Mercurial > hg > graal-compiler
view src/share/vm/interpreter/oopMapCache.cpp @ 3992:d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
Summary: There is a race between one thread successfully forwarding and copying the klass mirror for the SoftReference class (including the static master clock) and another thread attempting to use the master clock while attempting to discover a soft reference object. Maintain a shadow copy of the soft reference master clock and use the shadow during reference discovery and reference processing.
Reviewed-by: tonyp, brutisso, ysr
author | johnc |
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date | Wed, 12 Oct 2011 10:25:51 -0700 |
parents | f95d63e2154a |
children | d2a62e0f25eb |
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/* * Copyright (c) 1997, 2010, 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 "interpreter/oopMapCache.hpp" #include "memory/allocation.inline.hpp" #include "memory/resourceArea.hpp" #include "oops/oop.inline.hpp" #include "prims/jvmtiRedefineClassesTrace.hpp" #include "runtime/handles.inline.hpp" #include "runtime/signature.hpp" class OopMapCacheEntry: private InterpreterOopMap { friend class InterpreterOopMap; friend class OopMapForCacheEntry; friend class OopMapCache; friend class VerifyClosure; protected: // Initialization void fill(methodHandle method, int bci); // fills the bit mask for native calls void fill_for_native(methodHandle method); void set_mask(CellTypeState* vars, CellTypeState* stack, int stack_top); // Deallocate bit masks and initialize fields void flush(); private: void allocate_bit_mask(); // allocates the bit mask on C heap f necessary void deallocate_bit_mask(); // allocates the bit mask on C heap f necessary bool verify_mask(CellTypeState *vars, CellTypeState *stack, int max_locals, int stack_top); public: OopMapCacheEntry() : InterpreterOopMap() { #ifdef ASSERT _resource_allocate_bit_mask = false; #endif } }; // Implementation of OopMapForCacheEntry // (subclass of GenerateOopMap, initializes an OopMapCacheEntry for a given method and bci) class OopMapForCacheEntry: public GenerateOopMap { OopMapCacheEntry *_entry; int _bci; int _stack_top; virtual bool report_results() const { return false; } virtual bool possible_gc_point (BytecodeStream *bcs); virtual void fill_stackmap_prolog (int nof_gc_points); virtual void fill_stackmap_epilog (); virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs, CellTypeState* vars, CellTypeState* stack, int stack_top); virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars); public: OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry *entry); // Computes stack map for (method,bci) and initialize entry void compute_map(TRAPS); int size(); }; OopMapForCacheEntry::OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry* entry) : GenerateOopMap(method) { _bci = bci; _entry = entry; _stack_top = -1; } void OopMapForCacheEntry::compute_map(TRAPS) { assert(!method()->is_native(), "cannot compute oop map for native methods"); // First check if it is a method where the stackmap is always empty if (method()->code_size() == 0 || method()->max_locals() + method()->max_stack() == 0) { _entry->set_mask_size(0); } else { ResourceMark rm; GenerateOopMap::compute_map(CATCH); result_for_basicblock(_bci); } } bool OopMapForCacheEntry::possible_gc_point(BytecodeStream *bcs) { return false; // We are not reporting any result. We call result_for_basicblock directly } void OopMapForCacheEntry::fill_stackmap_prolog(int nof_gc_points) { // Do nothing } void OopMapForCacheEntry::fill_stackmap_epilog() { // Do nothing } void OopMapForCacheEntry::fill_init_vars(GrowableArray<intptr_t> *init_vars) { // Do nothing } void OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream *bcs, CellTypeState* vars, CellTypeState* stack, int stack_top) { // Only interested in one specific bci if (bcs->bci() == _bci) { _entry->set_mask(vars, stack, stack_top); _stack_top = stack_top; } } int OopMapForCacheEntry::size() { assert(_stack_top != -1, "compute_map must be called first"); return ((method()->is_static()) ? 0 : 1) + method()->max_locals() + _stack_top; } // Implementation of InterpreterOopMap and OopMapCacheEntry class VerifyClosure : public OffsetClosure { private: OopMapCacheEntry* _entry; bool _failed; public: VerifyClosure(OopMapCacheEntry* entry) { _entry = entry; _failed = false; } void offset_do(int offset) { if (!_entry->is_oop(offset)) _failed = true; } bool failed() const { return _failed; } }; InterpreterOopMap::InterpreterOopMap() { initialize(); #ifdef ASSERT _resource_allocate_bit_mask = true; #endif } InterpreterOopMap::~InterpreterOopMap() { // The expection is that the bit mask was allocated // last in this resource area. That would make the free of the // bit_mask effective (see how FREE_RESOURCE_ARRAY does a free). // If it was not allocated last, there is not a correctness problem // but the space for the bit_mask is not freed. assert(_resource_allocate_bit_mask, "Trying to free C heap space"); if (mask_size() > small_mask_limit) { FREE_RESOURCE_ARRAY(uintptr_t, _bit_mask[0], mask_word_size()); } } bool InterpreterOopMap::is_empty() { bool result = _method == NULL; assert(_method != NULL || (_bci == 0 && (_mask_size == 0 || _mask_size == USHRT_MAX) && _bit_mask[0] == 0), "Should be completely empty"); return result; } void InterpreterOopMap::initialize() { _method = NULL; _mask_size = USHRT_MAX; // This value should cause a failure quickly _bci = 0; _expression_stack_size = 0; for (int i = 0; i < N; i++) _bit_mask[i] = 0; } void InterpreterOopMap::oop_iterate(OopClosure *blk) { if (method() != NULL) { blk->do_oop((oop*) &_method); } } void InterpreterOopMap::oop_iterate(OopClosure *blk, MemRegion mr) { if (method() != NULL && mr.contains(&_method)) { blk->do_oop((oop*) &_method); } } void InterpreterOopMap::iterate_oop(OffsetClosure* oop_closure) { int n = number_of_entries(); int word_index = 0; uintptr_t value = 0; uintptr_t mask = 0; // iterate over entries for (int i = 0; i < n; i++, mask <<= bits_per_entry) { // get current word if (mask == 0) { value = bit_mask()[word_index++]; mask = 1; } // test for oop if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i); } } void InterpreterOopMap::verify() { // If we are doing mark sweep _method may not have a valid header // $$$ This used to happen only for m/s collections; we might want to // think of an appropriate generalization of this distinction. guarantee(Universe::heap()->is_gc_active() || _method->is_oop_or_null(), "invalid oop in oopMapCache"); } #ifdef ENABLE_ZAP_DEAD_LOCALS void InterpreterOopMap::iterate_all(OffsetClosure* oop_closure, OffsetClosure* value_closure, OffsetClosure* dead_closure) { int n = number_of_entries(); int word_index = 0; uintptr_t value = 0; uintptr_t mask = 0; // iterate over entries for (int i = 0; i < n; i++, mask <<= bits_per_entry) { // get current word if (mask == 0) { value = bit_mask()[word_index++]; mask = 1; } // test for dead values & oops, and for live values if ((value & (mask << dead_bit_number)) != 0) dead_closure->offset_do(i); // call this for all dead values or oops else if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i); // call this for all live oops else value_closure->offset_do(i); // call this for all live values } } #endif void InterpreterOopMap::print() { int n = number_of_entries(); tty->print("oop map for "); method()->print_value(); tty->print(" @ %d = [%d] { ", bci(), n); for (int i = 0; i < n; i++) { #ifdef ENABLE_ZAP_DEAD_LOCALS if (is_dead(i)) tty->print("%d+ ", i); else #endif if (is_oop(i)) tty->print("%d ", i); } tty->print_cr("}"); } class MaskFillerForNative: public NativeSignatureIterator { private: uintptr_t * _mask; // the bit mask to be filled int _size; // the mask size in bits void set_one(int i) { i *= InterpreterOopMap::bits_per_entry; assert(0 <= i && i < _size, "offset out of bounds"); _mask[i / BitsPerWord] |= (((uintptr_t) 1 << InterpreterOopMap::oop_bit_number) << (i % BitsPerWord)); } public: void pass_int() { /* ignore */ } void pass_long() { /* ignore */ } void pass_float() { /* ignore */ } void pass_double() { /* ignore */ } void pass_object() { set_one(offset()); } MaskFillerForNative(methodHandle method, uintptr_t* mask, int size) : NativeSignatureIterator(method) { _mask = mask; _size = size; // initialize with 0 int i = (size + BitsPerWord - 1) / BitsPerWord; while (i-- > 0) _mask[i] = 0; } void generate() { NativeSignatureIterator::iterate(); } }; bool OopMapCacheEntry::verify_mask(CellTypeState* vars, CellTypeState* stack, int max_locals, int stack_top) { // Check mask includes map VerifyClosure blk(this); iterate_oop(&blk); if (blk.failed()) return false; // Check if map is generated correctly // (Use ?: operator to make sure all 'true' & 'false' are represented exactly the same so we can use == afterwards) if (TraceOopMapGeneration && Verbose) tty->print("Locals (%d): ", max_locals); for(int i = 0; i < max_locals; i++) { bool v1 = is_oop(i) ? true : false; bool v2 = vars[i].is_reference() ? true : false; assert(v1 == v2, "locals oop mask generation error"); if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0); #ifdef ENABLE_ZAP_DEAD_LOCALS bool v3 = is_dead(i) ? true : false; bool v4 = !vars[i].is_live() ? true : false; assert(v3 == v4, "locals live mask generation error"); assert(!(v1 && v3), "dead value marked as oop"); #endif } if (TraceOopMapGeneration && Verbose) { tty->cr(); tty->print("Stack (%d): ", stack_top); } for(int j = 0; j < stack_top; j++) { bool v1 = is_oop(max_locals + j) ? true : false; bool v2 = stack[j].is_reference() ? true : false; assert(v1 == v2, "stack oop mask generation error"); if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0); #ifdef ENABLE_ZAP_DEAD_LOCALS bool v3 = is_dead(max_locals + j) ? true : false; bool v4 = !stack[j].is_live() ? true : false; assert(v3 == v4, "stack live mask generation error"); assert(!(v1 && v3), "dead value marked as oop"); #endif } if (TraceOopMapGeneration && Verbose) tty->cr(); return true; } void OopMapCacheEntry::allocate_bit_mask() { if (mask_size() > small_mask_limit) { assert(_bit_mask[0] == 0, "bit mask should be new or just flushed"); _bit_mask[0] = (intptr_t) NEW_C_HEAP_ARRAY(uintptr_t, mask_word_size()); } } void OopMapCacheEntry::deallocate_bit_mask() { if (mask_size() > small_mask_limit && _bit_mask[0] != 0) { assert(!Thread::current()->resource_area()->contains((void*)_bit_mask[0]), "This bit mask should not be in the resource area"); FREE_C_HEAP_ARRAY(uintptr_t, _bit_mask[0]); debug_only(_bit_mask[0] = 0;) } } void OopMapCacheEntry::fill_for_native(methodHandle mh) { assert(mh->is_native(), "method must be native method"); set_mask_size(mh->size_of_parameters() * bits_per_entry); allocate_bit_mask(); // fill mask for parameters MaskFillerForNative mf(mh, bit_mask(), mask_size()); mf.generate(); } void OopMapCacheEntry::fill(methodHandle method, int bci) { HandleMark hm; // Flush entry to deallocate an existing entry flush(); set_method(method()); set_bci(bci); if (method->is_native()) { // Native method activations have oops only among the parameters and one // extra oop following the parameters (the mirror for static native methods). fill_for_native(method); } else { EXCEPTION_MARK; OopMapForCacheEntry gen(method, bci, this); gen.compute_map(CATCH); } #ifdef ASSERT verify(); #endif } void OopMapCacheEntry::set_mask(CellTypeState *vars, CellTypeState *stack, int stack_top) { // compute bit mask size int max_locals = method()->max_locals(); int n_entries = max_locals + stack_top; set_mask_size(n_entries * bits_per_entry); allocate_bit_mask(); set_expression_stack_size(stack_top); // compute bits int word_index = 0; uintptr_t value = 0; uintptr_t mask = 1; CellTypeState* cell = vars; for (int entry_index = 0; entry_index < n_entries; entry_index++, mask <<= bits_per_entry, cell++) { // store last word if (mask == 0) { bit_mask()[word_index++] = value; value = 0; mask = 1; } // switch to stack when done with locals if (entry_index == max_locals) { cell = stack; } // set oop bit if ( cell->is_reference()) { value |= (mask << oop_bit_number ); } #ifdef ENABLE_ZAP_DEAD_LOCALS // set dead bit if (!cell->is_live()) { value |= (mask << dead_bit_number); assert(!cell->is_reference(), "dead value marked as oop"); } #endif } // make sure last word is stored bit_mask()[word_index] = value; // verify bit mask assert(verify_mask(vars, stack, max_locals, stack_top), "mask could not be verified"); } void OopMapCacheEntry::flush() { deallocate_bit_mask(); initialize(); } // Implementation of OopMapCache #ifndef PRODUCT static long _total_memory_usage = 0; long OopMapCache::memory_usage() { return _total_memory_usage; } #endif void InterpreterOopMap::resource_copy(OopMapCacheEntry* from) { assert(_resource_allocate_bit_mask, "Should not resource allocate the _bit_mask"); assert(from->method()->is_oop(), "MethodOop is bad"); set_method(from->method()); set_bci(from->bci()); set_mask_size(from->mask_size()); set_expression_stack_size(from->expression_stack_size()); // Is the bit mask contained in the entry? if (from->mask_size() <= small_mask_limit) { memcpy((void *)_bit_mask, (void *)from->_bit_mask, mask_word_size() * BytesPerWord); } else { // The expectation is that this InterpreterOopMap is a recently created // and empty. It is used to get a copy of a cached entry. // If the bit mask has a value, it should be in the // resource area. assert(_bit_mask[0] == 0 || Thread::current()->resource_area()->contains((void*)_bit_mask[0]), "The bit mask should have been allocated from a resource area"); // Allocate the bit_mask from a Resource area for performance. Allocating // from the C heap as is done for OopMapCache has a significant // performance impact. _bit_mask[0] = (uintptr_t) NEW_RESOURCE_ARRAY(uintptr_t, mask_word_size()); assert(_bit_mask[0] != 0, "bit mask was not allocated"); memcpy((void*) _bit_mask[0], (void*) from->_bit_mask[0], mask_word_size() * BytesPerWord); } } inline unsigned int OopMapCache::hash_value_for(methodHandle method, int bci) { // We use method->code_size() rather than method->identity_hash() below since // the mark may not be present if a pointer to the method is already reversed. return ((unsigned int) bci) ^ ((unsigned int) method->max_locals() << 2) ^ ((unsigned int) method->code_size() << 4) ^ ((unsigned int) method->size_of_parameters() << 6); } OopMapCache::OopMapCache() : _mut(Mutex::leaf, "An OopMapCache lock", true) { _array = NEW_C_HEAP_ARRAY(OopMapCacheEntry, _size); // Cannot call flush for initialization, since flush // will check if memory should be deallocated for(int i = 0; i < _size; i++) _array[i].initialize(); NOT_PRODUCT(_total_memory_usage += sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);) } OopMapCache::~OopMapCache() { assert(_array != NULL, "sanity check"); // Deallocate oop maps that are allocated out-of-line flush(); // Deallocate array NOT_PRODUCT(_total_memory_usage -= sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);) FREE_C_HEAP_ARRAY(OopMapCacheEntry, _array); } OopMapCacheEntry* OopMapCache::entry_at(int i) const { return &_array[i % _size]; } void OopMapCache::flush() { for (int i = 0; i < _size; i++) _array[i].flush(); } void OopMapCache::flush_obsolete_entries() { for (int i = 0; i < _size; i++) if (!_array[i].is_empty() && _array[i].method()->is_old()) { // Cache entry is occupied by an old redefined method and we don't want // to pin it down so flush the entry. RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d", _array[i].method()->name()->as_C_string(), _array[i].method()->signature()->as_C_string(), i)); _array[i].flush(); } } void OopMapCache::oop_iterate(OopClosure *blk) { for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk); } void OopMapCache::oop_iterate(OopClosure *blk, MemRegion mr) { for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk, mr); } void OopMapCache::verify() { for (int i = 0; i < _size; i++) _array[i].verify(); } void OopMapCache::lookup(methodHandle method, int bci, InterpreterOopMap* entry_for) { MutexLocker x(&_mut); OopMapCacheEntry* entry = NULL; int probe = hash_value_for(method, bci); // Search hashtable for match int i; for(i = 0; i < _probe_depth; i++) { entry = entry_at(probe + i); if (entry->match(method, bci)) { entry_for->resource_copy(entry); assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); return; } } if (TraceOopMapGeneration) { static int count = 0; ResourceMark rm; tty->print("%d - Computing oopmap at bci %d for ", ++count, bci); method->print_value(); tty->cr(); } // Entry is not in hashtable. // Compute entry and return it if (method->should_not_be_cached()) { // It is either not safe or not a good idea to cache this methodOop // at this time. We give the caller of lookup() a copy of the // interesting info via parameter entry_for, but we don't add it to // the cache. See the gory details in methodOop.cpp. compute_one_oop_map(method, bci, entry_for); return; } // First search for an empty slot for(i = 0; i < _probe_depth; i++) { entry = entry_at(probe + i); if (entry->is_empty()) { entry->fill(method, bci); entry_for->resource_copy(entry); assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); return; } } if (TraceOopMapGeneration) { ResourceMark rm; tty->print_cr("*** collision in oopmap cache - flushing item ***"); } // No empty slot (uncommon case). Use (some approximation of a) LRU algorithm //entry_at(probe + _probe_depth - 1)->flush(); //for(i = _probe_depth - 1; i > 0; i--) { // // Coping entry[i] = entry[i-1]; // OopMapCacheEntry *to = entry_at(probe + i); // OopMapCacheEntry *from = entry_at(probe + i - 1); // to->copy(from); // } assert(method->is_method(), "gaga"); entry = entry_at(probe + 0); entry->fill(method, bci); // Copy the newly cached entry to input parameter entry_for->resource_copy(entry); if (TraceOopMapGeneration) { ResourceMark rm; tty->print("Done with "); method->print_value(); tty->cr(); } assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); return; } void OopMapCache::compute_one_oop_map(methodHandle method, int bci, InterpreterOopMap* entry) { // Due to the invariants above it's tricky to allocate a temporary OopMapCacheEntry on the stack OopMapCacheEntry* tmp = NEW_C_HEAP_ARRAY(OopMapCacheEntry, 1); tmp->initialize(); tmp->fill(method, bci); entry->resource_copy(tmp); FREE_C_HEAP_ARRAY(OopMapCacheEntry, tmp); }