| /* |
| * Copyright (c) 2005, 2014, 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_CODE_DEPENDENCIES_HPP |
| #define SHARE_VM_CODE_DEPENDENCIES_HPP |
| |
| #include "ci/ciCallSite.hpp" |
| #include "ci/ciKlass.hpp" |
| #include "ci/ciMethodHandle.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "code/compressedStream.hpp" |
| #include "code/nmethod.hpp" |
| #include "utilities/growableArray.hpp" |
| |
| //** Dependencies represent assertions (approximate invariants) within |
| // the runtime system, e.g. class hierarchy changes. An example is an |
| // assertion that a given method is not overridden; another example is |
| // that a type has only one concrete subtype. Compiled code which |
| // relies on such assertions must be discarded if they are overturned |
| // by changes in the runtime system. We can think of these assertions |
| // as approximate invariants, because we expect them to be overturned |
| // very infrequently. We are willing to perform expensive recovery |
| // operations when they are overturned. The benefit, of course, is |
| // performing optimistic optimizations (!) on the object code. |
| // |
| // Changes in the class hierarchy due to dynamic linking or |
| // class evolution can violate dependencies. There is enough |
| // indexing between classes and nmethods to make dependency |
| // checking reasonably efficient. |
| |
| class ciEnv; |
| class nmethod; |
| class OopRecorder; |
| class xmlStream; |
| class CompileLog; |
| class DepChange; |
| class KlassDepChange; |
| class CallSiteDepChange; |
| class No_Safepoint_Verifier; |
| |
| class Dependencies: public ResourceObj { |
| public: |
| // Note: In the comments on dependency types, most uses of the terms |
| // subtype and supertype are used in a "non-strict" or "inclusive" |
| // sense, and are starred to remind the reader of this fact. |
| // Strict uses of the terms use the word "proper". |
| // |
| // Specifically, every class is its own subtype* and supertype*. |
| // (This trick is easier than continually saying things like "Y is a |
| // subtype of X or X itself".) |
| // |
| // Sometimes we write X > Y to mean X is a proper supertype of Y. |
| // The notation X > {Y, Z} means X has proper subtypes Y, Z. |
| // The notation X.m > Y means that Y inherits m from X, while |
| // X.m > Y.m means Y overrides X.m. A star denotes abstractness, |
| // as *I > A, meaning (abstract) interface I is a super type of A, |
| // or A.*m > B.m, meaning B.m implements abstract method A.m. |
| // |
| // In this module, the terms "subtype" and "supertype" refer to |
| // Java-level reference type conversions, as detected by |
| // "instanceof" and performed by "checkcast" operations. The method |
| // Klass::is_subtype_of tests these relations. Note that "subtype" |
| // is richer than "subclass" (as tested by Klass::is_subclass_of), |
| // since it takes account of relations involving interface and array |
| // types. |
| // |
| // To avoid needless complexity, dependencies involving array types |
| // are not accepted. If you need to make an assertion about an |
| // array type, make the assertion about its corresponding element |
| // types. Any assertion that might change about an array type can |
| // be converted to an assertion about its element type. |
| // |
| // Most dependencies are evaluated over a "context type" CX, which |
| // stands for the set Subtypes(CX) of every Java type that is a subtype* |
| // of CX. When the system loads a new class or interface N, it is |
| // responsible for re-evaluating changed dependencies whose context |
| // type now includes N, that is, all super types of N. |
| // |
| enum DepType { |
| end_marker = 0, |
| |
| // An 'evol' dependency simply notes that the contents of the |
| // method were used. If it evolves (is replaced), the nmethod |
| // must be recompiled. No other dependencies are implied. |
| evol_method, |
| FIRST_TYPE = evol_method, |
| |
| // A context type CX is a leaf it if has no proper subtype. |
| leaf_type, |
| |
| // An abstract class CX has exactly one concrete subtype CC. |
| abstract_with_unique_concrete_subtype, |
| |
| // The type CX is purely abstract, with no concrete subtype* at all. |
| abstract_with_no_concrete_subtype, |
| |
| // The concrete CX is free of concrete proper subtypes. |
| concrete_with_no_concrete_subtype, |
| |
| // Given a method M1 and a context class CX, the set MM(CX, M1) of |
| // "concrete matching methods" in CX of M1 is the set of every |
| // concrete M2 for which it is possible to create an invokevirtual |
| // or invokeinterface call site that can reach either M1 or M2. |
| // That is, M1 and M2 share a name, signature, and vtable index. |
| // We wish to notice when the set MM(CX, M1) is just {M1}, or |
| // perhaps a set of two {M1,M2}, and issue dependencies on this. |
| |
| // The set MM(CX, M1) can be computed by starting with any matching |
| // concrete M2 that is inherited into CX, and then walking the |
| // subtypes* of CX looking for concrete definitions. |
| |
| // The parameters to this dependency are the method M1 and the |
| // context class CX. M1 must be either inherited in CX or defined |
| // in a subtype* of CX. It asserts that MM(CX, M1) is no greater |
| // than {M1}. |
| unique_concrete_method, // one unique concrete method under CX |
| |
| // An "exclusive" assertion concerns two methods or subtypes, and |
| // declares that there are at most two (or perhaps later N>2) |
| // specific items that jointly satisfy the restriction. |
| // We list all items explicitly rather than just giving their |
| // count, for robustness in the face of complex schema changes. |
| |
| // A context class CX (which may be either abstract or concrete) |
| // has two exclusive concrete subtypes* C1, C2 if every concrete |
| // subtype* of CX is either C1 or C2. Note that if neither C1 or C2 |
| // are equal to CX, then CX itself must be abstract. But it is |
| // also possible (for example) that C1 is CX (a concrete class) |
| // and C2 is a proper subtype of C1. |
| abstract_with_exclusive_concrete_subtypes_2, |
| |
| // This dependency asserts that MM(CX, M1) is no greater than {M1,M2}. |
| exclusive_concrete_methods_2, |
| |
| // This dependency asserts that no instances of class or it's |
| // subclasses require finalization registration. |
| no_finalizable_subclasses, |
| |
| // This dependency asserts when the CallSite.target value changed. |
| call_site_target_value, |
| |
| TYPE_LIMIT |
| }; |
| enum { |
| LG2_TYPE_LIMIT = 4, // assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT)) |
| |
| // handy categorizations of dependency types: |
| all_types = ((1 << TYPE_LIMIT) - 1) & ((-1) << FIRST_TYPE), |
| |
| non_klass_types = (1 << call_site_target_value), |
| klass_types = all_types & ~non_klass_types, |
| |
| non_ctxk_types = (1 << evol_method), |
| implicit_ctxk_types = (1 << call_site_target_value), |
| explicit_ctxk_types = all_types & ~(non_ctxk_types | implicit_ctxk_types), |
| |
| max_arg_count = 3, // current maximum number of arguments (incl. ctxk) |
| |
| // A "context type" is a class or interface that |
| // provides context for evaluating a dependency. |
| // When present, it is one of the arguments (dep_context_arg). |
| // |
| // If a dependency does not have a context type, there is a |
| // default context, depending on the type of the dependency. |
| // This bit signals that a default context has been compressed away. |
| default_context_type_bit = (1<<LG2_TYPE_LIMIT) |
| }; |
| |
| static const char* dep_name(DepType dept); |
| static int dep_args(DepType dept); |
| |
| static bool is_klass_type( DepType dept) { return dept_in_mask(dept, klass_types ); } |
| |
| static bool has_explicit_context_arg(DepType dept) { return dept_in_mask(dept, explicit_ctxk_types); } |
| static bool has_implicit_context_arg(DepType dept) { return dept_in_mask(dept, implicit_ctxk_types); } |
| |
| static int dep_context_arg(DepType dept) { return has_explicit_context_arg(dept) ? 0 : -1; } |
| static int dep_implicit_context_arg(DepType dept) { return has_implicit_context_arg(dept) ? 0 : -1; } |
| |
| static void check_valid_dependency_type(DepType dept); |
| |
| private: |
| // State for writing a new set of dependencies: |
| GrowableArray<int>* _dep_seen; // (seen[h->ident] & (1<<dept)) |
| GrowableArray<ciBaseObject*>* _deps[TYPE_LIMIT]; |
| |
| static const char* _dep_name[TYPE_LIMIT]; |
| static int _dep_args[TYPE_LIMIT]; |
| |
| static bool dept_in_mask(DepType dept, int mask) { |
| return (int)dept >= 0 && dept < TYPE_LIMIT && ((1<<dept) & mask) != 0; |
| } |
| |
| bool note_dep_seen(int dept, ciBaseObject* x) { |
| assert(dept < BitsPerInt, "oob"); |
| int x_id = x->ident(); |
| assert(_dep_seen != NULL, "deps must be writable"); |
| int seen = _dep_seen->at_grow(x_id, 0); |
| _dep_seen->at_put(x_id, seen | (1<<dept)); |
| // return true if we've already seen dept/x |
| return (seen & (1<<dept)) != 0; |
| } |
| |
| bool maybe_merge_ctxk(GrowableArray<ciBaseObject*>* deps, |
| int ctxk_i, ciKlass* ctxk); |
| |
| void sort_all_deps(); |
| size_t estimate_size_in_bytes(); |
| |
| // Initialize _deps, etc. |
| void initialize(ciEnv* env); |
| |
| // State for making a new set of dependencies: |
| OopRecorder* _oop_recorder; |
| |
| // Logging support |
| CompileLog* _log; |
| |
| address _content_bytes; // everything but the oop references, encoded |
| size_t _size_in_bytes; |
| |
| public: |
| // Make a new empty dependencies set. |
| Dependencies(ciEnv* env) { |
| initialize(env); |
| } |
| |
| private: |
| // Check for a valid context type. |
| // Enforce the restriction against array types. |
| static void check_ctxk(ciKlass* ctxk) { |
| assert(ctxk->is_instance_klass(), "java types only"); |
| } |
| static void check_ctxk_concrete(ciKlass* ctxk) { |
| assert(is_concrete_klass(ctxk->as_instance_klass()), "must be concrete"); |
| } |
| static void check_ctxk_abstract(ciKlass* ctxk) { |
| check_ctxk(ctxk); |
| assert(!is_concrete_klass(ctxk->as_instance_klass()), "must be abstract"); |
| } |
| |
| void assert_common_1(DepType dept, ciBaseObject* x); |
| void assert_common_2(DepType dept, ciBaseObject* x0, ciBaseObject* x1); |
| void assert_common_3(DepType dept, ciKlass* ctxk, ciBaseObject* x1, ciBaseObject* x2); |
| |
| public: |
| // Adding assertions to a new dependency set at compile time: |
| void assert_evol_method(ciMethod* m); |
| void assert_leaf_type(ciKlass* ctxk); |
| void assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck); |
| void assert_abstract_with_no_concrete_subtype(ciKlass* ctxk); |
| void assert_concrete_with_no_concrete_subtype(ciKlass* ctxk); |
| void assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm); |
| void assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2); |
| void assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2); |
| void assert_has_no_finalizable_subclasses(ciKlass* ctxk); |
| void assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle); |
| |
| // Define whether a given method or type is concrete. |
| // These methods define the term "concrete" as used in this module. |
| // For this module, an "abstract" class is one which is non-concrete. |
| // |
| // Future optimizations may allow some classes to remain |
| // non-concrete until their first instantiation, and allow some |
| // methods to remain non-concrete until their first invocation. |
| // In that case, there would be a middle ground between concrete |
| // and abstract (as defined by the Java language and VM). |
| static bool is_concrete_klass(Klass* k); // k is instantiable |
| static bool is_concrete_method(Method* m, Klass* k); // m is invocable |
| static Klass* find_finalizable_subclass(Klass* k); |
| |
| // These versions of the concreteness queries work through the CI. |
| // The CI versions are allowed to skew sometimes from the VM |
| // (oop-based) versions. The cost of such a difference is a |
| // (safely) aborted compilation, or a deoptimization, or a missed |
| // optimization opportunity. |
| // |
| // In order to prevent spurious assertions, query results must |
| // remain stable within any single ciEnv instance. (I.e., they must |
| // not go back into the VM to get their value; they must cache the |
| // bit in the CI, either eagerly or lazily.) |
| static bool is_concrete_klass(ciInstanceKlass* k); // k appears instantiable |
| static bool has_finalizable_subclass(ciInstanceKlass* k); |
| |
| // As a general rule, it is OK to compile under the assumption that |
| // a given type or method is concrete, even if it at some future |
| // point becomes abstract. So dependency checking is one-sided, in |
| // that it permits supposedly concrete classes or methods to turn up |
| // as really abstract. (This shouldn't happen, except during class |
| // evolution, but that's the logic of the checking.) However, if a |
| // supposedly abstract class or method suddenly becomes concrete, a |
| // dependency on it must fail. |
| |
| // Checking old assertions at run-time (in the VM only): |
| static Klass* check_evol_method(Method* m); |
| static Klass* check_leaf_type(Klass* ctxk); |
| static Klass* check_abstract_with_unique_concrete_subtype(Klass* ctxk, Klass* conck, |
| KlassDepChange* changes = NULL); |
| static Klass* check_abstract_with_no_concrete_subtype(Klass* ctxk, |
| KlassDepChange* changes = NULL); |
| static Klass* check_concrete_with_no_concrete_subtype(Klass* ctxk, |
| KlassDepChange* changes = NULL); |
| static Klass* check_unique_concrete_method(Klass* ctxk, Method* uniqm, |
| KlassDepChange* changes = NULL); |
| static Klass* check_abstract_with_exclusive_concrete_subtypes(Klass* ctxk, Klass* k1, Klass* k2, |
| KlassDepChange* changes = NULL); |
| static Klass* check_exclusive_concrete_methods(Klass* ctxk, Method* m1, Method* m2, |
| KlassDepChange* changes = NULL); |
| static Klass* check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes = NULL); |
| static Klass* check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes = NULL); |
| // A returned Klass* is NULL if the dependency assertion is still |
| // valid. A non-NULL Klass* is a 'witness' to the assertion |
| // failure, a point in the class hierarchy where the assertion has |
| // been proven false. For example, if check_leaf_type returns |
| // non-NULL, the value is a subtype of the supposed leaf type. This |
| // witness value may be useful for logging the dependency failure. |
| // Note that, when a dependency fails, there may be several possible |
| // witnesses to the failure. The value returned from the check_foo |
| // method is chosen arbitrarily. |
| |
| // The 'changes' value, if non-null, requests a limited spot-check |
| // near the indicated recent changes in the class hierarchy. |
| // It is used by DepStream::spot_check_dependency_at. |
| |
| // Detecting possible new assertions: |
| static Klass* find_unique_concrete_subtype(Klass* ctxk); |
| static Method* find_unique_concrete_method(Klass* ctxk, Method* m); |
| static int find_exclusive_concrete_subtypes(Klass* ctxk, int klen, Klass* k[]); |
| |
| // Create the encoding which will be stored in an nmethod. |
| void encode_content_bytes(); |
| |
| address content_bytes() { |
| assert(_content_bytes != NULL, "encode it first"); |
| return _content_bytes; |
| } |
| size_t size_in_bytes() { |
| assert(_content_bytes != NULL, "encode it first"); |
| return _size_in_bytes; |
| } |
| |
| OopRecorder* oop_recorder() { return _oop_recorder; } |
| CompileLog* log() { return _log; } |
| |
| void copy_to(nmethod* nm); |
| |
| void log_all_dependencies(); |
| |
| void log_dependency(DepType dept, GrowableArray<ciBaseObject*>* args) { |
| ResourceMark rm; |
| int argslen = args->length(); |
| write_dependency_to(log(), dept, args); |
| guarantee(argslen == args->length(), |
| "args array cannot grow inside nested ResoureMark scope"); |
| } |
| |
| void log_dependency(DepType dept, |
| ciBaseObject* x0, |
| ciBaseObject* x1 = NULL, |
| ciBaseObject* x2 = NULL) { |
| if (log() == NULL) { |
| return; |
| } |
| ResourceMark rm; |
| GrowableArray<ciBaseObject*>* ciargs = |
| new GrowableArray<ciBaseObject*>(dep_args(dept)); |
| assert (x0 != NULL, "no log x0"); |
| ciargs->push(x0); |
| |
| if (x1 != NULL) { |
| ciargs->push(x1); |
| } |
| if (x2 != NULL) { |
| ciargs->push(x2); |
| } |
| assert(ciargs->length() == dep_args(dept), ""); |
| log_dependency(dept, ciargs); |
| } |
| |
| class DepArgument : public ResourceObj { |
| private: |
| bool _is_oop; |
| bool _valid; |
| void* _value; |
| public: |
| DepArgument() : _is_oop(false), _value(NULL), _valid(false) {} |
| DepArgument(oop v): _is_oop(true), _value(v), _valid(true) {} |
| DepArgument(Metadata* v): _is_oop(false), _value(v), _valid(true) {} |
| |
| bool is_null() const { return _value == NULL; } |
| bool is_oop() const { return _is_oop; } |
| bool is_metadata() const { return !_is_oop; } |
| bool is_klass() const { return is_metadata() && metadata_value()->is_klass(); } |
| bool is_method() const { return is_metadata() && metadata_value()->is_method(); } |
| |
| oop oop_value() const { assert(_is_oop && _valid, "must be"); return (oop) _value; } |
| Metadata* metadata_value() const { assert(!_is_oop && _valid, "must be"); return (Metadata*) _value; } |
| }; |
| |
| static void print_dependency(DepType dept, |
| GrowableArray<DepArgument>* args, |
| Klass* witness = NULL); |
| |
| private: |
| // helper for encoding common context types as zero: |
| static ciKlass* ctxk_encoded_as_null(DepType dept, ciBaseObject* x); |
| |
| static Klass* ctxk_encoded_as_null(DepType dept, Metadata* x); |
| |
| static void write_dependency_to(CompileLog* log, |
| DepType dept, |
| GrowableArray<ciBaseObject*>* args, |
| Klass* witness = NULL); |
| static void write_dependency_to(CompileLog* log, |
| DepType dept, |
| GrowableArray<DepArgument>* args, |
| Klass* witness = NULL); |
| static void write_dependency_to(xmlStream* xtty, |
| DepType dept, |
| GrowableArray<DepArgument>* args, |
| Klass* witness = NULL); |
| public: |
| // Use this to iterate over an nmethod's dependency set. |
| // Works on new and old dependency sets. |
| // Usage: |
| // |
| // ; |
| // Dependencies::DepType dept; |
| // for (Dependencies::DepStream deps(nm); deps.next(); ) { |
| // ... |
| // } |
| // |
| // The caller must be in the VM, since oops are not wrapped in handles. |
| class DepStream { |
| private: |
| nmethod* _code; // null if in a compiler thread |
| Dependencies* _deps; // null if not in a compiler thread |
| CompressedReadStream _bytes; |
| #ifdef ASSERT |
| size_t _byte_limit; |
| #endif |
| |
| // iteration variables: |
| DepType _type; |
| int _xi[max_arg_count+1]; |
| |
| void initial_asserts(size_t byte_limit) NOT_DEBUG({}); |
| |
| inline Metadata* recorded_metadata_at(int i); |
| inline oop recorded_oop_at(int i); |
| |
| Klass* check_klass_dependency(KlassDepChange* changes); |
| Klass* check_call_site_dependency(CallSiteDepChange* changes); |
| |
| void trace_and_log_witness(Klass* witness); |
| |
| public: |
| DepStream(Dependencies* deps) |
| : _deps(deps), |
| _code(NULL), |
| _bytes(deps->content_bytes()) |
| { |
| initial_asserts(deps->size_in_bytes()); |
| } |
| DepStream(nmethod* code) |
| : _deps(NULL), |
| _code(code), |
| _bytes(code->dependencies_begin()) |
| { |
| initial_asserts(code->dependencies_size()); |
| } |
| |
| bool next(); |
| |
| DepType type() { return _type; } |
| int argument_count() { return dep_args(type()); } |
| int argument_index(int i) { assert(0 <= i && i < argument_count(), "oob"); |
| return _xi[i]; } |
| Metadata* argument(int i); // => recorded_oop_at(argument_index(i)) |
| oop argument_oop(int i); // => recorded_oop_at(argument_index(i)) |
| Klass* context_type(); |
| |
| bool is_klass_type() { return Dependencies::is_klass_type(type()); } |
| |
| Method* method_argument(int i) { |
| Metadata* x = argument(i); |
| assert(x->is_method(), "type"); |
| return (Method*) x; |
| } |
| Klass* type_argument(int i) { |
| Metadata* x = argument(i); |
| assert(x->is_klass(), "type"); |
| return (Klass*) x; |
| } |
| |
| // The point of the whole exercise: Is this dep still OK? |
| Klass* check_dependency() { |
| Klass* result = check_klass_dependency(NULL); |
| if (result != NULL) return result; |
| return check_call_site_dependency(NULL); |
| } |
| |
| // A lighter version: Checks only around recent changes in a class |
| // hierarchy. (See Universe::flush_dependents_on.) |
| Klass* spot_check_dependency_at(DepChange& changes); |
| |
| // Log the current dependency to xtty or compilation log. |
| void log_dependency(Klass* witness = NULL); |
| |
| // Print the current dependency to tty. |
| void print_dependency(Klass* witness = NULL, bool verbose = false); |
| }; |
| friend class Dependencies::DepStream; |
| |
| static void print_statistics() PRODUCT_RETURN; |
| }; |
| |
| |
| // Every particular DepChange is a sub-class of this class. |
| class DepChange : public StackObj { |
| public: |
| // What kind of DepChange is this? |
| virtual bool is_klass_change() const { return false; } |
| virtual bool is_call_site_change() const { return false; } |
| |
| // Subclass casting with assertions. |
| KlassDepChange* as_klass_change() { |
| assert(is_klass_change(), "bad cast"); |
| return (KlassDepChange*) this; |
| } |
| CallSiteDepChange* as_call_site_change() { |
| assert(is_call_site_change(), "bad cast"); |
| return (CallSiteDepChange*) this; |
| } |
| |
| void print(); |
| |
| public: |
| enum ChangeType { |
| NO_CHANGE = 0, // an uninvolved klass |
| Change_new_type, // a newly loaded type |
| Change_new_sub, // a super with a new subtype |
| Change_new_impl, // an interface with a new implementation |
| CHANGE_LIMIT, |
| Start_Klass = CHANGE_LIMIT // internal indicator for ContextStream |
| }; |
| |
| // Usage: |
| // for (DepChange::ContextStream str(changes); str.next(); ) { |
| // Klass* k = str.klass(); |
| // switch (str.change_type()) { |
| // ... |
| // } |
| // } |
| class ContextStream : public StackObj { |
| private: |
| DepChange& _changes; |
| friend class DepChange; |
| |
| // iteration variables: |
| ChangeType _change_type; |
| Klass* _klass; |
| Array<Klass*>* _ti_base; // i.e., transitive_interfaces |
| int _ti_index; |
| int _ti_limit; |
| |
| // start at the beginning: |
| void start(); |
| |
| public: |
| ContextStream(DepChange& changes) |
| : _changes(changes) |
| { start(); } |
| |
| ContextStream(DepChange& changes, No_Safepoint_Verifier& nsv) |
| : _changes(changes) |
| // the nsv argument makes it safe to hold oops like _klass |
| { start(); } |
| |
| bool next(); |
| |
| ChangeType change_type() { return _change_type; } |
| Klass* klass() { return _klass; } |
| }; |
| friend class DepChange::ContextStream; |
| }; |
| |
| |
| // A class hierarchy change coming through the VM (under the Compile_lock). |
| // The change is structured as a single new type with any number of supers |
| // and implemented interface types. Other than the new type, any of the |
| // super types can be context types for a relevant dependency, which the |
| // new type could invalidate. |
| class KlassDepChange : public DepChange { |
| private: |
| // each change set is rooted in exactly one new type (at present): |
| KlassHandle _new_type; |
| |
| void initialize(); |
| |
| public: |
| // notes the new type, marks it and all its super-types |
| KlassDepChange(KlassHandle new_type) |
| : _new_type(new_type) |
| { |
| initialize(); |
| } |
| |
| // cleans up the marks |
| ~KlassDepChange(); |
| |
| // What kind of DepChange is this? |
| virtual bool is_klass_change() const { return true; } |
| |
| Klass* new_type() { return _new_type(); } |
| |
| // involves_context(k) is true if k is new_type or any of the super types |
| bool involves_context(Klass* k); |
| }; |
| |
| |
| // A CallSite has changed its target. |
| class CallSiteDepChange : public DepChange { |
| private: |
| Handle _call_site; |
| Handle _method_handle; |
| |
| public: |
| CallSiteDepChange(Handle call_site, Handle method_handle) |
| : _call_site(call_site), |
| _method_handle(method_handle) |
| { |
| assert(_call_site() ->is_a(SystemDictionary::CallSite_klass()), "must be"); |
| assert(_method_handle()->is_a(SystemDictionary::MethodHandle_klass()), "must be"); |
| } |
| |
| // What kind of DepChange is this? |
| virtual bool is_call_site_change() const { return true; } |
| |
| oop call_site() const { return _call_site(); } |
| oop method_handle() const { return _method_handle(); } |
| }; |
| |
| #endif // SHARE_VM_CODE_DEPENDENCIES_HPP |