/* * Copyright (c) 1997, 2017, 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. * */ #ifndef SHARE_VM_CLASSFILE_CLASSLOADER_HPP #define SHARE_VM_CLASSFILE_CLASSLOADER_HPP #include "classfile/jimage.hpp" #include "runtime/orderAccess.hpp" #include "runtime/perfData.hpp" #include "utilities/exceptions.hpp" #include "utilities/macros.hpp" // The VM class loader. #include // Name of boot "modules" image #define MODULES_IMAGE_NAME "modules" // Class path entry (directory or zip file) class JImageFile; class ClassFileStream; class PackageEntry; class ClassPathEntry : public CHeapObj { private: ClassPathEntry* volatile _next; public: // Next entry in class path ClassPathEntry* next() const { return OrderAccess::load_acquire(&_next); } virtual ~ClassPathEntry() {} void set_next(ClassPathEntry* next) { // may have unlocked readers, so ensure visibility. OrderAccess::release_store(&_next, next); } virtual bool is_jrt() = 0; virtual bool is_jar_file() const = 0; virtual const char* name() const = 0; virtual JImageFile* jimage() const = 0; // Constructor ClassPathEntry() : _next(NULL) {} // Attempt to locate file_name through this class path entry. // Returns a class file parsing stream if successfull. virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0; // Debugging NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;) }; class ClassPathDirEntry: public ClassPathEntry { private: const char* _dir; // Name of directory public: bool is_jrt() { return false; } bool is_jar_file() const { return false; } const char* name() const { return _dir; } JImageFile* jimage() const { return NULL; } ClassPathDirEntry(const char* dir); virtual ~ClassPathDirEntry() {} ClassFileStream* open_stream(const char* name, TRAPS); // Debugging NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) }; // Type definitions for zip file and zip file entry typedef void* jzfile; typedef struct { char *name; /* entry name */ jlong time; /* modification time */ jlong size; /* size of uncompressed data */ jlong csize; /* size of compressed data (zero if uncompressed) */ jint crc; /* crc of uncompressed data */ char *comment; /* optional zip file comment */ jbyte *extra; /* optional extra data */ jlong pos; /* position of LOC header (if negative) or data */ } jzentry; class ClassPathZipEntry: public ClassPathEntry { enum { _unknown = 0, _yes = 1, _no = 2 }; private: jzfile* _zip; // The zip archive const char* _zip_name; // Name of zip archive bool _is_boot_append; // entry coming from -Xbootclasspath/a u1 _multi_versioned; // indicates if the jar file has multi-versioned entries. // It can have value of "_unknown", "_yes", or "_no" public: bool is_jrt() { return false; } bool is_jar_file() const { return true; } const char* name() const { return _zip_name; } JImageFile* jimage() const { return NULL; } ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append); virtual ~ClassPathZipEntry(); u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); u1* open_versioned_entry(const char* name, jint* filesize, TRAPS) NOT_CDS_RETURN_(NULL); ClassFileStream* open_stream(const char* name, TRAPS); void contents_do(void f(const char* name, void* context), void* context); bool is_multiple_versioned(TRAPS) NOT_CDS_RETURN_(false); // Debugging NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) }; // For java image files class ClassPathImageEntry: public ClassPathEntry { private: JImageFile* _jimage; const char* _name; public: bool is_jrt(); bool is_jar_file() const { return false; } bool is_open() const { return _jimage != NULL; } const char* name() const { return _name == NULL ? "" : _name; } JImageFile* jimage() const { return _jimage; } ClassPathImageEntry(JImageFile* jimage, const char* name); virtual ~ClassPathImageEntry(); ClassFileStream* open_stream(const char* name, TRAPS); // Debugging NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) }; // ModuleClassPathList contains a linked list of ClassPathEntry's // that have been specified for a specific module. Currently, // the only way to specify a module/path pair is via the --patch-module // command line option. class ModuleClassPathList : public CHeapObj { private: Symbol* _module_name; // First and last entries of class path entries for a specific module ClassPathEntry* _module_first_entry; ClassPathEntry* _module_last_entry; public: Symbol* module_name() const { return _module_name; } ClassPathEntry* module_first_entry() const { return _module_first_entry; } ModuleClassPathList(Symbol* module_name); ~ModuleClassPathList(); void add_to_list(ClassPathEntry* new_entry); }; class SharedPathsMiscInfo; class ClassLoader: AllStatic { public: enum ClassLoaderType { BOOT_LOADER = 1, /* boot loader */ PLATFORM_LOADER = 2, /* PlatformClassLoader */ APP_LOADER = 3 /* AppClassLoader */ }; protected: // Performance counters static PerfCounter* _perf_accumulated_time; static PerfCounter* _perf_classes_inited; static PerfCounter* _perf_class_init_time; static PerfCounter* _perf_class_init_selftime; static PerfCounter* _perf_classes_verified; static PerfCounter* _perf_class_verify_time; static PerfCounter* _perf_class_verify_selftime; static PerfCounter* _perf_classes_linked; static PerfCounter* _perf_class_link_time; static PerfCounter* _perf_class_link_selftime; static PerfCounter* _perf_class_parse_time; static PerfCounter* _perf_class_parse_selftime; static PerfCounter* _perf_sys_class_lookup_time; static PerfCounter* _perf_shared_classload_time; static PerfCounter* _perf_sys_classload_time; static PerfCounter* _perf_app_classload_time; static PerfCounter* _perf_app_classload_selftime; static PerfCounter* _perf_app_classload_count; static PerfCounter* _perf_define_appclasses; static PerfCounter* _perf_define_appclass_time; static PerfCounter* _perf_define_appclass_selftime; static PerfCounter* _perf_app_classfile_bytes_read; static PerfCounter* _perf_sys_classfile_bytes_read; static PerfCounter* _sync_systemLoaderLockContentionRate; static PerfCounter* _sync_nonSystemLoaderLockContentionRate; static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; static PerfCounter* _sync_JVMDefineClassLockFreeCounter; static PerfCounter* _sync_JNIDefineClassLockFreeCounter; static PerfCounter* _unsafe_defineClassCallCounter; static PerfCounter* _isUnsyncloadClass; static PerfCounter* _load_instance_class_failCounter; // The boot class path consists of 3 ordered pieces: // 1. the module/path pairs specified to --patch-module // --patch-module==()* // 2. the base piece // [jimage | build with exploded modules] // 3. boot loader append path // [-Xbootclasspath/a]; [jvmti appended entries] // // The boot loader must obey this order when attempting // to load a class. // 1. Contains the module/path pairs specified to --patch-module static GrowableArray* _patch_mod_entries; // 2. the base piece // Contains the ClassPathEntry of the modular java runtime image. // If no java runtime image is present, this indicates a // build with exploded modules is being used instead. static ClassPathEntry* _jrt_entry; static GrowableArray* _exploded_entries; enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules // 3. the boot loader's append path // [-Xbootclasspath/a]; [jvmti appended entries] // Note: boot loader append path does not support named modules. static ClassPathEntry* _first_append_entry; // Last entry in linked list of appended ClassPathEntry instances static ClassPathEntry* _last_append_entry; // Note: _num_entries includes the java runtime image and all // the entries on the _first_append_entry linked list. static int _num_entries; // number of entries in the boot class path including the // java runtime image static int _num_boot_entries; // Array of module names associated with the boot class loader CDS_ONLY(static GrowableArray* _boot_modules_array;) // Array of module names associated with the platform class loader CDS_ONLY(static GrowableArray* _platform_modules_array;) // Info used by CDS CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;) // Initialization: // - setup the boot loader's system class path // - setup the boot loader's patch mod entries, if present // - create the ModuleEntry for java.base static void setup_bootstrap_search_path(); static void setup_search_path(const char *class_path, bool setting_bootstrap); static void setup_patch_mod_entries(); static void create_javabase(); static void load_zip_library(); static void load_jimage_library(); static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st, bool throw_exception, bool is_boot_append, TRAPS); public: // If the package for the fully qualified class name is in the boot // loader's package entry table then add_package() sets the classpath_index // field so that get_system_package() will know to return a non-null value // for the package's location. And, so that the package will be added to // the list of packages returned by get_system_packages(). // For packages whose classes are loaded from the boot loader class path, the // classpath_index indicates which entry on the boot loader class path. static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS); // Canonicalizes path names, so strcmp will work properly. This is mainly // to avoid confusing the zip library static bool get_canonical_path(const char* orig, char* out, int len); static const char* file_name_for_class_name(const char* class_name, int class_name_len); static PackageEntry* get_package_entry(const char* class_name, ClassLoaderData* loader_data, TRAPS); public: static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); static int crc32(int crc, const char* buf, int len); static bool update_class_path_entry_list(const char *path, bool check_for_duplicates, bool is_boot_append, bool throw_exception=true); static void print_bootclasspath(); // Timing static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } // Record how often system loader lock object is contended static PerfCounter* sync_systemLoaderLockContentionRate() { return _sync_systemLoaderLockContentionRate; } // Record how often non system loader lock object is contended static PerfCounter* sync_nonSystemLoaderLockContentionRate() { return _sync_nonSystemLoaderLockContentionRate; } // Record how many calls to JVM_FindLoadedClass w/o holding a lock static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { return _sync_JVMFindLoadedClassLockFreeCounter; } // Record how many calls to JVM_DefineClass w/o holding a lock static PerfCounter* sync_JVMDefineClassLockFreeCounter() { return _sync_JVMDefineClassLockFreeCounter; } // Record how many calls to jni_DefineClass w/o holding a lock static PerfCounter* sync_JNIDefineClassLockFreeCounter() { return _sync_JNIDefineClassLockFreeCounter; } // Record how many calls to Unsafe_DefineClass static PerfCounter* unsafe_defineClassCallCounter() { return _unsafe_defineClassCallCounter; } // Record how many times SystemDictionary::load_instance_class call // fails with linkageError when Unsyncloadclass flag is set. static PerfCounter* load_instance_class_failCounter() { return _load_instance_class_failCounter; } // Modular java runtime image is present vs. a build with exploded modules static bool has_jrt_entry() { return (_jrt_entry != NULL); } static ClassPathEntry* get_jrt_entry() { return _jrt_entry; } // Add a module's exploded directory to the boot loader's exploded module build list static void add_to_exploded_build_list(Symbol* module_name, TRAPS); // Attempt load of individual class from either the patched or exploded modules build lists static ClassFileStream* search_module_entries(const GrowableArray* const module_list, const char* const class_name, const char* const file_name, TRAPS); // Load individual .class file static InstanceKlass* load_class(Symbol* class_name, bool search_append_only, TRAPS); // If the specified package has been loaded by the system, then returns // the name of the directory or ZIP file that the package was loaded from. // Returns null if the package was not loaded. // Note: The specified name can either be the name of a class or package. // If a package name is specified, then it must be "/"-separator and also // end with a trailing "/". static oop get_system_package(const char* name, TRAPS); // Returns an array of Java strings representing all of the currently // loaded system packages. // Note: The package names returned are "/"-separated and end with a // trailing "/". static objArrayOop get_system_packages(TRAPS); // Initialization static void initialize(); static void classLoader_init2(TRAPS); CDS_ONLY(static void initialize_shared_path();) static int compute_Object_vtable(); static ClassPathEntry* classpath_entry(int n) { assert(n >= 0, "sanity"); assert(!has_jrt_entry() || n < _num_entries, "sanity"); if (n == 0) { assert(has_jrt_entry(), "No class path entry at 0 for exploded module builds"); return ClassLoader::_jrt_entry; } else { // The java runtime image is always the first entry // in the FileMapInfo::_classpath_entry_table. Even though // the _jrt_entry is not included in the _first_append_entry // linked list, it must be accounted for when comparing the // class path vs. the shared archive class path. ClassPathEntry* e = ClassLoader::_first_append_entry; while (--n >= 1) { assert(e != NULL, "Not that many classpath entries."); e = e->next(); } return e; } } static int number_of_classpath_entries() { return _num_entries; } static bool is_in_patch_mod_entries(Symbol* module_name); #if INCLUDE_CDS // Sharing dump and restore static void check_shared_classpath(const char *path); static void finalize_shared_paths_misc_info(); static int get_shared_paths_misc_info_size(); static void* get_shared_paths_misc_info(); static bool check_shared_paths_misc_info(void* info, int size); static void exit_with_path_failure(const char* error, const char* message); static void record_shared_class_loader_type(InstanceKlass* ik, const ClassFileStream* stream); #endif static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name, const char* file_name, jlong &size); static void trace_class_path(const char* msg, const char* name = NULL); // VM monitoring and management support static jlong classloader_time_ms(); static jlong class_method_total_size(); static jlong class_init_count(); static jlong class_init_time_ms(); static jlong class_verify_time_ms(); static jlong class_link_count(); static jlong class_link_time_ms(); static void set_first_append_entry(ClassPathEntry* entry); // indicates if class path already contains a entry (exact match by name) static bool contains_append_entry(const char* name); // adds a class path list static void add_to_list(ClassPathEntry* new_entry); // creates a class path zip entry (returns NULL if JAR file cannot be opened) static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append); // add a path to class path list static void add_to_list(const char* apath); static bool string_ends_with(const char* str, const char* str_to_find); // obtain package name from a fully qualified class name // *bad_class_name is set to true if there's a problem with parsing class_name, to // distinguish from a class_name with no package name, as both cases have a NULL return value static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL); static bool is_jrt(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); } // Debugging static void verify() PRODUCT_RETURN; // Force compilation of all methods in all classes in bootstrap class path (stress test) #ifndef PRODUCT protected: static int _compile_the_world_class_counter; static int _compile_the_world_method_counter; public: static void compile_the_world(); static void compile_the_world_in(char* name, Handle loader, TRAPS); static int compile_the_world_counter() { return _compile_the_world_class_counter; } #endif //PRODUCT }; // PerfClassTraceTime is used to measure time for class loading related events. // This class tracks cumulative time and exclusive time for specific event types. // During the execution of one event, other event types (e.g. class loading and // resolution) as well as recursive calls of the same event type could happen. // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime // instances have been created as multiple events are happening. class PerfClassTraceTime { public: enum { CLASS_LOAD = 0, PARSE_CLASS = 1, CLASS_LINK = 2, CLASS_VERIFY = 3, CLASS_CLINIT = 4, DEFINE_CLASS = 5, EVENT_TYPE_COUNT = 6 }; protected: // _t tracks time from initialization to destruction of this timer instance // including time for all other event types, and recursive calls of this type. // When a timer is called recursively, the elapsedTimer _t would not be used. elapsedTimer _t; PerfLongCounter* _timep; PerfLongCounter* _selftimep; PerfLongCounter* _eventp; // pointer to thread-local recursion counter and timer array // The thread_local timers track cumulative time for specific event types // exclusive of time for other event types, but including recursive calls // of the same type. int* _recursion_counters; elapsedTimer* _timers; int _event_type; int _prev_active_event; public: inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ PerfLongCounter* selftimep, /* counter incremented with exclusive time */ PerfLongCounter* eventp, /* event counter */ int* recursion_counters, /* thread-local recursion counter array */ elapsedTimer* timers, /* thread-local timer array */ int type /* event type */ ) : _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { initialize(); } inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ elapsedTimer* timers, /* thread-local timer array */ int type /* event type */ ) : _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { initialize(); } inline void suspend() { _t.stop(); _timers[_event_type].stop(); } inline void resume() { _t.start(); _timers[_event_type].start(); } ~PerfClassTraceTime(); void initialize(); }; #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP