jdk8-mips64-public/hotspot: src/share/vm/classfile/classLoaderData.cpp@da91efe96a93 (annotated)

src/share/vm/classfile/classLoaderData.cpp@da91efe96a93 (annotated)

src/share/vm/classfile/classLoaderData.cpp

Sat, 01 Sep 2012 13:25:18 -0400

author: coleenp
date: Sat, 01 Sep 2012 13:25:18 -0400
changeset 4037: da91efe96a93
child 4304: 90273fc0a981
permissions: -rw-r--r--

6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>

 /*
  * Copyright (c) 2012, 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.
  *
  */
 // A ClassLoaderData identifies the full set of class types that a class
 // loader's name resolution strategy produces for a given configuration of the
 // class loader.
 // Class types in the ClassLoaderData may be defined by from class file binaries
 // provided by the class loader, or from other class loader it interacts with
 // according to its name resolution strategy.
 //
 // Class loaders that implement a deterministic name resolution strategy
 // (including with respect to their delegation behavior), such as the boot, the
 // extension, and the system loaders of the JDK's built-in class loader
 // hierarchy, always produce the same linkset for a given configuration.
 //
 // ClassLoaderData carries information related to a linkset (e.g.,
 // metaspace holding its klass definitions).
 // The System Dictionary and related data structures (e.g., placeholder table,
 // loader constraints table) as well as the runtime representation of classes
 // only reference ClassLoaderData.
 //
 // Instances of java.lang.ClassLoader holds a pointer to a ClassLoaderData that
 // that represent the loader's "linking domain" in the JVM.
 //
 // The bootstrap loader (represented by NULL) also has a ClassLoaderData,
 // the singleton class the_null_class_loader_data().
 #include "precompiled.hpp"
 #include "classfile/classLoaderData.hpp"
 #include "classfile/classLoaderData.inline.hpp"
 #include "classfile/javaClasses.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "code/codeCache.hpp"
 #include "memory/metadataFactory.hpp"
 #include "memory/metaspaceShared.hpp"
 #include "prims/jvmtiRedefineClasses.hpp"
 #include "runtime/jniHandles.hpp"
 #include "runtime/mutex.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/synchronizer.hpp"
 #include "utilities/growableArray.hpp"
 #include "utilities/ostream.hpp"
 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
 ClassLoaderData::ClassLoaderData(Handle h_class_loader) : _class_loader(h_class_loader()),
   _metaspace(NULL), _unloading(false), _klasses(NULL),
   _claimed(0), _jmethod_ids(NULL), _handles(NULL),
   _deallocate_list(NULL), _next(NULL),
   _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
     // empty
 }
 bool ClassLoaderData::claim() {
   if (_claimed == 1) {
     return false;
   }
   return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0;
 }
 void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
   if (must_claim && !claim()) {
     return;
   }
   f->do_oop(&_class_loader);
   _handles->oops_do(f);
   if (klass_closure != NULL) {
     classes_do(klass_closure);
   }
 }
 void ClassLoaderData::classes_do(KlassClosure* klass_closure) {
   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
     klass_closure->do_klass(k);
   }
 }
 void ClassLoaderData::classes_do(void f(InstanceKlass*)) {
   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
     if (k->oop_is_instance()) {
       f(InstanceKlass::cast(k));
     }
   }
 }
 void ClassLoaderData::record_dependency(Klass* k, TRAPS) {
   ClassLoaderData * const from_cld = this;
   ClassLoaderData * const to_cld = k->class_loader_data();
   // Records dependency between non-null class loaders only.
   if (to_cld->is_the_null_class_loader_data() || from_cld->is_the_null_class_loader_data()) {
     return;
   }
   // Check that this dependency isn't from the same or parent class_loader
   oop to = to_cld->class_loader();
   oop from = from_cld->class_loader();
   oop curr = from;
   while (curr != NULL) {
     if (curr == to) {
       return; // this class loader is in the parent list, no need to add it.
     }
     curr = java_lang_ClassLoader::parent(curr);
   }
   // It's a dependency we won't find through GC, add it. This is relatively rare
   from_cld->add_dependency(to_cld, CHECK);
 }
 bool ClassLoaderData::has_dependency(ClassLoaderData* dependency) {
   oop loader = dependency->class_loader();
   // Get objArrayOop out of the class_loader oop and see if this dependency
   // is there.  Don't safepoint!  These are all oops.
   // Dependency list is (oop class_loader, objArrayOop next)
   objArrayOop ok = (objArrayOop)java_lang_ClassLoader::dependencies(class_loader());
   while (ok != NULL) {
     if (ok->obj_at(0) == loader) {
       return true;
     }
     ok = (objArrayOop)ok->obj_at(1);
   }
   return false;
 }
 void ClassLoaderData::add_dependency(ClassLoaderData* dependency, TRAPS) {
   // Minimize the number of duplicates in the list.
   if (has_dependency(dependency)) {
     return;
   }
   // Create a new dependency node with fields for (class_loader, next)
   objArrayOop deps = oopFactory::new_objectArray(2, CHECK);
   deps->obj_at_put(0, dependency->class_loader());
   // Add this lock free, using compare and exchange, need barriers for GC
   // Do the barrier first.
   HeapWord* addr = java_lang_ClassLoader::dependencies_addr(class_loader());
   while (true) {
     oop old_dependency = java_lang_ClassLoader::dependencies(class_loader());
     deps->obj_at_put(1, old_dependency);
     oop newold = oopDesc::atomic_compare_exchange_oop((oop)deps, addr, old_dependency, true);
     if (newold == old_dependency) {
       update_barrier_set((void*)addr, (oop)deps);
       // we won the race to add this dependency
       break;
     }
   }
 }
 void ClassLoaderDataGraph::clear_claimed_marks() {
   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
     cld->clear_claimed();
   }
 }
 void ClassLoaderData::add_class(Klass* k) {
   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
   Klass* old_value = _klasses;
   k->set_next_link(old_value);
   // link the new item into the list
   _klasses = k;
   if (TraceClassLoaderData && k->class_loader_data() != NULL) {
     ResourceMark rm;
     tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: "
                   PTR_FORMAT " loader: " PTR_FORMAT " %s",
                   k,
                   k->external_name(),
                   k->class_loader_data(),
                   k->class_loader(),
                   k->class_loader() != NULL ? k->class_loader()->klass()->external_name() : "NULL"
       );
   }
 }
 // This is called by InstanceKlass::deallocate_contents() to remove the
 // scratch_class for redefine classes.  We need a lock because there it may not
 // be called at a safepoint if there's an error.
 void ClassLoaderData::remove_class(Klass* scratch_class) {
   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
   Klass* prev = NULL;
   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
     if (k == scratch_class) {
       if (prev == NULL) {
         _klasses = k->next_link();
       } else {
         Klass* next = k->next_link();
         prev->set_next_link(next);
       }
       return;
     }
     prev = k;
   }
   ShouldNotReachHere();   // should have found this class!!
 }
 ClassLoaderData::~ClassLoaderData() {
   Metaspace *m = _metaspace;
   if (m != NULL) {
     _metaspace = NULL;
     // release the metaspace
     delete m;
     // release the handles
     if (_handles != NULL) {
       JNIHandleBlock::release_block(_handles);
       _handles = NULL;
     }
   }
   // Clear all the JNI handles for methods
   // These aren't deallocated and are going to look like a leak, but that's
   // needed because we can't really get rid of jmethodIDs because we don't
   // know when native code is going to stop using them.  The spec says that
   // they're "invalid" but existing programs likely rely on their being
   // NULL after class unloading.
   if (_jmethod_ids != NULL) {
     Method::clear_jmethod_ids(this);
   }
   // Delete lock
   delete _metaspace_lock;
   // Delete free list
   if (_deallocate_list != NULL) {
     delete _deallocate_list;
   }
 }
 Metaspace* ClassLoaderData::metaspace_non_null() {
   // If the metaspace has not been allocated, create a new one.  Might want
   // to create smaller arena for Reflection class loaders also.
   // The reason for the delayed allocation is because some class loaders are
   // simply for delegating with no metadata of their own.
   if (_metaspace == NULL) {
     MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
     // Check again if metaspace has been allocated while we were getting this lock.
     if (_metaspace != NULL) {
       return _metaspace;
     }
     if (class_loader() == NULL) {
       assert(this == the_null_class_loader_data(), "Must be");
       size_t word_size = Metaspace::first_chunk_word_size();
       set_metaspace(new Metaspace(_metaspace_lock, word_size));
     } else {
       set_metaspace(new Metaspace(_metaspace_lock));  // default size for now.
     }
   }
   return _metaspace;
 }
 JNIHandleBlock* ClassLoaderData::handles() const           { return _handles; }
 void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; }
 jobject ClassLoaderData::add_handle(Handle h) {
   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
   if (handles() == NULL) {
     set_handles(JNIHandleBlock::allocate_block());
   }
   return handles()->allocate_handle(h());
 }
 // Add this metadata pointer to be freed when it's safe.  This is only during
 // class unloading because Handles might point to this metadata field.
 void ClassLoaderData::add_to_deallocate_list(Metadata* m) {
   // Metadata in shared region isn't deleted.
   if (!m->is_shared()) {
     MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
     if (_deallocate_list == NULL) {
       _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true);
     }
     _deallocate_list->append_if_missing(m);
   }
 }
 // Deallocate free metadata on the free list.  How useful the PermGen was!
 void ClassLoaderData::free_deallocate_list() {
   // Don't need lock, at safepoint
   assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
   if (_deallocate_list == NULL) {
     return;
   }
   // Go backwards because this removes entries that are freed.
   for (int i = _deallocate_list->length() - 1; i >= 0; i--) {
     Metadata* m = _deallocate_list->at(i);
     if (!m->on_stack()) {
       _deallocate_list->remove_at(i);
       // There are only three types of metadata that we deallocate directly.
       // Cast them so they can be used by the template function.
       if (m->is_method()) {
         MetadataFactory::free_metadata(this, (Method*)m);
       } else if (m->is_constantPool()) {
         MetadataFactory::free_metadata(this, (ConstantPool*)m);
       } else if (m->is_klass()) {
         MetadataFactory::free_metadata(this, (InstanceKlass*)m);
       } else {
         ShouldNotReachHere();
       }
     }
   }
 }
 #ifndef PRODUCT
 void ClassLoaderData::print_loader(ClassLoaderData *loader_data, outputStream* out) {
   oop class_loader = loader_data->class_loader();
   out->print("%s", SystemDictionary::loader_name(class_loader));
 }
 // Define to dump klasses
 #undef CLD_DUMP_KLASSES
 void ClassLoaderData::dump(outputStream * const out) {
   ResourceMark rm;
   out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {",
       this, class_loader(),
       class_loader() != NULL ? class_loader()->klass() : NULL,
       class_loader() != NULL ? class_loader()->klass()->external_name() : "NULL");
   if (claimed()) out->print(" claimed ");
   if (is_unloading()) out->print(" unloading ");
   out->print(" handles " INTPTR_FORMAT, handles());
   out->cr();
   if (metaspace_or_null() != NULL) {
     out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null());
     metaspace_or_null()->dump(out);
   } else {
     out->print_cr("metaspace: NULL");
   }
 #ifdef CLD_DUMP_KLASSES
   if (Verbose) {
     ResourceMark rm;
     Klass* k = _klasses;
     while (k != NULL) {
       out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(),
           k->has_modified_oops(), k->has_accumulated_modified_oops());
       k = k->next_link();
     }
   }
 #endif  // CLD_DUMP_KLASSES
 #undef CLD_DUMP_KLASSES
   if (_jmethod_ids != NULL) {
     Method::print_jmethod_ids(this, out);
   }
   out->print_cr("}");
 }
 #endif // PRODUCT
 void ClassLoaderData::verify() {
   oop cl = class_loader();
   guarantee(this == class_loader_data(cl), "Must be the same");
   guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data(), "must be");
   // Verify the integrity of the allocated space.
   if (metaspace_or_null() != NULL) {
     metaspace_or_null()->verify();
   }
   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
     guarantee(k->class_loader_data() == this, "Must be the same");
     k->verify();
   }
 }
 // GC root of class loader data created.
 ClassLoaderData* ClassLoaderDataGraph::_head = NULL;
 ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL;
 ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
 // Add a new class loader data node to the list.  Assign the newly created
 // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
 ClassLoaderData* ClassLoaderDataGraph::add(ClassLoaderData** cld_addr, Handle loader_data) {
   // Not assigned a class loader data yet.
   // Create one.
   ClassLoaderData* *list_head = &_head;
   ClassLoaderData* next = _head;
   ClassLoaderData* cld = new ClassLoaderData(loader_data);
   // First, Atomically set it.
   ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
   if (old != NULL) {
     delete cld;
     // Returns the data.
     return old;
   }
   // We won the race, and therefore the task of adding the data to the list of
   // class loader data
   do {
     cld->set_next(next);
     ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next);
     if (exchanged == next) {
       if (TraceClassLoaderData) {
         tty->print("[ClassLoaderData: ");
         tty->print("create class loader data "PTR_FORMAT, cld);
         tty->print(" for instance "PTR_FORMAT" of ", cld->class_loader());
         loader_data->klass()->name()->print_symbol_on(tty);
         tty->print_cr("]");
       }
       return cld;
     }
     next = exchanged;
   } while (true);
 }
 void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
     cld->oops_do(f, klass_closure, must_claim);
   }
 }
 void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
   if (ClassUnloading) {
     ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim);
   } else {
     ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
   }
 }
 void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
     cld->classes_do(klass_closure);
   }
 }
 GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
   assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?");
   GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>();
   // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true);
   ClassLoaderData* curr = _head;
   while (curr != _saved_head) {
     if (!curr->claimed()) {
       array->push(curr);
       if (TraceClassLoaderData) {
         tty->print("[ClassLoaderData] found new CLD: ");
         curr->print_value_on(tty);
         tty->cr();
       }
     }
     curr = curr->_next;
   }
   return array;
 }
 #ifndef PRODUCT
 // for debugging and hsfind(x)
 bool ClassLoaderDataGraph::contains(address x) {
   // I think we need the _metaspace_lock taken here because the class loader
   // data graph could be changing while we are walking it (new entries added,
   // new entries being unloaded, etc).
   if (DumpSharedSpaces) {
     // There are only two metaspaces to worry about.
     ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
     return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x));
   }
   if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) {
     return true;
   }
   for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
     if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
       return true;
     }
   }
   // Could also be on an unloading list which is okay, ie. still allocated
   // for a little while.
   for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
     if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
       return true;
     }
   }
   return false;
 }
 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
     if (loader_data == data) {
       return true;
     }
   }
   return false;
 }
 #endif // PRODUCT
 // Move class loader data from main list to the unloaded list for unloading
 // and deallocation later.
 bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive) {
   ClassLoaderData* data = _head;
   ClassLoaderData* prev = NULL;
   bool seen_dead_loader = false;
   // mark metadata seen on the stack and code cache so we can delete
   // unneeded entries.
   bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
   MetadataOnStackMark md_on_stack;
   while (data != NULL) {
     if (data->class_loader() == NULL || is_alive->do_object_b(data->class_loader())) {
       assert(data->claimed(), "class loader data must have been claimed");
       if (has_redefined_a_class) {
         data->classes_do(InstanceKlass::purge_previous_versions);
       }
       data->free_deallocate_list();
       prev = data;
       data = data->next();
       continue;
     }
     seen_dead_loader = true;
     ClassLoaderData* dead = data;
     dead->mark_for_unload();
     if (TraceClassLoaderData) {
       tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, dead);
       tty->print(" for instance "PTR_FORMAT" of ", dead->class_loader());
       dead->class_loader()->klass()->name()->print_symbol_on(tty);
       tty->print_cr("]");
     }
     data = data->next();
     // Remove from loader list.
     if (prev != NULL) {
       prev->set_next(data);
     } else {
       assert(dead == _head, "sanity check");
       _head = data;
     }
     dead->set_next(_unloading);
     _unloading = dead;
   }
   return seen_dead_loader;
 }
 void ClassLoaderDataGraph::purge() {
   ClassLoaderData* list = _unloading;
   _unloading = NULL;
   ClassLoaderData* next = list;
   while (next != NULL) {
     ClassLoaderData* purge_me = next;
     next = purge_me->next();
     delete purge_me;
   }
 }
 // CDS support
 // Global metaspaces for writing information to the shared archive.  When
 // application CDS is supported, we may need one per metaspace, so this
 // sort of looks like it.
 Metaspace* ClassLoaderData::_ro_metaspace = NULL;
 Metaspace* ClassLoaderData::_rw_metaspace = NULL;
 static bool _shared_metaspaces_initialized = false;
 // Initialize shared metaspaces (change to call from somewhere not lazily)
 void ClassLoaderData::initialize_shared_metaspaces() {
   assert(DumpSharedSpaces, "only use this for dumping shared spaces");
   assert(this == ClassLoaderData::the_null_class_loader_data(),
          "only supported for null loader data for now");
   assert (!_shared_metaspaces_initialized, "only initialize once");
   MutexLockerEx ml(metaspace_lock(),  Mutex::_no_safepoint_check_flag);
   _ro_metaspace = new Metaspace(_metaspace_lock, SharedReadOnlySize/wordSize);
   _rw_metaspace = new Metaspace(_metaspace_lock, SharedReadWriteSize/wordSize);
   _shared_metaspaces_initialized = true;
 }
 Metaspace* ClassLoaderData::ro_metaspace() {
   assert(_ro_metaspace != NULL, "should already be initialized");
   return _ro_metaspace;
 }
 Metaspace* ClassLoaderData::rw_metaspace() {
   assert(_rw_metaspace != NULL, "should already be initialized");
   return _rw_metaspace;
 }
 ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
   _data = ClassLoaderDataGraph::_head;
 }
 ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
 #ifndef PRODUCT
 // callable from debugger
 extern "C" int print_loader_data_graph() {
   ClassLoaderDataGraph::dump_on(tty);
   return 0;
 }
 void ClassLoaderDataGraph::verify() {
   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
     data->verify();
   }
 }
 void ClassLoaderDataGraph::dump_on(outputStream * const out) {
   for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
     data->dump(out);
   }
   MetaspaceAux::dump(out);
 }
 void ClassLoaderData::print_value_on(outputStream* out) const {
   if (class_loader() == NULL) {
     out->print_cr("NULL class_loader");
   } else {
     out->print("class loader "PTR_FORMAT, this);
     class_loader()->print_value_on(out);
   }
 }
 #endif // PRODUCT

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/classfile/classLoaderData.cpp@da91efe96a93 (annotated)

src/share/vm/classfile/classLoaderData.cpp