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src/hotspot/share/classfile/classLoader.hpp

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  1 /*
  2  * Copyright (c) 1997, 2025, 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  *

 82   }
 83   virtual ~ClassPathDirEntry();
 84   ClassFileStream* open_stream(JavaThread* current, const char* name);
 85 };
 86 
 87 class ClassPathZipEntry: public ClassPathEntry {
 88  private:
 89   jzfile* _zip;              // The zip archive
 90   const char*   _zip_name;   // Name of zip archive
 91  public:
 92   bool is_jar_file() const { return true;  }
 93   const char* name() const { return _zip_name; }
 94   ClassPathZipEntry(jzfile* zip, const char* zip_name);
 95   virtual ~ClassPathZipEntry();
 96   bool has_entry(JavaThread* current, const char* name);
 97   u1* open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate);
 98   ClassFileStream* open_stream(JavaThread* current, const char* name);
 99 };
100 
101 
102 // For java image files

103 class ClassPathImageEntry: public ClassPathEntry {
104 private:
105   const char* _name;
106   DEBUG_ONLY(static ClassPathImageEntry* _singleton;)
107 public:
108   bool is_modules_image() const;
109   const char* name() const { return _name == nullptr ? "" : _name; }
110   JImageFile* jimage() const;
111   JImageFile* jimage_non_null() const;
112   void close_jimage();
113   ClassPathImageEntry(JImageFile* jimage, const char* name);

114   virtual ~ClassPathImageEntry() { ShouldNotReachHere(); }

115   ClassFileStream* open_stream(JavaThread* current, const char* name);
116   ClassFileStream* open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data);
117 };
118 
119 // ModuleClassPathList contains a linked list of ClassPathEntry's
120 // that have been specified for a specific module.  Currently,
121 // the only way to specify a module/path pair is via the --patch-module
122 // command line option.
123 class ModuleClassPathList : public CHeapObj<mtClass> {
124 private:
125   Symbol* _module_name;
126   // First and last entries of class path entries for a specific module
127   ClassPathEntry* _module_first_entry;
128   ClassPathEntry* _module_last_entry;
129 public:
130   Symbol* module_name() const { return _module_name; }
131   ClassPathEntry* module_first_entry() const { return _module_first_entry; }
132   ModuleClassPathList(Symbol* module_name);
133   ~ModuleClassPathList();
134   void add_to_list(ClassPathEntry* new_entry);

184 
185   // Count the time taken to hash the scondary superclass arrays.
186   static PerfCounter* _perf_secondary_hash_time;
187   static PerfCounter* _perf_change_wx_time;
188 
189   // The boot class path consists of 3 ordered pieces:
190   //  1. the module/path pairs specified to --patch-module
191   //    --patch-module=<module>=<file>(<pathsep><file>)*
192   //  2. the base piece
193   //    [jimage | build with exploded modules]
194   //  3. boot loader append path
195   //    [-Xbootclasspath/a]; [jvmti appended entries]
196   //
197   // The boot loader must obey this order when attempting
198   // to load a class.
199 
200   // 1. Contains the module/path pairs specified to --patch-module
201   static GrowableArray<ModuleClassPathList*>* _patch_mod_entries;
202 
203   // 2. the base piece
204   //    Contains the ClassPathEntry of the modular java runtime image.
205   //    If no java runtime image is present, this indicates a
206   //    build with exploded modules is being used instead.
207   static ClassPathEntry* _jrt_entry;
208   static GrowableArray<ModuleClassPathList*>* _exploded_entries;
209   enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules
210 
211   // 3. the boot loader's append path
212   //    [-Xbootclasspath/a]; [jvmti appended entries]
213   //    Note: boot loader append path does not support named modules.
214   static ClassPathEntry* volatile _first_append_entry_list;
215   static ClassPathEntry* first_append_entry() {
216     return AtomicAccess::load_acquire(&_first_append_entry_list);
217   }
218 
219   // Last entry in linked list of appended ClassPathEntry instances
220   static ClassPathEntry* volatile _last_append_entry;
221 
222  public:
223 
224   static bool has_bootclasspath_append() { return first_append_entry() != nullptr; }
225 
226  protected:
227   // Initialization:

316   static ClassFileStream* search_module_entries(JavaThread* current,
317                                                 const GrowableArray<ModuleClassPathList*>* const module_list,
318                                                 PackageEntry* pkg_entry, // Java package entry derived from the class name
319                                                 const char* const file_name);
320 
321   // Load individual .class file
322   static InstanceKlass* load_class(Symbol* class_name, PackageEntry* pkg_entry, bool search_append_only, TRAPS);
323 
324   // If the specified package has been loaded by the system, then returns
325   // the name of the directory or ZIP file that the package was loaded from.
326   // Returns null if the package was not loaded.
327   // Note: The specified name can either be the name of a class or package.
328   // If a package name is specified, then it must be "/"-separator and also
329   // end with a trailing "/".
330   static oop get_system_package(const char* name, TRAPS);
331 
332   // Returns an array of Java strings representing all of the currently
333   // loaded system packages.
334   // Note: The package names returned are "/"-separated and end with a
335   // trailing "/".
336   static objArrayOop get_system_packages(TRAPS);
337 
338   // Initialization
339   static void initialize(TRAPS);
340   static void classLoader_init2(JavaThread* current);
341 
342   static int compute_Object_vtable();
343 
344   static ClassPathEntry* classpath_entry(int n);
345 
346   static bool is_in_patch_mod_entries(Symbol* module_name);
347 
348 #if INCLUDE_CDS
349   static char* uri_to_path(const char* uri);
350   static void  record_result(JavaThread* current, InstanceKlass* ik,
351                              const ClassFileStream* stream, bool redefined);
352   static void record_result_for_builtin_loader(s2 classpath_index, InstanceKlass* result, bool redefined);
353   static void record_hidden_class(InstanceKlass* ik);
354   static void append_boot_classpath(ClassPathEntry* new_entry);
355 #endif
356 



357   static char* lookup_vm_options();
358 





359   // Determines if the named module is present in the
360   // modules jimage file or in the exploded modules directory.
361   static bool is_module_observable(const char* module_name);
362 
363   static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name,
364                                                 const char* file_name, jlong &size);
365 
366   static void  trace_class_path(const char* msg, const char* name = nullptr);
367 
368   // VM monitoring and management support
369   static jlong classloader_time_ms();
370   static jlong class_method_total_size();
371   static jlong class_init_count();
372   static jlong class_init_time_ms();
373   static jlong class_verify_time_ms();
374   static jlong class_link_count();
375   static jlong class_link_time_ms();
376 
377   // adds a class path to the boot append entries
378   static void add_to_boot_append_entries(ClassPathEntry* new_entry);
379 
380   // creates a class path zip entry (returns null if JAR file cannot be opened)
381   static ClassPathZipEntry* create_class_path_zip_entry(const char *path);
382 
383   static bool string_ends_with(const char* str, const char* str_to_find);
384 
385   // Extract package name from a fully qualified class name

  1 /*
  2  * Copyright (c) 1997, 2026, 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  *

 82   }
 83   virtual ~ClassPathDirEntry();
 84   ClassFileStream* open_stream(JavaThread* current, const char* name);
 85 };
 86 
 87 class ClassPathZipEntry: public ClassPathEntry {
 88  private:
 89   jzfile* _zip;              // The zip archive
 90   const char*   _zip_name;   // Name of zip archive
 91  public:
 92   bool is_jar_file() const { return true;  }
 93   const char* name() const { return _zip_name; }
 94   ClassPathZipEntry(jzfile* zip, const char* zip_name);
 95   virtual ~ClassPathZipEntry();
 96   bool has_entry(JavaThread* current, const char* name);
 97   u1* open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate);
 98   ClassFileStream* open_stream(JavaThread* current, const char* name);
 99 };
100 
101 
102 // A singleton path entry which takes ownership of the initialized JImageFile
103 // reference. Not used for exploded builds.
104 class ClassPathImageEntry: public ClassPathEntry {
105 private:
106   const char* _name;
107   DEBUG_ONLY(static ClassPathImageEntry* _singleton;)
108 public:
109   bool is_modules_image() const;
110   const char* name() const { return _name == nullptr ? "" : _name; }
111   // Called to close the JImage during os::abort (normally not called).

112   void close_jimage();
113   // Takes effective ownership of the static JImageFile pointer.
114   ClassPathImageEntry(const char* name);
115   virtual ~ClassPathImageEntry() { ShouldNotReachHere(); }
116 
117   ClassFileStream* open_stream(JavaThread* current, const char* name);
118   ClassFileStream* open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data);
119 };
120 
121 // ModuleClassPathList contains a linked list of ClassPathEntry's
122 // that have been specified for a specific module.  Currently,
123 // the only way to specify a module/path pair is via the --patch-module
124 // command line option.
125 class ModuleClassPathList : public CHeapObj<mtClass> {
126 private:
127   Symbol* _module_name;
128   // First and last entries of class path entries for a specific module
129   ClassPathEntry* _module_first_entry;
130   ClassPathEntry* _module_last_entry;
131 public:
132   Symbol* module_name() const { return _module_name; }
133   ClassPathEntry* module_first_entry() const { return _module_first_entry; }
134   ModuleClassPathList(Symbol* module_name);
135   ~ModuleClassPathList();
136   void add_to_list(ClassPathEntry* new_entry);

186 
187   // Count the time taken to hash the scondary superclass arrays.
188   static PerfCounter* _perf_secondary_hash_time;
189   static PerfCounter* _perf_change_wx_time;
190 
191   // The boot class path consists of 3 ordered pieces:
192   //  1. the module/path pairs specified to --patch-module
193   //    --patch-module=<module>=<file>(<pathsep><file>)*
194   //  2. the base piece
195   //    [jimage | build with exploded modules]
196   //  3. boot loader append path
197   //    [-Xbootclasspath/a]; [jvmti appended entries]
198   //
199   // The boot loader must obey this order when attempting
200   // to load a class.
201 
202   // 1. Contains the module/path pairs specified to --patch-module
203   static GrowableArray<ModuleClassPathList*>* _patch_mod_entries;
204 
205   // 2. the base piece
206   //    Contains the ClassPathImageEntry of the modular java runtime image.
207   //    If no java runtime image is present, this indicates a
208   //    build with exploded modules is being used instead.
209   static ClassPathImageEntry* _jrt_entry;
210   static GrowableArray<ModuleClassPathList*>* _exploded_entries;
211   enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules
212 
213   // 3. the boot loader's append path
214   //    [-Xbootclasspath/a]; [jvmti appended entries]
215   //    Note: boot loader append path does not support named modules.
216   static ClassPathEntry* volatile _first_append_entry_list;
217   static ClassPathEntry* first_append_entry() {
218     return AtomicAccess::load_acquire(&_first_append_entry_list);
219   }
220 
221   // Last entry in linked list of appended ClassPathEntry instances
222   static ClassPathEntry* volatile _last_append_entry;
223 
224  public:
225 
226   static bool has_bootclasspath_append() { return first_append_entry() != nullptr; }
227 
228  protected:
229   // Initialization:

318   static ClassFileStream* search_module_entries(JavaThread* current,
319                                                 const GrowableArray<ModuleClassPathList*>* const module_list,
320                                                 PackageEntry* pkg_entry, // Java package entry derived from the class name
321                                                 const char* const file_name);
322 
323   // Load individual .class file
324   static InstanceKlass* load_class(Symbol* class_name, PackageEntry* pkg_entry, bool search_append_only, TRAPS);
325 
326   // If the specified package has been loaded by the system, then returns
327   // the name of the directory or ZIP file that the package was loaded from.
328   // Returns null if the package was not loaded.
329   // Note: The specified name can either be the name of a class or package.
330   // If a package name is specified, then it must be "/"-separator and also
331   // end with a trailing "/".
332   static oop get_system_package(const char* name, TRAPS);
333 
334   // Returns an array of Java strings representing all of the currently
335   // loaded system packages.
336   // Note: The package names returned are "/"-separated and end with a
337   // trailing "/".
338   static refArrayOop get_system_packages(TRAPS);
339 
340   // Initialization
341   static void initialize(TRAPS);
342   static void classLoader_init2(JavaThread* current);
343 
344   static int compute_Object_vtable();
345 
346   static ClassPathEntry* classpath_entry(int n);
347 
348   static bool is_in_patch_mod_entries(Symbol* module_name);
349 
350 #if INCLUDE_CDS
351   static char* uri_to_path(const char* uri);
352   static void  record_result(JavaThread* current, InstanceKlass* ik,
353                              const ClassFileStream* stream, bool redefined);
354   static void record_result_for_builtin_loader(s2 classpath_index, InstanceKlass* result, bool redefined);
355   static void record_hidden_class(InstanceKlass* ik);
356   static void append_boot_classpath(ClassPathEntry* new_entry);
357 #endif
358 
359   // Retrieves additional VM options prior to flags processing. Options held
360   // in the JImage file are retrieved without fully initializing it. (this is
361   // the only JImage lookup which can succeed before init_jimage() is called).
362   static char* lookup_vm_options();
363 
364   // Called once, after all flags are processed, to finish initializing the
365   // JImage file. Until this is called, jimage_find_resource(), and any other
366   // JImage resource lookups or access will fail.
367   static void set_preview_mode(bool enable_preview);
368 
369   // Determines if the named module is present in the
370   // modules jimage file or in the exploded modules directory.
371   static bool is_module_observable(const char* module_name);
372 



373   static void  trace_class_path(const char* msg, const char* name = nullptr);
374 
375   // VM monitoring and management support
376   static jlong classloader_time_ms();
377   static jlong class_method_total_size();
378   static jlong class_init_count();
379   static jlong class_init_time_ms();
380   static jlong class_verify_time_ms();
381   static jlong class_link_count();
382   static jlong class_link_time_ms();
383 
384   // adds a class path to the boot append entries
385   static void add_to_boot_append_entries(ClassPathEntry* new_entry);
386 
387   // creates a class path zip entry (returns null if JAR file cannot be opened)
388   static ClassPathZipEntry* create_class_path_zip_entry(const char *path);
389 
390   static bool string_ends_with(const char* str, const char* str_to_find);
391 
392   // Extract package name from a fully qualified class name
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