Mercurial > hg > graal-compiler
view src/share/vm/memory/metaspaceShared.cpp @ 17748:d60ecdb2773e
8031703: Missing post-barrier in ReferenceProcessor
Reviewed-by: tonyp, tschatzl
author | pliden |
---|---|
date | Thu, 06 Feb 2014 14:12:43 +0100 |
parents | 4f9a42c33738 |
children | 63a4eb8bcd23 9c3dc501b5eb |
line wrap: on
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/* * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/dictionary.hpp" #include "classfile/loaderConstraints.hpp" #include "classfile/placeholders.hpp" #include "classfile/symbolTable.hpp" #include "classfile/systemDictionary.hpp" #include "code/codeCache.hpp" #include "memory/filemap.hpp" #include "memory/gcLocker.hpp" #include "memory/metaspace.hpp" #include "memory/metaspaceShared.hpp" #include "oops/objArrayOop.hpp" #include "oops/oop.inline.hpp" #include "runtime/signature.hpp" #include "runtime/vm_operations.hpp" #include "runtime/vmThread.hpp" #include "utilities/hashtable.inline.hpp" int MetaspaceShared::_max_alignment = 0; ReservedSpace* MetaspaceShared::_shared_rs = NULL; // Read/write a data stream for restoring/preserving metadata pointers and // miscellaneous data from/to the shared archive file. void MetaspaceShared::serialize(SerializeClosure* soc) { int tag = 0; soc->do_tag(--tag); // Verify the sizes of various metadata in the system. soc->do_tag(sizeof(Method)); soc->do_tag(sizeof(ConstMethod)); soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE)); soc->do_tag(sizeof(ConstantPool)); soc->do_tag(sizeof(ConstantPoolCache)); soc->do_tag(objArrayOopDesc::base_offset_in_bytes()); soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE)); soc->do_tag(sizeof(Symbol)); // Dump/restore miscellaneous metadata. Universe::serialize(soc, true); soc->do_tag(--tag); // Dump/restore references to commonly used names and signatures. vmSymbols::serialize(soc); soc->do_tag(--tag); soc->do_tag(666); } // CDS code for dumping shared archive. // Global object for holding classes that have been loaded. Since this // is run at a safepoint just before exit, this is the entire set of classes. static GrowableArray<Klass*>* _global_klass_objects; static void collect_classes(Klass* k) { _global_klass_objects->append_if_missing(k); if (k->oop_is_instance()) { // Add in the array classes too InstanceKlass* ik = InstanceKlass::cast(k); ik->array_klasses_do(collect_classes); } } static void remove_unshareable_in_classes() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); k->remove_unshareable_info(); } } // Walk all methods in the class list and assign a fingerprint. // so that this part of the ConstMethod* is read only. static void calculate_fingerprints() { for (int i = 0; i < _global_klass_objects->length(); i++) { Klass* k = _global_klass_objects->at(i); if (k->oop_is_instance()) { InstanceKlass* ik = InstanceKlass::cast(k); for (int i = 0; i < ik->methods()->length(); i++) { Method* m = ik->methods()->at(i); Fingerprinter fp(m); // The side effect of this call sets method's fingerprint field. fp.fingerprint(); } } } } // Patch C++ vtable pointer in metadata. // Klass and other metadata objects contain references to c++ vtables in the // JVM library. // Fix them to point to our constructed vtables. However, don't iterate // across the space while doing this, as that causes the vtables to be // patched, undoing our useful work. Instead, iterate to make a list, // then use the list to do the fixing. // // Our constructed vtables: // Dump time: // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs // 2. generate_vtable_methods: create jump table, appended to above vtbl_list // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and // associated metadata to point to jump table rather than to current vtbl // Table layout: NOTE FIXED SIZE // 1. vtbl pointers // 2. #Klass X #virtual methods per Klass // 1 entry for each, in the order: // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry // ... // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, // ... Klass<vtbl_list_size>:method<num_virtuals> entry // Sample entry: (Sparc): // save(sp, -256, sp) // ba,pt common_code // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) // // Restore time: // 1. initialize_shared_space: reserve space for table // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text // // Execution time: // First virtual method call for any object of these metadata types: // 1. object->klass // 2. vtable entry for that klass points to the jump table entries // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index // 4. common_code: // Get address of new vtbl pointer for this Klass from updated table // Update new vtbl pointer in the Klass: future virtual calls go direct // Jump to method, using new vtbl pointer and method index static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) { void* old_vtbl_ptr = *(void**)obj; for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) { if (vtbl_list[i] == old_vtbl_ptr) { return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals; } } ShouldNotReachHere(); return NULL; } // Assumes the vtable is in first slot in object. static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) { int n = _global_klass_objects->length(); for (int i = 0; i < n; i++) { Klass* obj = _global_klass_objects->at(i); // Note oop_is_instance() is a virtual call. After patching vtables // all virtual calls on the dummy vtables will restore the original! if (obj->oop_is_instance()) { InstanceKlass* ik = InstanceKlass::cast(obj); *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik); ConstantPool* cp = ik->constants(); *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp); for (int j = 0; j < ik->methods()->length(); j++) { Method* m = ik->methods()->at(j); *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m); } } else { // Array klasses Klass* k = obj; *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k); } } } // Closure for serializing initialization data out to a data area to be // written to the shared file. class WriteClosure : public SerializeClosure { private: intptr_t* top; char* end; inline void check_space() { if ((char*)top + sizeof(intptr_t) > end) { report_out_of_shared_space(SharedMiscData); } } public: WriteClosure(char* md_top, char* md_end) { top = (intptr_t*)md_top; end = md_end; } char* get_top() { return (char*)top; } void do_ptr(void** p) { check_space(); *top = (intptr_t)*p; ++top; } void do_tag(int tag) { check_space(); *top = (intptr_t)tag; ++top; } void do_region(u_char* start, size_t size) { if ((char*)top + size > end) { report_out_of_shared_space(SharedMiscData); } assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); assert(size % sizeof(intptr_t) == 0, "bad size"); do_tag((int)size); while (size > 0) { *top = *(intptr_t*)start; ++top; start += sizeof(intptr_t); size -= sizeof(intptr_t); } } bool reading() const { return false; } }; // This is for dumping detailed statistics for the allocations // in the shared spaces. class DumpAllocClosure : public Metaspace::AllocRecordClosure { public: // Here's poor man's enum inheritance #define SHAREDSPACE_OBJ_TYPES_DO(f) \ METASPACE_OBJ_TYPES_DO(f) \ f(SymbolHashentry) \ f(SymbolBuckets) \ f(Other) #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type, #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name; enum Type { // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE) _number_of_types }; static const char * type_name(Type type) { switch(type) { SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE) default: ShouldNotReachHere(); return NULL; } } public: enum { RO = 0, RW = 1 }; int _counts[2][_number_of_types]; int _bytes [2][_number_of_types]; int _which; DumpAllocClosure() { memset(_counts, 0, sizeof(_counts)); memset(_bytes, 0, sizeof(_bytes)); }; void iterate_metaspace(Metaspace* space, int which) { assert(which == RO || which == RW, "sanity"); _which = which; space->iterate(this); } virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) { assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity"); _counts[_which][type] ++; _bytes [_which][type] += byte_size; } void dump_stats(int ro_all, int rw_all, int md_all, int mc_all); }; void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) { rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write int other_bytes = md_all + mc_all; // Calculate size of data that was not allocated by Metaspace::allocate() int symbol_count = _counts[RO][MetaspaceObj::SymbolType]; int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>); int symbuck_count = SymbolTable::the_table()->table_size(); int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>); _counts[RW][SymbolHashentryType] = symbol_count; _bytes [RW][SymbolHashentryType] = symhash_bytes; other_bytes -= symhash_bytes; _counts[RW][SymbolBucketsType] = symbuck_count; _bytes [RW][SymbolBucketsType] = symbuck_bytes; other_bytes -= symbuck_bytes; // TODO: count things like dictionary, vtable, etc _bytes[RW][OtherType] = other_bytes; // prevent divide-by-zero if (ro_all < 1) { ro_all = 1; } if (rw_all < 1) { rw_all = 1; } int all_ro_count = 0; int all_ro_bytes = 0; int all_rw_count = 0; int all_rw_bytes = 0; const char *fmt = "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"; const char *sep = "--------------------+---------------------------+---------------------------+--------------------------"; const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %"; tty->print_cr("Detailed metadata info (rw includes md and mc):"); tty->print_cr(hdr); tty->print_cr(sep); for (int type = 0; type < int(_number_of_types); type ++) { const char *name = type_name((Type)type); int ro_count = _counts[RO][type]; int ro_bytes = _bytes [RO][type]; int rw_count = _counts[RW][type]; int rw_bytes = _bytes [RW][type]; int count = ro_count + rw_count; int bytes = ro_bytes + rw_bytes; double ro_perc = 100.0 * double(ro_bytes) / double(ro_all); double rw_perc = 100.0 * double(rw_bytes) / double(rw_all); double perc = 100.0 * double(bytes) / double(ro_all + rw_all); tty->print_cr(fmt, name, ro_count, ro_bytes, ro_perc, rw_count, rw_bytes, rw_perc, count, bytes, perc); all_ro_count += ro_count; all_ro_bytes += ro_bytes; all_rw_count += rw_count; all_rw_bytes += rw_bytes; } int all_count = all_ro_count + all_rw_count; int all_bytes = all_ro_bytes + all_rw_bytes; double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all); double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all); double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all); tty->print_cr(sep); tty->print_cr(fmt, "Total", all_ro_count, all_ro_bytes, all_ro_perc, all_rw_count, all_rw_bytes, all_rw_perc, all_count, all_bytes, all_perc); assert(all_ro_bytes == ro_all, "everything should have been counted"); assert(all_rw_bytes == rw_all, "everything should have been counted"); } // Populate the shared space. class VM_PopulateDumpSharedSpace: public VM_Operation { private: ClassLoaderData* _loader_data; GrowableArray<Klass*> *_class_promote_order; VirtualSpace _md_vs; VirtualSpace _mc_vs; public: VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data, GrowableArray<Klass*> *class_promote_order) : _loader_data(loader_data) { // Split up and initialize the misc code and data spaces ReservedSpace* shared_rs = MetaspaceShared::shared_rs(); int metadata_size = SharedReadOnlySize+SharedReadWriteSize; ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size); ReservedSpace misc_section = shared_rs->last_part(metadata_size); // Now split into misc sections. ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize); ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize); _md_vs.initialize(md_rs, SharedMiscDataSize); _mc_vs.initialize(mc_rs, SharedMiscCodeSize); _class_promote_order = class_promote_order; } VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } void doit(); // outline because gdb sucks }; // class VM_PopulateDumpSharedSpace void VM_PopulateDumpSharedSpace::doit() { Thread* THREAD = VMThread::vm_thread(); NOT_PRODUCT(SystemDictionary::verify();) // The following guarantee is meant to ensure that no loader constraints // exist yet, since the constraints table is not shared. This becomes // more important now that we don't re-initialize vtables/itables for // shared classes at runtime, where constraints were previously created. guarantee(SystemDictionary::constraints()->number_of_entries() == 0, "loader constraints are not saved"); guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, "placeholders are not saved"); // Revisit and implement this if we prelink method handle call sites: guarantee(SystemDictionary::invoke_method_table() == NULL || SystemDictionary::invoke_method_table()->number_of_entries() == 0, "invoke method table is not saved"); // At this point, many classes have been loaded. // Gather systemDictionary classes in a global array and do everything to // that so we don't have to walk the SystemDictionary again. _global_klass_objects = new GrowableArray<Klass*>(1000); Universe::basic_type_classes_do(collect_classes); SystemDictionary::classes_do(collect_classes); tty->print_cr("Number of classes %d", _global_klass_objects->length()); // Update all the fingerprints in the shared methods. tty->print("Calculating fingerprints ... "); calculate_fingerprints(); tty->print_cr("done. "); // Remove all references outside the metadata tty->print("Removing unshareable information ... "); remove_unshareable_in_classes(); tty->print_cr("done. "); // Set up the share data and shared code segments. char* md_low = _md_vs.low(); char* md_top = md_low; char* md_end = _md_vs.high(); char* mc_low = _mc_vs.low(); char* mc_top = mc_low; char* mc_end = _mc_vs.high(); // Reserve space for the list of Klass*s whose vtables are used // for patching others as needed. void** vtbl_list = (void**)md_top; int vtbl_list_size = MetaspaceShared::vtbl_list_size; Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); md_top += vtbl_list_size * sizeof(void*); void* vtable = md_top; // Reserve space for a new dummy vtable for klass objects in the // heap. Generate self-patching vtable entries. MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable, &md_top, md_end, &mc_top, mc_end); // Reorder the system dictionary. (Moving the symbols affects // how the hash table indices are calculated.) // Not doing this either. SystemDictionary::reorder_dictionary(); NOT_PRODUCT(SystemDictionary::verify();) // Copy the the symbol table, and the system dictionary to the shared // space in usable form. Copy the hastable // buckets first [read-write], then copy the linked lists of entries // [read-only]. SymbolTable::reverse(md_top); NOT_PRODUCT(SymbolTable::verify()); SymbolTable::copy_buckets(&md_top, md_end); SystemDictionary::reverse(); SystemDictionary::copy_buckets(&md_top, md_end); ClassLoader::verify(); ClassLoader::copy_package_info_buckets(&md_top, md_end); ClassLoader::verify(); SymbolTable::copy_table(&md_top, md_end); SystemDictionary::copy_table(&md_top, md_end); ClassLoader::verify(); ClassLoader::copy_package_info_table(&md_top, md_end); ClassLoader::verify(); // Write the other data to the output array. WriteClosure wc(md_top, md_end); MetaspaceShared::serialize(&wc); md_top = wc.get_top(); // Print shared spaces all the time const char* fmt = "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT; Metaspace* ro_space = _loader_data->ro_metaspace(); Metaspace* rw_space = _loader_data->rw_metaspace(); // Allocated size of each space (may not be all occupied) const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType); const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType); const size_t md_alloced = md_end-md_low; const size_t mc_alloced = mc_end-mc_low; const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced; // Occupied size of each space. const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType); const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType); const size_t md_bytes = size_t(md_top - md_low); const size_t mc_bytes = size_t(mc_top - mc_low); // Percent of total size const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes; const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0; const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0; const double md_t_perc = md_bytes / double(total_bytes) * 100.0; const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0; // Percent of fullness of each space const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0; const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0; const double md_u_perc = md_bytes / double(md_alloced) * 100.0; const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0; const double total_u_perc = total_bytes / double(total_alloced) * 100.0; tty->print_cr(fmt, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom()); tty->print_cr(fmt, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom()); tty->print_cr(fmt, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low); tty->print_cr(fmt, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low); tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]", total_bytes, total_alloced, total_u_perc); // Update the vtable pointers in all of the Klass objects in the // heap. They should point to newly generated vtable. patch_klass_vtables(vtbl_list, vtable); // dunno what this is for. char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass); memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); // Create and write the archive file that maps the shared spaces. FileMapInfo* mapinfo = new FileMapInfo(); mapinfo->populate_header(MetaspaceShared::max_alignment()); // Pass 1 - update file offsets in header. mapinfo->write_header(); mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), pointer_delta(md_top, _md_vs.low(), sizeof(char)), SharedMiscDataSize, false, false); mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), SharedMiscCodeSize, true, true); // Pass 2 - write data. mapinfo->open_for_write(); mapinfo->write_header(); mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), pointer_delta(md_top, _md_vs.low(), sizeof(char)), SharedMiscDataSize, false, false); mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), SharedMiscCodeSize, true, true); mapinfo->close(); memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); if (PrintSharedSpaces) { DumpAllocClosure dac; dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO); dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW); dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes)); } } static void link_shared_classes(Klass* obj, TRAPS) { Klass* k = obj; if (k->oop_is_instance()) { InstanceKlass* ik = (InstanceKlass*) k; // Link the class to cause the bytecodes to be rewritten and the // cpcache to be created. if (ik->init_state() < InstanceKlass::linked) { ik->link_class(THREAD); guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting"); } } } // Support for a simple checksum of the contents of the class list // file to prevent trivial tampering. The algorithm matches that in // the MakeClassList program used by the J2SE build process. #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe)) static jlong jsum(jlong start, const char *buf, const int len) { jlong h = start; char *p = (char *)buf, *e = p + len; while (p < e) { char c = *p++; if (c <= ' ') { /* Skip spaces and control characters */ continue; } h = 31 * h + c; } return h; } // Preload classes from a list, populate the shared spaces and dump to a // file. void MetaspaceShared::preload_and_dump(TRAPS) { TraceTime timer("Dump Shared Spaces", TraceStartupTime); ResourceMark rm; // Lock out GC - is it necessary? I don't think we care. No_GC_Verifier no_gc; // Preload classes to be shared. // Should use some os:: method rather than fopen() here. aB. // Construct the path to the class list (in jre/lib) // Walk up two directories from the location of the VM and // optionally tack on "lib" (depending on platform) char class_list_path[JVM_MAXPATHLEN]; os::jvm_path(class_list_path, sizeof(class_list_path)); for (int i = 0; i < 3; i++) { char *end = strrchr(class_list_path, *os::file_separator()); if (end != NULL) *end = '\0'; } int class_list_path_len = (int)strlen(class_list_path); if (class_list_path_len >= 3) { if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) { strcat(class_list_path, os::file_separator()); strcat(class_list_path, "lib"); } } strcat(class_list_path, os::file_separator()); strcat(class_list_path, "classlist"); FILE* file = fopen(class_list_path, "r"); if (file != NULL) { jlong computed_jsum = JSUM_SEED; jlong file_jsum = 0; char class_name[256]; int class_count = 0; GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>(); // sun.io.Converters static const char obj_array_sig[] = "[[Ljava/lang/Object;"; SymbolTable::new_permanent_symbol(obj_array_sig, THREAD); // java.util.HashMap static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD); tty->print("Loading classes to share ... "); while ((fgets(class_name, sizeof class_name, file)) != NULL) { if (*class_name == '#') { jint fsh, fsl; if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) { file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff); } continue; } // Remove trailing newline size_t name_len = strlen(class_name); class_name[name_len-1] = '\0'; computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1); // Got a class name - load it. TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD); guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol, THREAD); guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class."); if (klass != NULL) { if (PrintSharedSpaces && Verbose && WizardMode) { tty->print_cr("Shared spaces preloaded: %s", class_name); } InstanceKlass* ik = InstanceKlass::cast(klass); // Should be class load order as per -XX:+TraceClassLoadingPreorder class_promote_order->append(ik); // Link the class to cause the bytecodes to be rewritten and the // cpcache to be created. The linking is done as soon as classes // are loaded in order that the related data structures (klass and // cpCache) are located together. if (ik->init_state() < InstanceKlass::linked) { ik->link_class(THREAD); guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting"); } // TODO: Resolve klasses in constant pool ik->constants()->resolve_class_constants(THREAD); class_count++; } else { if (PrintSharedSpaces && Verbose && WizardMode) { tty->cr(); tty->print_cr(" Preload failed: %s", class_name); } } file_jsum = 0; // Checksum must be on last line of file } if (computed_jsum != file_jsum) { tty->cr(); tty->print_cr("Preload failed: checksum of class list was incorrect."); exit(1); } tty->print_cr("done. "); if (PrintSharedSpaces) { tty->print_cr("Shared spaces: preloaded %d classes", class_count); } // Rewrite and unlink classes. tty->print("Rewriting and linking classes ... "); // Link any classes which got missed. (It's not quite clear why // they got missed.) This iteration would be unsafe if we weren't // single-threaded at this point; however we can't do it on the VM // thread because it requires object allocation. SystemDictionary::classes_do(link_shared_classes, CATCH); tty->print_cr("done. "); // Create and dump the shared spaces. Everything so far is loaded // with the null class loader. ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); VM_PopulateDumpSharedSpace op(loader_data, class_promote_order); VMThread::execute(&op); } else { char errmsg[JVM_MAXPATHLEN]; os::lasterror(errmsg, JVM_MAXPATHLEN); tty->print_cr("Loading classlist failed: %s", errmsg); exit(1); } // Since various initialization steps have been undone by this process, // it is not reasonable to continue running a java process. exit(0); } // Closure for serializing initialization data in from a data area // (ptr_array) read from the shared file. class ReadClosure : public SerializeClosure { private: intptr_t** _ptr_array; inline intptr_t nextPtr() { return *(*_ptr_array)++; } public: ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } void do_ptr(void** p) { assert(*p == NULL, "initializing previous initialized pointer."); intptr_t obj = nextPtr(); assert((intptr_t)obj >= 0 || (intptr_t)obj < -100, "hit tag while initializing ptrs."); *p = (void*)obj; } void do_tag(int tag) { int old_tag; old_tag = (int)(intptr_t)nextPtr(); // do_int(&old_tag); assert(tag == old_tag, "old tag doesn't match"); FileMapInfo::assert_mark(tag == old_tag); } void do_region(u_char* start, size_t size) { assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); assert(size % sizeof(intptr_t) == 0, "bad size"); do_tag((int)size); while (size > 0) { *(intptr_t*)start = nextPtr(); start += sizeof(intptr_t); size -= sizeof(intptr_t); } } bool reading() const { return true; } }; // Return true if given address is in the mapped shared space. bool MetaspaceShared::is_in_shared_space(const void* p) { return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p); } void MetaspaceShared::print_shared_spaces() { if (UseSharedSpaces) { FileMapInfo::current_info()->print_shared_spaces(); } } // Map shared spaces at requested addresses and return if succeeded. // Need to keep the bounds of the ro and rw space for the Metaspace::contains // call, or is_in_shared_space. bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) { size_t image_alignment = mapinfo->alignment(); #ifndef _WINDOWS // Map in the shared memory and then map the regions on top of it. // On Windows, don't map the memory here because it will cause the // mappings of the regions to fail. ReservedSpace shared_rs = mapinfo->reserve_shared_memory(); if (!shared_rs.is_reserved()) return false; #endif assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces"); char* _ro_base = NULL; char* _rw_base = NULL; char* _md_base = NULL; char* _mc_base = NULL; // Map each shared region if ((_ro_base = mapinfo->map_region(ro)) != NULL && (_rw_base = mapinfo->map_region(rw)) != NULL && (_md_base = mapinfo->map_region(md)) != NULL && (_mc_base = mapinfo->map_region(mc)) != NULL && (image_alignment == (size_t)max_alignment())) { // Success (no need to do anything) return true; } else { // If there was a failure in mapping any of the spaces, unmap the ones // that succeeded if (_ro_base != NULL) mapinfo->unmap_region(ro); if (_rw_base != NULL) mapinfo->unmap_region(rw); if (_md_base != NULL) mapinfo->unmap_region(md); if (_mc_base != NULL) mapinfo->unmap_region(mc); #ifndef _WINDOWS // Release the entire mapped region shared_rs.release(); #endif // If -Xshare:on is specified, print out the error message and exit VM, // otherwise, set UseSharedSpaces to false and continue. if (RequireSharedSpaces) { vm_exit_during_initialization("Unable to use shared archive.", NULL); } else { FLAG_SET_DEFAULT(UseSharedSpaces, false); } return false; } } // Read the miscellaneous data from the shared file, and // serialize it out to its various destinations. void MetaspaceShared::initialize_shared_spaces() { FileMapInfo *mapinfo = FileMapInfo::current_info(); char* buffer = mapinfo->region_base(md); // Skip over (reserve space for) a list of addresses of C++ vtables // for Klass objects. They get filled in later. void** vtbl_list = (void**)buffer; buffer += MetaspaceShared::vtbl_list_size * sizeof(void*); Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); // Skip over (reserve space for) dummy C++ vtables Klass objects. // They are used as is. intptr_t vtable_size = *(intptr_t*)buffer; buffer += sizeof(intptr_t); buffer += vtable_size; // Create the symbol table using the bucket array at this spot in the // misc data space. Since the symbol table is often modified, this // region (of mapped pages) will be copy-on-write. int symbolTableLen = *(intptr_t*)buffer; buffer += sizeof(intptr_t); int number_of_entries = *(intptr_t*)buffer; buffer += sizeof(intptr_t); SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen, number_of_entries); buffer += symbolTableLen; // Create the shared dictionary using the bucket array at this spot in // the misc data space. Since the shared dictionary table is never // modified, this region (of mapped pages) will be (effectively, if // not explicitly) read-only. int sharedDictionaryLen = *(intptr_t*)buffer; buffer += sizeof(intptr_t); number_of_entries = *(intptr_t*)buffer; buffer += sizeof(intptr_t); SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer, sharedDictionaryLen, number_of_entries); buffer += sharedDictionaryLen; // Create the package info table using the bucket array at this spot in // the misc data space. Since the package info table is never // modified, this region (of mapped pages) will be (effectively, if // not explicitly) read-only. int pkgInfoLen = *(intptr_t*)buffer; buffer += sizeof(intptr_t); number_of_entries = *(intptr_t*)buffer; buffer += sizeof(intptr_t); ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen, number_of_entries); buffer += pkgInfoLen; ClassLoader::verify(); // The following data in the shared misc data region are the linked // list elements (HashtableEntry objects) for the symbol table, string // table, and shared dictionary. The heap objects refered to by the // symbol table, string table, and shared dictionary are permanent and // unmovable. Since new entries added to the string and symbol tables // are always added at the beginning of the linked lists, THESE LINKED // LIST ELEMENTS ARE READ-ONLY. int len = *(intptr_t*)buffer; // skip over symbol table entries buffer += sizeof(intptr_t); buffer += len; len = *(intptr_t*)buffer; // skip over shared dictionary entries buffer += sizeof(intptr_t); buffer += len; len = *(intptr_t*)buffer; // skip over package info table entries buffer += sizeof(intptr_t); buffer += len; len = *(intptr_t*)buffer; // skip over package info table char[] arrays. buffer += sizeof(intptr_t); buffer += len; intptr_t* array = (intptr_t*)buffer; ReadClosure rc(&array); serialize(&rc); // Close the mapinfo file mapinfo->close(); } // JVM/TI RedefineClasses() support: bool MetaspaceShared::remap_shared_readonly_as_readwrite() { assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); if (UseSharedSpaces) { // remap the shared readonly space to shared readwrite, private FileMapInfo* mapinfo = FileMapInfo::current_info(); if (!mapinfo->remap_shared_readonly_as_readwrite()) { return false; } } return true; }