src/share/vm/memory/metaspaceShared.cpp
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rev 6853 : 8046070: Class Data Sharing clean up and refactoring
Summary: Cleaned up CDS to be more configurable, maintainable and extensible
Reviewed-by: dholmes, coleenp, acorn, mchung
*** 24,33 ****
--- 24,34 ----
#include "precompiled.hpp"
#include "classfile/dictionary.hpp"
#include "classfile/loaderConstraints.hpp"
#include "classfile/placeholders.hpp"
+ #include "classfile/sharedClassUtil.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/codeCache.hpp"
#include "memory/filemap.hpp"
#include "memory/gcLocker.hpp"
*** 45,54 ****
--- 46,59 ----
int MetaspaceShared::_max_alignment = 0;
ReservedSpace* MetaspaceShared::_shared_rs = NULL;
+ bool MetaspaceShared::_link_classes_made_progress;
+ bool MetaspaceShared::_check_classes_made_progress;
+ bool MetaspaceShared::_has_error_classes;
+ bool MetaspaceShared::_archive_loading_failed = false;
// 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;
*** 444,453 ****
--- 449,475 ----
_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());
+ {
+ int num_type_array = 0, num_obj_array = 0, num_inst = 0;
+ for (int i = 0; i < _global_klass_objects->length(); i++) {
+ Klass* k = _global_klass_objects->at(i);
+ if (k->oop_is_instance()) {
+ num_inst ++;
+ } else if (k->oop_is_objArray()) {
+ num_obj_array ++;
+ } else {
+ assert(k->oop_is_typeArray(), "sanity");
+ num_type_array ++;
+ }
+ }
+ tty->print_cr(" instance classes = %5d", num_inst);
+ tty->print_cr(" obj array classes = %5d", num_obj_array);
+ tty->print_cr(" type array classes = %5d", num_type_array);
+ }
// Update all the fingerprints in the shared methods.
tty->print("Calculating fingerprints ... ");
calculate_fingerprints();
tty->print_cr("done. ");
*** 609,685 ****
dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
}
#undef fmt_space
}
! 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;
// 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;";
--- 631,731 ----
dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes));
}
#undef fmt_space
}
!
! void MetaspaceShared::link_one_shared_class(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. Class verification is done according
! // to -Xverify setting.
! _link_classes_made_progress |= try_link_class(ik, THREAD);
! guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
}
}
+ void MetaspaceShared::check_one_shared_class(Klass* k) {
+ if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) {
+ _check_classes_made_progress = true;
+ }
+ }
! void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
! // We need to iterate because verification may cause additional classes
! // to be loaded.
! do {
! _link_classes_made_progress = false;
! SystemDictionary::classes_do(link_one_shared_class, THREAD);
! guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
! } while (_link_classes_made_progress);
!
! if (_has_error_classes) {
! // Mark all classes whose super class or interfaces failed verification.
! do {
! // Not completely sure if we need to do this iteratively. Anyway,
! // we should come here only if there are unverifiable classes, which
! // shouldn't happen in normal cases. So better safe than sorry.
! _check_classes_made_progress = false;
! SystemDictionary::classes_do(check_one_shared_class);
! } while (_check_classes_made_progress);
!
! if (IgnoreUnverifiableClassesDuringDump) {
! // This is useful when running JCK or SQE tests. You should not
! // enable this when running real apps.
! SystemDictionary::remove_classes_in_error_state();
! } else {
! tty->print_cr("Please remove the unverifiable classes from your class list and try again");
! exit(1);
}
}
! }
!
! void MetaspaceShared::prepare_for_dumping() {
! ClassLoader::initialize_shared_path();
! FileMapInfo::allocate_classpath_entry_table();
}
// 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;
+ tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT,
+ MetaspaceShared::shared_rs()->size(),
+ MetaspaceShared::shared_rs()->base());
+
// Preload classes to be shared.
// Should use some os:: method rather than fopen() here. aB.
+ const char* class_list_path;
+ if (SharedClassListFile == NULL) {
// 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_str[JVM_MAXPATHLEN];
! os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
for (int i = 0; i < 3; i++) {
! char *end = strrchr(class_list_path_str, *os::file_separator());
if (end != NULL) *end = '\0';
}
! int class_list_path_len = (int)strlen(class_list_path_str);
if (class_list_path_len >= 3) {
! if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
! strcat(class_list_path_str, os::file_separator());
! strcat(class_list_path_str, "lib");
}
}
! strcat(class_list_path_str, os::file_separator());
! strcat(class_list_path_str, "classlist");
! class_list_path = class_list_path_str;
! } else {
! class_list_path = SharedClassListFile;
! }
int class_count = 0;
GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>();
// sun.io.Converters
static const char obj_array_sig[] = "[[Ljava/lang/Object;";
*** 687,791 ****
// 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 {
--- 733,863 ----
// 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_cr("Loading classes to share ...");
! _has_error_classes = false;
! class_count += preload_and_dump(class_list_path, class_promote_order,
! THREAD);
! if (ExtraSharedClassListFile) {
! class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order,
! THREAD);
! }
! tty->print_cr("Loading classes to share: done.");
!
! if (PrintSharedSpaces) {
! tty->print_cr("Shared spaces: preloaded %d classes", class_count);
}
+ // Rewrite and link classes
+ tty->print_cr("Rewriting and linking classes ...");
+
+ // Link any classes which got missed. This would happen if we have loaded classes that
+ // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
+ // fails verification, all other interfaces that were not specified in the classlist but
+ // are implemented by K are not verified.
+ link_and_cleanup_shared_classes(CATCH);
+ tty->print_cr("Rewriting and linking classes: 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);
+
+ // Since various initialization steps have been undone by this process,
+ // it is not reasonable to continue running a java process.
+ exit(0);
+ }
+
+ int MetaspaceShared::preload_and_dump(const char * class_list_path,
+ GrowableArray<Klass*>* class_promote_order,
+ TRAPS) {
+ FILE* file = fopen(class_list_path, "r");
+ char class_name[256];
+ int class_count = 0;
+
+ if (file != NULL) {
+ while ((fgets(class_name, sizeof class_name, file)) != NULL) {
+ if (*class_name == '#') { // comment
continue;
}
// Remove trailing newline
size_t name_len = strlen(class_name);
+ if (class_name[name_len-1] == '\n') {
class_name[name_len-1] = '\0';
! }
// 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);
! CLEAR_PENDING_EXCEPTION;
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.
! try_link_class(ik, THREAD);
! guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
class_count++;
} else {
! //tty->print_cr("Preload failed: %s", class_name);
}
}
} else {
char errmsg[JVM_MAXPATHLEN];
os::lasterror(errmsg, JVM_MAXPATHLEN);
tty->print_cr("Loading classlist failed: %s", errmsg);
exit(1);
}
! return class_count;
}
+ // Returns true if the class's status has changed
+ bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
+ assert(DumpSharedSpaces, "should only be called during dumping");
+ if (ik->init_state() < InstanceKlass::linked) {
+ bool saved = BytecodeVerificationLocal;
+ if (!SharedClassUtil::is_shared_boot_class(ik)) {
+ // The verification decision is based on BytecodeVerificationRemote
+ // for non-system classes. Since we are using the NULL classloader
+ // to load non-system classes during dumping, we need to temporarily
+ // change BytecodeVerificationLocal to be the same as
+ // BytecodeVerificationRemote. Note this can cause the parent system
+ // classes also being verified. The extra overhead is acceptable during
+ // dumping.
+ BytecodeVerificationLocal = BytecodeVerificationRemote;
+ }
+ ik->link_class(THREAD);
+ if (HAS_PENDING_EXCEPTION) {
+ ResourceMark rm;
+ tty->print_cr("Preload Error: Verification failed for %s",
+ ik->external_name());
+ CLEAR_PENDING_EXCEPTION;
+ ik->set_in_error_state();
+ _has_error_classes = true;
+ }
+ BytecodeVerificationLocal = saved;
+ return true;
+ } else {
+ return false;
+ }
+ }
// Closure for serializing initialization data in from a data area
// (ptr_array) read from the shared file.
class ReadClosure : public SerializeClosure {
*** 865,875 ****
// 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
--- 937,948 ----
// 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()) &&
! mapinfo->validate_classpath_entry_table()) {
// 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
*** 882,892 ****
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;
}
--- 955,965 ----
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.", "Failed map_region for using -Xshare:on.");
} else {
FLAG_SET_DEFAULT(UseSharedSpaces, false);
}
return false;
}
*** 982,991 ****
--- 1055,1078 ----
ReadClosure rc(&array);
serialize(&rc);
// Close the mapinfo file
mapinfo->close();
+
+ if (PrintSharedArchiveAndExit) {
+ if (PrintSharedDictionary) {
+ tty->print_cr("\nShared classes:\n");
+ SystemDictionary::print_shared(false);
+ }
+ if (_archive_loading_failed) {
+ tty->print_cr("archive is invalid");
+ vm_exit(1);
+ } else {
+ tty->print_cr("archive is valid");
+ vm_exit(0);
+ }
+ }
}
// JVM/TI RedefineClasses() support:
bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");