/* * Copyright (c) 1999, 2013, 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_PRIMS_JVMTIIMPL_HPP #define SHARE_VM_PRIMS_JVMTIIMPL_HPP #include "classfile/systemDictionary.hpp" #include "jvmtifiles/jvmti.h" #include "oops/objArrayOop.hpp" #include "prims/jvmtiEnvThreadState.hpp" #include "prims/jvmtiEventController.hpp" #include "prims/jvmtiTrace.hpp" #include "prims/jvmtiUtil.hpp" #include "runtime/stackValueCollection.hpp" #include "runtime/vm_operations.hpp" // // Forward Declarations // class JvmtiBreakpoint; class JvmtiBreakpoints; /////////////////////////////////////////////////////////////// // // class GrowableCache, GrowableElement // Used by : JvmtiBreakpointCache // Used by JVMTI methods: none directly. // // GrowableCache is a permanent CHeap growable array of // // In addition, the GrowableCache maintains a NULL terminated cache array of type address // that's created from the element array using the function: // address GrowableElement::getCacheValue(). // // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated // block of memory. Additionally, every time the cache changes its position in memory, the // void (*_listener_fun)(void *this_obj, address* cache) // gets called with the cache's new address. This gives the user of the GrowableCache a callback // to update its pointer to the address cache. // class GrowableElement : public CHeapObj { public: virtual address getCacheValue() =0; virtual bool equals(GrowableElement* e) =0; virtual bool lessThan(GrowableElement *e)=0; virtual GrowableElement *clone() =0; virtual void oops_do(OopClosure* f) =0; virtual void metadata_do(void f(Metadata*)) =0; }; class GrowableCache VALUE_OBJ_CLASS_SPEC { private: // Object pointer passed into cache & listener functions. void *_this_obj; // Array of elements in the collection GrowableArray *_elements; // Parallel array of cached values address *_cache; // Listener for changes to the _cache field. // Called whenever the _cache field has it's value changed // (but NOT when cached elements are recomputed). void (*_listener_fun)(void *, address*); static bool equals(void *, GrowableElement *); // recache all elements after size change, notify listener void recache(); public: GrowableCache(); ~GrowableCache(); void initialize(void *this_obj, void listener_fun(void *, address*) ); // number of elements in the collection int length(); // get the value of the index element in the collection GrowableElement* at(int index); // find the index of the element, -1 if it doesn't exist int find(GrowableElement* e); // append a copy of the element to the end of the collection, notify listener void append(GrowableElement* e); // insert a copy of the element using lessthan(), notify listener void insert(GrowableElement* e); // remove the element at index, notify listener void remove (int index); // clear out all elements and release all heap space, notify listener void clear(); // apply f to every element and update the cache void oops_do(OopClosure* f); // walk metadata to preserve for RedefineClasses void metadata_do(void f(Metadata*)); // update the cache after a full gc void gc_epilogue(); }; /////////////////////////////////////////////////////////////// // // class JvmtiBreakpointCache // Used by : JvmtiBreakpoints // Used by JVMTI methods: none directly. // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint // class JvmtiBreakpointCache : public CHeapObj { private: GrowableCache _cache; public: JvmtiBreakpointCache() {} ~JvmtiBreakpointCache() {} void initialize(void *this_obj, void listener_fun(void *, address*) ) { _cache.initialize(this_obj,listener_fun); } int length() { return _cache.length(); } JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } void remove (int index) { _cache.remove(index); } void clear() { _cache.clear(); } void oops_do(OopClosure* f) { _cache.oops_do(f); } void metadata_do(void f(Metadata*)) { _cache.metadata_do(f); } void gc_epilogue() { _cache.gc_epilogue(); } }; /////////////////////////////////////////////////////////////// // // class JvmtiBreakpoint // Used by : JvmtiBreakpoints // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints // Note: Extends GrowableElement for use in a GrowableCache // // A JvmtiBreakpoint describes a location (class, method, bci) to break at. // typedef void (Method::*method_action)(int _bci); class JvmtiBreakpoint : public GrowableElement { private: Method* _method; int _bci; Bytecodes::Code _orig_bytecode; oop _class_holder; // keeps _method memory from being deallocated public: JvmtiBreakpoint(); JvmtiBreakpoint(Method* m_method, jlocation location); bool equals(JvmtiBreakpoint& bp); bool lessThan(JvmtiBreakpoint &bp); void copy(JvmtiBreakpoint& bp); bool is_valid(); address getBcp(); void each_method_version_do(method_action meth_act); void set(); void clear(); void print(); Method* method() { return _method; } // GrowableElement implementation address getCacheValue() { return getBcp(); } bool lessThan(GrowableElement* e) { Unimplemented(); return false; } bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } void oops_do(OopClosure* f) { // Mark the method loader as live so the Method* class loader doesn't get // unloaded and Method* memory reclaimed. f->do_oop(&_class_holder); } void metadata_do(void f(Metadata*)) { // walk metadata to preserve for RedefineClasses f(_method); } GrowableElement *clone() { JvmtiBreakpoint *bp = new JvmtiBreakpoint(); bp->copy(*this); return bp; } }; /////////////////////////////////////////////////////////////// // // class JvmtiBreakpoints // Used by : JvmtiCurrentBreakpoints // Used by JVMTI methods: none directly // Note: A Helper class // // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. // // Because _bps is only modified at safepoints, its possible to always use the // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). // // It would be possible to make JvmtiBreakpoints a static class, but I've made it // CHeap allocated to emphasize its similarity to JvmtiFramePops. // class JvmtiBreakpoints : public CHeapObj { private: JvmtiBreakpointCache _bps; // These should only be used by VM_ChangeBreakpoints // to insure they only occur at safepoints. // Todo: add checks for safepoint friend class VM_ChangeBreakpoints; void set_at_safepoint(JvmtiBreakpoint& bp); void clear_at_safepoint(JvmtiBreakpoint& bp); static void do_element(GrowableElement *e); public: JvmtiBreakpoints(void listener_fun(void *, address *)); ~JvmtiBreakpoints(); int length(); void oops_do(OopClosure* f); void metadata_do(void f(Metadata*)); void print(); int set(JvmtiBreakpoint& bp); int clear(JvmtiBreakpoint& bp); void clearall_in_class_at_safepoint(Klass* klass); void gc_epilogue(); }; /////////////////////////////////////////////////////////////// // // class JvmtiCurrentBreakpoints // // A static wrapper class for the JvmtiBreakpoints that provides: // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, // but I'm copying the code from JvmtiThreadState which needs to lazily initialize // JvmtiFramePops). // 3. An oops_do entry point for GC'ing the breakpoint array. // class JvmtiCurrentBreakpoints : public AllStatic { private: // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); static JvmtiBreakpoints *_jvmti_breakpoints; // NULL terminated cache of byte-code pointers corresponding to current breakpoints. // Updated only at safepoints (with listener_fun) when the cache is moved. // It exists only to make is_breakpoint fast. static address *_breakpoint_list; static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } static inline address *get_breakpoint_list() { return _breakpoint_list; } // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. static void listener_fun(void *this_obj, address *cache); public: static void initialize(); static void destroy(); // lazily create _jvmti_breakpoints and _breakpoint_list static JvmtiBreakpoints& get_jvmti_breakpoints(); // quickly test whether the bcp matches a cached breakpoint in the list static inline bool is_breakpoint(address bcp); static void oops_do(OopClosure* f); static void metadata_do(void f(Metadata*)) NOT_JVMTI_RETURN; static void gc_epilogue(); }; // quickly test whether the bcp matches a cached breakpoint in the list bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) { address *bps = get_breakpoint_list(); if (bps == NULL) return false; for ( ; (*bps) != NULL; bps++) { if ((*bps) == bcp) return true; } return false; } /////////////////////////////////////////////////////////////// // // class VM_ChangeBreakpoints // Used by : JvmtiBreakpoints // Used by JVMTI methods: none directly. // Note: A Helper class. // // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. // class VM_ChangeBreakpoints : public VM_Operation { private: JvmtiBreakpoints* _breakpoints; int _operation; JvmtiBreakpoint* _bp; public: enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 }; VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) { JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); _breakpoints = ¤t_bps; _bp = bp; _operation = operation; assert(bp != NULL, "bp != NULL"); } VMOp_Type type() const { return VMOp_ChangeBreakpoints; } void doit(); void oops_do(OopClosure* f); void metadata_do(void f(Metadata*)); }; /////////////////////////////////////////////////////////////// // The get/set local operations must only be done by the VM thread // because the interpreter version needs to access oop maps, which can // only safely be done by the VM thread // // I'm told that in 1.5 oop maps are now protected by a lock and // we could get rid of the VM op // However if the VM op is removed then the target thread must // be suspended AND a lock will be needed to prevent concurrent // setting of locals to the same java thread. This lock is needed // to prevent compiledVFrames from trying to add deferred updates // to the thread simultaneously. // class VM_GetOrSetLocal : public VM_Operation { protected: JavaThread* _thread; JavaThread* _calling_thread; jint _depth; jint _index; BasicType _type; jvalue _value; javaVFrame* _jvf; bool _set; // It is possible to get the receiver out of a non-static native wrapper // frame. Use VM_GetReceiver to do this. virtual bool getting_receiver() const { return false; } jvmtiError _result; vframe* get_vframe(); javaVFrame* get_java_vframe(); bool check_slot_type(javaVFrame* vf); public: // Constructor for non-object getter VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); // Constructor for object or non-object setter VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); // Constructor for object getter VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index); VMOp_Type type() const { return VMOp_GetOrSetLocal; } jvalue value() { return _value; } jvmtiError result() { return _result; } bool doit_prologue(); void doit(); bool allow_nested_vm_operations() const; const char* name() const { return "get/set locals"; } // Check that the klass is assignable to a type with the given signature. static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); }; class VM_GetReceiver : public VM_GetOrSetLocal { protected: virtual bool getting_receiver() const { return true; } public: VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); const char* name() const { return "get receiver"; } }; /////////////////////////////////////////////////////////////// // // class JvmtiSuspendControl // // Convenience routines for suspending and resuming threads. // // All attempts by JVMTI to suspend and resume threads must go through the // JvmtiSuspendControl interface. // // methods return true if successful // class JvmtiSuspendControl : public AllStatic { public: // suspend the thread, taking it to a safepoint static bool suspend(JavaThread *java_thread); // resume the thread static bool resume(JavaThread *java_thread); static void print(); }; /** * When a thread (such as the compiler thread or VM thread) cannot post a * JVMTI event itself because the event needs to be posted from a Java * thread, then it can defer the event to the Service thread for posting. * The information needed to post the event is encapsulated into this class * and then enqueued onto the JvmtiDeferredEventQueue, where the Service * thread will pick it up and post it. * * This is currently only used for posting compiled-method-load and unload * events, which we don't want posted from the compiler thread. */ class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { friend class JvmtiDeferredEventQueue; private: typedef enum { TYPE_NONE, TYPE_COMPILED_METHOD_LOAD, TYPE_COMPILED_METHOD_UNLOAD, TYPE_DYNAMIC_CODE_GENERATED } Type; Type _type; union { nmethod* compiled_method_load; struct { nmethod* nm; jmethodID method_id; const void* code_begin; } compiled_method_unload; struct { const char* name; const void* code_begin; const void* code_end; } dynamic_code_generated; } _event_data; JvmtiDeferredEvent(Type t) : _type(t) {} public: JvmtiDeferredEvent() : _type(TYPE_NONE) {} // Factory methods static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm, jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); static JvmtiDeferredEvent dynamic_code_generated_event( const char* name, const void* begin, const void* end) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); // Actually posts the event. void post() NOT_JVMTI_RETURN; }; /** * Events enqueued on this queue wake up the Service thread which dequeues * and posts the events. The Service_lock is required to be held * when operating on the queue (except for the "pending" events). */ class JvmtiDeferredEventQueue : AllStatic { friend class JvmtiDeferredEvent; private: class QueueNode : public CHeapObj { private: JvmtiDeferredEvent _event; QueueNode* _next; public: QueueNode(const JvmtiDeferredEvent& event) : _event(event), _next(NULL) {} const JvmtiDeferredEvent& event() const { return _event; } QueueNode* next() const { return _next; } void set_next(QueueNode* next) { _next = next; } }; static QueueNode* _queue_head; // Hold Service_lock to access static QueueNode* _queue_tail; // Hold Service_lock to access static volatile QueueNode* _pending_list; // Uses CAS for read/update // Transfers events from the _pending_list to the _queue. static void process_pending_events() NOT_JVMTI_RETURN; public: // Must be holding Service_lock when calling these static bool has_events() NOT_JVMTI_RETURN_(false); static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN; static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); // Used to enqueue events without using a lock, for times (such as during // safepoint) when we can't or don't want to lock the Service_lock. // // Events will be held off to the side until there's a call to // dequeue(), enqueue(), or process_pending_events() (all of which require // the holding of the Service_lock), and will be enqueued at that time. static void add_pending_event(const JvmtiDeferredEvent&) NOT_JVMTI_RETURN; }; // Utility macro that checks for NULL pointers: #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP