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hotspot/src/share/vm/interpreter/oopMapCache.cpp

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+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_oopMapCache.cpp.incl"
+
+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 */ }
+#ifdef _LP64
+  void pass_float()                              { /* ignore */ }
+#endif
+  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.
+      _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
+
+  // 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");
+      if (method->is_old()) {
+        // The caller of lookup() will receive a copy of the interesting
+        // info via entry_for, but we don't keep an old redefined method in
+        // the cache to avoid pinning down the method.
+        entry->flush();
+      }
+      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");
+
+  if (method->is_old()) {
+    // The caller of lookup() will receive a copy of the interesting
+    // info via entry_for, but we don't keep an old redefined method in
+    // the cache to avoid pinning down the method.
+    entry->flush();
+  }
+
+  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);
+}