* klass() { return _klass; } duke@435: }; duke@435: friend class DepChange::ContextStream; twisti@3050: }; duke@435: twisti@3050: twisti@3050: // A class hierarchy change coming through the VM (under the Compile_lock). twisti@3050: // The change is structured as a single new type with any number of supers twisti@3050: // and implemented interface types. Other than the new type, any of the twisti@3050: // super types can be context types for a relevant dependency, which the twisti@3050: // new type could invalidate. twisti@3050: class KlassDepChange : public DepChange { twisti@3050: private: twisti@3050: // each change set is rooted in exactly one new type (at present): twisti@3050: KlassHandle _new_type; twisti@3050: twisti@3050: void initialize(); twisti@3050: twisti@3050: public: twisti@3050: // notes the new type, marks it and all its super-types twisti@3050: KlassDepChange(KlassHandle new_type) twisti@3050: : _new_type(new_type) twisti@3050: { twisti@3050: initialize(); twisti@3050: } twisti@3050: twisti@3050: // cleans up the marks twisti@3050: ~KlassDepChange(); twisti@3050: twisti@3050: // What kind of DepChange is this? twisti@3050: virtual bool is_klass_change() const { return true; } twisti@3050: coleenp@4037: Klass* new_type() { return _new_type(); } twisti@3050: twisti@3050: // involves_context(k) is true if k is new_type or any of the super types coleenp@4037: bool involves_context(Klass* k); twisti@3050: }; twisti@3050: twisti@3050: twisti@3050: // A CallSite has changed its target. twisti@3050: class CallSiteDepChange : public DepChange { twisti@3050: private: twisti@3050: Handle _call_site; twisti@3050: Handle _method_handle; twisti@3050: twisti@3050: public: twisti@3050: CallSiteDepChange(Handle call_site, Handle method_handle) twisti@3050: : _call_site(call_site), twisti@3050: _method_handle(method_handle) twisti@3050: { twisti@3050: assert(_call_site() ->is_a(SystemDictionary::CallSite_klass()), "must be"); twisti@3050: assert(_method_handle()->is_a(SystemDictionary::MethodHandle_klass()), "must be"); twisti@3050: } twisti@3050: twisti@3050: // What kind of DepChange is this? twisti@3050: virtual bool is_call_site_change() const { return true; } twisti@3050: twisti@3050: oop call_site() const { return _call_site(); } twisti@3050: oop method_handle() const { return _method_handle(); } duke@435: }; stefank@2314: stefank@2314: #endif // SHARE_VM_CODE_DEPENDENCIES_HPP