/* * Copyright (c) 1997, 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_COMPILEDIC_HPP #define SHARE_VM_CODE_COMPILEDIC_HPP #include "code/nativeInst.hpp" #include "interpreter/linkResolver.hpp" #include "oops/compiledICHolder.hpp" //----------------------------------------------------------------------------- // The CompiledIC represents a compiled inline cache. // // In order to make patching of the inline cache MT-safe, we only allow the following // transitions (when not at a safepoint): // // // [1] --<-- Clean -->--- [1] // / (null) \ // / \ /-<-\ // / [2] \ / \ // Interpreted ---------> Monomorphic | [3] // (CompiledICHolder*) (Klass*) | // \ / \ / // [4] \ / [4] \->-/ // \->- Megamorphic -<-/ // (Method*) // // The text in paranteses () refere to the value of the inline cache receiver (mov instruction) // // The numbers in square brackets refere to the kind of transition: // [1]: Initial fixup. Receiver it found from debug information // [2]: Compilation of a method // [3]: Recompilation of a method (note: only entry is changed. The Klass* must stay the same) // [4]: Inline cache miss. We go directly to megamorphic call. // // The class automatically inserts transition stubs (using the InlineCacheBuffer) when an MT-unsafe // transition is made to a stub. // class CompiledIC; class ICStub; class CompiledICInfo : public StackObj { private: address _entry; // entry point for call void* _cached_value; // Value of cached_value (either in stub or inline cache) bool _is_icholder; // Is the cached value a CompiledICHolder* bool _is_optimized; // it is an optimized virtual call (i.e., can be statically bound) bool _to_interpreter; // Call it to interpreter bool _release_icholder; public: address entry() const { return _entry; } Metadata* cached_metadata() const { assert(!_is_icholder, ""); return (Metadata*)_cached_value; } CompiledICHolder* claim_cached_icholder() { assert(_is_icholder, ""); assert(_cached_value != NULL, "must be non-NULL"); _release_icholder = false; CompiledICHolder* icholder = (CompiledICHolder*)_cached_value; icholder->claim(); return icholder; } bool is_optimized() const { return _is_optimized; } bool to_interpreter() const { return _to_interpreter; } void set_compiled_entry(address entry, Klass* klass, bool is_optimized) { _entry = entry; _cached_value = (void*)klass; _to_interpreter = false; _is_icholder = false; _is_optimized = is_optimized; _release_icholder = false; } void set_interpreter_entry(address entry, Method* method) { _entry = entry; _cached_value = (void*)method; _to_interpreter = true; _is_icholder = false; _is_optimized = true; _release_icholder = false; } void set_icholder_entry(address entry, CompiledICHolder* icholder) { _entry = entry; _cached_value = (void*)icholder; _to_interpreter = true; _is_icholder = true; _is_optimized = false; _release_icholder = true; } CompiledICInfo(): _entry(NULL), _cached_value(NULL), _is_icholder(false), _to_interpreter(false), _is_optimized(false), _release_icholder(false) { } ~CompiledICInfo() { // In rare cases the info is computed but not used, so release any // CompiledICHolder* that was created if (_release_icholder) { assert(_is_icholder, "must be"); CompiledICHolder* icholder = (CompiledICHolder*)_cached_value; icholder->claim(); delete icholder; } } }; class CompiledIC: public ResourceObj { friend class InlineCacheBuffer; friend class ICStub; private: NativeCall* _ic_call; // the call instruction NativeMovConstReg* _value; // patchable value cell for this IC bool _is_optimized; // an optimized virtual call (i.e., no compiled IC) CompiledIC(nmethod* nm, NativeCall* ic_call); static bool is_icholder_entry(address entry); // low-level inline-cache manipulation. Cannot be accessed directly, since it might not be MT-safe // to change an inline-cache. These changes the underlying inline-cache directly. They *newer* make // changes to a transition stub. void internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder); void set_ic_destination(ICStub* stub); void set_ic_destination(address entry_point) { assert(_is_optimized, "use set_ic_destination_and_value instead"); internal_set_ic_destination(entry_point, false, NULL, false); } // This only for use by ICStubs where the type of the value isn't known void set_ic_destination_and_value(address entry_point, void* value) { internal_set_ic_destination(entry_point, false, value, is_icholder_entry(entry_point)); } void set_ic_destination_and_value(address entry_point, Metadata* value) { internal_set_ic_destination(entry_point, false, value, false); } void set_ic_destination_and_value(address entry_point, CompiledICHolder* value) { internal_set_ic_destination(entry_point, false, value, true); } // Reads the location of the transition stub. This will fail with an assertion, if no transition stub is // associated with the inline cache. address stub_address() const; bool is_in_transition_state() const; // Use InlineCacheBuffer public: // conversion (machine PC to CompiledIC*) friend CompiledIC* CompiledIC_before(nmethod* nm, address return_addr); friend CompiledIC* CompiledIC_at(nmethod* nm, address call_site); friend CompiledIC* CompiledIC_at(Relocation* call_site); // This is used to release CompiledICHolder*s from nmethods that // are about to be freed. The callsite might contain other stale // values of other kinds so it must be careful. static void cleanup_call_site(virtual_call_Relocation* call_site); static bool is_icholder_call_site(virtual_call_Relocation* call_site); // Return the cached_metadata/destination associated with this inline cache. If the cache currently points // to a transition stub, it will read the values from the transition stub. void* cached_value() const; CompiledICHolder* cached_icholder() const { assert(is_icholder_call(), "must be"); return (CompiledICHolder*) cached_value(); } Metadata* cached_metadata() const { assert(!is_icholder_call(), "must be"); return (Metadata*) cached_value(); } address ic_destination() const; bool is_optimized() const { return _is_optimized; } // State bool is_clean() const; bool is_megamorphic() const; bool is_call_to_compiled() const; bool is_call_to_interpreted() const; bool is_icholder_call() const; address end_of_call() { return _ic_call->return_address(); } // MT-safe patching of inline caches. Note: Only safe to call is_xxx when holding the CompiledIC_ock // so you are guaranteed that no patching takes place. The same goes for verify. // // Note: We do not provide any direct access to the stub code, to prevent parts of the code // to manipulate the inline cache in MT-unsafe ways. // // They all takes a TRAP argument, since they can cause a GC if the inline-cache buffer is full. // void set_to_clean(); // Can only be called during a safepoint operation void set_to_monomorphic(CompiledICInfo& info); // Returns true if successful and false otherwise. The call can fail if memory // allocation in the code cache fails. bool set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS); static void compute_monomorphic_entry(methodHandle method, KlassHandle receiver_klass, bool is_optimized, bool static_bound, CompiledICInfo& info, TRAPS); // Location address instruction_address() const { return _ic_call->instruction_address(); } // Misc void print() PRODUCT_RETURN; void print_compiled_ic() PRODUCT_RETURN; void verify() PRODUCT_RETURN; }; inline CompiledIC* CompiledIC_before(nmethod* nm, address return_addr) { CompiledIC* c_ic = new CompiledIC(nm, nativeCall_before(return_addr)); c_ic->verify(); return c_ic; } inline CompiledIC* CompiledIC_at(nmethod* nm, address call_site) { CompiledIC* c_ic = new CompiledIC(nm, nativeCall_at(call_site)); c_ic->verify(); return c_ic; } inline CompiledIC* CompiledIC_at(Relocation* call_site) { assert(call_site->type() == relocInfo::virtual_call_type || call_site->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info"); CompiledIC* c_ic = new CompiledIC(call_site->code(), nativeCall_at(call_site->addr())); c_ic->verify(); return c_ic; } //----------------------------------------------------------------------------- // The CompiledStaticCall represents a call to a static method in the compiled // // Transition diagram of a static call site is somewhat simpler than for an inlined cache: // // // -----<----- Clean ----->----- // / \ // / \ // compilled code <------------> interpreted code // // Clean: Calls directly to runtime method for fixup // Compiled code: Calls directly to compiled code // Interpreted code: Calls to stub that set Method* reference // // class CompiledStaticCall; class StaticCallInfo { private: address _entry; // Entrypoint methodHandle _callee; // Callee (used when calling interpreter) bool _to_interpreter; // call to interpreted method (otherwise compiled) friend class CompiledStaticCall; public: address entry() const { return _entry; } methodHandle callee() const { return _callee; } }; class CompiledStaticCall: public NativeCall { friend class CompiledIC; // Also used by CompiledIC void set_to_interpreted(methodHandle callee, address entry); bool is_optimized_virtual(); public: friend CompiledStaticCall* compiledStaticCall_before(address return_addr); friend CompiledStaticCall* compiledStaticCall_at(address native_call); friend CompiledStaticCall* compiledStaticCall_at(Relocation* call_site); // Code static void emit_to_interp_stub(CodeBuffer &cbuf); static int to_interp_stub_size(); static int reloc_to_interp_stub(); // State bool is_clean() const; bool is_call_to_compiled() const; bool is_call_to_interpreted() const; // Clean static call (will force resolving on next use) void set_to_clean(); // Set state. The entry must be the same, as computed by compute_entry. // Computation and setting is split up, since the actions are separate during // a OptoRuntime::resolve_xxx. void set(const StaticCallInfo& info); // Compute entry point given a method static void compute_entry(methodHandle m, StaticCallInfo& info); // Stub support address find_stub(); static void set_stub_to_clean(static_stub_Relocation* static_stub); // Misc. void print() PRODUCT_RETURN; void verify() PRODUCT_RETURN; }; inline CompiledStaticCall* compiledStaticCall_before(address return_addr) { CompiledStaticCall* st = (CompiledStaticCall*)nativeCall_before(return_addr); st->verify(); return st; } inline CompiledStaticCall* compiledStaticCall_at(address native_call) { CompiledStaticCall* st = (CompiledStaticCall*)native_call; st->verify(); return st; } inline CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) { return compiledStaticCall_at(call_site->addr()); } #endif // SHARE_VM_CODE_COMPILEDIC_HPP