Mercurial > hg > graal-compiler
diff src/share/vm/classfile/classLoaderData.cpp @ 7185:90273fc0a981
8000662: NPG: nashorn ant clean test262 out-of-memory with Java heap
Summary: Add ClassLoaderData object for each anonymous class with metaspaces to allocate in.
Reviewed-by: twisti, jrose, stefank
author | coleenp |
---|---|
date | Thu, 29 Nov 2012 16:50:29 -0500 |
parents | da91efe96a93 |
children | 30866cd626b0 1b1e16471e46 |
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--- a/src/share/vm/classfile/classLoaderData.cpp Tue Nov 27 14:11:37 2012 -0800 +++ b/src/share/vm/classfile/classLoaderData.cpp Thu Nov 29 16:50:29 2012 -0500 @@ -65,13 +65,19 @@ 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(NULL), _unloading(false), _keep_alive(false), _klasses(NULL), + _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL), + _next(NULL), _dependencies(NULL), _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) { // empty } +void ClassLoaderData::init_dependencies(TRAPS) { + // Create empty dependencies array to add to. CMS requires this to be + // an oop so that it can track additions via card marks. We think. + _dependencies = (oop)oopFactory::new_objectArray(2, CHECK); +} + bool ClassLoaderData::claim() { if (_claimed == 1) { return false; @@ -86,6 +92,7 @@ } f->do_oop(&_class_loader); + f->do_oop(&_dependencies); _handles->oops_do(f); if (klass_closure != NULL) { classes_do(klass_closure); @@ -110,70 +117,100 @@ 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()) { + // Dependency to the null class loader data doesn't need to be recorded + // because the null class loader data never goes away. + if (to_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 to; + if (to_cld->is_anonymous()) { + // Anonymous class dependencies are through the mirror. + to = k->java_mirror(); + } else { + to = to_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. + // If from_cld is anonymous, even if it's class_loader is a parent of 'to' + // we still have to add it. The class_loader won't keep from_cld alive. + if (!from_cld->is_anonymous()) { + // Check that this dependency isn't from the same or parent 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); + } } - 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); + // Must handle over GC point. + Handle dependency(THREAD, to); + from_cld->add_dependency(dependency, 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()); +void ClassLoaderData::add_dependency(Handle dependency, TRAPS) { + // Check first if this dependency is already in the list. + // Save a pointer to the last to add to under the lock. + objArrayOop ok = (objArrayOop)_dependencies; + objArrayOop last = NULL; while (ok != NULL) { - if (ok->obj_at(0) == loader) { - return true; + last = ok; + if (ok->obj_at(0) == dependency()) { + // Don't need to add it + return; } ok = (objArrayOop)ok->obj_at(1); } - return false; + + // Create a new dependency node with fields for (class_loader or mirror, next) + objArrayOop deps = oopFactory::new_objectArray(2, CHECK); + deps->obj_at_put(0, dependency()); + + // Must handle over more GC points + objArrayHandle new_dependency(THREAD, deps); + + // Add the dependency under lock + assert (last != NULL, "dependencies should be initialized"); + objArrayHandle last_handle(THREAD, last); + locked_add_dependency(last_handle, new_dependency); } -void ClassLoaderData::add_dependency(ClassLoaderData* dependency, TRAPS) { - // Minimize the number of duplicates in the list. - if (has_dependency(dependency)) { - return; - } +void ClassLoaderData::locked_add_dependency(objArrayHandle last_handle, + objArrayHandle new_dependency) { - // 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()); + // Have to lock and put the new dependency on the end of the dependency + // array so the card mark for CMS sees that this dependency is new. + // Can probably do this lock free with some effort. + MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); + + oop loader_or_mirror = new_dependency->obj_at(0); - // 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; + // Since the dependencies are only added, add to the end. + objArrayOop end = last_handle(); + objArrayOop last = NULL; + while (end != NULL) { + last = end; + // check again if another thread added it to the end. + if (end->obj_at(0) == loader_or_mirror) { + // Don't need to add it + return; } + end = (objArrayOop)end->obj_at(1); + } + assert (last != NULL, "dependencies should be initialized"); + // fill in the first element with the oop in new_dependency. + if (last->obj_at(0) == NULL) { + last->obj_at_put(0, new_dependency->obj_at(0)); + } else { + last->obj_at_put(1, new_dependency()); } } - void ClassLoaderDataGraph::clear_claimed_marks() { for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { cld->clear_claimed(); @@ -187,7 +224,7 @@ // link the new item into the list _klasses = k; - if (TraceClassLoaderData && k->class_loader_data() != NULL) { + if (TraceClassLoaderData && Verbose && k->class_loader_data() != NULL) { ResourceMark rm; tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: " PTR_FORMAT " loader: " PTR_FORMAT " %s", @@ -195,8 +232,7 @@ k->external_name(), k->class_loader_data(), k->class_loader(), - k->class_loader() != NULL ? k->class_loader()->klass()->external_name() : "NULL" - ); + loader_name()); } } @@ -221,6 +257,38 @@ ShouldNotReachHere(); // should have found this class!! } + +bool ClassLoaderData::is_anonymous() const { + Klass* k = _klasses; + return (_keep_alive || (k != NULL && k->oop_is_instance() && + InstanceKlass::cast(k)->is_anonymous())); +} + +void ClassLoaderData::unload() { + _unloading = true; + + if (TraceClassLoaderData) { + ResourceMark rm; + tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this); + tty->print(" for instance "PTR_FORMAT" of %s", class_loader(), + loader_name()); + if (is_anonymous()) { + tty->print(" for anonymous class "PTR_FORMAT " ", _klasses); + } + tty->print_cr("]"); + } +} + +bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const { + bool alive = + is_anonymous() ? + is_alive_closure->do_object_b(_klasses->java_mirror()) : + class_loader() == NULL || is_alive_closure->do_object_b(class_loader()); + assert(!alive || claimed(), "must be claimed"); + return alive; +} + + ClassLoaderData::~ClassLoaderData() { Metaspace *m = _metaspace; if (m != NULL) { @@ -263,8 +331,8 @@ if (_metaspace != NULL) { return _metaspace; } - if (class_loader() == NULL) { - assert(this == the_null_class_loader_data(), "Must be"); + if (this == the_null_class_loader_data()) { + assert (class_loader() == NULL, "Must be"); size_t word_size = Metaspace::first_chunk_word_size(); set_metaspace(new Metaspace(_metaspace_lock, word_size)); } else { @@ -325,12 +393,19 @@ } } -#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)); +// These anonymous class loaders are to contain classes used for JSR292 +ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) { + // Add a new class loader data to the graph. + ClassLoaderData* cld = ClassLoaderDataGraph::add(NULL, loader, CHECK_NULL); + return cld; } +const char* ClassLoaderData::loader_name() { + // Handles null class loader + return SystemDictionary::loader_name(class_loader()); +} + +#ifndef PRODUCT // Define to dump klasses #undef CLD_DUMP_KLASSES @@ -338,8 +413,7 @@ 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"); + class_loader() != NULL ? class_loader()->klass() : NULL, loader_name()); if (claimed()) out->print(" claimed "); if (is_unloading()) out->print(" unloading "); out->print(" handles " INTPTR_FORMAT, handles()); @@ -373,8 +447,8 @@ 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"); + guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same"); + guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be"); // Verify the integrity of the allocated space. if (metaspace_or_null() != NULL) { @@ -387,6 +461,7 @@ } } + // GC root of class loader data created. ClassLoaderData* ClassLoaderDataGraph::_head = NULL; ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL; @@ -395,19 +470,25 @@ // 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) { +ClassLoaderData* ClassLoaderDataGraph::add(ClassLoaderData** cld_addr, Handle loader, TRAPS) { // Not assigned a class loader data yet. // Create one. ClassLoaderData* *list_head = &_head; ClassLoaderData* next = _head; - ClassLoaderData* cld = new ClassLoaderData(loader_data); + ClassLoaderData* cld = new ClassLoaderData(loader); - // First, Atomically set it. - ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL); - if (old != NULL) { - delete cld; - // Returns the data. - return old; + if (cld_addr != NULL) { + // First, Atomically set it + ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL); + if (old != NULL) { + delete cld; + // Returns the data. + return old; + } + } else { + // Disallow unloading for this CLD during initialization if there is no + // class_loader oop to link this to. + cld->set_keep_alive(true); } // We won the race, and therefore the task of adding the data to the list of @@ -417,16 +498,22 @@ ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next); if (exchanged == next) { if (TraceClassLoaderData) { + ResourceMark rm; 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(" for instance "PTR_FORMAT" of %s", cld->class_loader(), + cld->loader_name()); tty->print_cr("]"); } + // Create dependencies after the CLD is added to the list. Otherwise, + // the GC GC will not find the CLD and the _class_loader field will + // not be updated. + cld->init_dependencies(CHECK_NULL); return cld; } next = exchanged; } while (true); + } void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { @@ -435,9 +522,19 @@ } } +void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { + for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { + if (cld->keep_alive()) { + 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); + // keep any special CLDs alive. + ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim); } else { ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim); } @@ -516,9 +613,10 @@ } #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) { +bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) { ClassLoaderData* data = _head; ClassLoaderData* prev = NULL; bool seen_dead_loader = false; @@ -527,8 +625,7 @@ 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 (data->keep_alive() || data->is_alive(is_alive_closure)) { if (has_redefined_a_class) { data->classes_do(InstanceKlass::purge_previous_versions); } @@ -539,13 +636,7 @@ } 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("]"); - } + dead->unload(); data = data->next(); // Remove from loader list. if (prev != NULL) {