1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_CLASSFILE_CLASSLOADER_HPP
  26 #define SHARE_VM_CLASSFILE_CLASSLOADER_HPP
  27 
  28 #include "runtime/orderAccess.hpp"
  29 #include "runtime/perfData.hpp"
  30 #include "utilities/exceptions.hpp"
  31 #include "utilities/macros.hpp"
  32 
  33 // The VM class loader.
  34 #include <sys/stat.h>
  35 
  36 // Name of boot module image
  37 #define  BOOT_IMAGE_NAME "bootmodules.jimage"
  38 
  39 class JImageFile;
  40 class ClassFileStream;
  41 
  42 class ClassPathEntry : public CHeapObj<mtClass> {
  43 private:
  44   ClassPathEntry* _next;
  45 public:
  46   // Next entry in class path
  47   ClassPathEntry* next() const { return _next; }
  48   void set_next(ClassPathEntry* next) {
  49     // may have unlocked readers, so write atomically.
  50     OrderAccess::release_store_ptr(&_next, next);
  51   }
  52   virtual bool is_jar_file() const = 0;
  53   virtual const char* name() const = 0;
  54   virtual JImageFile* jimage() const = 0;
  55   // Constructor
  56   ClassPathEntry() : _next(NULL) {}
  57   // Attempt to locate file_name through this class path entry.
  58   // Returns a class file parsing stream if successfull.
  59   virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
  60   // Debugging
  61   NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
  62     NOT_PRODUCT(virtual bool is_jrt() = 0;)
  63 };
  64 
  65 class ClassPathDirEntry: public ClassPathEntry {
  66  private:
  67   const char* _dir;           // Name of directory
  68  public:
  69   bool is_jar_file() const { return false;  }
  70   const char* name() const { return _dir; }
  71   JImageFile* jimage() const { return NULL; }
  72   ClassPathDirEntry(const char* dir);
  73   ClassFileStream* open_stream(const char* name, TRAPS);
  74   // Debugging
  75   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
  76   NOT_PRODUCT(bool is_jrt();)
  77 };
  78 
  79 
  80 // Type definitions for zip file and zip file entry
  81 typedef void* jzfile;
  82 typedef struct {
  83   char *name;                   /* entry name */
  84   jlong time;                   /* modification time */
  85   jlong size;                   /* size of uncompressed data */
  86   jlong csize;                  /* size of compressed data (zero if uncompressed) */
  87   jint crc;                     /* crc of uncompressed data */
  88   char *comment;                /* optional zip file comment */
  89   jbyte *extra;                 /* optional extra data */
  90   jlong pos;                    /* position of LOC header (if negative) or data */
  91 } jzentry;
  92 
  93 
  94 class ClassPathZipEntry: public ClassPathEntry {
  95  private:
  96   jzfile* _zip;              // The zip archive
  97   const char*   _zip_name;   // Name of zip archive
  98  public:
  99   bool is_jar_file() const { return true;  }
 100   const char* name() const { return _zip_name; }
 101   JImageFile* jimage() const { return NULL; }
 102   ClassPathZipEntry(jzfile* zip, const char* zip_name);
 103   ~ClassPathZipEntry();
 104   u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
 105   ClassFileStream* open_stream(const char* name, TRAPS);
 106   void contents_do(void f(const char* name, void* context), void* context);
 107   // Debugging
 108   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
 109   NOT_PRODUCT(bool is_jrt();)
 110 };
 111 
 112 
 113 // For java image files
 114 class ClassPathImageEntry: public ClassPathEntry {
 115 private:
 116   JImageFile* _jimage;
 117   const char* _name;
 118 public:
 119   bool is_jar_file() const { return false; }
 120   bool is_open() const { return _jimage != NULL; }
 121   const char* name() const { return _name == NULL ? "" : _name; }
 122   JImageFile* jimage() const { return _jimage; }
 123   ClassPathImageEntry(JImageFile* jimage, const char* name);
 124   ~ClassPathImageEntry();
 125   static void name_to_package(const char* name, char* buffer, int length);
 126   ClassFileStream* open_stream(const char* name, TRAPS);
 127 
 128   // Debugging
 129   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
 130   NOT_PRODUCT(bool is_jrt();)
 131 };
 132 
 133 class PackageHashtable;
 134 class PackageInfo;
 135 class SharedPathsMiscInfo;
 136 template <MEMFLAGS F> class HashtableBucket;
 137 
 138 class ClassLoader: AllStatic {
 139  public:
 140   enum SomeConstants {
 141     package_hash_table_size = 31  // Number of buckets
 142   };
 143  protected:
 144 
 145   // Performance counters
 146   static PerfCounter* _perf_accumulated_time;
 147   static PerfCounter* _perf_classes_inited;
 148   static PerfCounter* _perf_class_init_time;
 149   static PerfCounter* _perf_class_init_selftime;
 150   static PerfCounter* _perf_classes_verified;
 151   static PerfCounter* _perf_class_verify_time;
 152   static PerfCounter* _perf_class_verify_selftime;
 153   static PerfCounter* _perf_classes_linked;
 154   static PerfCounter* _perf_class_link_time;
 155   static PerfCounter* _perf_class_link_selftime;
 156   static PerfCounter* _perf_class_parse_time;
 157   static PerfCounter* _perf_class_parse_selftime;
 158   static PerfCounter* _perf_sys_class_lookup_time;
 159   static PerfCounter* _perf_shared_classload_time;
 160   static PerfCounter* _perf_sys_classload_time;
 161   static PerfCounter* _perf_app_classload_time;
 162   static PerfCounter* _perf_app_classload_selftime;
 163   static PerfCounter* _perf_app_classload_count;
 164   static PerfCounter* _perf_define_appclasses;
 165   static PerfCounter* _perf_define_appclass_time;
 166   static PerfCounter* _perf_define_appclass_selftime;
 167   static PerfCounter* _perf_app_classfile_bytes_read;
 168   static PerfCounter* _perf_sys_classfile_bytes_read;
 169 
 170   static PerfCounter* _sync_systemLoaderLockContentionRate;
 171   static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
 172   static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
 173   static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
 174   static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
 175 
 176   static PerfCounter* _unsafe_defineClassCallCounter;
 177   static PerfCounter* _isUnsyncloadClass;
 178   static PerfCounter* _load_instance_class_failCounter;
 179 
 180   // First entry in linked list of ClassPathEntry instances
 181   static ClassPathEntry* _first_entry;
 182   // Last entry in linked list of ClassPathEntry instances
 183   static ClassPathEntry* _last_entry;
 184   static int _num_entries;
 185 
 186   // Hash table used to keep track of loaded packages
 187   static PackageHashtable* _package_hash_table;
 188   static const char* _shared_archive;
 189 
 190   // Info used by CDS
 191   CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
 192 
 193   // Hash function
 194   static unsigned int hash(const char *s, int n);
 195   // Returns the package file name corresponding to the specified package
 196   // or class name, or null if not found.
 197   static PackageInfo* lookup_package(const char *pkgname);
 198   // Adds a new package entry for the specified class or package name and
 199   // corresponding directory or jar file name.
 200   static bool add_package(const char *pkgname, int classpath_index, TRAPS);
 201 
 202   // Initialization
 203   static void setup_bootstrap_search_path();
 204   static void setup_search_path(const char *class_path);
 205 
 206   static void load_zip_library();
 207   static void load_jimage_library();
 208   static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
 209                                                  bool throw_exception, TRAPS);
 210 
 211   // Canonicalizes path names, so strcmp will work properly. This is mainly
 212   // to avoid confusing the zip library
 213   static bool get_canonical_path(const char* orig, char* out, int len);
 214 
 215   static const char* file_name_for_class_name(const char* class_name,
 216                                               int class_name_len);
 217 
 218  public:
 219   static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
 220   static int crc32(int crc, const char* buf, int len);
 221   static bool update_class_path_entry_list(const char *path,
 222                                            bool check_for_duplicates,
 223                                            bool throw_exception=true);
 224   static void print_bootclasspath();
 225 
 226   // Timing
 227   static PerfCounter* perf_accumulated_time()         { return _perf_accumulated_time; }
 228   static PerfCounter* perf_classes_inited()           { return _perf_classes_inited; }
 229   static PerfCounter* perf_class_init_time()          { return _perf_class_init_time; }
 230   static PerfCounter* perf_class_init_selftime()      { return _perf_class_init_selftime; }
 231   static PerfCounter* perf_classes_verified()         { return _perf_classes_verified; }
 232   static PerfCounter* perf_class_verify_time()        { return _perf_class_verify_time; }
 233   static PerfCounter* perf_class_verify_selftime()    { return _perf_class_verify_selftime; }
 234   static PerfCounter* perf_classes_linked()           { return _perf_classes_linked; }
 235   static PerfCounter* perf_class_link_time()          { return _perf_class_link_time; }
 236   static PerfCounter* perf_class_link_selftime()      { return _perf_class_link_selftime; }
 237   static PerfCounter* perf_class_parse_time()         { return _perf_class_parse_time; }
 238   static PerfCounter* perf_class_parse_selftime()     { return _perf_class_parse_selftime; }
 239   static PerfCounter* perf_sys_class_lookup_time()    { return _perf_sys_class_lookup_time; }
 240   static PerfCounter* perf_shared_classload_time()    { return _perf_shared_classload_time; }
 241   static PerfCounter* perf_sys_classload_time()       { return _perf_sys_classload_time; }
 242   static PerfCounter* perf_app_classload_time()       { return _perf_app_classload_time; }
 243   static PerfCounter* perf_app_classload_selftime()   { return _perf_app_classload_selftime; }
 244   static PerfCounter* perf_app_classload_count()      { return _perf_app_classload_count; }
 245   static PerfCounter* perf_define_appclasses()        { return _perf_define_appclasses; }
 246   static PerfCounter* perf_define_appclass_time()     { return _perf_define_appclass_time; }
 247   static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
 248   static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
 249   static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
 250 
 251   // Record how often system loader lock object is contended
 252   static PerfCounter* sync_systemLoaderLockContentionRate() {
 253     return _sync_systemLoaderLockContentionRate;
 254   }
 255 
 256   // Record how often non system loader lock object is contended
 257   static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
 258     return _sync_nonSystemLoaderLockContentionRate;
 259   }
 260 
 261   // Record how many calls to JVM_FindLoadedClass w/o holding a lock
 262   static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
 263     return _sync_JVMFindLoadedClassLockFreeCounter;
 264   }
 265 
 266   // Record how many calls to JVM_DefineClass w/o holding a lock
 267   static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
 268     return _sync_JVMDefineClassLockFreeCounter;
 269   }
 270 
 271   // Record how many calls to jni_DefineClass w/o holding a lock
 272   static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
 273     return _sync_JNIDefineClassLockFreeCounter;
 274   }
 275 
 276   // Record how many calls to Unsafe_DefineClass
 277   static PerfCounter* unsafe_defineClassCallCounter() {
 278     return _unsafe_defineClassCallCounter;
 279   }
 280 
 281   // Record how many times SystemDictionary::load_instance_class call
 282   // fails with linkageError when Unsyncloadclass flag is set.
 283   static PerfCounter* load_instance_class_failCounter() {
 284     return _load_instance_class_failCounter;
 285   }
 286 
 287   // Load individual .class file
 288   static instanceKlassHandle load_class(Symbol* class_name, TRAPS);
 289 
 290   // If the specified package has been loaded by the system, then returns
 291   // the name of the directory or ZIP file that the package was loaded from.
 292   // Returns null if the package was not loaded.
 293   // Note: The specified name can either be the name of a class or package.
 294   // If a package name is specified, then it must be "/"-separator and also
 295   // end with a trailing "/".
 296   static oop get_system_package(const char* name, TRAPS);
 297 
 298   // Returns an array of Java strings representing all of the currently
 299   // loaded system packages.
 300   // Note: The package names returned are "/"-separated and end with a
 301   // trailing "/".
 302   static objArrayOop get_system_packages(TRAPS);
 303 
 304   // Initialization
 305   static void initialize();
 306   CDS_ONLY(static void initialize_shared_path();)
 307   static void create_package_info_table();
 308   static void create_package_info_table(HashtableBucket<mtClass> *t, int length,
 309                                         int number_of_entries);
 310   static int compute_Object_vtable();
 311 
 312   static ClassPathEntry* classpath_entry(int n) {
 313     ClassPathEntry* e = ClassLoader::_first_entry;
 314     while (--n >= 0) {
 315       assert(e != NULL, "Not that many classpath entries.");
 316       e = e->next();
 317     }
 318     return e;
 319   }
 320 
 321 #if INCLUDE_CDS
 322   // Sharing dump and restore
 323   static void copy_package_info_buckets(char** top, char* end);
 324   static void copy_package_info_table(char** top, char* end);
 325 
 326   static void  check_shared_classpath(const char *path);
 327   static void  finalize_shared_paths_misc_info();
 328   static int   get_shared_paths_misc_info_size();
 329   static void* get_shared_paths_misc_info();
 330   static bool  check_shared_paths_misc_info(void* info, int size);
 331   static void  exit_with_path_failure(const char* error, const char* message);
 332 #endif
 333 
 334   static void  trace_class_path(outputStream* out, const char* msg, const char* name = NULL);
 335 
 336   // VM monitoring and management support
 337   static jlong classloader_time_ms();
 338   static jlong class_method_total_size();
 339   static jlong class_init_count();
 340   static jlong class_init_time_ms();
 341   static jlong class_verify_time_ms();
 342   static jlong class_link_count();
 343   static jlong class_link_time_ms();
 344 
 345   // indicates if class path already contains a entry (exact match by name)
 346   static bool contains_entry(ClassPathEntry* entry);
 347 
 348   // adds a class path list
 349   static void add_to_list(ClassPathEntry* new_entry);
 350 
 351   // creates a class path zip entry (returns NULL if JAR file cannot be opened)
 352   static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
 353 
 354   // Debugging
 355   static void verify()              PRODUCT_RETURN;
 356 
 357   // Force compilation of all methods in all classes in bootstrap class path (stress test)
 358 #ifndef PRODUCT
 359  protected:
 360   static int _compile_the_world_class_counter;
 361   static int _compile_the_world_method_counter;
 362  public:
 363   static void compile_the_world();
 364   static void compile_the_world_in(char* name, Handle loader, TRAPS);
 365   static int  compile_the_world_counter() { return _compile_the_world_class_counter; }
 366 #endif //PRODUCT
 367 };
 368 
 369 // PerfClassTraceTime is used to measure time for class loading related events.
 370 // This class tracks cumulative time and exclusive time for specific event types.
 371 // During the execution of one event, other event types (e.g. class loading and
 372 // resolution) as well as recursive calls of the same event type could happen.
 373 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
 374 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
 375 // instances have been created as multiple events are happening.
 376 class PerfClassTraceTime {
 377  public:
 378   enum {
 379     CLASS_LOAD   = 0,
 380     PARSE_CLASS  = 1,
 381     CLASS_LINK   = 2,
 382     CLASS_VERIFY = 3,
 383     CLASS_CLINIT = 4,
 384     DEFINE_CLASS = 5,
 385     EVENT_TYPE_COUNT = 6
 386   };
 387  protected:
 388   // _t tracks time from initialization to destruction of this timer instance
 389   // including time for all other event types, and recursive calls of this type.
 390   // When a timer is called recursively, the elapsedTimer _t would not be used.
 391   elapsedTimer     _t;
 392   PerfLongCounter* _timep;
 393   PerfLongCounter* _selftimep;
 394   PerfLongCounter* _eventp;
 395   // pointer to thread-local recursion counter and timer array
 396   // The thread_local timers track cumulative time for specific event types
 397   // exclusive of time for other event types, but including recursive calls
 398   // of the same type.
 399   int*             _recursion_counters;
 400   elapsedTimer*    _timers;
 401   int              _event_type;
 402   int              _prev_active_event;
 403 
 404  public:
 405 
 406   inline PerfClassTraceTime(PerfLongCounter* timep,     /* counter incremented with inclusive time */
 407                             PerfLongCounter* selftimep, /* counter incremented with exclusive time */
 408                             PerfLongCounter* eventp,    /* event counter */
 409                             int* recursion_counters,    /* thread-local recursion counter array */
 410                             elapsedTimer* timers,       /* thread-local timer array */
 411                             int type                    /* event type */ ) :
 412       _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
 413     initialize();
 414   }
 415 
 416   inline PerfClassTraceTime(PerfLongCounter* timep,     /* counter incremented with inclusive time */
 417                             elapsedTimer* timers,       /* thread-local timer array */
 418                             int type                    /* event type */ ) :
 419       _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
 420     initialize();
 421   }
 422 
 423   inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
 424   inline void resume()  { _t.start(); _timers[_event_type].start(); }
 425 
 426   ~PerfClassTraceTime();
 427   void initialize();
 428 };
 429 
 430 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP
--- EOF ---