duke@435: /*
trims@1907:  * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: // The VM class loader.
duke@435: #include <sys/stat.h>
duke@435: 
duke@435: 
duke@435: // Meta-index (optional, to be able to skip opening boot classpath jar files)
duke@435: class MetaIndex: public CHeapObj {
duke@435:  private:
duke@435:   char** _meta_package_names;
duke@435:   int    _num_meta_package_names;
duke@435:  public:
duke@435:   MetaIndex(char** meta_package_names, int num_meta_package_names);
duke@435:   ~MetaIndex();
duke@435:   bool may_contain(const char* class_name);
duke@435: };
duke@435: 
duke@435: 
duke@435: // Class path entry (directory or zip file)
duke@435: 
duke@435: class ClassPathEntry: public CHeapObj {
duke@435:  private:
duke@435:   ClassPathEntry* _next;
duke@435:  public:
duke@435:   // Next entry in class path
duke@435:   ClassPathEntry* next()              { return _next; }
duke@435:   void set_next(ClassPathEntry* next) {
duke@435:     // may have unlocked readers, so write atomically.
duke@435:     OrderAccess::release_store_ptr(&_next, next);
duke@435:   }
duke@435:   virtual bool is_jar_file() = 0;
duke@435:   virtual const char* name() = 0;
duke@435:   virtual bool is_lazy();
duke@435:   // Constructor
duke@435:   ClassPathEntry();
duke@435:   // Attempt to locate file_name through this class path entry.
duke@435:   // Returns a class file parsing stream if successfull.
duke@435:   virtual ClassFileStream* open_stream(const char* name) = 0;
duke@435:   // Debugging
duke@435:   NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
duke@435:   NOT_PRODUCT(virtual bool is_rt_jar() = 0;)
duke@435: };
duke@435: 
duke@435: 
duke@435: class ClassPathDirEntry: public ClassPathEntry {
duke@435:  private:
duke@435:   char* _dir;           // Name of directory
duke@435:  public:
duke@435:   bool is_jar_file()  { return false;  }
duke@435:   const char* name()  { return _dir; }
duke@435:   ClassPathDirEntry(char* dir);
duke@435:   ClassFileStream* open_stream(const char* name);
duke@435:   // Debugging
duke@435:   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
duke@435:   NOT_PRODUCT(bool is_rt_jar();)
duke@435: };
duke@435: 
duke@435: 
duke@435: // Type definitions for zip file and zip file entry
duke@435: typedef void* jzfile;
duke@435: typedef struct {
duke@435:   char *name;                   /* entry name */
duke@435:   jlong time;                   /* modification time */
duke@435:   jlong size;                   /* size of uncompressed data */
duke@435:   jlong csize;                  /* size of compressed data (zero if uncompressed) */
duke@435:   jint crc;                     /* crc of uncompressed data */
duke@435:   char *comment;                /* optional zip file comment */
duke@435:   jbyte *extra;                 /* optional extra data */
duke@435:   jlong pos;                    /* position of LOC header (if negative) or data */
duke@435: } jzentry;
duke@435: 
duke@435: 
duke@435: class ClassPathZipEntry: public ClassPathEntry {
duke@435:  private:
duke@435:   jzfile* _zip;        // The zip archive
duke@435:   char*   _zip_name;   // Name of zip archive
duke@435:  public:
duke@435:   bool is_jar_file()  { return true;  }
duke@435:   const char* name()  { return _zip_name; }
duke@435:   ClassPathZipEntry(jzfile* zip, const char* zip_name);
duke@435:   ~ClassPathZipEntry();
duke@435:   ClassFileStream* open_stream(const char* name);
duke@435:   void contents_do(void f(const char* name, void* context), void* context);
duke@435:   // Debugging
duke@435:   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
duke@435:   NOT_PRODUCT(void compile_the_world12(Handle loader, TRAPS);) // JDK 1.2 version
duke@435:   NOT_PRODUCT(void compile_the_world13(Handle loader, TRAPS);) // JDK 1.3 version
duke@435:   NOT_PRODUCT(bool is_rt_jar();)
duke@435:   NOT_PRODUCT(bool is_rt_jar12();)
duke@435:   NOT_PRODUCT(bool is_rt_jar13();)
duke@435: };
duke@435: 
duke@435: 
duke@435: // For lazier loading of boot class path entries
duke@435: class LazyClassPathEntry: public ClassPathEntry {
duke@435:  private:
duke@435:   char* _path; // dir or file
duke@435:   struct stat _st;
duke@435:   MetaIndex* _meta_index;
duke@435:   volatile ClassPathEntry* _resolved_entry;
duke@435:   ClassPathEntry* resolve_entry();
duke@435:  public:
duke@435:   bool is_jar_file();
duke@435:   const char* name()  { return _path; }
duke@435:   LazyClassPathEntry(char* path, struct stat st);
duke@435:   ClassFileStream* open_stream(const char* name);
duke@435:   void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; }
duke@435:   virtual bool is_lazy();
duke@435:   // Debugging
duke@435:   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
duke@435:   NOT_PRODUCT(bool is_rt_jar();)
duke@435: };
duke@435: 
duke@435: class PackageHashtable;
duke@435: class PackageInfo;
duke@435: class HashtableBucket;
duke@435: 
duke@435: class ClassLoader: AllStatic {
duke@435:  public:
duke@435:   enum SomeConstants {
duke@435:     package_hash_table_size = 31  // Number of buckets
duke@435:   };
duke@435:  private:
duke@435:   friend class LazyClassPathEntry;
duke@435: 
duke@435:   // Performance counters
duke@435:   static PerfCounter* _perf_accumulated_time;
duke@435:   static PerfCounter* _perf_classes_inited;
duke@435:   static PerfCounter* _perf_class_init_time;
mchung@1310:   static PerfCounter* _perf_class_init_selftime;
mchung@1310:   static PerfCounter* _perf_classes_verified;
duke@435:   static PerfCounter* _perf_class_verify_time;
mchung@1310:   static PerfCounter* _perf_class_verify_selftime;
duke@435:   static PerfCounter* _perf_classes_linked;
duke@435:   static PerfCounter* _perf_class_link_time;
mchung@1310:   static PerfCounter* _perf_class_link_selftime;
mchung@1310:   static PerfCounter* _perf_class_parse_time;
mchung@1310:   static PerfCounter* _perf_class_parse_selftime;
mchung@1310:   static PerfCounter* _perf_sys_class_lookup_time;
mchung@1310:   static PerfCounter* _perf_shared_classload_time;
mchung@1310:   static PerfCounter* _perf_sys_classload_time;
mchung@1310:   static PerfCounter* _perf_app_classload_time;
mchung@1310:   static PerfCounter* _perf_app_classload_selftime;
mchung@1310:   static PerfCounter* _perf_app_classload_count;
mchung@1310:   static PerfCounter* _perf_define_appclasses;
mchung@1310:   static PerfCounter* _perf_define_appclass_time;
mchung@1310:   static PerfCounter* _perf_define_appclass_selftime;
mchung@1310:   static PerfCounter* _perf_app_classfile_bytes_read;
mchung@1310:   static PerfCounter* _perf_sys_classfile_bytes_read;
duke@435: 
duke@435:   static PerfCounter* _sync_systemLoaderLockContentionRate;
duke@435:   static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
duke@435:   static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
duke@435:   static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
duke@435:   static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
duke@435: 
duke@435:   static PerfCounter* _unsafe_defineClassCallCounter;
duke@435:   static PerfCounter* _isUnsyncloadClass;
duke@435:   static PerfCounter* _load_instance_class_failCounter;
duke@435: 
duke@435:   // First entry in linked list of ClassPathEntry instances
duke@435:   static ClassPathEntry* _first_entry;
duke@435:   // Last entry in linked list of ClassPathEntry instances
duke@435:   static ClassPathEntry* _last_entry;
duke@435:   // Hash table used to keep track of loaded packages
duke@435:   static PackageHashtable* _package_hash_table;
duke@435:   static const char* _shared_archive;
duke@435: 
duke@435:   // Hash function
duke@435:   static unsigned int hash(const char *s, int n);
duke@435:   // Returns the package file name corresponding to the specified package
duke@435:   // or class name, or null if not found.
duke@435:   static PackageInfo* lookup_package(const char *pkgname);
duke@435:   // Adds a new package entry for the specified class or package name and
duke@435:   // corresponding directory or jar file name.
duke@435:   static bool add_package(const char *pkgname, int classpath_index, TRAPS);
duke@435: 
duke@435:   // Initialization
duke@435:   static void setup_meta_index();
duke@435:   static void setup_bootstrap_search_path();
duke@435:   static void load_zip_library();
duke@435:   static void create_class_path_entry(char *path, struct stat st, ClassPathEntry **new_entry, bool lazy);
duke@435: 
duke@435:   // Canonicalizes path names, so strcmp will work properly. This is mainly
duke@435:   // to avoid confusing the zip library
duke@435:   static bool get_canonical_path(char* orig, char* out, int len);
duke@435:  public:
duke@435:   // Used by the kernel jvm.
duke@435:   static void update_class_path_entry_list(const char *path,
duke@435:                                            bool check_for_duplicates);
duke@435:   static void print_bootclasspath();
duke@435: 
duke@435:   // Timing
mchung@1310:   static PerfCounter* perf_accumulated_time()         { return _perf_accumulated_time; }
mchung@1310:   static PerfCounter* perf_classes_inited()           { return _perf_classes_inited; }
mchung@1310:   static PerfCounter* perf_class_init_time()          { return _perf_class_init_time; }
mchung@1310:   static PerfCounter* perf_class_init_selftime()      { return _perf_class_init_selftime; }
mchung@1310:   static PerfCounter* perf_classes_verified()         { return _perf_classes_verified; }
mchung@1310:   static PerfCounter* perf_class_verify_time()        { return _perf_class_verify_time; }
mchung@1310:   static PerfCounter* perf_class_verify_selftime()    { return _perf_class_verify_selftime; }
mchung@1310:   static PerfCounter* perf_classes_linked()           { return _perf_classes_linked; }
mchung@1310:   static PerfCounter* perf_class_link_time()          { return _perf_class_link_time; }
mchung@1310:   static PerfCounter* perf_class_link_selftime()      { return _perf_class_link_selftime; }
mchung@1310:   static PerfCounter* perf_class_parse_time()         { return _perf_class_parse_time; }
mchung@1310:   static PerfCounter* perf_class_parse_selftime()     { return _perf_class_parse_selftime; }
mchung@1310:   static PerfCounter* perf_sys_class_lookup_time()    { return _perf_sys_class_lookup_time; }
mchung@1310:   static PerfCounter* perf_shared_classload_time()    { return _perf_shared_classload_time; }
mchung@1310:   static PerfCounter* perf_sys_classload_time()       { return _perf_sys_classload_time; }
mchung@1310:   static PerfCounter* perf_app_classload_time()       { return _perf_app_classload_time; }
mchung@1310:   static PerfCounter* perf_app_classload_selftime()   { return _perf_app_classload_selftime; }
mchung@1310:   static PerfCounter* perf_app_classload_count()      { return _perf_app_classload_count; }
mchung@1310:   static PerfCounter* perf_define_appclasses()        { return _perf_define_appclasses; }
mchung@1310:   static PerfCounter* perf_define_appclass_time()     { return _perf_define_appclass_time; }
mchung@1310:   static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
mchung@1310:   static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
mchung@1310:   static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
duke@435: 
duke@435:   // Record how often system loader lock object is contended
duke@435:   static PerfCounter* sync_systemLoaderLockContentionRate() {
duke@435:     return _sync_systemLoaderLockContentionRate;
duke@435:   }
duke@435: 
duke@435:   // Record how often non system loader lock object is contended
duke@435:   static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
duke@435:     return _sync_nonSystemLoaderLockContentionRate;
duke@435:   }
duke@435: 
duke@435:   // Record how many calls to JVM_FindLoadedClass w/o holding a lock
duke@435:   static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
duke@435:     return _sync_JVMFindLoadedClassLockFreeCounter;
duke@435:   }
duke@435: 
duke@435:   // Record how many calls to JVM_DefineClass w/o holding a lock
duke@435:   static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
duke@435:     return _sync_JVMDefineClassLockFreeCounter;
duke@435:   }
duke@435: 
duke@435:   // Record how many calls to jni_DefineClass w/o holding a lock
duke@435:   static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
duke@435:     return _sync_JNIDefineClassLockFreeCounter;
duke@435:   }
duke@435: 
duke@435:   // Record how many calls to Unsafe_DefineClass
duke@435:   static PerfCounter* unsafe_defineClassCallCounter() {
duke@435:     return _unsafe_defineClassCallCounter;
duke@435:   }
duke@435: 
duke@435:   // Record how many times SystemDictionary::load_instance_class call
duke@435:   // fails with linkageError when Unsyncloadclass flag is set.
duke@435:   static PerfCounter* load_instance_class_failCounter() {
duke@435:     return _load_instance_class_failCounter;
duke@435:   }
duke@435: 
duke@435:   // Load individual .class file
duke@435:   static instanceKlassHandle load_classfile(symbolHandle h_name, TRAPS);
duke@435: 
duke@435:   // If the specified package has been loaded by the system, then returns
duke@435:   // the name of the directory or ZIP file that the package was loaded from.
duke@435:   // Returns null if the package was not loaded.
duke@435:   // Note: The specified name can either be the name of a class or package.
duke@435:   // If a package name is specified, then it must be "/"-separator and also
duke@435:   // end with a trailing "/".
duke@435:   static oop get_system_package(const char* name, TRAPS);
duke@435: 
duke@435:   // Returns an array of Java strings representing all of the currently
duke@435:   // loaded system packages.
duke@435:   // Note: The package names returned are "/"-separated and end with a
duke@435:   // trailing "/".
duke@435:   static objArrayOop get_system_packages(TRAPS);
duke@435: 
duke@435:   // Initialization
duke@435:   static void initialize();
duke@435:   static void create_package_info_table();
duke@435:   static void create_package_info_table(HashtableBucket *t, int length,
duke@435:                                         int number_of_entries);
duke@435:   static int compute_Object_vtable();
duke@435: 
duke@435:   static ClassPathEntry* classpath_entry(int n) {
duke@435:     ClassPathEntry* e = ClassLoader::_first_entry;
duke@435:     while (--n >= 0) {
duke@435:       assert(e != NULL, "Not that many classpath entries.");
duke@435:       e = e->next();
duke@435:     }
duke@435:     return e;
duke@435:   }
duke@435: 
duke@435:   // Sharing dump and restore
duke@435:   static void copy_package_info_buckets(char** top, char* end);
duke@435:   static void copy_package_info_table(char** top, char* end);
duke@435: 
duke@435:   // VM monitoring and management support
duke@435:   static jlong classloader_time_ms();
duke@435:   static jlong class_method_total_size();
duke@435:   static jlong class_init_count();
duke@435:   static jlong class_init_time_ms();
duke@435:   static jlong class_verify_time_ms();
duke@435:   static jlong class_link_count();
duke@435:   static jlong class_link_time_ms();
duke@435: 
duke@435:   // indicates if class path already contains a entry (exact match by name)
duke@435:   static bool contains_entry(ClassPathEntry* entry);
duke@435: 
duke@435:   // adds a class path list
duke@435:   static void add_to_list(ClassPathEntry* new_entry);
duke@435: 
duke@435:   // creates a class path zip entry (returns NULL if JAR file cannot be opened)
duke@435:   static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
duke@435: 
duke@435:   // Debugging
duke@435:   static void verify()              PRODUCT_RETURN;
duke@435: 
duke@435:   // Force compilation of all methods in all classes in bootstrap class path (stress test)
duke@435: #ifndef PRODUCT
duke@435:  private:
duke@435:   static int _compile_the_world_counter;
duke@435:  public:
duke@435:   static void compile_the_world();
duke@435:   static void compile_the_world_in(char* name, Handle loader, TRAPS);
duke@435:   static int  compile_the_world_counter() { return _compile_the_world_counter; }
duke@435: #endif //PRODUCT
duke@435: };
mchung@1310: 
mchung@1310: // PerfClassTraceTime is used to measure time for class loading related events.
mchung@1310: // This class tracks cumulative time and exclusive time for specific event types.
mchung@1310: // During the execution of one event, other event types (e.g. class loading and
mchung@1310: // resolution) as well as recursive calls of the same event type could happen.
mchung@1310: // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
mchung@1310: // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
mchung@1310: // instances have been created as multiple events are happening.
mchung@1310: class PerfClassTraceTime {
mchung@1310:   public:
mchung@1310:     enum {
mchung@1310:        CLASS_LOAD   = 0,
mchung@1310:        PARSE_CLASS  = 1,
mchung@1310:        CLASS_LINK   = 2,
mchung@1310:        CLASS_VERIFY = 3,
mchung@1310:        CLASS_CLINIT = 4,
mchung@1310:        DEFINE_CLASS = 5,
mchung@1310:        EVENT_TYPE_COUNT = 6
mchung@1310:     };
mchung@1310:   protected:
mchung@1310:     // _t tracks time from initialization to destruction of this timer instance
mchung@1310:     // including time for all other event types, and recursive calls of this type.
mchung@1310:     // When a timer is called recursively, the elapsedTimer _t would not be used.
mchung@1310:     elapsedTimer     _t;
mchung@1310:     PerfLongCounter* _timep;
mchung@1310:     PerfLongCounter* _selftimep;
mchung@1310:     PerfLongCounter* _eventp;
mchung@1310:     // pointer to thread-local recursion counter and timer array
mchung@1310:     // The thread_local timers track cumulative time for specific event types
mchung@1310:     // exclusive of time for other event types, but including recursive calls
mchung@1310:     // of the same type.
mchung@1310:     int*             _recursion_counters;
mchung@1310:     elapsedTimer*    _timers;
mchung@1310:     int              _event_type;
mchung@1310:     int              _prev_active_event;
mchung@1310: 
mchung@1310:   public:
mchung@1310: 
mchung@1310:     inline PerfClassTraceTime(PerfLongCounter* timep,     /* counter incremented with inclusive time */
mchung@1310:                               PerfLongCounter* selftimep, /* counter incremented with exclusive time */
mchung@1310:                               PerfLongCounter* eventp,    /* event counter */
mchung@1310:                               int* recursion_counters,    /* thread-local recursion counter array */
mchung@1310:                               elapsedTimer* timers,       /* thread-local timer array */
mchung@1310:                               int type                    /* event type */ ) :
mchung@1310:         _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
mchung@1310:       initialize();
mchung@1310:     }
mchung@1310: 
mchung@1310:     inline PerfClassTraceTime(PerfLongCounter* timep,     /* counter incremented with inclusive time */
mchung@1310:                               elapsedTimer* timers,       /* thread-local timer array */
mchung@1310:                               int type                    /* event type */ ) :
mchung@1310:         _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
mchung@1310:       initialize();
mchung@1310:     }
mchung@1310: 
mchung@1310:     void initialize() {
mchung@1310:       if (!UsePerfData) return;
mchung@1310: 
mchung@1310:       if (_eventp != NULL) {
mchung@1310:         // increment the event counter
mchung@1310:         _eventp->inc();
mchung@1310:       }
mchung@1310: 
mchung@1310:       // stop the current active thread-local timer to measure inclusive time
mchung@1310:       _prev_active_event = -1;
mchung@1310:       for (int i=0; i < EVENT_TYPE_COUNT; i++) {
mchung@1310:          if (_timers[i].is_active()) {
mchung@1310:            assert(_prev_active_event == -1, "should have only one active timer");
mchung@1310:            _prev_active_event = i;
mchung@1310:            _timers[i].stop();
mchung@1310:          }
mchung@1310:       }
mchung@1310: 
mchung@1310:       if (_recursion_counters == NULL || (_recursion_counters[_event_type])++ == 0) {
mchung@1310:         // start the inclusive timer if not recursively called
mchung@1310:         _t.start();
mchung@1310:       }
mchung@1310: 
mchung@1310:       // start thread-local timer of the given event type
mchung@1310:       if (!_timers[_event_type].is_active()) {
mchung@1310:         _timers[_event_type].start();
mchung@1310:       }
mchung@1310:     }
mchung@1310: 
mchung@1310:     inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
mchung@1310:     inline void resume()  { _t.start(); _timers[_event_type].start(); }
mchung@1310: 
mchung@1310:     ~PerfClassTraceTime() {
mchung@1310:       if (!UsePerfData) return;
mchung@1310: 
mchung@1310:       // stop the thread-local timer as the event completes
mchung@1310:       // and resume the thread-local timer of the event next on the stack
mchung@1310:       _timers[_event_type].stop();
mchung@1310:       jlong selftime = _timers[_event_type].ticks();
mchung@1310: 
mchung@1310:       if (_prev_active_event >= 0) {
mchung@1310:         _timers[_prev_active_event].start();
mchung@1310:       }
mchung@1310: 
mchung@1310:       if (_recursion_counters != NULL && --(_recursion_counters[_event_type]) > 0) return;
mchung@1310: 
mchung@1310:       // increment the counters only on the leaf call
mchung@1310:       _t.stop();
mchung@1310:       _timep->inc(_t.ticks());
mchung@1310:       if (_selftimep != NULL) {
mchung@1310:         _selftimep->inc(selftime);
mchung@1310:       }
mchung@1310:       // add all class loading related event selftime to the accumulated time counter
mchung@1310:       ClassLoader::perf_accumulated_time()->inc(selftime);
mchung@1310: 
mchung@1310:       // reset the timer
mchung@1310:       _timers[_event_type].reset();
mchung@1310:     }
mchung@1310: };
mchung@1310: