truffle: src/share/vm/memory/metaspaceShared.cpp comparison

comparison src/share/vm/memory/metaspaceShared.cpp @ 6725:da91efe96a93

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>

author	coleenp
date	Sat, 01 Sep 2012 13:25:18 -0400
parents
children	fa6e618671d7

comparison

equal deleted inserted replaced

-:36d1d483d5d6
+:da91efe96a93
+/*
+* 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.
+*
+*/
+#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;
+int MetaspaceShared::max_alignment()                   { return _max_alignment; }
+void MetaspaceShared::set_max_alignment(int alignment) { _max_alignment = alignment; }
+// Accessor functions to save shared space created for metadata, which has
+// extra space allocated at the end for miscellaneous data and code.
+ReservedSpace* MetaspaceShared::_shared_rs = NULL;
+ReservedSpace* MetaspaceShared::shared_rs()            { return _shared_rs; }
+void MetaspaceShared::set_shared_rs(ReservedSpace* rs) { _shared_rs = rs; }
+// 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);
+assert(!UseCompressedOops, "UseCompressedOops doesn't work with shared archive");
+// 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++) {
+ResourceMark rm;
+Method* m = ik->methods()->at(i);
+(new Fingerprinter(m))->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->klass_part
+//   2. vtable entry for that klass_part points to the jump table entries
+//   3. branches to common_code with %O0/klass_part, %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; }
+};
+// 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: " PTR_FORMAT " out of " PTR_FORMAT " words allocated at " PTR_FORMAT ".";
+Metaspace* ro_space = _loader_data->ro_metaspace();
+Metaspace* rw_space = _loader_data->rw_metaspace();
+tty->print_cr(fmt, "ro", ro_space->used_words(Metaspace::NonClassType),
+ro_space->capacity_words(Metaspace::NonClassType),
+ro_space->bottom());
+tty->print_cr(fmt, "rw", rw_space->used_words(Metaspace::NonClassType),
+rw_space->capacity_words(Metaspace::NonClassType),
+rw_space->bottom());
+tty->print_cr(fmt, "md", md_top - md_low, md_end-md_low, md_low);
+tty->print_cr(fmt, "mc", mc_top - mc_low, mc_end-mc_low, mc_low);
+// 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*));
+}
+static void link_shared_classes(Klass* obj, TRAPS) {
+Klass* k = Klass::cast(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; }
+};
+// Save bounds of shared spaces mapped in.
+static char* _ro_base = NULL;
+static char* _rw_base = NULL;
+static char* _md_base = NULL;
+static char* _mc_base = NULL;
+// Return true if given address is in the mapped shared space.
+bool MetaspaceShared::is_in_shared_space(const void* p) {
+if (_ro_base == NULL || _rw_base == NULL) {
+return false;
+} else {
+return ((p > _ro_base && p < (_ro_base + SharedReadOnlySize)) ||
+(p > _rw_base && p < (_rw_base + SharedReadWriteSize)));
+}
+}
+void MetaspaceShared::print_shared_spaces() {
+gclog_or_tty->print_cr("Shared Spaces:");
+gclog_or_tty->print("  read-only " INTPTR_FORMAT "-" INTPTR_FORMAT,
+_ro_base, _ro_base + SharedReadOnlySize);
+gclog_or_tty->print("  read-write " INTPTR_FORMAT "-" INTPTR_FORMAT,
+_rw_base, _rw_base + SharedReadWriteSize);
+gclog_or_tty->cr();
+gclog_or_tty->print("  misc-data " INTPTR_FORMAT "-" INTPTR_FORMAT,
+_md_base, _md_base + SharedMiscDataSize);
+gclog_or_tty->print("  misc-code " INTPTR_FORMAT "-" INTPTR_FORMAT,
+_mc_base, _mc_base + SharedMiscCodeSize);
+gclog_or_tty->cr();
+}
+// 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();
+// Map in the shared memory and then map the regions on top of it
+ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
+if (!shared_rs.is_reserved()) return false;
+// Split reserved memory into pieces (windows needs this)
+ReservedSpace ro_rs   = shared_rs.first_part(SharedReadOnlySize);
+ReservedSpace tmp_rs1 = shared_rs.last_part(SharedReadOnlySize);
+ReservedSpace rw_rs   = tmp_rs1.first_part(SharedReadWriteSize);
+ReservedSpace tmp_rs2 = tmp_rs1.last_part(SharedReadWriteSize);
+ReservedSpace md_rs   = tmp_rs2.first_part(SharedMiscDataSize);
+ReservedSpace mc_rs   = tmp_rs2.last_part(SharedMiscDataSize);
+// 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);
+// Release the entire mapped region
+shared_rs.release();
+// 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;
+}

Mercurial > hg > truffle

comparison src/share/vm/memory/metaspaceShared.cpp @ 6725:da91efe96a93