| /* |
| * Copyright (c) 2003, 2016, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/javaClasses.inline.hpp" |
| #include "classfile/symbolTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "code/codeCache.hpp" |
| #include "jvmtifiles/jvmtiEnv.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/instanceMirrorKlass.hpp" |
| #include "oops/objArrayKlass.hpp" |
| #include "oops/objArrayOop.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "prims/jvmtiEventController.hpp" |
| #include "prims/jvmtiEventController.inline.hpp" |
| #include "prims/jvmtiExport.hpp" |
| #include "prims/jvmtiImpl.hpp" |
| #include "prims/jvmtiTagMap.hpp" |
| #include "runtime/biasedLocking.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/jniHandles.hpp" |
| #include "runtime/mutex.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/reflectionUtils.hpp" |
| #include "runtime/vframe.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "runtime/vm_operations.hpp" |
| #include "services/serviceUtil.hpp" |
| #include "utilities/macros.hpp" |
| #if INCLUDE_ALL_GCS |
| #include "gc/parallel/parallelScavengeHeap.hpp" |
| #endif // INCLUDE_ALL_GCS |
| |
| // JvmtiTagHashmapEntry |
| // |
| // Each entry encapsulates a reference to the tagged object |
| // and the tag value. In addition an entry includes a next pointer which |
| // is used to chain entries together. |
| |
| class JvmtiTagHashmapEntry : public CHeapObj<mtInternal> { |
| private: |
| friend class JvmtiTagMap; |
| |
| oop _object; // tagged object |
| jlong _tag; // the tag |
| JvmtiTagHashmapEntry* _next; // next on the list |
| |
| inline void init(oop object, jlong tag) { |
| _object = object; |
| _tag = tag; |
| _next = NULL; |
| } |
| |
| // constructor |
| JvmtiTagHashmapEntry(oop object, jlong tag) { init(object, tag); } |
| |
| public: |
| |
| // accessor methods |
| inline oop object() const { return _object; } |
| inline oop* object_addr() { return &_object; } |
| inline jlong tag() const { return _tag; } |
| |
| inline void set_tag(jlong tag) { |
| assert(tag != 0, "can't be zero"); |
| _tag = tag; |
| } |
| |
| inline JvmtiTagHashmapEntry* next() const { return _next; } |
| inline void set_next(JvmtiTagHashmapEntry* next) { _next = next; } |
| }; |
| |
| |
| // JvmtiTagHashmap |
| // |
| // A hashmap is essentially a table of pointers to entries. Entries |
| // are hashed to a location, or position in the table, and then |
| // chained from that location. The "key" for hashing is address of |
| // the object, or oop. The "value" is the tag value. |
| // |
| // A hashmap maintains a count of the number entries in the hashmap |
| // and resizes if the number of entries exceeds a given threshold. |
| // The threshold is specified as a percentage of the size - for |
| // example a threshold of 0.75 will trigger the hashmap to resize |
| // if the number of entries is >75% of table size. |
| // |
| // A hashmap provides functions for adding, removing, and finding |
| // entries. It also provides a function to iterate over all entries |
| // in the hashmap. |
| |
| class JvmtiTagHashmap : public CHeapObj<mtInternal> { |
| private: |
| friend class JvmtiTagMap; |
| |
| enum { |
| small_trace_threshold = 10000, // threshold for tracing |
| medium_trace_threshold = 100000, |
| large_trace_threshold = 1000000, |
| initial_trace_threshold = small_trace_threshold |
| }; |
| |
| static int _sizes[]; // array of possible hashmap sizes |
| int _size; // actual size of the table |
| int _size_index; // index into size table |
| |
| int _entry_count; // number of entries in the hashmap |
| |
| float _load_factor; // load factor as a % of the size |
| int _resize_threshold; // computed threshold to trigger resizing. |
| bool _resizing_enabled; // indicates if hashmap can resize |
| |
| int _trace_threshold; // threshold for trace messages |
| |
| JvmtiTagHashmapEntry** _table; // the table of entries. |
| |
| // private accessors |
| int resize_threshold() const { return _resize_threshold; } |
| int trace_threshold() const { return _trace_threshold; } |
| |
| // initialize the hashmap |
| void init(int size_index=0, float load_factor=4.0f) { |
| int initial_size = _sizes[size_index]; |
| _size_index = size_index; |
| _size = initial_size; |
| _entry_count = 0; |
| if (TraceJVMTIObjectTagging) { |
| _trace_threshold = initial_trace_threshold; |
| } else { |
| _trace_threshold = -1; |
| } |
| _load_factor = load_factor; |
| _resize_threshold = (int)(_load_factor * _size); |
| _resizing_enabled = true; |
| size_t s = initial_size * sizeof(JvmtiTagHashmapEntry*); |
| _table = (JvmtiTagHashmapEntry**)os::malloc(s, mtInternal); |
| if (_table == NULL) { |
| vm_exit_out_of_memory(s, OOM_MALLOC_ERROR, |
| "unable to allocate initial hashtable for jvmti object tags"); |
| } |
| for (int i=0; i<initial_size; i++) { |
| _table[i] = NULL; |
| } |
| } |
| |
| // hash a given key (oop) with the specified size |
| static unsigned int hash(oop key, int size) { |
| // shift right to get better distribution (as these bits will be zero |
| // with aligned addresses) |
| unsigned int addr = (unsigned int)(cast_from_oop<intptr_t>(key)); |
| #ifdef _LP64 |
| return (addr >> 3) % size; |
| #else |
| return (addr >> 2) % size; |
| #endif |
| } |
| |
| // hash a given key (oop) |
| unsigned int hash(oop key) { |
| return hash(key, _size); |
| } |
| |
| // resize the hashmap - allocates a large table and re-hashes |
| // all entries into the new table. |
| void resize() { |
| int new_size_index = _size_index+1; |
| int new_size = _sizes[new_size_index]; |
| if (new_size < 0) { |
| // hashmap already at maximum capacity |
| return; |
| } |
| |
| // allocate new table |
| size_t s = new_size * sizeof(JvmtiTagHashmapEntry*); |
| JvmtiTagHashmapEntry** new_table = (JvmtiTagHashmapEntry**)os::malloc(s, mtInternal); |
| if (new_table == NULL) { |
| warning("unable to allocate larger hashtable for jvmti object tags"); |
| set_resizing_enabled(false); |
| return; |
| } |
| |
| // initialize new table |
| int i; |
| for (i=0; i<new_size; i++) { |
| new_table[i] = NULL; |
| } |
| |
| // rehash all entries into the new table |
| for (i=0; i<_size; i++) { |
| JvmtiTagHashmapEntry* entry = _table[i]; |
| while (entry != NULL) { |
| JvmtiTagHashmapEntry* next = entry->next(); |
| oop key = entry->object(); |
| assert(key != NULL, "jni weak reference cleared!!"); |
| unsigned int h = hash(key, new_size); |
| JvmtiTagHashmapEntry* anchor = new_table[h]; |
| if (anchor == NULL) { |
| new_table[h] = entry; |
| entry->set_next(NULL); |
| } else { |
| entry->set_next(anchor); |
| new_table[h] = entry; |
| } |
| entry = next; |
| } |
| } |
| |
| // free old table and update settings. |
| os::free((void*)_table); |
| _table = new_table; |
| _size_index = new_size_index; |
| _size = new_size; |
| |
| // compute new resize threshold |
| _resize_threshold = (int)(_load_factor * _size); |
| } |
| |
| |
| // internal remove function - remove an entry at a given position in the |
| // table. |
| inline void remove(JvmtiTagHashmapEntry* prev, int pos, JvmtiTagHashmapEntry* entry) { |
| assert(pos >= 0 && pos < _size, "out of range"); |
| if (prev == NULL) { |
| _table[pos] = entry->next(); |
| } else { |
| prev->set_next(entry->next()); |
| } |
| assert(_entry_count > 0, "checking"); |
| _entry_count--; |
| } |
| |
| // resizing switch |
| bool is_resizing_enabled() const { return _resizing_enabled; } |
| void set_resizing_enabled(bool enable) { _resizing_enabled = enable; } |
| |
| // debugging |
| void print_memory_usage(); |
| void compute_next_trace_threshold(); |
| |
| public: |
| |
| // create a JvmtiTagHashmap of a preferred size and optionally a load factor. |
| // The preferred size is rounded down to an actual size. |
| JvmtiTagHashmap(int size, float load_factor=0.0f) { |
| int i=0; |
| while (_sizes[i] < size) { |
| if (_sizes[i] < 0) { |
| assert(i > 0, "sanity check"); |
| i--; |
| break; |
| } |
| i++; |
| } |
| |
| // if a load factor is specified then use it, otherwise use default |
| if (load_factor > 0.01f) { |
| init(i, load_factor); |
| } else { |
| init(i); |
| } |
| } |
| |
| // create a JvmtiTagHashmap with default settings |
| JvmtiTagHashmap() { |
| init(); |
| } |
| |
| // release table when JvmtiTagHashmap destroyed |
| ~JvmtiTagHashmap() { |
| if (_table != NULL) { |
| os::free((void*)_table); |
| _table = NULL; |
| } |
| } |
| |
| // accessors |
| int size() const { return _size; } |
| JvmtiTagHashmapEntry** table() const { return _table; } |
| int entry_count() const { return _entry_count; } |
| |
| // find an entry in the hashmap, returns NULL if not found. |
| inline JvmtiTagHashmapEntry* find(oop key) { |
| unsigned int h = hash(key); |
| JvmtiTagHashmapEntry* entry = _table[h]; |
| while (entry != NULL) { |
| if (entry->object() == key) { |
| return entry; |
| } |
| entry = entry->next(); |
| } |
| return NULL; |
| } |
| |
| |
| // add a new entry to hashmap |
| inline void add(oop key, JvmtiTagHashmapEntry* entry) { |
| assert(key != NULL, "checking"); |
| assert(find(key) == NULL, "duplicate detected"); |
| unsigned int h = hash(key); |
| JvmtiTagHashmapEntry* anchor = _table[h]; |
| if (anchor == NULL) { |
| _table[h] = entry; |
| entry->set_next(NULL); |
| } else { |
| entry->set_next(anchor); |
| _table[h] = entry; |
| } |
| |
| _entry_count++; |
| if (trace_threshold() > 0 && entry_count() >= trace_threshold()) { |
| assert(TraceJVMTIObjectTagging, "should only get here when tracing"); |
| print_memory_usage(); |
| compute_next_trace_threshold(); |
| } |
| |
| // if the number of entries exceed the threshold then resize |
| if (entry_count() > resize_threshold() && is_resizing_enabled()) { |
| resize(); |
| } |
| } |
| |
| // remove an entry with the given key. |
| inline JvmtiTagHashmapEntry* remove(oop key) { |
| unsigned int h = hash(key); |
| JvmtiTagHashmapEntry* entry = _table[h]; |
| JvmtiTagHashmapEntry* prev = NULL; |
| while (entry != NULL) { |
| if (key == entry->object()) { |
| break; |
| } |
| prev = entry; |
| entry = entry->next(); |
| } |
| if (entry != NULL) { |
| remove(prev, h, entry); |
| } |
| return entry; |
| } |
| |
| // iterate over all entries in the hashmap |
| void entry_iterate(JvmtiTagHashmapEntryClosure* closure); |
| }; |
| |
| // possible hashmap sizes - odd primes that roughly double in size. |
| // To avoid excessive resizing the odd primes from 4801-76831 and |
| // 76831-307261 have been removed. The list must be terminated by -1. |
| int JvmtiTagHashmap::_sizes[] = { 4801, 76831, 307261, 614563, 1228891, |
| 2457733, 4915219, 9830479, 19660831, 39321619, 78643219, -1 }; |
| |
| |
| // A supporting class for iterating over all entries in Hashmap |
| class JvmtiTagHashmapEntryClosure { |
| public: |
| virtual void do_entry(JvmtiTagHashmapEntry* entry) = 0; |
| }; |
| |
| |
| // iterate over all entries in the hashmap |
| void JvmtiTagHashmap::entry_iterate(JvmtiTagHashmapEntryClosure* closure) { |
| for (int i=0; i<_size; i++) { |
| JvmtiTagHashmapEntry* entry = _table[i]; |
| JvmtiTagHashmapEntry* prev = NULL; |
| while (entry != NULL) { |
| // obtain the next entry before invoking do_entry - this is |
| // necessary because do_entry may remove the entry from the |
| // hashmap. |
| JvmtiTagHashmapEntry* next = entry->next(); |
| closure->do_entry(entry); |
| entry = next; |
| } |
| } |
| } |
| |
| // debugging |
| void JvmtiTagHashmap::print_memory_usage() { |
| intptr_t p = (intptr_t)this; |
| tty->print("[JvmtiTagHashmap @ " INTPTR_FORMAT, p); |
| |
| // table + entries in KB |
| int hashmap_usage = (size()*sizeof(JvmtiTagHashmapEntry*) + |
| entry_count()*sizeof(JvmtiTagHashmapEntry))/K; |
| |
| int weak_globals_usage = (int)(JNIHandles::weak_global_handle_memory_usage()/K); |
| tty->print_cr(", %d entries (%d KB) <JNI weak globals: %d KB>]", |
| entry_count(), hashmap_usage, weak_globals_usage); |
| } |
| |
| // compute threshold for the next trace message |
| void JvmtiTagHashmap::compute_next_trace_threshold() { |
| if (trace_threshold() < medium_trace_threshold) { |
| _trace_threshold += small_trace_threshold; |
| } else { |
| if (trace_threshold() < large_trace_threshold) { |
| _trace_threshold += medium_trace_threshold; |
| } else { |
| _trace_threshold += large_trace_threshold; |
| } |
| } |
| } |
| |
| // create a JvmtiTagMap |
| JvmtiTagMap::JvmtiTagMap(JvmtiEnv* env) : |
| _env(env), |
| _lock(Mutex::nonleaf+2, "JvmtiTagMap._lock", false), |
| _free_entries(NULL), |
| _free_entries_count(0) |
| { |
| assert(JvmtiThreadState_lock->is_locked(), "sanity check"); |
| assert(((JvmtiEnvBase *)env)->tag_map() == NULL, "tag map already exists for environment"); |
| |
| _hashmap = new JvmtiTagHashmap(); |
| |
| // finally add us to the environment |
| ((JvmtiEnvBase *)env)->set_tag_map(this); |
| } |
| |
| |
| // destroy a JvmtiTagMap |
| JvmtiTagMap::~JvmtiTagMap() { |
| |
| // no lock acquired as we assume the enclosing environment is |
| // also being destroryed. |
| ((JvmtiEnvBase *)_env)->set_tag_map(NULL); |
| |
| JvmtiTagHashmapEntry** table = _hashmap->table(); |
| for (int j = 0; j < _hashmap->size(); j++) { |
| JvmtiTagHashmapEntry* entry = table[j]; |
| while (entry != NULL) { |
| JvmtiTagHashmapEntry* next = entry->next(); |
| delete entry; |
| entry = next; |
| } |
| } |
| |
| // finally destroy the hashmap |
| delete _hashmap; |
| _hashmap = NULL; |
| |
| // remove any entries on the free list |
| JvmtiTagHashmapEntry* entry = _free_entries; |
| while (entry != NULL) { |
| JvmtiTagHashmapEntry* next = entry->next(); |
| delete entry; |
| entry = next; |
| } |
| _free_entries = NULL; |
| } |
| |
| // create a hashmap entry |
| // - if there's an entry on the (per-environment) free list then this |
| // is returned. Otherwise an new entry is allocated. |
| JvmtiTagHashmapEntry* JvmtiTagMap::create_entry(oop ref, jlong tag) { |
| assert(Thread::current()->is_VM_thread() || is_locked(), "checking"); |
| JvmtiTagHashmapEntry* entry; |
| if (_free_entries == NULL) { |
| entry = new JvmtiTagHashmapEntry(ref, tag); |
| } else { |
| assert(_free_entries_count > 0, "mismatched _free_entries_count"); |
| _free_entries_count--; |
| entry = _free_entries; |
| _free_entries = entry->next(); |
| entry->init(ref, tag); |
| } |
| return entry; |
| } |
| |
| // destroy an entry by returning it to the free list |
| void JvmtiTagMap::destroy_entry(JvmtiTagHashmapEntry* entry) { |
| assert(SafepointSynchronize::is_at_safepoint() || is_locked(), "checking"); |
| // limit the size of the free list |
| if (_free_entries_count >= max_free_entries) { |
| delete entry; |
| } else { |
| entry->set_next(_free_entries); |
| _free_entries = entry; |
| _free_entries_count++; |
| } |
| } |
| |
| // returns the tag map for the given environments. If the tag map |
| // doesn't exist then it is created. |
| JvmtiTagMap* JvmtiTagMap::tag_map_for(JvmtiEnv* env) { |
| JvmtiTagMap* tag_map = ((JvmtiEnvBase*)env)->tag_map(); |
| if (tag_map == NULL) { |
| MutexLocker mu(JvmtiThreadState_lock); |
| tag_map = ((JvmtiEnvBase*)env)->tag_map(); |
| if (tag_map == NULL) { |
| tag_map = new JvmtiTagMap(env); |
| } |
| } else { |
| CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); |
| } |
| return tag_map; |
| } |
| |
| // iterate over all entries in the tag map. |
| void JvmtiTagMap::entry_iterate(JvmtiTagHashmapEntryClosure* closure) { |
| hashmap()->entry_iterate(closure); |
| } |
| |
| // returns true if the hashmaps are empty |
| bool JvmtiTagMap::is_empty() { |
| assert(SafepointSynchronize::is_at_safepoint() || is_locked(), "checking"); |
| return hashmap()->entry_count() == 0; |
| } |
| |
| |
| // Return the tag value for an object, or 0 if the object is |
| // not tagged |
| // |
| static inline jlong tag_for(JvmtiTagMap* tag_map, oop o) { |
| JvmtiTagHashmapEntry* entry = tag_map->hashmap()->find(o); |
| if (entry == NULL) { |
| return 0; |
| } else { |
| return entry->tag(); |
| } |
| } |
| |
| |
| // A CallbackWrapper is a support class for querying and tagging an object |
| // around a callback to a profiler. The constructor does pre-callback |
| // work to get the tag value, klass tag value, ... and the destructor |
| // does the post-callback work of tagging or untagging the object. |
| // |
| // { |
| // CallbackWrapper wrapper(tag_map, o); |
| // |
| // (*callback)(wrapper.klass_tag(), wrapper.obj_size(), wrapper.obj_tag_p(), ...) |
| // |
| // } // wrapper goes out of scope here which results in the destructor |
| // checking to see if the object has been tagged, untagged, or the |
| // tag value has changed. |
| // |
| class CallbackWrapper : public StackObj { |
| private: |
| JvmtiTagMap* _tag_map; |
| JvmtiTagHashmap* _hashmap; |
| JvmtiTagHashmapEntry* _entry; |
| oop _o; |
| jlong _obj_size; |
| jlong _obj_tag; |
| jlong _klass_tag; |
| |
| protected: |
| JvmtiTagMap* tag_map() const { return _tag_map; } |
| |
| // invoked post-callback to tag, untag, or update the tag of an object |
| void inline post_callback_tag_update(oop o, JvmtiTagHashmap* hashmap, |
| JvmtiTagHashmapEntry* entry, jlong obj_tag); |
| public: |
| CallbackWrapper(JvmtiTagMap* tag_map, oop o) { |
| assert(Thread::current()->is_VM_thread() || tag_map->is_locked(), |
| "MT unsafe or must be VM thread"); |
| |
| // object to tag |
| _o = o; |
| |
| // object size |
| _obj_size = (jlong)_o->size() * wordSize; |
| |
| // record the context |
| _tag_map = tag_map; |
| _hashmap = tag_map->hashmap(); |
| _entry = _hashmap->find(_o); |
| |
| // get object tag |
| _obj_tag = (_entry == NULL) ? 0 : _entry->tag(); |
| |
| // get the class and the class's tag value |
| assert(SystemDictionary::Class_klass()->is_mirror_instance_klass(), "Is not?"); |
| |
| _klass_tag = tag_for(tag_map, _o->klass()->java_mirror()); |
| } |
| |
| ~CallbackWrapper() { |
| post_callback_tag_update(_o, _hashmap, _entry, _obj_tag); |
| } |
| |
| inline jlong* obj_tag_p() { return &_obj_tag; } |
| inline jlong obj_size() const { return _obj_size; } |
| inline jlong obj_tag() const { return _obj_tag; } |
| inline jlong klass_tag() const { return _klass_tag; } |
| }; |
| |
| |
| |
| // callback post-callback to tag, untag, or update the tag of an object |
| void inline CallbackWrapper::post_callback_tag_update(oop o, |
| JvmtiTagHashmap* hashmap, |
| JvmtiTagHashmapEntry* entry, |
| jlong obj_tag) { |
| if (entry == NULL) { |
| if (obj_tag != 0) { |
| // callback has tagged the object |
| assert(Thread::current()->is_VM_thread(), "must be VMThread"); |
| entry = tag_map()->create_entry(o, obj_tag); |
| hashmap->add(o, entry); |
| } |
| } else { |
| // object was previously tagged - the callback may have untagged |
| // the object or changed the tag value |
| if (obj_tag == 0) { |
| |
| JvmtiTagHashmapEntry* entry_removed = hashmap->remove(o); |
| assert(entry_removed == entry, "checking"); |
| tag_map()->destroy_entry(entry); |
| |
| } else { |
| if (obj_tag != entry->tag()) { |
| entry->set_tag(obj_tag); |
| } |
| } |
| } |
| } |
| |
| // An extended CallbackWrapper used when reporting an object reference |
| // to the agent. |
| // |
| // { |
| // TwoOopCallbackWrapper wrapper(tag_map, referrer, o); |
| // |
| // (*callback)(wrapper.klass_tag(), |
| // wrapper.obj_size(), |
| // wrapper.obj_tag_p() |
| // wrapper.referrer_tag_p(), ...) |
| // |
| // } // wrapper goes out of scope here which results in the destructor |
| // checking to see if the referrer object has been tagged, untagged, |
| // or the tag value has changed. |
| // |
| class TwoOopCallbackWrapper : public CallbackWrapper { |
| private: |
| bool _is_reference_to_self; |
| JvmtiTagHashmap* _referrer_hashmap; |
| JvmtiTagHashmapEntry* _referrer_entry; |
| oop _referrer; |
| jlong _referrer_obj_tag; |
| jlong _referrer_klass_tag; |
| jlong* _referrer_tag_p; |
| |
| bool is_reference_to_self() const { return _is_reference_to_self; } |
| |
| public: |
| TwoOopCallbackWrapper(JvmtiTagMap* tag_map, oop referrer, oop o) : |
| CallbackWrapper(tag_map, o) |
| { |
| // self reference needs to be handled in a special way |
| _is_reference_to_self = (referrer == o); |
| |
| if (_is_reference_to_self) { |
| _referrer_klass_tag = klass_tag(); |
| _referrer_tag_p = obj_tag_p(); |
| } else { |
| _referrer = referrer; |
| // record the context |
| _referrer_hashmap = tag_map->hashmap(); |
| _referrer_entry = _referrer_hashmap->find(_referrer); |
| |
| // get object tag |
| _referrer_obj_tag = (_referrer_entry == NULL) ? 0 : _referrer_entry->tag(); |
| _referrer_tag_p = &_referrer_obj_tag; |
| |
| // get referrer class tag. |
| _referrer_klass_tag = tag_for(tag_map, _referrer->klass()->java_mirror()); |
| } |
| } |
| |
| ~TwoOopCallbackWrapper() { |
| if (!is_reference_to_self()){ |
| post_callback_tag_update(_referrer, |
| _referrer_hashmap, |
| _referrer_entry, |
| _referrer_obj_tag); |
| } |
| } |
| |
| // address of referrer tag |
| // (for a self reference this will return the same thing as obj_tag_p()) |
| inline jlong* referrer_tag_p() { return _referrer_tag_p; } |
| |
| // referrer's class tag |
| inline jlong referrer_klass_tag() { return _referrer_klass_tag; } |
| }; |
| |
| // tag an object |
| // |
| // This function is performance critical. If many threads attempt to tag objects |
| // around the same time then it's possible that the Mutex associated with the |
| // tag map will be a hot lock. |
| void JvmtiTagMap::set_tag(jobject object, jlong tag) { |
| MutexLocker ml(lock()); |
| |
| // resolve the object |
| oop o = JNIHandles::resolve_non_null(object); |
| |
| // see if the object is already tagged |
| JvmtiTagHashmap* hashmap = _hashmap; |
| JvmtiTagHashmapEntry* entry = hashmap->find(o); |
| |
| // if the object is not already tagged then we tag it |
| if (entry == NULL) { |
| if (tag != 0) { |
| entry = create_entry(o, tag); |
| hashmap->add(o, entry); |
| } else { |
| // no-op |
| } |
| } else { |
| // if the object is already tagged then we either update |
| // the tag (if a new tag value has been provided) |
| // or remove the object if the new tag value is 0. |
| if (tag == 0) { |
| hashmap->remove(o); |
| destroy_entry(entry); |
| } else { |
| entry->set_tag(tag); |
| } |
| } |
| } |
| |
| // get the tag for an object |
| jlong JvmtiTagMap::get_tag(jobject object) { |
| MutexLocker ml(lock()); |
| |
| // resolve the object |
| oop o = JNIHandles::resolve_non_null(object); |
| |
| return tag_for(this, o); |
| } |
| |
| |
| // Helper class used to describe the static or instance fields of a class. |
| // For each field it holds the field index (as defined by the JVMTI specification), |
| // the field type, and the offset. |
| |
| class ClassFieldDescriptor: public CHeapObj<mtInternal> { |
| private: |
| int _field_index; |
| int _field_offset; |
| char _field_type; |
| public: |
| ClassFieldDescriptor(int index, char type, int offset) : |
| _field_index(index), _field_type(type), _field_offset(offset) { |
| } |
| int field_index() const { return _field_index; } |
| char field_type() const { return _field_type; } |
| int field_offset() const { return _field_offset; } |
| }; |
| |
| class ClassFieldMap: public CHeapObj<mtInternal> { |
| private: |
| enum { |
| initial_field_count = 5 |
| }; |
| |
| // list of field descriptors |
| GrowableArray<ClassFieldDescriptor*>* _fields; |
| |
| // constructor |
| ClassFieldMap(); |
| |
| // add a field |
| void add(int index, char type, int offset); |
| |
| // returns the field count for the given class |
| static int compute_field_count(instanceKlassHandle ikh); |
| |
| public: |
| ~ClassFieldMap(); |
| |
| // access |
| int field_count() { return _fields->length(); } |
| ClassFieldDescriptor* field_at(int i) { return _fields->at(i); } |
| |
| // functions to create maps of static or instance fields |
| static ClassFieldMap* create_map_of_static_fields(Klass* k); |
| static ClassFieldMap* create_map_of_instance_fields(oop obj); |
| }; |
| |
| ClassFieldMap::ClassFieldMap() { |
| _fields = new (ResourceObj::C_HEAP, mtInternal) |
| GrowableArray<ClassFieldDescriptor*>(initial_field_count, true); |
| } |
| |
| ClassFieldMap::~ClassFieldMap() { |
| for (int i=0; i<_fields->length(); i++) { |
| delete _fields->at(i); |
| } |
| delete _fields; |
| } |
| |
| void ClassFieldMap::add(int index, char type, int offset) { |
| ClassFieldDescriptor* field = new ClassFieldDescriptor(index, type, offset); |
| _fields->append(field); |
| } |
| |
| // Returns a heap allocated ClassFieldMap to describe the static fields |
| // of the given class. |
| // |
| ClassFieldMap* ClassFieldMap::create_map_of_static_fields(Klass* k) { |
| HandleMark hm; |
| instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k); |
| |
| // create the field map |
| ClassFieldMap* field_map = new ClassFieldMap(); |
| |
| FilteredFieldStream f(ikh, false, false); |
| int max_field_index = f.field_count()-1; |
| |
| int index = 0; |
| for (FilteredFieldStream fld(ikh, true, true); !fld.eos(); fld.next(), index++) { |
| // ignore instance fields |
| if (!fld.access_flags().is_static()) { |
| continue; |
| } |
| field_map->add(max_field_index - index, fld.signature()->byte_at(0), fld.offset()); |
| } |
| return field_map; |
| } |
| |
| // Returns a heap allocated ClassFieldMap to describe the instance fields |
| // of the given class. All instance fields are included (this means public |
| // and private fields declared in superclasses and superinterfaces too). |
| // |
| ClassFieldMap* ClassFieldMap::create_map_of_instance_fields(oop obj) { |
| HandleMark hm; |
| instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), obj->klass()); |
| |
| // create the field map |
| ClassFieldMap* field_map = new ClassFieldMap(); |
| |
| FilteredFieldStream f(ikh, false, false); |
| |
| int max_field_index = f.field_count()-1; |
| |
| int index = 0; |
| for (FilteredFieldStream fld(ikh, false, false); !fld.eos(); fld.next(), index++) { |
| // ignore static fields |
| if (fld.access_flags().is_static()) { |
| continue; |
| } |
| field_map->add(max_field_index - index, fld.signature()->byte_at(0), fld.offset()); |
| } |
| |
| return field_map; |
| } |
| |
| // Helper class used to cache a ClassFileMap for the instance fields of |
| // a cache. A JvmtiCachedClassFieldMap can be cached by an InstanceKlass during |
| // heap iteration and avoid creating a field map for each object in the heap |
| // (only need to create the map when the first instance of a class is encountered). |
| // |
| class JvmtiCachedClassFieldMap : public CHeapObj<mtInternal> { |
| private: |
| enum { |
| initial_class_count = 200 |
| }; |
| ClassFieldMap* _field_map; |
| |
| ClassFieldMap* field_map() const { return _field_map; } |
| |
| JvmtiCachedClassFieldMap(ClassFieldMap* field_map); |
| ~JvmtiCachedClassFieldMap(); |
| |
| static GrowableArray<InstanceKlass*>* _class_list; |
| static void add_to_class_list(InstanceKlass* ik); |
| |
| public: |
| // returns the field map for a given object (returning map cached |
| // by InstanceKlass if possible |
| static ClassFieldMap* get_map_of_instance_fields(oop obj); |
| |
| // removes the field map from all instanceKlasses - should be |
| // called before VM operation completes |
| static void clear_cache(); |
| |
| // returns the number of ClassFieldMap cached by instanceKlasses |
| static int cached_field_map_count(); |
| }; |
| |
| GrowableArray<InstanceKlass*>* JvmtiCachedClassFieldMap::_class_list; |
| |
| JvmtiCachedClassFieldMap::JvmtiCachedClassFieldMap(ClassFieldMap* field_map) { |
| _field_map = field_map; |
| } |
| |
| JvmtiCachedClassFieldMap::~JvmtiCachedClassFieldMap() { |
| if (_field_map != NULL) { |
| delete _field_map; |
| } |
| } |
| |
| // Marker class to ensure that the class file map cache is only used in a defined |
| // scope. |
| class ClassFieldMapCacheMark : public StackObj { |
| private: |
| static bool _is_active; |
| public: |
| ClassFieldMapCacheMark() { |
| assert(Thread::current()->is_VM_thread(), "must be VMThread"); |
| assert(JvmtiCachedClassFieldMap::cached_field_map_count() == 0, "cache not empty"); |
| assert(!_is_active, "ClassFieldMapCacheMark cannot be nested"); |
| _is_active = true; |
| } |
| ~ClassFieldMapCacheMark() { |
| JvmtiCachedClassFieldMap::clear_cache(); |
| _is_active = false; |
| } |
| static bool is_active() { return _is_active; } |
| }; |
| |
| bool ClassFieldMapCacheMark::_is_active; |
| |
| |
| // record that the given InstanceKlass is caching a field map |
| void JvmtiCachedClassFieldMap::add_to_class_list(InstanceKlass* ik) { |
| if (_class_list == NULL) { |
| _class_list = new (ResourceObj::C_HEAP, mtInternal) |
| GrowableArray<InstanceKlass*>(initial_class_count, true); |
| } |
| _class_list->push(ik); |
| } |
| |
| // returns the instance field map for the given object |
| // (returns field map cached by the InstanceKlass if possible) |
| ClassFieldMap* JvmtiCachedClassFieldMap::get_map_of_instance_fields(oop obj) { |
| assert(Thread::current()->is_VM_thread(), "must be VMThread"); |
| assert(ClassFieldMapCacheMark::is_active(), "ClassFieldMapCacheMark not active"); |
| |
| Klass* k = obj->klass(); |
| InstanceKlass* ik = InstanceKlass::cast(k); |
| |
| // return cached map if possible |
| JvmtiCachedClassFieldMap* cached_map = ik->jvmti_cached_class_field_map(); |
| if (cached_map != NULL) { |
| assert(cached_map->field_map() != NULL, "missing field list"); |
| return cached_map->field_map(); |
| } else { |
| ClassFieldMap* field_map = ClassFieldMap::create_map_of_instance_fields(obj); |
| cached_map = new JvmtiCachedClassFieldMap(field_map); |
| ik->set_jvmti_cached_class_field_map(cached_map); |
| add_to_class_list(ik); |
| return field_map; |
| } |
| } |
| |
| // remove the fields maps cached from all instanceKlasses |
| void JvmtiCachedClassFieldMap::clear_cache() { |
| assert(Thread::current()->is_VM_thread(), "must be VMThread"); |
| if (_class_list != NULL) { |
| for (int i = 0; i < _class_list->length(); i++) { |
| InstanceKlass* ik = _class_list->at(i); |
| JvmtiCachedClassFieldMap* cached_map = ik->jvmti_cached_class_field_map(); |
| assert(cached_map != NULL, "should not be NULL"); |
| ik->set_jvmti_cached_class_field_map(NULL); |
| delete cached_map; // deletes the encapsulated field map |
| } |
| delete _class_list; |
| _class_list = NULL; |
| } |
| } |
| |
| // returns the number of ClassFieldMap cached by instanceKlasses |
| int JvmtiCachedClassFieldMap::cached_field_map_count() { |
| return (_class_list == NULL) ? 0 : _class_list->length(); |
| } |
| |
| // helper function to indicate if an object is filtered by its tag or class tag |
| static inline bool is_filtered_by_heap_filter(jlong obj_tag, |
| jlong klass_tag, |
| int heap_filter) { |
| // apply the heap filter |
| if (obj_tag != 0) { |
| // filter out tagged objects |
| if (heap_filter & JVMTI_HEAP_FILTER_TAGGED) return true; |
| } else { |
| // filter out untagged objects |
| if (heap_filter & JVMTI_HEAP_FILTER_UNTAGGED) return true; |
| } |
| if (klass_tag != 0) { |
| // filter out objects with tagged classes |
| if (heap_filter & JVMTI_HEAP_FILTER_CLASS_TAGGED) return true; |
| } else { |
| // filter out objects with untagged classes. |
| if (heap_filter & JVMTI_HEAP_FILTER_CLASS_UNTAGGED) return true; |
| } |
| return false; |
| } |
| |
| // helper function to indicate if an object is filtered by a klass filter |
| static inline bool is_filtered_by_klass_filter(oop obj, KlassHandle klass_filter) { |
| if (!klass_filter.is_null()) { |
| if (obj->klass() != klass_filter()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // helper function to tell if a field is a primitive field or not |
| static inline bool is_primitive_field_type(char type) { |
| return (type != 'L' && type != '['); |
| } |
| |
| // helper function to copy the value from location addr to jvalue. |
| static inline void copy_to_jvalue(jvalue *v, address addr, jvmtiPrimitiveType value_type) { |
| switch (value_type) { |
| case JVMTI_PRIMITIVE_TYPE_BOOLEAN : { v->z = *(jboolean*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_BYTE : { v->b = *(jbyte*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_CHAR : { v->c = *(jchar*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_SHORT : { v->s = *(jshort*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_INT : { v->i = *(jint*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_LONG : { v->j = *(jlong*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_FLOAT : { v->f = *(jfloat*)addr; break; } |
| case JVMTI_PRIMITIVE_TYPE_DOUBLE : { v->d = *(jdouble*)addr; break; } |
| default: ShouldNotReachHere(); |
| } |
| } |
| |
| // helper function to invoke string primitive value callback |
| // returns visit control flags |
| static jint invoke_string_value_callback(jvmtiStringPrimitiveValueCallback cb, |
| CallbackWrapper* wrapper, |
| oop str, |
| void* user_data) |
| { |
| assert(str->klass() == SystemDictionary::String_klass(), "not a string"); |
| |
| typeArrayOop s_value = java_lang_String::value(str); |
| |
| // JDK-6584008: the value field may be null if a String instance is |
| // partially constructed. |
| if (s_value == NULL) { |
| return 0; |
| } |
| // get the string value and length |
| // (string value may be offset from the base) |
| int s_len = java_lang_String::length(str); |
| bool is_latin1 = java_lang_String::is_latin1(str); |
| jchar* value; |
| if (s_len > 0) { |
| if (!is_latin1) { |
| value = s_value->char_at_addr(0); |
| } else { |
| // Inflate latin1 encoded string to UTF16 |
| jchar* buf = NEW_C_HEAP_ARRAY(jchar, s_len, mtInternal); |
| for (int i = 0; i < s_len; i++) { |
| buf[i] = ((jchar) s_value->byte_at(i)) & 0xff; |
| } |
| value = &buf[0]; |
| } |
| } else { |
| // Don't use char_at_addr(0) if length is 0 |
| value = (jchar*) s_value->base(T_CHAR); |
| } |
| |
| // invoke the callback |
| jint res = (*cb)(wrapper->klass_tag(), |
| wrapper->obj_size(), |
| wrapper->obj_tag_p(), |
| value, |
| (jint)s_len, |
| user_data); |
| |
| if (is_latin1 && s_len > 0) { |
| FREE_C_HEAP_ARRAY(jchar, value); |
| } |
| return res; |
| } |
| |
| // helper function to invoke string primitive value callback |
| // returns visit control flags |
| static jint invoke_array_primitive_value_callback(jvmtiArrayPrimitiveValueCallback cb, |
| CallbackWrapper* wrapper, |
| oop obj, |
| void* user_data) |
| { |
| assert(obj->is_typeArray(), "not a primitive array"); |
| |
| // get base address of first element |
| typeArrayOop array = typeArrayOop(obj); |
| BasicType type = TypeArrayKlass::cast(array->klass())->element_type(); |
| void* elements = array->base(type); |
| |
| // jvmtiPrimitiveType is defined so this mapping is always correct |
| jvmtiPrimitiveType elem_type = (jvmtiPrimitiveType)type2char(type); |
| |
| return (*cb)(wrapper->klass_tag(), |
| wrapper->obj_size(), |
| wrapper->obj_tag_p(), |
| (jint)array->length(), |
| elem_type, |
| elements, |
| user_data); |
| } |
| |
| // helper function to invoke the primitive field callback for all static fields |
| // of a given class |
| static jint invoke_primitive_field_callback_for_static_fields |
| (CallbackWrapper* wrapper, |
| oop obj, |
| jvmtiPrimitiveFieldCallback cb, |
| void* user_data) |
| { |
| // for static fields only the index will be set |
| static jvmtiHeapReferenceInfo reference_info = { 0 }; |
| |
| assert(obj->klass() == SystemDictionary::Class_klass(), "not a class"); |
| if (java_lang_Class::is_primitive(obj)) { |
| return 0; |
| } |
| Klass* klass = java_lang_Class::as_Klass(obj); |
| |
| // ignore classes for object and type arrays |
| if (!klass->is_instance_klass()) { |
| return 0; |
| } |
| |
| // ignore classes which aren't linked yet |
| InstanceKlass* ik = InstanceKlass::cast(klass); |
| if (!ik->is_linked()) { |
| return 0; |
| } |
| |
| // get the field map |
| ClassFieldMap* field_map = ClassFieldMap::create_map_of_static_fields(klass); |
| |
| // invoke the callback for each static primitive field |
| for (int i=0; i<field_map->field_count(); i++) { |
| ClassFieldDescriptor* field = field_map->field_at(i); |
| |
| // ignore non-primitive fields |
| char type = field->field_type(); |
| if (!is_primitive_field_type(type)) { |
| continue; |
| } |
| // one-to-one mapping |
| jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; |
| |
| // get offset and field value |
| int offset = field->field_offset(); |
| address addr = (address)klass->java_mirror() + offset; |
| jvalue value; |
| copy_to_jvalue(&value, addr, value_type); |
| |
| // field index |
| reference_info.field.index = field->field_index(); |
| |
| // invoke the callback |
| jint res = (*cb)(JVMTI_HEAP_REFERENCE_STATIC_FIELD, |
| &reference_info, |
| wrapper->klass_tag(), |
| wrapper->obj_tag_p(), |
| value, |
| value_type, |
| user_data); |
| if (res & JVMTI_VISIT_ABORT) { |
| delete field_map; |
| return res; |
| } |
| } |
| |
| delete field_map; |
| return 0; |
| } |
| |
| // helper function to invoke the primitive field callback for all instance fields |
| // of a given object |
| static jint invoke_primitive_field_callback_for_instance_fields( |
| CallbackWrapper* wrapper, |
| oop obj, |
| jvmtiPrimitiveFieldCallback cb, |
| void* user_data) |
| { |
| // for instance fields only the index will be set |
| static jvmtiHeapReferenceInfo reference_info = { 0 }; |
| |
| // get the map of the instance fields |
| ClassFieldMap* fields = JvmtiCachedClassFieldMap::get_map_of_instance_fields(obj); |
| |
| // invoke the callback for each instance primitive field |
| for (int i=0; i<fields->field_count(); i++) { |
| ClassFieldDescriptor* field = fields->field_at(i); |
| |
| // ignore non-primitive fields |
| char type = field->field_type(); |
| if (!is_primitive_field_type(type)) { |
| continue; |
| } |
| // one-to-one mapping |
| jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; |
| |
| // get offset and field value |
| int offset = field->field_offset(); |
| address addr = (address)obj + offset; |
| jvalue value; |
| copy_to_jvalue(&value, addr, value_type); |
| |
| // field index |
| reference_info.field.index = field->field_index(); |
| |
| // invoke the callback |
| jint res = (*cb)(JVMTI_HEAP_REFERENCE_FIELD, |
| &reference_info, |
| wrapper->klass_tag(), |
| wrapper->obj_tag_p(), |
| value, |
| value_type, |
| user_data); |
| if (res & JVMTI_VISIT_ABORT) { |
| return res; |
| } |
| } |
| return 0; |
| } |
| |
| |
| // VM operation to iterate over all objects in the heap (both reachable |
| // and unreachable) |
| class VM_HeapIterateOperation: public VM_Operation { |
| private: |
| ObjectClosure* _blk; |
| public: |
| VM_HeapIterateOperation(ObjectClosure* blk) { _blk = blk; } |
| |
| VMOp_Type type() const { return VMOp_HeapIterateOperation; } |
| void doit() { |
| // allows class files maps to be cached during iteration |
| ClassFieldMapCacheMark cm; |
| |
| // make sure that heap is parsable (fills TLABs with filler objects) |
| Universe::heap()->ensure_parsability(false); // no need to retire TLABs |
| |
| // Verify heap before iteration - if the heap gets corrupted then |
| // JVMTI's IterateOverHeap will crash. |
| if (VerifyBeforeIteration) { |
| Universe::verify(); |
| } |
| |
| // do the iteration |
| // If this operation encounters a bad object when using CMS, |
| // consider using safe_object_iterate() which avoids perm gen |
| // objects that may contain bad references. |
| Universe::heap()->object_iterate(_blk); |
| } |
| |
| }; |
| |
| |
| // An ObjectClosure used to support the deprecated IterateOverHeap and |
| // IterateOverInstancesOfClass functions |
| class IterateOverHeapObjectClosure: public ObjectClosure { |
| private: |
| JvmtiTagMap* _tag_map; |
| KlassHandle _klass; |
| jvmtiHeapObjectFilter _object_filter; |
| jvmtiHeapObjectCallback _heap_object_callback; |
| const void* _user_data; |
| |
| // accessors |
| JvmtiTagMap* tag_map() const { return _tag_map; } |
| jvmtiHeapObjectFilter object_filter() const { return _object_filter; } |
| jvmtiHeapObjectCallback object_callback() const { return _heap_object_callback; } |
| KlassHandle klass() const { return _klass; } |
| const void* user_data() const { return _user_data; } |
| |
| // indicates if iteration has been aborted |
| bool _iteration_aborted; |
| bool is_iteration_aborted() const { return _iteration_aborted; } |
| void set_iteration_aborted(bool aborted) { _iteration_aborted = aborted; } |
| |
| public: |
| IterateOverHeapObjectClosure(JvmtiTagMap* tag_map, |
| KlassHandle klass, |
| jvmtiHeapObjectFilter object_filter, |
| jvmtiHeapObjectCallback heap_object_callback, |
| const void* user_data) : |
| _tag_map(tag_map), |
| _klass(klass), |
| _object_filter(object_filter), |
| _heap_object_callback(heap_object_callback), |
| _user_data(user_data), |
| _iteration_aborted(false) |
| { |
| } |
| |
| void do_object(oop o); |
| }; |
| |
| // invoked for each object in the heap |
| void IterateOverHeapObjectClosure::do_object(oop o) { |
| // check if iteration has been halted |
| if (is_iteration_aborted()) return; |
| |
| // ignore any objects that aren't visible to profiler |
| if (!ServiceUtil::visible_oop(o)) return; |
| |
| // instanceof check when filtering by klass |
| if (!klass().is_null() && !o->is_a(klass()())) { |
| return; |
| } |
| // prepare for the calllback |
| CallbackWrapper wrapper(tag_map(), o); |
| |
| // if the object is tagged and we're only interested in untagged objects |
| // then don't invoke the callback. Similiarly, if the object is untagged |
| // and we're only interested in tagged objects we skip the callback. |
| if (wrapper.obj_tag() != 0) { |
| if (object_filter() == JVMTI_HEAP_OBJECT_UNTAGGED) return; |
| } else { |
| if (object_filter() == JVMTI_HEAP_OBJECT_TAGGED) return; |
| } |
| |
| // invoke the agent's callback |
| jvmtiIterationControl control = (*object_callback())(wrapper.klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| (void*)user_data()); |
| if (control == JVMTI_ITERATION_ABORT) { |
| set_iteration_aborted(true); |
| } |
| } |
| |
| // An ObjectClosure used to support the IterateThroughHeap function |
| class IterateThroughHeapObjectClosure: public ObjectClosure { |
| private: |
| JvmtiTagMap* _tag_map; |
| KlassHandle _klass; |
| int _heap_filter; |
| const jvmtiHeapCallbacks* _callbacks; |
| const void* _user_data; |
| |
| // accessor functions |
| JvmtiTagMap* tag_map() const { return _tag_map; } |
| int heap_filter() const { return _heap_filter; } |
| const jvmtiHeapCallbacks* callbacks() const { return _callbacks; } |
| KlassHandle klass() const { return _klass; } |
| const void* user_data() const { return _user_data; } |
| |
| // indicates if the iteration has been aborted |
| bool _iteration_aborted; |
| bool is_iteration_aborted() const { return _iteration_aborted; } |
| |
| // used to check the visit control flags. If the abort flag is set |
| // then we set the iteration aborted flag so that the iteration completes |
| // without processing any further objects |
| bool check_flags_for_abort(jint flags) { |
| bool is_abort = (flags & JVMTI_VISIT_ABORT) != 0; |
| if (is_abort) { |
| _iteration_aborted = true; |
| } |
| return is_abort; |
| } |
| |
| public: |
| IterateThroughHeapObjectClosure(JvmtiTagMap* tag_map, |
| KlassHandle klass, |
| int heap_filter, |
| const jvmtiHeapCallbacks* heap_callbacks, |
| const void* user_data) : |
| _tag_map(tag_map), |
| _klass(klass), |
| _heap_filter(heap_filter), |
| _callbacks(heap_callbacks), |
| _user_data(user_data), |
| _iteration_aborted(false) |
| { |
| } |
| |
| void do_object(oop o); |
| }; |
| |
| // invoked for each object in the heap |
| void IterateThroughHeapObjectClosure::do_object(oop obj) { |
| // check if iteration has been halted |
| if (is_iteration_aborted()) return; |
| |
| // ignore any objects that aren't visible to profiler |
| if (!ServiceUtil::visible_oop(obj)) return; |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, klass())) return; |
| |
| // prepare for callback |
| CallbackWrapper wrapper(tag_map(), obj); |
| |
| // check if filtered by the heap filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), wrapper.klass_tag(), heap_filter())) { |
| return; |
| } |
| |
| // for arrays we need the length, otherwise -1 |
| bool is_array = obj->is_array(); |
| int len = is_array ? arrayOop(obj)->length() : -1; |
| |
| // invoke the object callback (if callback is provided) |
| if (callbacks()->heap_iteration_callback != NULL) { |
| jvmtiHeapIterationCallback cb = callbacks()->heap_iteration_callback; |
| jint res = (*cb)(wrapper.klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| (jint)len, |
| (void*)user_data()); |
| if (check_flags_for_abort(res)) return; |
| } |
| |
| // for objects and classes we report primitive fields if callback provided |
| if (callbacks()->primitive_field_callback != NULL && obj->is_instance()) { |
| jint res; |
| jvmtiPrimitiveFieldCallback cb = callbacks()->primitive_field_callback; |
| if (obj->klass() == SystemDictionary::Class_klass()) { |
| res = invoke_primitive_field_callback_for_static_fields(&wrapper, |
| obj, |
| cb, |
| (void*)user_data()); |
| } else { |
| res = invoke_primitive_field_callback_for_instance_fields(&wrapper, |
| obj, |
| cb, |
| (void*)user_data()); |
| } |
| if (check_flags_for_abort(res)) return; |
| } |
| |
| // string callback |
| if (!is_array && |
| callbacks()->string_primitive_value_callback != NULL && |
| obj->klass() == SystemDictionary::String_klass()) { |
| jint res = invoke_string_value_callback( |
| callbacks()->string_primitive_value_callback, |
| &wrapper, |
| obj, |
| (void*)user_data() ); |
| if (check_flags_for_abort(res)) return; |
| } |
| |
| // array callback |
| if (is_array && |
| callbacks()->array_primitive_value_callback != NULL && |
| obj->is_typeArray()) { |
| jint res = invoke_array_primitive_value_callback( |
| callbacks()->array_primitive_value_callback, |
| &wrapper, |
| obj, |
| (void*)user_data() ); |
| if (check_flags_for_abort(res)) return; |
| } |
| }; |
| |
| |
| // Deprecated function to iterate over all objects in the heap |
| void JvmtiTagMap::iterate_over_heap(jvmtiHeapObjectFilter object_filter, |
| KlassHandle klass, |
| jvmtiHeapObjectCallback heap_object_callback, |
| const void* user_data) |
| { |
| MutexLocker ml(Heap_lock); |
| IterateOverHeapObjectClosure blk(this, |
| klass, |
| object_filter, |
| heap_object_callback, |
| user_data); |
| VM_HeapIterateOperation op(&blk); |
| VMThread::execute(&op); |
| } |
| |
| |
| // Iterates over all objects in the heap |
| void JvmtiTagMap::iterate_through_heap(jint heap_filter, |
| KlassHandle klass, |
| const jvmtiHeapCallbacks* callbacks, |
| const void* user_data) |
| { |
| MutexLocker ml(Heap_lock); |
| IterateThroughHeapObjectClosure blk(this, |
| klass, |
| heap_filter, |
| callbacks, |
| user_data); |
| VM_HeapIterateOperation op(&blk); |
| VMThread::execute(&op); |
| } |
| |
| // support class for get_objects_with_tags |
| |
| class TagObjectCollector : public JvmtiTagHashmapEntryClosure { |
| private: |
| JvmtiEnv* _env; |
| jlong* _tags; |
| jint _tag_count; |
| |
| GrowableArray<jobject>* _object_results; // collected objects (JNI weak refs) |
| GrowableArray<uint64_t>* _tag_results; // collected tags |
| |
| public: |
| TagObjectCollector(JvmtiEnv* env, const jlong* tags, jint tag_count) { |
| _env = env; |
| _tags = (jlong*)tags; |
| _tag_count = tag_count; |
| _object_results = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<jobject>(1,true); |
| _tag_results = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<uint64_t>(1,true); |
| } |
| |
| ~TagObjectCollector() { |
| delete _object_results; |
| delete _tag_results; |
| } |
| |
| // for each tagged object check if the tag value matches |
| // - if it matches then we create a JNI local reference to the object |
| // and record the reference and tag value. |
| // |
| void do_entry(JvmtiTagHashmapEntry* entry) { |
| for (int i=0; i<_tag_count; i++) { |
| if (_tags[i] == entry->tag()) { |
| oop o = entry->object(); |
| assert(o != NULL && Universe::heap()->is_in_reserved(o), "sanity check"); |
| jobject ref = JNIHandles::make_local(JavaThread::current(), o); |
| _object_results->append(ref); |
| _tag_results->append((uint64_t)entry->tag()); |
| } |
| } |
| } |
| |
| // return the results from the collection |
| // |
| jvmtiError result(jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) { |
| jvmtiError error; |
| int count = _object_results->length(); |
| assert(count >= 0, "sanity check"); |
| |
| // if object_result_ptr is not NULL then allocate the result and copy |
| // in the object references. |
| if (object_result_ptr != NULL) { |
| error = _env->Allocate(count * sizeof(jobject), (unsigned char**)object_result_ptr); |
| if (error != JVMTI_ERROR_NONE) { |
| return error; |
| } |
| for (int i=0; i<count; i++) { |
| (*object_result_ptr)[i] = _object_results->at(i); |
| } |
| } |
| |
| // if tag_result_ptr is not NULL then allocate the result and copy |
| // in the tag values. |
| if (tag_result_ptr != NULL) { |
| error = _env->Allocate(count * sizeof(jlong), (unsigned char**)tag_result_ptr); |
| if (error != JVMTI_ERROR_NONE) { |
| if (object_result_ptr != NULL) { |
| _env->Deallocate((unsigned char*)object_result_ptr); |
| } |
| return error; |
| } |
| for (int i=0; i<count; i++) { |
| (*tag_result_ptr)[i] = (jlong)_tag_results->at(i); |
| } |
| } |
| |
| *count_ptr = count; |
| return JVMTI_ERROR_NONE; |
| } |
| }; |
| |
| // return the list of objects with the specified tags |
| jvmtiError JvmtiTagMap::get_objects_with_tags(const jlong* tags, |
| jint count, jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) { |
| |
| TagObjectCollector collector(env(), tags, count); |
| { |
| // iterate over all tagged objects |
| MutexLocker ml(lock()); |
| entry_iterate(&collector); |
| } |
| return collector.result(count_ptr, object_result_ptr, tag_result_ptr); |
| } |
| |
| |
| // ObjectMarker is used to support the marking objects when walking the |
| // heap. |
| // |
| // This implementation uses the existing mark bits in an object for |
| // marking. Objects that are marked must later have their headers restored. |
| // As most objects are unlocked and don't have their identity hash computed |
| // we don't have to save their headers. Instead we save the headers that |
| // are "interesting". Later when the headers are restored this implementation |
| // restores all headers to their initial value and then restores the few |
| // objects that had interesting headers. |
| // |
| // Future work: This implementation currently uses growable arrays to save |
| // the oop and header of interesting objects. As an optimization we could |
| // use the same technique as the GC and make use of the unused area |
| // between top() and end(). |
| // |
| |
| // An ObjectClosure used to restore the mark bits of an object |
| class RestoreMarksClosure : public ObjectClosure { |
| public: |
| void do_object(oop o) { |
| if (o != NULL) { |
| markOop mark = o->mark(); |
| if (mark->is_marked()) { |
| o->init_mark(); |
| } |
| } |
| } |
| }; |
| |
| // ObjectMarker provides the mark and visited functions |
| class ObjectMarker : AllStatic { |
| private: |
| // saved headers |
| static GrowableArray<oop>* _saved_oop_stack; |
| static GrowableArray<markOop>* _saved_mark_stack; |
| static bool _needs_reset; // do we need to reset mark bits? |
| |
| public: |
| static void init(); // initialize |
| static void done(); // clean-up |
| |
| static inline void mark(oop o); // mark an object |
| static inline bool visited(oop o); // check if object has been visited |
| |
| static inline bool needs_reset() { return _needs_reset; } |
| static inline void set_needs_reset(bool v) { _needs_reset = v; } |
| }; |
| |
| GrowableArray<oop>* ObjectMarker::_saved_oop_stack = NULL; |
| GrowableArray<markOop>* ObjectMarker::_saved_mark_stack = NULL; |
| bool ObjectMarker::_needs_reset = true; // need to reset mark bits by default |
| |
| // initialize ObjectMarker - prepares for object marking |
| void ObjectMarker::init() { |
| assert(Thread::current()->is_VM_thread(), "must be VMThread"); |
| |
| // prepare heap for iteration |
| Universe::heap()->ensure_parsability(false); // no need to retire TLABs |
| |
| // create stacks for interesting headers |
| _saved_mark_stack = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<markOop>(4000, true); |
| _saved_oop_stack = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(4000, true); |
| |
| if (UseBiasedLocking) { |
| BiasedLocking::preserve_marks(); |
| } |
| } |
| |
| // Object marking is done so restore object headers |
| void ObjectMarker::done() { |
| // iterate over all objects and restore the mark bits to |
| // their initial value |
| RestoreMarksClosure blk; |
| if (needs_reset()) { |
| Universe::heap()->object_iterate(&blk); |
| } else { |
| // We don't need to reset mark bits on this call, but reset the |
| // flag to the default for the next call. |
| set_needs_reset(true); |
| } |
| |
| // now restore the interesting headers |
| for (int i = 0; i < _saved_oop_stack->length(); i++) { |
| oop o = _saved_oop_stack->at(i); |
| markOop mark = _saved_mark_stack->at(i); |
| o->set_mark(mark); |
| } |
| |
| if (UseBiasedLocking) { |
| BiasedLocking::restore_marks(); |
| } |
| |
| // free the stacks |
| delete _saved_oop_stack; |
| delete _saved_mark_stack; |
| } |
| |
| // mark an object |
| inline void ObjectMarker::mark(oop o) { |
| assert(Universe::heap()->is_in(o), "sanity check"); |
| assert(!o->mark()->is_marked(), "should only mark an object once"); |
| |
| // object's mark word |
| markOop mark = o->mark(); |
| |
| if (mark->must_be_preserved(o)) { |
| _saved_mark_stack->push(mark); |
| _saved_oop_stack->push(o); |
| } |
| |
| // mark the object |
| o->set_mark(markOopDesc::prototype()->set_marked()); |
| } |
| |
| // return true if object is marked |
| inline bool ObjectMarker::visited(oop o) { |
| return o->mark()->is_marked(); |
| } |
| |
| // Stack allocated class to help ensure that ObjectMarker is used |
| // correctly. Constructor initializes ObjectMarker, destructor calls |
| // ObjectMarker's done() function to restore object headers. |
| class ObjectMarkerController : public StackObj { |
| public: |
| ObjectMarkerController() { |
| ObjectMarker::init(); |
| } |
| ~ObjectMarkerController() { |
| ObjectMarker::done(); |
| } |
| }; |
| |
| |
| // helper to map a jvmtiHeapReferenceKind to an old style jvmtiHeapRootKind |
| // (not performance critical as only used for roots) |
| static jvmtiHeapRootKind toJvmtiHeapRootKind(jvmtiHeapReferenceKind kind) { |
| switch (kind) { |
| case JVMTI_HEAP_REFERENCE_JNI_GLOBAL: return JVMTI_HEAP_ROOT_JNI_GLOBAL; |
| case JVMTI_HEAP_REFERENCE_SYSTEM_CLASS: return JVMTI_HEAP_ROOT_SYSTEM_CLASS; |
| case JVMTI_HEAP_REFERENCE_MONITOR: return JVMTI_HEAP_ROOT_MONITOR; |
| case JVMTI_HEAP_REFERENCE_STACK_LOCAL: return JVMTI_HEAP_ROOT_STACK_LOCAL; |
| case JVMTI_HEAP_REFERENCE_JNI_LOCAL: return JVMTI_HEAP_ROOT_JNI_LOCAL; |
| case JVMTI_HEAP_REFERENCE_THREAD: return JVMTI_HEAP_ROOT_THREAD; |
| case JVMTI_HEAP_REFERENCE_OTHER: return JVMTI_HEAP_ROOT_OTHER; |
| default: ShouldNotReachHere(); return JVMTI_HEAP_ROOT_OTHER; |
| } |
| } |
| |
| // Base class for all heap walk contexts. The base class maintains a flag |
| // to indicate if the context is valid or not. |
| class HeapWalkContext VALUE_OBJ_CLASS_SPEC { |
| private: |
| bool _valid; |
| public: |
| HeapWalkContext(bool valid) { _valid = valid; } |
| void invalidate() { _valid = false; } |
| bool is_valid() const { return _valid; } |
| }; |
| |
| // A basic heap walk context for the deprecated heap walking functions. |
| // The context for a basic heap walk are the callbacks and fields used by |
| // the referrer caching scheme. |
| class BasicHeapWalkContext: public HeapWalkContext { |
| private: |
| jvmtiHeapRootCallback _heap_root_callback; |
| jvmtiStackReferenceCallback _stack_ref_callback; |
| jvmtiObjectReferenceCallback _object_ref_callback; |
| |
| // used for caching |
| oop _last_referrer; |
| jlong _last_referrer_tag; |
| |
| public: |
| BasicHeapWalkContext() : HeapWalkContext(false) { } |
| |
| BasicHeapWalkContext(jvmtiHeapRootCallback heap_root_callback, |
| jvmtiStackReferenceCallback stack_ref_callback, |
| jvmtiObjectReferenceCallback object_ref_callback) : |
| HeapWalkContext(true), |
| _heap_root_callback(heap_root_callback), |
| _stack_ref_callback(stack_ref_callback), |
| _object_ref_callback(object_ref_callback), |
| _last_referrer(NULL), |
| _last_referrer_tag(0) { |
| } |
| |
| // accessors |
| jvmtiHeapRootCallback heap_root_callback() const { return _heap_root_callback; } |
| jvmtiStackReferenceCallback stack_ref_callback() const { return _stack_ref_callback; } |
| jvmtiObjectReferenceCallback object_ref_callback() const { return _object_ref_callback; } |
| |
| oop last_referrer() const { return _last_referrer; } |
| void set_last_referrer(oop referrer) { _last_referrer = referrer; } |
| jlong last_referrer_tag() const { return _last_referrer_tag; } |
| void set_last_referrer_tag(jlong value) { _last_referrer_tag = value; } |
| }; |
| |
| // The advanced heap walk context for the FollowReferences functions. |
| // The context is the callbacks, and the fields used for filtering. |
| class AdvancedHeapWalkContext: public HeapWalkContext { |
| private: |
| jint _heap_filter; |
| KlassHandle _klass_filter; |
| const jvmtiHeapCallbacks* _heap_callbacks; |
| |
| public: |
| AdvancedHeapWalkContext() : HeapWalkContext(false) { } |
| |
| AdvancedHeapWalkContext(jint heap_filter, |
| KlassHandle klass_filter, |
| const jvmtiHeapCallbacks* heap_callbacks) : |
| HeapWalkContext(true), |
| _heap_filter(heap_filter), |
| _klass_filter(klass_filter), |
| _heap_callbacks(heap_callbacks) { |
| } |
| |
| // accessors |
| jint heap_filter() const { return _heap_filter; } |
| KlassHandle klass_filter() const { return _klass_filter; } |
| |
| const jvmtiHeapReferenceCallback heap_reference_callback() const { |
| return _heap_callbacks->heap_reference_callback; |
| }; |
| const jvmtiPrimitiveFieldCallback primitive_field_callback() const { |
| return _heap_callbacks->primitive_field_callback; |
| } |
| const jvmtiArrayPrimitiveValueCallback array_primitive_value_callback() const { |
| return _heap_callbacks->array_primitive_value_callback; |
| } |
| const jvmtiStringPrimitiveValueCallback string_primitive_value_callback() const { |
| return _heap_callbacks->string_primitive_value_callback; |
| } |
| }; |
| |
| // The CallbackInvoker is a class with static functions that the heap walk can call |
| // into to invoke callbacks. It works in one of two modes. The "basic" mode is |
| // used for the deprecated IterateOverReachableObjects functions. The "advanced" |
| // mode is for the newer FollowReferences function which supports a lot of |
| // additional callbacks. |
| class CallbackInvoker : AllStatic { |
| private: |
| // heap walk styles |
| enum { basic, advanced }; |
| static int _heap_walk_type; |
| static bool is_basic_heap_walk() { return _heap_walk_type == basic; } |
| static bool is_advanced_heap_walk() { return _heap_walk_type == advanced; } |
| |
| // context for basic style heap walk |
| static BasicHeapWalkContext _basic_context; |
| static BasicHeapWalkContext* basic_context() { |
| assert(_basic_context.is_valid(), "invalid"); |
| return &_basic_context; |
| } |
| |
| // context for advanced style heap walk |
| static AdvancedHeapWalkContext _advanced_context; |
| static AdvancedHeapWalkContext* advanced_context() { |
| assert(_advanced_context.is_valid(), "invalid"); |
| return &_advanced_context; |
| } |
| |
| // context needed for all heap walks |
| static JvmtiTagMap* _tag_map; |
| static const void* _user_data; |
| static GrowableArray<oop>* _visit_stack; |
| |
| // accessors |
| static JvmtiTagMap* tag_map() { return _tag_map; } |
| static const void* user_data() { return _user_data; } |
| static GrowableArray<oop>* visit_stack() { return _visit_stack; } |
| |
| // if the object hasn't been visited then push it onto the visit stack |
| // so that it will be visited later |
| static inline bool check_for_visit(oop obj) { |
| if (!ObjectMarker::visited(obj)) visit_stack()->push(obj); |
| return true; |
| } |
| |
| // invoke basic style callbacks |
| static inline bool invoke_basic_heap_root_callback |
| (jvmtiHeapRootKind root_kind, oop obj); |
| static inline bool invoke_basic_stack_ref_callback |
| (jvmtiHeapRootKind root_kind, jlong thread_tag, jint depth, jmethodID method, |
| int slot, oop obj); |
| static inline bool invoke_basic_object_reference_callback |
| (jvmtiObjectReferenceKind ref_kind, oop referrer, oop referree, jint index); |
| |
| // invoke advanced style callbacks |
| static inline bool invoke_advanced_heap_root_callback |
| (jvmtiHeapReferenceKind ref_kind, oop obj); |
| static inline bool invoke_advanced_stack_ref_callback |
| (jvmtiHeapReferenceKind ref_kind, jlong thread_tag, jlong tid, int depth, |
| jmethodID method, jlocation bci, jint slot, oop obj); |
| static inline bool invoke_advanced_object_reference_callback |
| (jvmtiHeapReferenceKind ref_kind, oop referrer, oop referree, jint index); |
| |
| // used to report the value of primitive fields |
| static inline bool report_primitive_field |
| (jvmtiHeapReferenceKind ref_kind, oop obj, jint index, address addr, char type); |
| |
| public: |
| // initialize for basic mode |
| static void initialize_for_basic_heap_walk(JvmtiTagMap* tag_map, |
| GrowableArray<oop>* visit_stack, |
| const void* user_data, |
| BasicHeapWalkContext context); |
| |
| // initialize for advanced mode |
| static void initialize_for_advanced_heap_walk(JvmtiTagMap* tag_map, |
| GrowableArray<oop>* visit_stack, |
| const void* user_data, |
| AdvancedHeapWalkContext context); |
| |
| // functions to report roots |
| static inline bool report_simple_root(jvmtiHeapReferenceKind kind, oop o); |
| static inline bool report_jni_local_root(jlong thread_tag, jlong tid, jint depth, |
| jmethodID m, oop o); |
| static inline bool report_stack_ref_root(jlong thread_tag, jlong tid, jint depth, |
| jmethodID method, jlocation bci, jint slot, oop o); |
| |
| // functions to report references |
| static inline bool report_array_element_reference(oop referrer, oop referree, jint index); |
| static inline bool report_class_reference(oop referrer, oop referree); |
| static inline bool report_class_loader_reference(oop referrer, oop referree); |
| static inline bool report_signers_reference(oop referrer, oop referree); |
| static inline bool report_protection_domain_reference(oop referrer, oop referree); |
| static inline bool report_superclass_reference(oop referrer, oop referree); |
| static inline bool report_interface_reference(oop referrer, oop referree); |
| static inline bool report_static_field_reference(oop referrer, oop referree, jint slot); |
| static inline bool report_field_reference(oop referrer, oop referree, jint slot); |
| static inline bool report_constant_pool_reference(oop referrer, oop referree, jint index); |
| static inline bool report_primitive_array_values(oop array); |
| static inline bool report_string_value(oop str); |
| static inline bool report_primitive_instance_field(oop o, jint index, address value, char type); |
| static inline bool report_primitive_static_field(oop o, jint index, address value, char type); |
| }; |
| |
| // statics |
| int CallbackInvoker::_heap_walk_type; |
| BasicHeapWalkContext CallbackInvoker::_basic_context; |
| AdvancedHeapWalkContext CallbackInvoker::_advanced_context; |
| JvmtiTagMap* CallbackInvoker::_tag_map; |
| const void* CallbackInvoker::_user_data; |
| GrowableArray<oop>* CallbackInvoker::_visit_stack; |
| |
| // initialize for basic heap walk (IterateOverReachableObjects et al) |
| void CallbackInvoker::initialize_for_basic_heap_walk(JvmtiTagMap* tag_map, |
| GrowableArray<oop>* visit_stack, |
| const void* user_data, |
| BasicHeapWalkContext context) { |
| _tag_map = tag_map; |
| _visit_stack = visit_stack; |
| _user_data = user_data; |
| _basic_context = context; |
| _advanced_context.invalidate(); // will trigger assertion if used |
| _heap_walk_type = basic; |
| } |
| |
| // initialize for advanced heap walk (FollowReferences) |
| void CallbackInvoker::initialize_for_advanced_heap_walk(JvmtiTagMap* tag_map, |
| GrowableArray<oop>* visit_stack, |
| const void* user_data, |
| AdvancedHeapWalkContext context) { |
| _tag_map = tag_map; |
| _visit_stack = visit_stack; |
| _user_data = user_data; |
| _advanced_context = context; |
| _basic_context.invalidate(); // will trigger assertion if used |
| _heap_walk_type = advanced; |
| } |
| |
| |
| // invoke basic style heap root callback |
| inline bool CallbackInvoker::invoke_basic_heap_root_callback(jvmtiHeapRootKind root_kind, oop obj) { |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| // if we heap roots should be reported |
| jvmtiHeapRootCallback cb = basic_context()->heap_root_callback(); |
| if (cb == NULL) { |
| return check_for_visit(obj); |
| } |
| |
| CallbackWrapper wrapper(tag_map(), obj); |
| jvmtiIterationControl control = (*cb)(root_kind, |
| wrapper.klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| (void*)user_data()); |
| // push root to visit stack when following references |
| if (control == JVMTI_ITERATION_CONTINUE && |
| basic_context()->object_ref_callback() != NULL) { |
| visit_stack()->push(obj); |
| } |
| return control != JVMTI_ITERATION_ABORT; |
| } |
| |
| // invoke basic style stack ref callback |
| inline bool CallbackInvoker::invoke_basic_stack_ref_callback(jvmtiHeapRootKind root_kind, |
| jlong thread_tag, |
| jint depth, |
| jmethodID method, |
| jint slot, |
| oop obj) { |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| // if we stack refs should be reported |
| jvmtiStackReferenceCallback cb = basic_context()->stack_ref_callback(); |
| if (cb == NULL) { |
| return check_for_visit(obj); |
| } |
| |
| CallbackWrapper wrapper(tag_map(), obj); |
| jvmtiIterationControl control = (*cb)(root_kind, |
| wrapper.klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| thread_tag, |
| depth, |
| method, |
| slot, |
| (void*)user_data()); |
| // push root to visit stack when following references |
| if (control == JVMTI_ITERATION_CONTINUE && |
| basic_context()->object_ref_callback() != NULL) { |
| visit_stack()->push(obj); |
| } |
| return control != JVMTI_ITERATION_ABORT; |
| } |
| |
| // invoke basic style object reference callback |
| inline bool CallbackInvoker::invoke_basic_object_reference_callback(jvmtiObjectReferenceKind ref_kind, |
| oop referrer, |
| oop referree, |
| jint index) { |
| |
| assert(ServiceUtil::visible_oop(referrer), "checking"); |
| assert(ServiceUtil::visible_oop(referree), "checking"); |
| |
| BasicHeapWalkContext* context = basic_context(); |
| |
| // callback requires the referrer's tag. If it's the same referrer |
| // as the last call then we use the cached value. |
| jlong referrer_tag; |
| if (referrer == context->last_referrer()) { |
| referrer_tag = context->last_referrer_tag(); |
| } else { |
| referrer_tag = tag_for(tag_map(), referrer); |
| } |
| |
| // do the callback |
| CallbackWrapper wrapper(tag_map(), referree); |
| jvmtiObjectReferenceCallback cb = context->object_ref_callback(); |
| jvmtiIterationControl control = (*cb)(ref_kind, |
| wrapper.klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| referrer_tag, |
| index, |
| (void*)user_data()); |
| |
| // record referrer and referrer tag. For self-references record the |
| // tag value from the callback as this might differ from referrer_tag. |
| context->set_last_referrer(referrer); |
| if (referrer == referree) { |
| context->set_last_referrer_tag(*wrapper.obj_tag_p()); |
| } else { |
| context->set_last_referrer_tag(referrer_tag); |
| } |
| |
| if (control == JVMTI_ITERATION_CONTINUE) { |
| return check_for_visit(referree); |
| } else { |
| return control != JVMTI_ITERATION_ABORT; |
| } |
| } |
| |
| // invoke advanced style heap root callback |
| inline bool CallbackInvoker::invoke_advanced_heap_root_callback(jvmtiHeapReferenceKind ref_kind, |
| oop obj) { |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| |
| // check that callback is provided |
| jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); |
| if (cb == NULL) { |
| return check_for_visit(obj); |
| } |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, context->klass_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // setup the callback wrapper |
| CallbackWrapper wrapper(tag_map(), obj); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // for arrays we need the length, otherwise -1 |
| jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); |
| |
| // invoke the callback |
| jint res = (*cb)(ref_kind, |
| NULL, // referrer info |
| wrapper.klass_tag(), |
| 0, // referrer_class_tag is 0 for heap root |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| NULL, // referrer_tag_p |
| len, |
| (void*)user_data()); |
| if (res & JVMTI_VISIT_ABORT) { |
| return false;// referrer class tag |
| } |
| if (res & JVMTI_VISIT_OBJECTS) { |
| check_for_visit(obj); |
| } |
| return true; |
| } |
| |
| // report a reference from a thread stack to an object |
| inline bool CallbackInvoker::invoke_advanced_stack_ref_callback(jvmtiHeapReferenceKind ref_kind, |
| jlong thread_tag, |
| jlong tid, |
| int depth, |
| jmethodID method, |
| jlocation bci, |
| jint slot, |
| oop obj) { |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| |
| // check that callback is provider |
| jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); |
| if (cb == NULL) { |
| return check_for_visit(obj); |
| } |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, context->klass_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // setup the callback wrapper |
| CallbackWrapper wrapper(tag_map(), obj); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // setup the referrer info |
| jvmtiHeapReferenceInfo reference_info; |
| reference_info.stack_local.thread_tag = thread_tag; |
| reference_info.stack_local.thread_id = tid; |
| reference_info.stack_local.depth = depth; |
| reference_info.stack_local.method = method; |
| reference_info.stack_local.location = bci; |
| reference_info.stack_local.slot = slot; |
| |
| // for arrays we need the length, otherwise -1 |
| jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); |
| |
| // call into the agent |
| int res = (*cb)(ref_kind, |
| &reference_info, |
| wrapper.klass_tag(), |
| 0, // referrer_class_tag is 0 for heap root (stack) |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| NULL, // referrer_tag is 0 for root |
| len, |
| (void*)user_data()); |
| |
| if (res & JVMTI_VISIT_ABORT) { |
| return false; |
| } |
| if (res & JVMTI_VISIT_OBJECTS) { |
| check_for_visit(obj); |
| } |
| return true; |
| } |
| |
| // This mask is used to pass reference_info to a jvmtiHeapReferenceCallback |
| // only for ref_kinds defined by the JVM TI spec. Otherwise, NULL is passed. |
| #define REF_INFO_MASK ((1 << JVMTI_HEAP_REFERENCE_FIELD) \ |
| | (1 << JVMTI_HEAP_REFERENCE_STATIC_FIELD) \ |
| | (1 << JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT) \ |
| | (1 << JVMTI_HEAP_REFERENCE_CONSTANT_POOL) \ |
| | (1 << JVMTI_HEAP_REFERENCE_STACK_LOCAL) \ |
| | (1 << JVMTI_HEAP_REFERENCE_JNI_LOCAL)) |
| |
| // invoke the object reference callback to report a reference |
| inline bool CallbackInvoker::invoke_advanced_object_reference_callback(jvmtiHeapReferenceKind ref_kind, |
| oop referrer, |
| oop obj, |
| jint index) |
| { |
| // field index is only valid field in reference_info |
| static jvmtiHeapReferenceInfo reference_info = { 0 }; |
| |
| assert(ServiceUtil::visible_oop(referrer), "checking"); |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| |
| // check that callback is provider |
| jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); |
| if (cb == NULL) { |
| return check_for_visit(obj); |
| } |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, context->klass_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // setup the callback wrapper |
| TwoOopCallbackWrapper wrapper(tag_map(), referrer, obj); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return check_for_visit(obj); |
| } |
| |
| // field index is only valid field in reference_info |
| reference_info.field.index = index; |
| |
| // for arrays we need the length, otherwise -1 |
| jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); |
| |
| // invoke the callback |
| int res = (*cb)(ref_kind, |
| (REF_INFO_MASK & (1 << ref_kind)) ? &reference_info : NULL, |
| wrapper.klass_tag(), |
| wrapper.referrer_klass_tag(), |
| wrapper.obj_size(), |
| wrapper.obj_tag_p(), |
| wrapper.referrer_tag_p(), |
| len, |
| (void*)user_data()); |
| |
| if (res & JVMTI_VISIT_ABORT) { |
| return false; |
| } |
| if (res & JVMTI_VISIT_OBJECTS) { |
| check_for_visit(obj); |
| } |
| return true; |
| } |
| |
| // report a "simple root" |
| inline bool CallbackInvoker::report_simple_root(jvmtiHeapReferenceKind kind, oop obj) { |
| assert(kind != JVMTI_HEAP_REFERENCE_STACK_LOCAL && |
| kind != JVMTI_HEAP_REFERENCE_JNI_LOCAL, "not a simple root"); |
| assert(ServiceUtil::visible_oop(obj), "checking"); |
| |
| if (is_basic_heap_walk()) { |
| // map to old style root kind |
| jvmtiHeapRootKind root_kind = toJvmtiHeapRootKind(kind); |
| return invoke_basic_heap_root_callback(root_kind, obj); |
| } else { |
| assert(is_advanced_heap_walk(), "wrong heap walk type"); |
| return invoke_advanced_heap_root_callback(kind, obj); |
| } |
| } |
| |
| |
| // invoke the primitive array values |
| inline bool CallbackInvoker::report_primitive_array_values(oop obj) { |
| assert(obj->is_typeArray(), "not a primitive array"); |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| assert(context->array_primitive_value_callback() != NULL, "no callback"); |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, context->klass_filter())) { |
| return true; |
| } |
| |
| CallbackWrapper wrapper(tag_map(), obj); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return true; |
| } |
| |
| // invoke the callback |
| int res = invoke_array_primitive_value_callback(context->array_primitive_value_callback(), |
| &wrapper, |
| obj, |
| (void*)user_data()); |
| return (!(res & JVMTI_VISIT_ABORT)); |
| } |
| |
| // invoke the string value callback |
| inline bool CallbackInvoker::report_string_value(oop str) { |
| assert(str->klass() == SystemDictionary::String_klass(), "not a string"); |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| assert(context->string_primitive_value_callback() != NULL, "no callback"); |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(str, context->klass_filter())) { |
| return true; |
| } |
| |
| CallbackWrapper wrapper(tag_map(), str); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return true; |
| } |
| |
| // invoke the callback |
| int res = invoke_string_value_callback(context->string_primitive_value_callback(), |
| &wrapper, |
| str, |
| (void*)user_data()); |
| return (!(res & JVMTI_VISIT_ABORT)); |
| } |
| |
| // invoke the primitive field callback |
| inline bool CallbackInvoker::report_primitive_field(jvmtiHeapReferenceKind ref_kind, |
| oop obj, |
| jint index, |
| address addr, |
| char type) |
| { |
| // for primitive fields only the index will be set |
| static jvmtiHeapReferenceInfo reference_info = { 0 }; |
| |
| AdvancedHeapWalkContext* context = advanced_context(); |
| assert(context->primitive_field_callback() != NULL, "no callback"); |
| |
| // apply class filter |
| if (is_filtered_by_klass_filter(obj, context->klass_filter())) { |
| return true; |
| } |
| |
| CallbackWrapper wrapper(tag_map(), obj); |
| |
| // apply tag filter |
| if (is_filtered_by_heap_filter(wrapper.obj_tag(), |
| wrapper.klass_tag(), |
| context->heap_filter())) { |
| return true; |
| } |
| |
| // the field index in the referrer |
| reference_info.field.index = index; |
| |
| // map the type |
| jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; |
| |
| // setup the jvalue |
| jvalue value; |
| copy_to_jvalue(&value, addr, value_type); |
| |
| jvmtiPrimitiveFieldCallback cb = context->primitive_field_callback(); |
| int res = (*cb)(ref_kind, |
| &reference_info, |
| wrapper.klass_tag(), |
| wrapper.obj_tag_p(), |
| value, |
| value_type, |
| (void*)user_data()); |
| return (!(res & JVMTI_VISIT_ABORT)); |
| } |
| |
| |
| // instance field |
| inline bool CallbackInvoker::report_primitive_instance_field(oop obj, |
| jint index, |
| address value, |
| char type) { |
| return report_primitive_field(JVMTI_HEAP_REFERENCE_FIELD, |
| obj, |
| index, |
| value, |
| type); |
| } |
| |
| // static field |
| inline bool CallbackInvoker::report_primitive_static_field(oop obj, |
| jint index, |
| address value, |
| char type) { |
| return report_primitive_field(JVMTI_HEAP_REFERENCE_STATIC_FIELD, |
| obj, |
| index, |
| value, |
| type); |
| } |
| |
| // report a JNI local (root object) to the profiler |
| inline bool CallbackInvoker::report_jni_local_root(jlong thread_tag, jlong tid, jint depth, jmethodID m, oop obj) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_stack_ref_callback(JVMTI_HEAP_ROOT_JNI_LOCAL, |
| thread_tag, |
| depth, |
| m, |
| -1, |
| obj); |
| } else { |
| return invoke_advanced_stack_ref_callback(JVMTI_HEAP_REFERENCE_JNI_LOCAL, |
| thread_tag, tid, |
| depth, |
| m, |
| (jlocation)-1, |
| -1, |
| obj); |
| } |
| } |
| |
| |
| // report a local (stack reference, root object) |
| inline bool CallbackInvoker::report_stack_ref_root(jlong thread_tag, |
| jlong tid, |
| jint depth, |
| jmethodID method, |
| jlocation bci, |
| jint slot, |
| oop obj) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_stack_ref_callback(JVMTI_HEAP_ROOT_STACK_LOCAL, |
| thread_tag, |
| depth, |
| method, |
| slot, |
| obj); |
| } else { |
| return invoke_advanced_stack_ref_callback(JVMTI_HEAP_REFERENCE_STACK_LOCAL, |
| thread_tag, |
| tid, |
| depth, |
| method, |
| bci, |
| slot, |
| obj); |
| } |
| } |
| |
| // report an object referencing a class. |
| inline bool CallbackInvoker::report_class_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CLASS, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing its class loader. |
| inline bool CallbackInvoker::report_class_loader_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS_LOADER, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CLASS_LOADER, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing its signers. |
| inline bool CallbackInvoker::report_signers_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_SIGNERS, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_SIGNERS, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing its protection domain.. |
| inline bool CallbackInvoker::report_protection_domain_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_PROTECTION_DOMAIN, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing its superclass. |
| inline bool CallbackInvoker::report_superclass_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| // Send this to be consistent with past implementation |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_SUPERCLASS, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing one of its interfaces. |
| inline bool CallbackInvoker::report_interface_reference(oop referrer, oop referree) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_INTERFACE, referrer, referree, -1); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_INTERFACE, referrer, referree, -1); |
| } |
| } |
| |
| // report a class referencing one of its static fields. |
| inline bool CallbackInvoker::report_static_field_reference(oop referrer, oop referree, jint slot) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_STATIC_FIELD, referrer, referree, slot); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_STATIC_FIELD, referrer, referree, slot); |
| } |
| } |
| |
| // report an array referencing an element object |
| inline bool CallbackInvoker::report_array_element_reference(oop referrer, oop referree, jint index) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_ARRAY_ELEMENT, referrer, referree, index); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT, referrer, referree, index); |
| } |
| } |
| |
| // report an object referencing an instance field object |
| inline bool CallbackInvoker::report_field_reference(oop referrer, oop referree, jint slot) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_FIELD, referrer, referree, slot); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_FIELD, referrer, referree, slot); |
| } |
| } |
| |
| // report an array referencing an element object |
| inline bool CallbackInvoker::report_constant_pool_reference(oop referrer, oop referree, jint index) { |
| if (is_basic_heap_walk()) { |
| return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CONSTANT_POOL, referrer, referree, index); |
| } else { |
| return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CONSTANT_POOL, referrer, referree, index); |
| } |
| } |
| |
| // A supporting closure used to process simple roots |
| class SimpleRootsClosure : public OopClosure { |
| private: |
| jvmtiHeapReferenceKind _kind; |
| bool _continue; |
| |
| jvmtiHeapReferenceKind root_kind() { return _kind; } |
| |
| public: |
| void set_kind(jvmtiHeapReferenceKind kind) { |
| _kind = kind; |
| _continue = true; |
| } |
| |
| inline bool stopped() { |
| return !_continue; |
| } |
| |
| void do_oop(oop* obj_p) { |
| // iteration has terminated |
| if (stopped()) { |
| return; |
| } |
| |
| // ignore null or deleted handles |
| oop o = *obj_p; |
| if (o == NULL || o == JNIHandles::deleted_handle()) { |
| return; |
| } |
| |
| assert(Universe::heap()->is_in_reserved(o), "should be impossible"); |
| |
| jvmtiHeapReferenceKind kind = root_kind(); |
| if (kind == JVMTI_HEAP_REFERENCE_SYSTEM_CLASS) { |
| // SystemDictionary::always_strong_oops_do reports the application |
| // class loader as a root. We want this root to be reported as |
| // a root kind of "OTHER" rather than "SYSTEM_CLASS". |
| if (!o->is_instance() || !InstanceKlass::cast(o->klass())->is_mirror_instance_klass()) { |
| kind = JVMTI_HEAP_REFERENCE_OTHER; |
| } |
| } |
| |
| // some objects are ignored - in the case of simple |
| // roots it's mostly Symbol*s that we are skipping |
| // here. |
| if (!ServiceUtil::visible_oop(o)) { |
| return; |
| } |
| |
| // invoke the callback |
| _continue = CallbackInvoker::report_simple_root(kind, o); |
| |
| } |
| virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } |
| }; |
| |
| // A supporting closure used to process JNI locals |
| class JNILocalRootsClosure : public OopClosure { |
| private: |
| jlong _thread_tag; |
| jlong _tid; |
| jint _depth; |
| jmethodID _method; |
| bool _continue; |
| public: |
| void set_context(jlong thread_tag, jlong tid, jint depth, jmethodID method) { |
| _thread_tag = thread_tag; |
| _tid = tid; |
| _depth = depth; |
| _method = method; |
| _continue = true; |
| } |
| |
| inline bool stopped() { |
| return !_continue; |
| } |
| |
| void do_oop(oop* obj_p) { |
| // iteration has terminated |
| if (stopped()) { |
| return; |
| } |
| |
| // ignore null or deleted handles |
| oop o = *obj_p; |
| if (o == NULL || o == JNIHandles::deleted_handle()) { |
| return; |
| } |
| |
| if (!ServiceUtil::visible_oop(o)) { |
| return; |
| } |
| |
| // invoke the callback |
| _continue = CallbackInvoker::report_jni_local_root(_thread_tag, _tid, _depth, _method, o); |
| } |
| virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } |
| }; |
| |
| |
| // A VM operation to iterate over objects that are reachable from |
| // a set of roots or an initial object. |
| // |
| // For VM_HeapWalkOperation the set of roots used is :- |
| // |
| // - All JNI global references |
| // - All inflated monitors |
| // - All classes loaded by the boot class loader (or all classes |
| // in the event that class unloading is disabled) |
| // - All java threads |
| // - For each java thread then all locals and JNI local references |
| // on the thread's execution stack |
| // - All visible/explainable objects from Universes::oops_do |
| // |
| class VM_HeapWalkOperation: public VM_Operation { |
| private: |
| enum { |
| initial_visit_stack_size = 4000 |
| }; |
| |
| bool _is_advanced_heap_walk; // indicates FollowReferences |
| JvmtiTagMap* _tag_map; |
| Handle _initial_object; |
| GrowableArray<oop>* _visit_stack; // the visit stack |
| |
| bool _collecting_heap_roots; // are we collecting roots |
| bool _following_object_refs; // are we following object references |
| |
| bool _reporting_primitive_fields; // optional reporting |
| bool _reporting_primitive_array_values; |
| bool _reporting_string_values; |
| |
| GrowableArray<oop>* create_visit_stack() { |
| return new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(initial_visit_stack_size, true); |
| } |
| |
| // accessors |
| bool is_advanced_heap_walk() const { return _is_advanced_heap_walk; } |
| JvmtiTagMap* tag_map() const { return _tag_map; } |
| Handle initial_object() const { return _initial_object; } |
| |
| bool is_following_references() const { return _following_object_refs; } |
| |
| bool is_reporting_primitive_fields() const { return _reporting_primitive_fields; } |
| bool is_reporting_primitive_array_values() const { return _reporting_primitive_array_values; } |
| bool is_reporting_string_values() const { return _reporting_string_values; } |
| |
| GrowableArray<oop>* visit_stack() const { return _visit_stack; } |
| |
| // iterate over the various object types |
| inline bool iterate_over_array(oop o); |
| inline bool iterate_over_type_array(oop o); |
| inline bool iterate_over_class(oop o); |
| inline bool iterate_over_object(oop o); |
| |
| // root collection |
| inline bool collect_simple_roots(); |
| inline bool collect_stack_roots(); |
| inline bool collect_stack_roots(JavaThread* java_thread, JNILocalRootsClosure* blk); |
| |
| // visit an object |
| inline bool visit(oop o); |
| |
| public: |
| VM_HeapWalkOperation(JvmtiTagMap* tag_map, |
| Handle initial_object, |
| BasicHeapWalkContext callbacks, |
| const void* user_data); |
| |
| VM_HeapWalkOperation(JvmtiTagMap* tag_map, |
| Handle initial_object, |
| AdvancedHeapWalkContext callbacks, |
| const void* user_data); |
| |
| ~VM_HeapWalkOperation(); |
| |
| VMOp_Type type() const { return VMOp_HeapWalkOperation; } |
| void doit(); |
| }; |
| |
| |
| VM_HeapWalkOperation::VM_HeapWalkOperation(JvmtiTagMap* tag_map, |
| Handle initial_object, |
| BasicHeapWalkContext callbacks, |
| const void* user_data) { |
| _is_advanced_heap_walk = false; |
| _tag_map = tag_map; |
| _initial_object = initial_object; |
| _following_object_refs = (callbacks.object_ref_callback() != NULL); |
| _reporting_primitive_fields = false; |
| _reporting_primitive_array_values = false; |
| _reporting_string_values = false; |
| _visit_stack = create_visit_stack(); |
| |
| |
| CallbackInvoker::initialize_for_basic_heap_walk(tag_map, _visit_stack, user_data, callbacks); |
| } |
| |
| VM_HeapWalkOperation::VM_HeapWalkOperation(JvmtiTagMap* tag_map, |
| Handle initial_object, |
| AdvancedHeapWalkContext callbacks, |
| const void* user_data) { |
| _is_advanced_heap_walk = true; |
| _tag_map = tag_map; |
| _initial_object = initial_object; |
| _following_object_refs = true; |
| _reporting_primitive_fields = (callbacks.primitive_field_callback() != NULL);; |
| _reporting_primitive_array_values = (callbacks.array_primitive_value_callback() != NULL);; |
| _reporting_string_values = (callbacks.string_primitive_value_callback() != NULL);; |
| _visit_stack = create_visit_stack(); |
| |
| CallbackInvoker::initialize_for_advanced_heap_walk(tag_map, _visit_stack, user_data, callbacks); |
| } |
| |
| VM_HeapWalkOperation::~VM_HeapWalkOperation() { |
| if (_following_object_refs) { |
| assert(_visit_stack != NULL, "checking"); |
| delete _visit_stack; |
| _visit_stack = NULL; |
| } |
| } |
| |
| // an array references its class and has a reference to |
| // each element in the array |
| inline bool VM_HeapWalkOperation::iterate_over_array(oop o) { |
| objArrayOop array = objArrayOop(o); |
| |
| // array reference to its class |
| oop mirror = ObjArrayKlass::cast(array->klass())->java_mirror(); |
| if (!CallbackInvoker::report_class_reference(o, mirror)) { |
| return false; |
| } |
| |
| // iterate over the array and report each reference to a |
| // non-null element |
| for (int index=0; index<array->length(); index++) { |
| oop elem = array->obj_at(index); |
| if (elem == NULL) { |
| continue; |
| } |
| |
| // report the array reference o[index] = elem |
| if (!CallbackInvoker::report_array_element_reference(o, elem, index)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // a type array references its class |
| inline bool VM_HeapWalkOperation::iterate_over_type_array(oop o) { |
| Klass* k = o->klass(); |
| oop mirror = k->java_mirror(); |
| if (!CallbackInvoker::report_class_reference(o, mirror)) { |
| return false; |
| } |
| |
| // report the array contents if required |
| if (is_reporting_primitive_array_values()) { |
| if (!CallbackInvoker::report_primitive_array_values(o)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| #ifdef ASSERT |
| // verify that a static oop field is in range |
| static inline bool verify_static_oop(InstanceKlass* ik, |
| oop mirror, int offset) { |
| address obj_p = (address)mirror + offset; |
| address start = (address)InstanceMirrorKlass::start_of_static_fields(mirror); |
| address end = start + (java_lang_Class::static_oop_field_count(mirror) * heapOopSize); |
| assert(end >= start, "sanity check"); |
| |
| if (obj_p >= start && obj_p < end) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| #endif // #ifdef ASSERT |
| |
| // a class references its super class, interfaces, class loader, ... |
| // and finally its static fields |
| inline bool VM_HeapWalkOperation::iterate_over_class(oop java_class) { |
| int i; |
| Klass* klass = java_lang_Class::as_Klass(java_class); |
| |
| if (klass->is_instance_klass()) { |
| InstanceKlass* ik = InstanceKlass::cast(klass); |
| |
| // Ignore the class if it hasn't been initialized yet |
| if (!ik->is_linked()) { |
| return true; |
| } |
| |
| // get the java mirror |
| oop mirror = klass->java_mirror(); |
| |
| // super (only if something more interesting than java.lang.Object) |
| Klass* java_super = ik->java_super(); |
| if (java_super != NULL && java_super != SystemDictionary::Object_klass()) { |
| oop super = java_super->java_mirror(); |
| if (!CallbackInvoker::report_superclass_reference(mirror, super)) { |
| return false; |
| } |
| } |
| |
| // class loader |
| oop cl = ik->class_loader(); |
| if (cl != NULL) { |
| if (!CallbackInvoker::report_class_loader_reference(mirror, cl)) { |
| return false; |
| } |
| } |
| |
| // protection domain |
| oop pd = ik->protection_domain(); |
| if (pd != NULL) { |
| if (!CallbackInvoker::report_protection_domain_reference(mirror, pd)) { |
| return false; |
| } |
| } |
| |
| // signers |
| oop signers = ik->signers(); |
| if (signers != NULL) { |
| if (!CallbackInvoker::report_signers_reference(mirror, signers)) { |
| return false; |
| } |
| } |
| |
| // references from the constant pool |
| { |
| ConstantPool* pool = ik->constants(); |
| for (int i = 1; i < pool->length(); i++) { |
| constantTag tag = pool->tag_at(i).value(); |
| if (tag.is_string() || tag.is_klass()) { |
| oop entry; |
| if (tag.is_string()) { |
| entry = pool->resolved_string_at(i); |
| // If the entry is non-null it is resolved. |
| if (entry == NULL) continue; |
| } else { |
| entry = pool->resolved_klass_at(i)->java_mirror(); |
| } |
| if (!CallbackInvoker::report_constant_pool_reference(mirror, entry, (jint)i)) { |
| return false; |
| } |
| } |
| } |
| } |
| |
| // interfaces |
| // (These will already have been reported as references from the constant pool |
| // but are specified by IterateOverReachableObjects and must be reported). |
| Array<Klass*>* interfaces = ik->local_interfaces(); |
| for (i = 0; i < interfaces->length(); i++) { |
| oop interf = ((Klass*)interfaces->at(i))->java_mirror(); |
| if (interf == NULL) { |
| continue; |
| } |
| if (!CallbackInvoker::report_interface_reference(mirror, interf)) { |
| return false; |
| } |
| } |
| |
| // iterate over the static fields |
| |
| ClassFieldMap* field_map = ClassFieldMap::create_map_of_static_fields(klass); |
| for (i=0; i<field_map->field_count(); i++) { |
| ClassFieldDescriptor* field = field_map->field_at(i); |
| char type = field->field_type(); |
| if (!is_primitive_field_type(type)) { |
| oop fld_o = mirror->obj_field(field->field_offset()); |
| assert(verify_static_oop(ik, mirror, field->field_offset()), "sanity check"); |
| if (fld_o != NULL) { |
| int slot = field->field_index(); |
| if (!CallbackInvoker::report_static_field_reference(mirror, fld_o, slot)) { |
| delete field_map; |
| return false; |
| } |
| } |
| } else { |
| if (is_reporting_primitive_fields()) { |
| address addr = (address)mirror + field->field_offset(); |
| int slot = field->field_index(); |
| if (!CallbackInvoker::report_primitive_static_field(mirror, slot, addr, type)) { |
| delete field_map; |
| return false; |
| } |
| } |
| } |
| } |
| delete field_map; |
| |
| return true; |
| } |
| |
| return true; |
| } |
| |
| // an object references a class and its instance fields |
| // (static fields are ignored here as we report these as |
| // references from the class). |
| inline bool VM_HeapWalkOperation::iterate_over_object(oop o) { |
| // reference to the class |
| if (!CallbackInvoker::report_class_reference(o, o->klass()->java_mirror())) { |
| return false; |
| } |
| |
| // iterate over instance fields |
| ClassFieldMap* field_map = JvmtiCachedClassFieldMap::get_map_of_instance_fields(o); |
| for (int i=0; i<field_map->field_count(); i++) { |
| ClassFieldDescriptor* field = field_map->field_at(i); |
| char type = field->field_type(); |
| if (!is_primitive_field_type(type)) { |
| oop fld_o = o->obj_field(field->field_offset()); |
| // ignore any objects that aren't visible to profiler |
| if (fld_o != NULL && ServiceUtil::visible_oop(fld_o)) { |
| assert(Universe::heap()->is_in_reserved(fld_o), "unsafe code should not " |
| "have references to Klass* anymore"); |
| int slot = field->field_index(); |
| if (!CallbackInvoker::report_field_reference(o, fld_o, slot)) { |
| return false; |
| } |
| } |
| } else { |
| if (is_reporting_primitive_fields()) { |
| // primitive instance field |
| address addr = (address)o + field->field_offset(); |
| int slot = field->field_index(); |
| if (!CallbackInvoker::report_primitive_instance_field(o, slot, addr, type)) { |
| return false; |
| } |
| } |
| } |
| } |
| |
| // if the object is a java.lang.String |
| if (is_reporting_string_values() && |
| o->klass() == SystemDictionary::String_klass()) { |
| if (!CallbackInvoker::report_string_value(o)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| |
| // Collects all simple (non-stack) roots except for threads; |
| // threads are handled in collect_stack_roots() as an optimization. |
| // if there's a heap root callback provided then the callback is |
| // invoked for each simple root. |
| // if an object reference callback is provided then all simple |
| // roots are pushed onto the marking stack so that they can be |
| // processed later |
| // |
| inline bool VM_HeapWalkOperation::collect_simple_roots() { |
| SimpleRootsClosure blk; |
| |
| // JNI globals |
| blk.set_kind(JVMTI_HEAP_REFERENCE_JNI_GLOBAL); |
| JNIHandles::oops_do(&blk); |
| if (blk.stopped()) { |
| return false; |
| } |
| |
| // Preloaded classes and loader from the system dictionary |
| blk.set_kind(JVMTI_HEAP_REFERENCE_SYSTEM_CLASS); |
| SystemDictionary::always_strong_oops_do(&blk); |
| KlassToOopClosure klass_blk(&blk); |
| ClassLoaderDataGraph::always_strong_oops_do(&blk, &klass_blk, false); |
| if (blk.stopped()) { |
| return false; |
| } |
| |
| // Inflated monitors |
| blk.set_kind(JVMTI_HEAP_REFERENCE_MONITOR); |
| ObjectSynchronizer::oops_do(&blk); |
| if (blk.stopped()) { |
| return false; |
| } |
| |
| // threads are now handled in collect_stack_roots() |
| |
| // Other kinds of roots maintained by HotSpot |
| // Many of these won't be visible but others (such as instances of important |
| // exceptions) will be visible. |
| blk.set_kind(JVMTI_HEAP_REFERENCE_OTHER); |
| Universe::oops_do(&blk); |
| |
| // If there are any non-perm roots in the code cache, visit them. |
| blk.set_kind(JVMTI_HEAP_REFERENCE_OTHER); |
| CodeBlobToOopClosure look_in_blobs(&blk, !CodeBlobToOopClosure::FixRelocations); |
| CodeCache::scavenge_root_nmethods_do(&look_in_blobs); |
| |
| return true; |
| } |
| |
| // Walk the stack of a given thread and find all references (locals |
| // and JNI calls) and report these as stack references |
| inline bool VM_HeapWalkOperation::collect_stack_roots(JavaThread* java_thread, |
| JNILocalRootsClosure* blk) |
| { |
| oop threadObj = java_thread->threadObj(); |
| assert(threadObj != NULL, "sanity check"); |
| |
| // only need to get the thread's tag once per thread |
| jlong thread_tag = tag_for(_tag_map, threadObj); |
| |
| // also need the thread id |
| jlong tid = java_lang_Thread::thread_id(threadObj); |
| |
| |
| if (java_thread->has_last_Java_frame()) { |
| |
| // vframes are resource allocated |
| Thread* current_thread = Thread::current(); |
| ResourceMark rm(current_thread); |
| HandleMark hm(current_thread); |
| |
| RegisterMap reg_map(java_thread); |
| frame f = java_thread->last_frame(); |
| vframe* vf = vframe::new_vframe(&f, ®_map, java_thread); |
| |
| bool is_top_frame = true; |
| int depth = 0; |
| frame* last_entry_frame = NULL; |
| |
| while (vf != NULL) { |
| if (vf->is_java_frame()) { |
| |
| // java frame (interpreted, compiled, ...) |
| javaVFrame *jvf = javaVFrame::cast(vf); |
| |
| // the jmethodID |
| jmethodID method = jvf->method()->jmethod_id(); |
| |
| if (!(jvf->method()->is_native())) { |
| jlocation bci = (jlocation)jvf->bci(); |
| StackValueCollection* locals = jvf->locals(); |
| for (int slot=0; slot<locals->size(); slot++) { |
| if (locals->at(slot)->type() == T_OBJECT) { |
| oop o = locals->obj_at(slot)(); |
| if (o == NULL) { |
| continue; |
| } |
| |
| // stack reference |
| if (!CallbackInvoker::report_stack_ref_root(thread_tag, tid, depth, method, |
| bci, slot, o)) { |
| return false; |
| } |
| } |
| } |
| |
| StackValueCollection* exprs = jvf->expressions(); |
| for (int index=0; index < exprs->size(); index++) { |
| if (exprs->at(index)->type() == T_OBJECT) { |
| oop o = exprs->obj_at(index)(); |
| if (o == NULL) { |
| continue; |
| } |
| |
| // stack reference |
| if (!CallbackInvoker::report_stack_ref_root(thread_tag, tid, depth, method, |
| bci, locals->size() + index, o)) { |
| return false; |
| } |
| } |
| } |
| |
| } else { |
| blk->set_context(thread_tag, tid, depth, method); |
| if (is_top_frame) { |
| // JNI locals for the top frame. |
| java_thread->active_handles()->oops_do(blk); |
| } else { |
| if (last_entry_frame != NULL) { |
| // JNI locals for the entry frame |
| assert(last_entry_frame->is_entry_frame(), "checking"); |
| last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(blk); |
| } |
| } |
| } |
| last_entry_frame = NULL; |
| depth++; |
| } else { |
| // externalVFrame - for an entry frame then we report the JNI locals |
| // when we find the corresponding javaVFrame |
| frame* fr = vf->frame_pointer(); |
| assert(fr != NULL, "sanity check"); |
| if (fr->is_entry_frame()) { |
| last_entry_frame = fr; |
| } |
| } |
| |
| vf = vf->sender(); |
| is_top_frame = false; |
| } |
| } else { |
| // no last java frame but there may be JNI locals |
| blk->set_context(thread_tag, tid, 0, (jmethodID)NULL); |
| java_thread->active_handles()->oops_do(blk); |
| } |
| return true; |
| } |
| |
| |
| // Collects the simple roots for all threads and collects all |
| // stack roots - for each thread it walks the execution |
| // stack to find all references and local JNI refs. |
| inline bool VM_HeapWalkOperation::collect_stack_roots() { |
| JNILocalRootsClosure blk; |
| for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) { |
| oop threadObj = thread->threadObj(); |
| if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) { |
| // Collect the simple root for this thread before we |
| // collect its stack roots |
| if (!CallbackInvoker::report_simple_root(JVMTI_HEAP_REFERENCE_THREAD, |
| threadObj)) { |
| return false; |
| } |
| if (!collect_stack_roots(thread, &blk)) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| // visit an object |
| // first mark the object as visited |
| // second get all the outbound references from this object (in other words, all |
| // the objects referenced by this object). |
| // |
| bool VM_HeapWalkOperation::visit(oop o) { |
| // mark object as visited |
| assert(!ObjectMarker::visited(o), "can't visit same object more than once"); |
| ObjectMarker::mark(o); |
| |
| // instance |
| if (o->is_instance()) { |
| if (o->klass() == SystemDictionary::Class_klass()) { |
| if (!java_lang_Class::is_primitive(o)) { |
| // a java.lang.Class |
| return iterate_over_class(o); |
| } |
| } else { |
| return iterate_over_object(o); |
| } |
| } |
| |
| // object array |
| if (o->is_objArray()) { |
| return iterate_over_array(o); |
| } |
| |
| // type array |
| if (o->is_typeArray()) { |
| return iterate_over_type_array(o); |
| } |
| |
| return true; |
| } |
| |
| void VM_HeapWalkOperation::doit() { |
| ResourceMark rm; |
| ObjectMarkerController marker; |
| ClassFieldMapCacheMark cm; |
| |
| assert(visit_stack()->is_empty(), "visit stack must be empty"); |
| |
| // the heap walk starts with an initial object or the heap roots |
| if (initial_object().is_null()) { |
| // If either collect_stack_roots() or collect_simple_roots() |
| // returns false at this point, then there are no mark bits |
| // to reset. |
| ObjectMarker::set_needs_reset(false); |
| |
| // Calling collect_stack_roots() before collect_simple_roots() |
| // can result in a big performance boost for an agent that is |
| // focused on analyzing references in the thread stacks. |
| if (!collect_stack_roots()) return; |
| |
| if (!collect_simple_roots()) return; |
| |
| // no early return so enable heap traversal to reset the mark bits |
| ObjectMarker::set_needs_reset(true); |
| } else { |
| visit_stack()->push(initial_object()()); |
| } |
| |
| // object references required |
| if (is_following_references()) { |
| |
| // visit each object until all reachable objects have been |
| // visited or the callback asked to terminate the iteration. |
| while (!visit_stack()->is_empty()) { |
| oop o = visit_stack()->pop(); |
| if (!ObjectMarker::visited(o)) { |
| if (!visit(o)) { |
| break; |
| } |
| } |
| } |
| } |
| } |
| |
| // iterate over all objects that are reachable from a set of roots |
| void JvmtiTagMap::iterate_over_reachable_objects(jvmtiHeapRootCallback heap_root_callback, |
| jvmtiStackReferenceCallback stack_ref_callback, |
| jvmtiObjectReferenceCallback object_ref_callback, |
| const void* user_data) { |
| MutexLocker ml(Heap_lock); |
| BasicHeapWalkContext context(heap_root_callback, stack_ref_callback, object_ref_callback); |
| VM_HeapWalkOperation op(this, Handle(), context, user_data); |
| VMThread::execute(&op); |
| } |
| |
| // iterate over all objects that are reachable from a given object |
| void JvmtiTagMap::iterate_over_objects_reachable_from_object(jobject object, |
| jvmtiObjectReferenceCallback object_ref_callback, |
| const void* user_data) { |
| oop obj = JNIHandles::resolve(object); |
| Handle initial_object(Thread::current(), obj); |
| |
| MutexLocker ml(Heap_lock); |
| BasicHeapWalkContext context(NULL, NULL, object_ref_callback); |
| VM_HeapWalkOperation op(this, initial_object, context, user_data); |
| VMThread::execute(&op); |
| } |
| |
| // follow references from an initial object or the GC roots |
| void JvmtiTagMap::follow_references(jint heap_filter, |
| KlassHandle klass, |
| jobject object, |
| const jvmtiHeapCallbacks* callbacks, |
| const void* user_data) |
| { |
| oop obj = JNIHandles::resolve(object); |
| Handle initial_object(Thread::current(), obj); |
| |
| MutexLocker ml(Heap_lock); |
| AdvancedHeapWalkContext context(heap_filter, klass, callbacks); |
| VM_HeapWalkOperation op(this, initial_object, context, user_data); |
| VMThread::execute(&op); |
| } |
| |
| |
| void JvmtiTagMap::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f) { |
| // No locks during VM bring-up (0 threads) and no safepoints after main |
| // thread creation and before VMThread creation (1 thread); initial GC |
| // verification can happen in that window which gets to here. |
| assert(Threads::number_of_threads() <= 1 || |
| SafepointSynchronize::is_at_safepoint(), |
| "must be executed at a safepoint"); |
| if (JvmtiEnv::environments_might_exist()) { |
| JvmtiEnvIterator it; |
| for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { |
| JvmtiTagMap* tag_map = env->tag_map(); |
| if (tag_map != NULL && !tag_map->is_empty()) { |
| tag_map->do_weak_oops(is_alive, f); |
| } |
| } |
| } |
| } |
| |
| void JvmtiTagMap::do_weak_oops(BoolObjectClosure* is_alive, OopClosure* f) { |
| |
| // does this environment have the OBJECT_FREE event enabled |
| bool post_object_free = env()->is_enabled(JVMTI_EVENT_OBJECT_FREE); |
| |
| // counters used for trace message |
| int freed = 0; |
| int moved = 0; |
| |
| JvmtiTagHashmap* hashmap = this->hashmap(); |
| |
| // reenable sizing (if disabled) |
| hashmap->set_resizing_enabled(true); |
| |
| // if the hashmap is empty then we can skip it |
| if (hashmap->_entry_count == 0) { |
| return; |
| } |
| |
| // now iterate through each entry in the table |
| |
| JvmtiTagHashmapEntry** table = hashmap->table(); |
| int size = hashmap->size(); |
| |
| JvmtiTagHashmapEntry* delayed_add = NULL; |
| |
| for (int pos = 0; pos < size; ++pos) { |
| JvmtiTagHashmapEntry* entry = table[pos]; |
| JvmtiTagHashmapEntry* prev = NULL; |
| |
| while (entry != NULL) { |
| JvmtiTagHashmapEntry* next = entry->next(); |
| |
| oop* obj = entry->object_addr(); |
| |
| // has object been GC'ed |
| if (!is_alive->do_object_b(entry->object())) { |
| // grab the tag |
| jlong tag = entry->tag(); |
| guarantee(tag != 0, "checking"); |
| |
| // remove GC'ed entry from hashmap and return the |
| // entry to the free list |
| hashmap->remove(prev, pos, entry); |
| destroy_entry(entry); |
| |
| // post the event to the profiler |
| if (post_object_free) { |
| JvmtiExport::post_object_free(env(), tag); |
| } |
| |
| ++freed; |
| } else { |
| f->do_oop(entry->object_addr()); |
| oop new_oop = entry->object(); |
| |
| // if the object has moved then re-hash it and move its |
| // entry to its new location. |
| unsigned int new_pos = JvmtiTagHashmap::hash(new_oop, size); |
| if (new_pos != (unsigned int)pos) { |
| if (prev == NULL) { |
| table[pos] = next; |
| } else { |
| prev->set_next(next); |
| } |
| if (new_pos < (unsigned int)pos) { |
| entry->set_next(table[new_pos]); |
| table[new_pos] = entry; |
| } else { |
| // Delay adding this entry to it's new position as we'd end up |
| // hitting it again during this iteration. |
| entry->set_next(delayed_add); |
| delayed_add = entry; |
| } |
| moved++; |
| } else { |
| // object didn't move |
| prev = entry; |
| } |
| } |
| |
| entry = next; |
| } |
| } |
| |
| // Re-add all the entries which were kept aside |
| while (delayed_add != NULL) { |
| JvmtiTagHashmapEntry* next = delayed_add->next(); |
| unsigned int pos = JvmtiTagHashmap::hash(delayed_add->object(), size); |
| delayed_add->set_next(table[pos]); |
| table[pos] = delayed_add; |
| delayed_add = next; |
| } |
| |
| // stats |
| if (TraceJVMTIObjectTagging) { |
| int post_total = hashmap->_entry_count; |
| int pre_total = post_total + freed; |
| |
| tty->print_cr("(%d->%d, %d freed, %d total moves)", |
| pre_total, post_total, freed, moved); |
| } |
| } |