coleenp@4037: /*
coleenp@4434:  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
coleenp@4037:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4037:  *
coleenp@4037:  * This code is free software; you can redistribute it and/or modify it
coleenp@4037:  * under the terms of the GNU General Public License version 2 only, as
coleenp@4037:  * published by the Free Software Foundation.
coleenp@4037:  *
coleenp@4037:  * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4037:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4037:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
coleenp@4037:  * version 2 for more details (a copy is included in the LICENSE file that
coleenp@4037:  * accompanied this code).
coleenp@4037:  *
coleenp@4037:  * You should have received a copy of the GNU General Public License version
coleenp@4037:  * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4037:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4037:  *
coleenp@4037:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4037:  * or visit www.oracle.com if you need additional information or have any
coleenp@4037:  * questions.
coleenp@4037:  *
coleenp@4037:  */
coleenp@4037: 
coleenp@4037: #include "precompiled.hpp"
coleenp@4037: #include "classfile/dictionary.hpp"
coleenp@4037: #include "classfile/loaderConstraints.hpp"
coleenp@4037: #include "classfile/placeholders.hpp"
coleenp@4037: #include "classfile/symbolTable.hpp"
coleenp@4037: #include "classfile/systemDictionary.hpp"
coleenp@4037: #include "code/codeCache.hpp"
coleenp@4037: #include "memory/filemap.hpp"
coleenp@4037: #include "memory/gcLocker.hpp"
coleenp@4037: #include "memory/metaspace.hpp"
coleenp@4037: #include "memory/metaspaceShared.hpp"
coleenp@4037: #include "oops/objArrayOop.hpp"
coleenp@4037: #include "oops/oop.inline.hpp"
coleenp@4037: #include "runtime/signature.hpp"
coleenp@4037: #include "runtime/vm_operations.hpp"
coleenp@4037: #include "runtime/vmThread.hpp"
coleenp@4037: #include "utilities/hashtable.inline.hpp"
coleenp@4037: 
coleenp@4037: 
coleenp@4037: int MetaspaceShared::_max_alignment = 0;
coleenp@4037: 
coleenp@4037: ReservedSpace* MetaspaceShared::_shared_rs = NULL;
coleenp@4037: 
coleenp@4037: // Read/write a data stream for restoring/preserving metadata pointers and
coleenp@4037: // miscellaneous data from/to the shared archive file.
coleenp@4037: 
coleenp@4037: void MetaspaceShared::serialize(SerializeClosure* soc) {
coleenp@4037:   int tag = 0;
coleenp@4037:   soc->do_tag(--tag);
coleenp@4037: 
coleenp@4037:   assert(!UseCompressedOops, "UseCompressedOops doesn't work with shared archive");
coleenp@4037:   // Verify the sizes of various metadata in the system.
coleenp@4037:   soc->do_tag(sizeof(Method));
coleenp@4037:   soc->do_tag(sizeof(ConstMethod));
coleenp@4037:   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
coleenp@4037:   soc->do_tag(sizeof(ConstantPool));
coleenp@4037:   soc->do_tag(sizeof(ConstantPoolCache));
coleenp@4037:   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
coleenp@4037:   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
coleenp@4037:   soc->do_tag(sizeof(Symbol));
coleenp@4037: 
coleenp@4037:   // Dump/restore miscellaneous metadata.
coleenp@4037:   Universe::serialize(soc, true);
coleenp@4037:   soc->do_tag(--tag);
coleenp@4037: 
coleenp@4037:   // Dump/restore references to commonly used names and signatures.
coleenp@4037:   vmSymbols::serialize(soc);
coleenp@4037:   soc->do_tag(--tag);
coleenp@4037: 
coleenp@4037:   soc->do_tag(666);
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // CDS code for dumping shared archive.
coleenp@4037: 
coleenp@4037: // Global object for holding classes that have been loaded.  Since this
coleenp@4037: // is run at a safepoint just before exit, this is the entire set of classes.
coleenp@4037: static GrowableArray<Klass*>* _global_klass_objects;
coleenp@4037: static void collect_classes(Klass* k) {
coleenp@4037:   _global_klass_objects->append_if_missing(k);
coleenp@4037:   if (k->oop_is_instance()) {
coleenp@4037:     // Add in the array classes too
coleenp@4037:     InstanceKlass* ik = InstanceKlass::cast(k);
coleenp@4037:     ik->array_klasses_do(collect_classes);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: static void remove_unshareable_in_classes() {
coleenp@4037:   for (int i = 0; i < _global_klass_objects->length(); i++) {
coleenp@4037:     Klass* k = _global_klass_objects->at(i);
coleenp@4037:     k->remove_unshareable_info();
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Walk all methods in the class list and assign a fingerprint.
coleenp@4037: // so that this part of the ConstMethod* is read only.
coleenp@4037: static void calculate_fingerprints() {
coleenp@4037:   for (int i = 0; i < _global_klass_objects->length(); i++) {
coleenp@4037:     Klass* k = _global_klass_objects->at(i);
coleenp@4037:     if (k->oop_is_instance()) {
coleenp@4037:       InstanceKlass* ik = InstanceKlass::cast(k);
coleenp@4037:       for (int i = 0; i < ik->methods()->length(); i++) {
coleenp@4037:         ResourceMark rm;
coleenp@4037:         Method* m = ik->methods()->at(i);
coleenp@4037:         (new Fingerprinter(m))->fingerprint();
coleenp@4037:       }
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Patch C++ vtable pointer in metadata.
coleenp@4037: 
coleenp@4037: // Klass and other metadata objects contain references to c++ vtables in the
coleenp@4037: // JVM library.
coleenp@4037: // Fix them to point to our constructed vtables.  However, don't iterate
coleenp@4037: // across the space while doing this, as that causes the vtables to be
coleenp@4037: // patched, undoing our useful work.  Instead, iterate to make a list,
coleenp@4037: // then use the list to do the fixing.
coleenp@4037: //
coleenp@4037: // Our constructed vtables:
coleenp@4037: // Dump time:
coleenp@4037: //  1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs
coleenp@4037: //  2. generate_vtable_methods: create jump table, appended to above vtbl_list
coleenp@4037: //  3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and
coleenp@4037: //     associated metadata to point to jump table rather than to current vtbl
coleenp@4037: // Table layout: NOTE FIXED SIZE
coleenp@4037: //   1. vtbl pointers
coleenp@4037: //   2. #Klass X #virtual methods per Klass
coleenp@4037: //   1 entry for each, in the order:
coleenp@4037: //   Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry
coleenp@4037: //   Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry
coleenp@4037: //   ...
coleenp@4037: //   Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry,
coleenp@4037: //       ... Klass<vtbl_list_size>:method<num_virtuals> entry
coleenp@4037: //  Sample entry: (Sparc):
coleenp@4037: //   save(sp, -256, sp)
coleenp@4037: //   ba,pt common_code
coleenp@4037: //   mov XXX, %L0       %L0 gets: Klass index <<8 + method index (note: max method index 255)
coleenp@4037: //
coleenp@4037: // Restore time:
coleenp@4037: //   1. initialize_shared_space: reserve space for table
coleenp@4037: //   2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text
coleenp@4037: //
coleenp@4037: // Execution time:
coleenp@4037: //   First virtual method call for any object of these metadata types:
coleenp@4045: //   1. object->klass
coleenp@4045: //   2. vtable entry for that klass points to the jump table entries
coleenp@4045: //   3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index
coleenp@4037: //   4. common_code:
coleenp@4037: //      Get address of new vtbl pointer for this Klass from updated table
coleenp@4037: //      Update new vtbl pointer in the Klass: future virtual calls go direct
coleenp@4037: //      Jump to method, using new vtbl pointer and method index
coleenp@4037: 
coleenp@4037: 
coleenp@4037: static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) {
coleenp@4037:   void* old_vtbl_ptr = *(void**)obj;
coleenp@4037:   for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) {
coleenp@4037:     if (vtbl_list[i] == old_vtbl_ptr) {
coleenp@4037:       return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   ShouldNotReachHere();
coleenp@4037:   return NULL;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Assumes the vtable is in first slot in object.
coleenp@4037: static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) {
coleenp@4037:   int n = _global_klass_objects->length();
coleenp@4037:   for (int i = 0; i < n; i++) {
coleenp@4037:     Klass* obj = _global_klass_objects->at(i);
coleenp@4037:     // Note oop_is_instance() is a virtual call.  After patching vtables
coleenp@4037:     // all virtual calls on the dummy vtables will restore the original!
coleenp@4037:     if (obj->oop_is_instance()) {
coleenp@4037:       InstanceKlass* ik = InstanceKlass::cast(obj);
coleenp@4037:       *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik);
coleenp@4037:       ConstantPool* cp = ik->constants();
coleenp@4037:       *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp);
coleenp@4037:       for (int j = 0; j < ik->methods()->length(); j++) {
coleenp@4037:         Method* m = ik->methods()->at(j);
coleenp@4037:         *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m);
coleenp@4037:       }
coleenp@4037:     } else {
coleenp@4037:       // Array klasses
coleenp@4037:       Klass* k = obj;
coleenp@4037:       *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k);
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Closure for serializing initialization data out to a data area to be
coleenp@4037: // written to the shared file.
coleenp@4037: 
coleenp@4037: class WriteClosure : public SerializeClosure {
coleenp@4037: private:
coleenp@4037:   intptr_t* top;
coleenp@4037:   char* end;
coleenp@4037: 
coleenp@4037:   inline void check_space() {
coleenp@4037:     if ((char*)top + sizeof(intptr_t) > end) {
coleenp@4037:       report_out_of_shared_space(SharedMiscData);
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037: public:
coleenp@4037:   WriteClosure(char* md_top, char* md_end) {
coleenp@4037:     top = (intptr_t*)md_top;
coleenp@4037:     end = md_end;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   char* get_top() { return (char*)top; }
coleenp@4037: 
coleenp@4037:   void do_ptr(void** p) {
coleenp@4037:     check_space();
coleenp@4037:     *top = (intptr_t)*p;
coleenp@4037:     ++top;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   void do_tag(int tag) {
coleenp@4037:     check_space();
coleenp@4037:     *top = (intptr_t)tag;
coleenp@4037:     ++top;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   void do_region(u_char* start, size_t size) {
coleenp@4037:     if ((char*)top + size > end) {
coleenp@4037:       report_out_of_shared_space(SharedMiscData);
coleenp@4037:     }
coleenp@4037:     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
coleenp@4037:     assert(size % sizeof(intptr_t) == 0, "bad size");
coleenp@4037:     do_tag((int)size);
coleenp@4037:     while (size > 0) {
coleenp@4037:       *top = *(intptr_t*)start;
coleenp@4037:       ++top;
coleenp@4037:       start += sizeof(intptr_t);
coleenp@4037:       size -= sizeof(intptr_t);
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   bool reading() const { return false; }
coleenp@4037: };
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // Populate the shared space.
coleenp@4037: 
coleenp@4037: class VM_PopulateDumpSharedSpace: public VM_Operation {
coleenp@4037: private:
coleenp@4037:   ClassLoaderData* _loader_data;
coleenp@4037:   GrowableArray<Klass*> *_class_promote_order;
coleenp@4037:   VirtualSpace _md_vs;
coleenp@4037:   VirtualSpace _mc_vs;
coleenp@4037: 
coleenp@4037: public:
coleenp@4037:   VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data,
coleenp@4037:                              GrowableArray<Klass*> *class_promote_order) :
coleenp@4037:     _loader_data(loader_data) {
coleenp@4037: 
coleenp@4037:     // Split up and initialize the misc code and data spaces
coleenp@4037:     ReservedSpace* shared_rs = MetaspaceShared::shared_rs();
coleenp@4037:     int metadata_size = SharedReadOnlySize+SharedReadWriteSize;
coleenp@4037:     ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size);
coleenp@4037:     ReservedSpace misc_section = shared_rs->last_part(metadata_size);
coleenp@4037: 
coleenp@4037:     // Now split into misc sections.
coleenp@4037:     ReservedSpace md_rs   = misc_section.first_part(SharedMiscDataSize);
coleenp@4037:     ReservedSpace mc_rs   = misc_section.last_part(SharedMiscDataSize);
coleenp@4037:     _md_vs.initialize(md_rs, SharedMiscDataSize);
coleenp@4037:     _mc_vs.initialize(mc_rs, SharedMiscCodeSize);
coleenp@4037:     _class_promote_order = class_promote_order;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
coleenp@4037:   void doit();   // outline because gdb sucks
coleenp@4037: }; // class VM_PopulateDumpSharedSpace
coleenp@4037: 
coleenp@4037: 
coleenp@4037: void VM_PopulateDumpSharedSpace::doit() {
coleenp@4037:   Thread* THREAD = VMThread::vm_thread();
coleenp@4037:   NOT_PRODUCT(SystemDictionary::verify();)
coleenp@4037:   // The following guarantee is meant to ensure that no loader constraints
coleenp@4037:   // exist yet, since the constraints table is not shared.  This becomes
coleenp@4037:   // more important now that we don't re-initialize vtables/itables for
coleenp@4037:   // shared classes at runtime, where constraints were previously created.
coleenp@4037:   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
coleenp@4037:             "loader constraints are not saved");
coleenp@4037:   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
coleenp@4037:           "placeholders are not saved");
coleenp@4037:   // Revisit and implement this if we prelink method handle call sites:
coleenp@4037:   guarantee(SystemDictionary::invoke_method_table() == NULL ||
coleenp@4037:             SystemDictionary::invoke_method_table()->number_of_entries() == 0,
coleenp@4037:             "invoke method table is not saved");
coleenp@4037: 
coleenp@4037:   // At this point, many classes have been loaded.
coleenp@4037:   // Gather systemDictionary classes in a global array and do everything to
coleenp@4037:   // that so we don't have to walk the SystemDictionary again.
coleenp@4037:   _global_klass_objects = new GrowableArray<Klass*>(1000);
coleenp@4037:   Universe::basic_type_classes_do(collect_classes);
coleenp@4037:   SystemDictionary::classes_do(collect_classes);
coleenp@4037: 
coleenp@4037:   tty->print_cr("Number of classes %d", _global_klass_objects->length());
coleenp@4037: 
coleenp@4037:   // Update all the fingerprints in the shared methods.
coleenp@4037:   tty->print("Calculating fingerprints ... ");
coleenp@4037:   calculate_fingerprints();
coleenp@4037:   tty->print_cr("done. ");
coleenp@4037: 
coleenp@4037:   // Remove all references outside the metadata
coleenp@4037:   tty->print("Removing unshareable information ... ");
coleenp@4037:   remove_unshareable_in_classes();
coleenp@4037:   tty->print_cr("done. ");
coleenp@4037: 
coleenp@4037:   // Set up the share data and shared code segments.
coleenp@4037:   char* md_low = _md_vs.low();
coleenp@4037:   char* md_top = md_low;
coleenp@4037:   char* md_end = _md_vs.high();
coleenp@4037:   char* mc_low = _mc_vs.low();
coleenp@4037:   char* mc_top = mc_low;
coleenp@4037:   char* mc_end = _mc_vs.high();
coleenp@4037: 
coleenp@4037:   // Reserve space for the list of Klass*s whose vtables are used
coleenp@4037:   // for patching others as needed.
coleenp@4037: 
coleenp@4037:   void** vtbl_list = (void**)md_top;
coleenp@4037:   int vtbl_list_size = MetaspaceShared::vtbl_list_size;
coleenp@4037:   Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
coleenp@4037: 
coleenp@4037:   md_top += vtbl_list_size * sizeof(void*);
coleenp@4037:   void* vtable = md_top;
coleenp@4037: 
coleenp@4037:   // Reserve space for a new dummy vtable for klass objects in the
coleenp@4037:   // heap.  Generate self-patching vtable entries.
coleenp@4037: 
coleenp@4037:   MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable,
coleenp@4037:                                      &md_top, md_end,
coleenp@4037:                                      &mc_top, mc_end);
coleenp@4037: 
coleenp@4037:   // Reorder the system dictionary.  (Moving the symbols affects
coleenp@4037:   // how the hash table indices are calculated.)
coleenp@4037:   // Not doing this either.
coleenp@4037: 
coleenp@4037:   SystemDictionary::reorder_dictionary();
coleenp@4037: 
coleenp@4037:   NOT_PRODUCT(SystemDictionary::verify();)
coleenp@4037: 
coleenp@4037:   // Copy the the symbol table, and the system dictionary to the shared
coleenp@4037:   // space in usable form.  Copy the hastable
coleenp@4037:   // buckets first [read-write], then copy the linked lists of entries
coleenp@4037:   // [read-only].
coleenp@4037: 
coleenp@4037:   SymbolTable::reverse(md_top);
coleenp@4037:   NOT_PRODUCT(SymbolTable::verify());
coleenp@4037:   SymbolTable::copy_buckets(&md_top, md_end);
coleenp@4037: 
coleenp@4037:   SystemDictionary::reverse();
coleenp@4037:   SystemDictionary::copy_buckets(&md_top, md_end);
coleenp@4037: 
coleenp@4037:   ClassLoader::verify();
coleenp@4037:   ClassLoader::copy_package_info_buckets(&md_top, md_end);
coleenp@4037:   ClassLoader::verify();
coleenp@4037: 
coleenp@4037:   SymbolTable::copy_table(&md_top, md_end);
coleenp@4037:   SystemDictionary::copy_table(&md_top, md_end);
coleenp@4037:   ClassLoader::verify();
coleenp@4037:   ClassLoader::copy_package_info_table(&md_top, md_end);
coleenp@4037:   ClassLoader::verify();
coleenp@4037: 
coleenp@4037:   // Write the other data to the output array.
coleenp@4037:   WriteClosure wc(md_top, md_end);
coleenp@4037:   MetaspaceShared::serialize(&wc);
coleenp@4037:   md_top = wc.get_top();
coleenp@4037: 
coleenp@4037:   // Print shared spaces all the time
coleenp@4434:   const char* fmt = "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT;
coleenp@4037:   Metaspace* ro_space = _loader_data->ro_metaspace();
coleenp@4037:   Metaspace* rw_space = _loader_data->rw_metaspace();
coleenp@4434:   const size_t BPW = BytesPerWord;
coleenp@4434: 
coleenp@4434:   // Allocated size of each space (may not be all occupied)
coleenp@4434:   const size_t ro_alloced = ro_space->capacity_words(Metaspace::NonClassType) * BPW;
coleenp@4434:   const size_t rw_alloced = rw_space->capacity_words(Metaspace::NonClassType) * BPW;
coleenp@4434:   const size_t md_alloced = md_end-md_low;
coleenp@4434:   const size_t mc_alloced = mc_end-mc_low;
coleenp@4434:   const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
coleenp@4434: 
coleenp@4434:   // Occupied size of each space.
coleenp@4434:   const size_t ro_bytes = ro_space->used_words(Metaspace::NonClassType) * BPW;
coleenp@4434:   const size_t rw_bytes = rw_space->used_words(Metaspace::NonClassType) * BPW;
coleenp@4434:   const size_t md_bytes = size_t(md_top - md_low);
coleenp@4434:   const size_t mc_bytes = size_t(mc_top - mc_low);
coleenp@4434: 
coleenp@4434:   // Percent of total size
coleenp@4434:   const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes;
coleenp@4434:   const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
coleenp@4434:   const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
coleenp@4434:   const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
coleenp@4434:   const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
coleenp@4434: 
coleenp@4434:   // Percent of fullness of each space
coleenp@4434:   const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
coleenp@4434:   const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
coleenp@4434:   const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
coleenp@4434:   const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
coleenp@4434:   const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
coleenp@4434: 
coleenp@4434:   tty->print_cr(fmt, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom());
coleenp@4434:   tty->print_cr(fmt, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom());
coleenp@4434:   tty->print_cr(fmt, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low);
coleenp@4434:   tty->print_cr(fmt, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low);
coleenp@4434:   tty->print_cr("total   : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]",
coleenp@4434:                  total_bytes, total_alloced, total_u_perc);
coleenp@4037: 
coleenp@4037:   // Update the vtable pointers in all of the Klass objects in the
coleenp@4037:   // heap. They should point to newly generated vtable.
coleenp@4037:   patch_klass_vtables(vtbl_list, vtable);
coleenp@4037: 
coleenp@4037:   // dunno what this is for.
coleenp@4037:   char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass);
coleenp@4037:   memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
coleenp@4037:   memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
coleenp@4037: 
coleenp@4037:   // Create and write the archive file that maps the shared spaces.
coleenp@4037: 
coleenp@4037:   FileMapInfo* mapinfo = new FileMapInfo();
coleenp@4037:   mapinfo->populate_header(MetaspaceShared::max_alignment());
coleenp@4037: 
coleenp@4037:   // Pass 1 - update file offsets in header.
coleenp@4037:   mapinfo->write_header();
coleenp@4037:   mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
coleenp@4037:   mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
coleenp@4037:   mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
coleenp@4037:                         pointer_delta(md_top, _md_vs.low(), sizeof(char)),
coleenp@4037:                         SharedMiscDataSize,
coleenp@4037:                         false, false);
coleenp@4037:   mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
coleenp@4037:                         pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
coleenp@4037:                         SharedMiscCodeSize,
coleenp@4037:                         true, true);
coleenp@4037: 
coleenp@4037:   // Pass 2 - write data.
coleenp@4037:   mapinfo->open_for_write();
coleenp@4037:   mapinfo->write_header();
coleenp@4037:   mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true);
coleenp@4037:   mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false);
coleenp@4037:   mapinfo->write_region(MetaspaceShared::md, _md_vs.low(),
coleenp@4037:                         pointer_delta(md_top, _md_vs.low(), sizeof(char)),
coleenp@4037:                         SharedMiscDataSize,
coleenp@4037:                         false, false);
coleenp@4037:   mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(),
coleenp@4037:                         pointer_delta(mc_top, _mc_vs.low(), sizeof(char)),
coleenp@4037:                         SharedMiscCodeSize,
coleenp@4037:                         true, true);
coleenp@4037:   mapinfo->close();
coleenp@4037: 
coleenp@4037:   memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
coleenp@4037: }
coleenp@4037: 
coleenp@4037: static void link_shared_classes(Klass* obj, TRAPS) {
hseigel@4278:   Klass* k = obj;
coleenp@4037:   if (k->oop_is_instance()) {
coleenp@4037:     InstanceKlass* ik = (InstanceKlass*) k;
coleenp@4037:     // Link the class to cause the bytecodes to be rewritten and the
coleenp@4037:     // cpcache to be created.
coleenp@4037:     if (ik->init_state() < InstanceKlass::linked) {
coleenp@4037:       ik->link_class(THREAD);
coleenp@4037:       guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // Support for a simple checksum of the contents of the class list
coleenp@4037: // file to prevent trivial tampering. The algorithm matches that in
coleenp@4037: // the MakeClassList program used by the J2SE build process.
coleenp@4037: #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
coleenp@4037: static jlong
coleenp@4037: jsum(jlong start, const char *buf, const int len)
coleenp@4037: {
coleenp@4037:     jlong h = start;
coleenp@4037:     char *p = (char *)buf, *e = p + len;
coleenp@4037:     while (p < e) {
coleenp@4037:         char c = *p++;
coleenp@4037:         if (c <= ' ') {
coleenp@4037:             /* Skip spaces and control characters */
coleenp@4037:             continue;
coleenp@4037:         }
coleenp@4037:         h = 31 * h + c;
coleenp@4037:     }
coleenp@4037:     return h;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Preload classes from a list, populate the shared spaces and dump to a
coleenp@4037: // file.
coleenp@4037: void MetaspaceShared::preload_and_dump(TRAPS) {
coleenp@4037:   TraceTime timer("Dump Shared Spaces", TraceStartupTime);
coleenp@4037:   ResourceMark rm;
coleenp@4037: 
coleenp@4037:   // Lock out GC - is it necessary? I don't think we care.
coleenp@4037:   No_GC_Verifier no_gc;
coleenp@4037: 
coleenp@4037:   // Preload classes to be shared.
coleenp@4037:   // Should use some os:: method rather than fopen() here. aB.
coleenp@4037:   // Construct the path to the class list (in jre/lib)
coleenp@4037:   // Walk up two directories from the location of the VM and
coleenp@4037:   // optionally tack on "lib" (depending on platform)
coleenp@4037:   char class_list_path[JVM_MAXPATHLEN];
coleenp@4037:   os::jvm_path(class_list_path, sizeof(class_list_path));
coleenp@4037:   for (int i = 0; i < 3; i++) {
coleenp@4037:     char *end = strrchr(class_list_path, *os::file_separator());
coleenp@4037:     if (end != NULL) *end = '\0';
coleenp@4037:   }
coleenp@4037:   int class_list_path_len = (int)strlen(class_list_path);
coleenp@4037:   if (class_list_path_len >= 3) {
coleenp@4037:     if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
coleenp@4037:       strcat(class_list_path, os::file_separator());
coleenp@4037:       strcat(class_list_path, "lib");
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   strcat(class_list_path, os::file_separator());
coleenp@4037:   strcat(class_list_path, "classlist");
coleenp@4037: 
coleenp@4037:   FILE* file = fopen(class_list_path, "r");
coleenp@4037:   if (file != NULL) {
coleenp@4037:     jlong computed_jsum  = JSUM_SEED;
coleenp@4037:     jlong file_jsum      = 0;
coleenp@4037: 
coleenp@4037:     char class_name[256];
coleenp@4037:     int class_count = 0;
coleenp@4037:     GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
coleenp@4037: 
coleenp@4037:     // sun.io.Converters
coleenp@4037:     static const char obj_array_sig[] = "[[Ljava/lang/Object;";
coleenp@4037:     SymbolTable::new_permanent_symbol(obj_array_sig, THREAD);
coleenp@4037: 
coleenp@4037:     // java.util.HashMap
coleenp@4037:     static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
coleenp@4037:     SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD);
coleenp@4037: 
coleenp@4037:     tty->print("Loading classes to share ... ");
coleenp@4037:     while ((fgets(class_name, sizeof class_name, file)) != NULL) {
coleenp@4037:       if (*class_name == '#') {
coleenp@4037:         jint fsh, fsl;
coleenp@4037:         if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
coleenp@4037:           file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
coleenp@4037:         }
coleenp@4037: 
coleenp@4037:         continue;
coleenp@4037:       }
coleenp@4037:       // Remove trailing newline
coleenp@4037:       size_t name_len = strlen(class_name);
coleenp@4037:       class_name[name_len-1] = '\0';
coleenp@4037: 
coleenp@4037:       computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
coleenp@4037: 
coleenp@4037:       // Got a class name - load it.
coleenp@4037:       TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD);
coleenp@4037:       guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
coleenp@4037:       Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol,
coleenp@4037:                                                          THREAD);
coleenp@4037:       guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
coleenp@4037:       if (klass != NULL) {
coleenp@4037:         if (PrintSharedSpaces && Verbose && WizardMode) {
coleenp@4037:           tty->print_cr("Shared spaces preloaded: %s", class_name);
coleenp@4037:         }
coleenp@4037: 
coleenp@4037: 
coleenp@4037:         InstanceKlass* ik = InstanceKlass::cast(klass);
coleenp@4037: 
coleenp@4037:         // Should be class load order as per -XX:+TraceClassLoadingPreorder
coleenp@4037:         class_promote_order->append(ik);
coleenp@4037: 
coleenp@4037:         // Link the class to cause the bytecodes to be rewritten and the
coleenp@4037:         // cpcache to be created. The linking is done as soon as classes
coleenp@4037:         // are loaded in order that the related data structures (klass and
coleenp@4037:         // cpCache) are located together.
coleenp@4037: 
coleenp@4037:         if (ik->init_state() < InstanceKlass::linked) {
coleenp@4037:           ik->link_class(THREAD);
coleenp@4037:           guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
coleenp@4037:         }
coleenp@4037: 
coleenp@4037:         // TODO: Resolve klasses in constant pool
coleenp@4037:         ik->constants()->resolve_class_constants(THREAD);
coleenp@4037: 
coleenp@4037:         class_count++;
coleenp@4037:       } else {
coleenp@4037:         if (PrintSharedSpaces && Verbose && WizardMode) {
coleenp@4037:           tty->cr();
coleenp@4037:           tty->print_cr(" Preload failed: %s", class_name);
coleenp@4037:         }
coleenp@4037:       }
coleenp@4037:       file_jsum = 0; // Checksum must be on last line of file
coleenp@4037:     }
coleenp@4037:     if (computed_jsum != file_jsum) {
coleenp@4037:       tty->cr();
coleenp@4037:       tty->print_cr("Preload failed: checksum of class list was incorrect.");
coleenp@4037:       exit(1);
coleenp@4037:     }
coleenp@4037: 
coleenp@4037:     tty->print_cr("done. ");
coleenp@4037: 
coleenp@4037:     if (PrintSharedSpaces) {
coleenp@4037:       tty->print_cr("Shared spaces: preloaded %d classes", class_count);
coleenp@4037:     }
coleenp@4037: 
coleenp@4037:     // Rewrite and unlink classes.
coleenp@4037:     tty->print("Rewriting and linking classes ... ");
coleenp@4037: 
coleenp@4037:     // Link any classes which got missed.  (It's not quite clear why
coleenp@4037:     // they got missed.)  This iteration would be unsafe if we weren't
coleenp@4037:     // single-threaded at this point; however we can't do it on the VM
coleenp@4037:     // thread because it requires object allocation.
coleenp@4037:     SystemDictionary::classes_do(link_shared_classes, CATCH);
coleenp@4037:     tty->print_cr("done. ");
coleenp@4037: 
coleenp@4037:     // Create and dump the shared spaces.   Everything so far is loaded
coleenp@4037:     // with the null class loader.
coleenp@4037:     ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
coleenp@4037:     VM_PopulateDumpSharedSpace op(loader_data, class_promote_order);
coleenp@4037:     VMThread::execute(&op);
coleenp@4037: 
coleenp@4037:   } else {
coleenp@4037:     char errmsg[JVM_MAXPATHLEN];
coleenp@4037:     os::lasterror(errmsg, JVM_MAXPATHLEN);
coleenp@4037:     tty->print_cr("Loading classlist failed: %s", errmsg);
coleenp@4037:     exit(1);
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   // Since various initialization steps have been undone by this process,
coleenp@4037:   // it is not reasonable to continue running a java process.
coleenp@4037:   exit(0);
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // Closure for serializing initialization data in from a data area
coleenp@4037: // (ptr_array) read from the shared file.
coleenp@4037: 
coleenp@4037: class ReadClosure : public SerializeClosure {
coleenp@4037: private:
coleenp@4037:   intptr_t** _ptr_array;
coleenp@4037: 
coleenp@4037:   inline intptr_t nextPtr() {
coleenp@4037:     return *(*_ptr_array)++;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037: public:
coleenp@4037:   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
coleenp@4037: 
coleenp@4037:   void do_ptr(void** p) {
coleenp@4037:     assert(*p == NULL, "initializing previous initialized pointer.");
coleenp@4037:     intptr_t obj = nextPtr();
coleenp@4037:     assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
coleenp@4037:            "hit tag while initializing ptrs.");
coleenp@4037:     *p = (void*)obj;
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   void do_tag(int tag) {
coleenp@4037:     int old_tag;
coleenp@4037:     old_tag = (int)(intptr_t)nextPtr();
coleenp@4037:     // do_int(&old_tag);
coleenp@4037:     assert(tag == old_tag, "old tag doesn't match");
coleenp@4037:     FileMapInfo::assert_mark(tag == old_tag);
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   void do_region(u_char* start, size_t size) {
coleenp@4037:     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
coleenp@4037:     assert(size % sizeof(intptr_t) == 0, "bad size");
coleenp@4037:     do_tag((int)size);
coleenp@4037:     while (size > 0) {
coleenp@4037:       *(intptr_t*)start = nextPtr();
coleenp@4037:       start += sizeof(intptr_t);
coleenp@4037:       size -= sizeof(intptr_t);
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: 
coleenp@4037:   bool reading() const { return true; }
coleenp@4037: };
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // Save bounds of shared spaces mapped in.
coleenp@4037: static char* _ro_base = NULL;
coleenp@4037: static char* _rw_base = NULL;
coleenp@4037: static char* _md_base = NULL;
coleenp@4037: static char* _mc_base = NULL;
coleenp@4037: 
coleenp@4037: // Return true if given address is in the mapped shared space.
coleenp@4037: bool MetaspaceShared::is_in_shared_space(const void* p) {
coleenp@4037:   if (_ro_base == NULL || _rw_base == NULL) {
coleenp@4037:     return false;
coleenp@4037:   } else {
zgu@4193:     return ((p >= _ro_base && p < (_ro_base + SharedReadOnlySize)) ||
zgu@4193:             (p >= _rw_base && p < (_rw_base + SharedReadWriteSize)));
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void MetaspaceShared::print_shared_spaces() {
coleenp@4037:   gclog_or_tty->print_cr("Shared Spaces:");
coleenp@4037:   gclog_or_tty->print("  read-only " INTPTR_FORMAT "-" INTPTR_FORMAT,
coleenp@4037:     _ro_base, _ro_base + SharedReadOnlySize);
coleenp@4037:   gclog_or_tty->print("  read-write " INTPTR_FORMAT "-" INTPTR_FORMAT,
coleenp@4037:     _rw_base, _rw_base + SharedReadWriteSize);
coleenp@4037:   gclog_or_tty->cr();
coleenp@4037:   gclog_or_tty->print("  misc-data " INTPTR_FORMAT "-" INTPTR_FORMAT,
coleenp@4037:     _md_base, _md_base + SharedMiscDataSize);
coleenp@4037:   gclog_or_tty->print("  misc-code " INTPTR_FORMAT "-" INTPTR_FORMAT,
coleenp@4037:     _mc_base, _mc_base + SharedMiscCodeSize);
coleenp@4037:   gclog_or_tty->cr();
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: // Map shared spaces at requested addresses and return if succeeded.
coleenp@4037: // Need to keep the bounds of the ro and rw space for the Metaspace::contains
coleenp@4037: // call, or is_in_shared_space.
coleenp@4037: bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
coleenp@4037:   size_t image_alignment = mapinfo->alignment();
coleenp@4037: 
hseigel@4396: #ifndef _WINDOWS
hseigel@4396:   // Map in the shared memory and then map the regions on top of it.
hseigel@4396:   // On Windows, don't map the memory here because it will cause the
hseigel@4396:   // mappings of the regions to fail.
coleenp@4037:   ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
coleenp@4037:   if (!shared_rs.is_reserved()) return false;
hseigel@4396: #endif
hseigel@4396: 
hseigel@4396:   assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
coleenp@4037: 
coleenp@4037:   // Map each shared region
coleenp@4037:   if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
coleenp@4037:       (_rw_base = mapinfo->map_region(rw)) != NULL &&
coleenp@4037:       (_md_base = mapinfo->map_region(md)) != NULL &&
coleenp@4037:       (_mc_base = mapinfo->map_region(mc)) != NULL &&
coleenp@4037:       (image_alignment == (size_t)max_alignment())) {
coleenp@4037:     // Success (no need to do anything)
coleenp@4037:     return true;
coleenp@4037:   } else {
coleenp@4037:     // If there was a failure in mapping any of the spaces, unmap the ones
coleenp@4037:     // that succeeded
coleenp@4037:     if (_ro_base != NULL) mapinfo->unmap_region(ro);
coleenp@4037:     if (_rw_base != NULL) mapinfo->unmap_region(rw);
coleenp@4037:     if (_md_base != NULL) mapinfo->unmap_region(md);
coleenp@4037:     if (_mc_base != NULL) mapinfo->unmap_region(mc);
hseigel@4396: #ifndef _WINDOWS
coleenp@4037:     // Release the entire mapped region
coleenp@4037:     shared_rs.release();
hseigel@4396: #endif
coleenp@4037:     // If -Xshare:on is specified, print out the error message and exit VM,
coleenp@4037:     // otherwise, set UseSharedSpaces to false and continue.
coleenp@4037:     if (RequireSharedSpaces) {
coleenp@4037:       vm_exit_during_initialization("Unable to use shared archive.", NULL);
coleenp@4037:     } else {
coleenp@4037:       FLAG_SET_DEFAULT(UseSharedSpaces, false);
coleenp@4037:     }
coleenp@4037:     return false;
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // Read the miscellaneous data from the shared file, and
coleenp@4037: // serialize it out to its various destinations.
coleenp@4037: 
coleenp@4037: void MetaspaceShared::initialize_shared_spaces() {
coleenp@4037:   FileMapInfo *mapinfo = FileMapInfo::current_info();
coleenp@4037: 
coleenp@4037:   char* buffer = mapinfo->region_base(md);
coleenp@4037: 
coleenp@4037:   // Skip over (reserve space for) a list of addresses of C++ vtables
coleenp@4037:   // for Klass objects.  They get filled in later.
coleenp@4037: 
coleenp@4037:   void** vtbl_list = (void**)buffer;
coleenp@4037:   buffer += MetaspaceShared::vtbl_list_size * sizeof(void*);
coleenp@4037:   Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
coleenp@4037: 
coleenp@4037:   // Skip over (reserve space for) dummy C++ vtables Klass objects.
coleenp@4037:   // They are used as is.
coleenp@4037: 
coleenp@4037:   intptr_t vtable_size = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   buffer += vtable_size;
coleenp@4037: 
coleenp@4037:   // Create the symbol table using the bucket array at this spot in the
coleenp@4037:   // misc data space.  Since the symbol table is often modified, this
coleenp@4037:   // region (of mapped pages) will be copy-on-write.
coleenp@4037: 
coleenp@4037:   int symbolTableLen = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   int number_of_entries = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen,
coleenp@4037:                             number_of_entries);
coleenp@4037:   buffer += symbolTableLen;
coleenp@4037: 
coleenp@4037:   // Create the shared dictionary using the bucket array at this spot in
coleenp@4037:   // the misc data space.  Since the shared dictionary table is never
coleenp@4037:   // modified, this region (of mapped pages) will be (effectively, if
coleenp@4037:   // not explicitly) read-only.
coleenp@4037: 
coleenp@4037:   int sharedDictionaryLen = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   number_of_entries = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
coleenp@4037:                                           sharedDictionaryLen,
coleenp@4037:                                           number_of_entries);
coleenp@4037:   buffer += sharedDictionaryLen;
coleenp@4037: 
coleenp@4037:   // Create the package info table using the bucket array at this spot in
coleenp@4037:   // the misc data space.  Since the package info table is never
coleenp@4037:   // modified, this region (of mapped pages) will be (effectively, if
coleenp@4037:   // not explicitly) read-only.
coleenp@4037: 
coleenp@4037:   int pkgInfoLen = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   number_of_entries = *(intptr_t*)buffer;
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen,
coleenp@4037:                                          number_of_entries);
coleenp@4037:   buffer += pkgInfoLen;
coleenp@4037:   ClassLoader::verify();
coleenp@4037: 
coleenp@4037:   // The following data in the shared misc data region are the linked
coleenp@4037:   // list elements (HashtableEntry objects) for the symbol table, string
coleenp@4037:   // table, and shared dictionary.  The heap objects refered to by the
coleenp@4037:   // symbol table, string table, and shared dictionary are permanent and
coleenp@4037:   // unmovable.  Since new entries added to the string and symbol tables
coleenp@4037:   // are always added at the beginning of the linked lists, THESE LINKED
coleenp@4037:   // LIST ELEMENTS ARE READ-ONLY.
coleenp@4037: 
coleenp@4037:   int len = *(intptr_t*)buffer; // skip over symbol table entries
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   buffer += len;
coleenp@4037: 
coleenp@4037:   len = *(intptr_t*)buffer;     // skip over shared dictionary entries
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   buffer += len;
coleenp@4037: 
coleenp@4037:   len = *(intptr_t*)buffer;     // skip over package info table entries
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   buffer += len;
coleenp@4037: 
coleenp@4037:   len = *(intptr_t*)buffer;     // skip over package info table char[] arrays.
coleenp@4037:   buffer += sizeof(intptr_t);
coleenp@4037:   buffer += len;
coleenp@4037: 
coleenp@4037:   intptr_t* array = (intptr_t*)buffer;
coleenp@4037:   ReadClosure rc(&array);
coleenp@4037:   serialize(&rc);
coleenp@4037: 
coleenp@4037:   // Close the mapinfo file
coleenp@4037:   mapinfo->close();
coleenp@4037: }
coleenp@4037: 
coleenp@4037: // JVM/TI RedefineClasses() support:
coleenp@4037: bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
coleenp@4037:   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
coleenp@4037: 
coleenp@4037:   if (UseSharedSpaces) {
coleenp@4037:     // remap the shared readonly space to shared readwrite, private
coleenp@4037:     FileMapInfo* mapinfo = FileMapInfo::current_info();
coleenp@4037:     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
coleenp@4037:       return false;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   return true;
coleenp@4037: }