hotspot/src/share/vm/classfile/classLoader.hpp - platform/libcore - Git at Google

 /*
  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */

 // The VM class loader.
 #include <sys/stat.h>


 // Meta-index (optional, to be able to skip opening boot classpath jar files)
 class MetaIndex: public CHeapObj {
  private:
   char** _meta_package_names;
   int    _num_meta_package_names;
  public:
   MetaIndex(char** meta_package_names, int num_meta_package_names);
   ~MetaIndex();
   bool may_contain(const char* class_name);
 };


 // Class path entry (directory or zip file)

 class ClassPathEntry: public CHeapObj {
  private:
   ClassPathEntry* _next;
  public:
   // Next entry in class path
   ClassPathEntry* next()              { return _next; }
   void set_next(ClassPathEntry* next) {
     // may have unlocked readers, so write atomically.
     OrderAccess::release_store_ptr(&_next, next);
   }
   virtual bool is_jar_file() = 0;
   virtual const char* name() = 0;
   virtual bool is_lazy();
   // Constructor
   ClassPathEntry();
   // 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) = 0;
   // Debugging
   NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
   NOT_PRODUCT(virtual bool is_rt_jar() = 0;)
 };


 class ClassPathDirEntry: public ClassPathEntry {
  private:
   char* _dir;           // Name of directory
  public:
   bool is_jar_file()  { return false;  }
   const char* name()  { return _dir; }
   ClassPathDirEntry(char* dir);
   ClassFileStream* open_stream(const char* name);
   // Debugging
   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
   NOT_PRODUCT(bool is_rt_jar();)
 };


 // 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 {
  private:
   jzfile* _zip;        // The zip archive
   char*   _zip_name;   // Name of zip archive
  public:
   bool is_jar_file()  { return true;  }
   const char* name()  { return _zip_name; }
   ClassPathZipEntry(jzfile* zip, const char* zip_name);
   ~ClassPathZipEntry();
   ClassFileStream* open_stream(const char* name);
   void contents_do(void f(const char* name, void* context), void* context);
   // Debugging
   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
   NOT_PRODUCT(void compile_the_world12(Handle loader, TRAPS);) // JDK 1.2 version
   NOT_PRODUCT(void compile_the_world13(Handle loader, TRAPS);) // JDK 1.3 version
   NOT_PRODUCT(bool is_rt_jar();)
   NOT_PRODUCT(bool is_rt_jar12();)
   NOT_PRODUCT(bool is_rt_jar13();)
 };


 // For lazier loading of boot class path entries
 class LazyClassPathEntry: public ClassPathEntry {
  private:
   char* _path; // dir or file
   struct stat _st;
   MetaIndex* _meta_index;
   volatile ClassPathEntry* _resolved_entry;
   ClassPathEntry* resolve_entry();
  public:
   bool is_jar_file();
   const char* name()  { return _path; }
   LazyClassPathEntry(char* path, struct stat st);
   ClassFileStream* open_stream(const char* name);
   void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; }
   virtual bool is_lazy();
   // Debugging
   NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
   NOT_PRODUCT(bool is_rt_jar();)
 };

 class PackageHashtable;
 class PackageInfo;
 class HashtableBucket;

 class ClassLoader: AllStatic {
  public:
   enum SomeConstants {
     package_hash_table_size = 31  // Number of buckets
   };
  private:
   friend class LazyClassPathEntry;

   // Performance counters
   static PerfCounter* _perf_accumulated_time;
   static PerfCounter* _perf_classes_inited;
   static PerfCounter* _perf_class_init_time;
   static PerfCounter* _perf_class_verify_time;
   static PerfCounter* _perf_classes_linked;
   static PerfCounter* _perf_class_link_time;

   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;

   // First entry in linked list of ClassPathEntry instances
   static ClassPathEntry* _first_entry;
   // Last entry in linked list of ClassPathEntry instances
   static ClassPathEntry* _last_entry;
   // Hash table used to keep track of loaded packages
   static PackageHashtable* _package_hash_table;
   static const char* _shared_archive;

   // Hash function
   static unsigned int hash(const char *s, int n);
   // Returns the package file name corresponding to the specified package
   // or class name, or null if not found.
   static PackageInfo* lookup_package(const char *pkgname);
   // Adds a new package entry for the specified class or package name and
   // corresponding directory or jar file name.
   static bool add_package(const char *pkgname, int classpath_index, TRAPS);

   // Initialization
   static void setup_meta_index();
   static void setup_bootstrap_search_path();
   static void load_zip_library();
   static void create_class_path_entry(char *path, struct stat st, ClassPathEntry **new_entry, bool lazy);

   // Canonicalizes path names, so strcmp will work properly. This is mainly
   // to avoid confusing the zip library
   static bool get_canonical_path(char* orig, char* out, int len);
  public:
   // Used by the kernel jvm.
   static void update_class_path_entry_list(const char *path,
                                            bool check_for_duplicates);
   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_verify_time() { return _perf_class_verify_time; }
   static PerfCounter* perf_classes_linked()    { return _perf_classes_linked; }
   static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }

   // 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;
   }

   // Load individual .class file
   static instanceKlassHandle load_classfile(symbolHandle h_name, 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 create_package_info_table();
   static void create_package_info_table(HashtableBucket *t, int length,
                                         int number_of_entries);
   static int compute_Object_vtable();

   static ClassPathEntry* classpath_entry(int n) {
     ClassPathEntry* e = ClassLoader::_first_entry;
     while (--n >= 0) {
       assert(e != NULL, "Not that many classpath entries.");
       e = e->next();
     }
     return e;
   }

   // Sharing dump and restore
   static void copy_package_info_buckets(char** top, char* end);
   static void copy_package_info_table(char** top, char* end);

   // 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();

   // indicates if class path already contains a entry (exact match by name)
   static bool contains_entry(ClassPathEntry* entry);

   // 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);

   // Debugging
   static void verify()              PRODUCT_RETURN;

   // Force compilation of all methods in all classes in bootstrap class path (stress test)
 #ifndef PRODUCT
  private:
   static int _compile_the_world_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_counter; }
 #endif //PRODUCT
 };
	/*
	* Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
	* CA 95054 USA or visit www.sun.com if you need additional information or
	* have any questions.
	*
	*/

	// The VM class loader.
	#include <sys/stat.h>


	// Meta-index (optional, to be able to skip opening boot classpath jar files)
	class MetaIndex: public CHeapObj {
	private:
	char** _meta_package_names;
	int _num_meta_package_names;
	public:
	MetaIndex(char** meta_package_names, int num_meta_package_names);
	~MetaIndex();
	bool may_contain(const char* class_name);
	};


	// Class path entry (directory or zip file)

	class ClassPathEntry: public CHeapObj {
	private:
	ClassPathEntry* _next;
	public:
	// Next entry in class path
	ClassPathEntry* next() { return _next; }
	void set_next(ClassPathEntry* next) {
	// may have unlocked readers, so write atomically.
	OrderAccess::release_store_ptr(&_next, next);
	}
	virtual bool is_jar_file() = 0;
	virtual const char* name() = 0;
	virtual bool is_lazy();
	// Constructor
	ClassPathEntry();
	// 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) = 0;
	// Debugging
	NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
	NOT_PRODUCT(virtual bool is_rt_jar() = 0;)
	};


	class ClassPathDirEntry: public ClassPathEntry {
	private:
	char* _dir; // Name of directory
	public:
	bool is_jar_file() { return false; }
	const char* name() { return _dir; }
	ClassPathDirEntry(char* dir);
	ClassFileStream* open_stream(const char* name);
	// Debugging
	NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
	NOT_PRODUCT(bool is_rt_jar();)
	};


	// 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 {
	private:
	jzfile* _zip; // The zip archive
	char* _zip_name; // Name of zip archive
	public:
	bool is_jar_file() { return true; }
	const char* name() { return _zip_name; }
	ClassPathZipEntry(jzfile* zip, const char* zip_name);
	~ClassPathZipEntry();
	ClassFileStream* open_stream(const char* name);
	void contents_do(void f(const char* name, void* context), void* context);
	// Debugging
	NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
	NOT_PRODUCT(void compile_the_world12(Handle loader, TRAPS);) // JDK 1.2 version
	NOT_PRODUCT(void compile_the_world13(Handle loader, TRAPS);) // JDK 1.3 version
	NOT_PRODUCT(bool is_rt_jar();)
	NOT_PRODUCT(bool is_rt_jar12();)
	NOT_PRODUCT(bool is_rt_jar13();)
	};


	// For lazier loading of boot class path entries
	class LazyClassPathEntry: public ClassPathEntry {
	private:
	char* _path; // dir or file
	struct stat _st;
	MetaIndex* _meta_index;
	volatile ClassPathEntry* _resolved_entry;
	ClassPathEntry* resolve_entry();
	public:
	bool is_jar_file();
	const char* name() { return _path; }
	LazyClassPathEntry(char* path, struct stat st);
	ClassFileStream* open_stream(const char* name);
	void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; }
	virtual bool is_lazy();
	// Debugging
	NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
	NOT_PRODUCT(bool is_rt_jar();)
	};

	class PackageHashtable;
	class PackageInfo;
	class HashtableBucket;

	class ClassLoader: AllStatic {
	public:
	enum SomeConstants {
	package_hash_table_size = 31 // Number of buckets
	};
	private:
	friend class LazyClassPathEntry;

	// Performance counters
	static PerfCounter* _perf_accumulated_time;
	static PerfCounter* _perf_classes_inited;
	static PerfCounter* _perf_class_init_time;
	static PerfCounter* _perf_class_verify_time;
	static PerfCounter* _perf_classes_linked;
	static PerfCounter* _perf_class_link_time;

	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;

	// First entry in linked list of ClassPathEntry instances
	static ClassPathEntry* _first_entry;
	// Last entry in linked list of ClassPathEntry instances
	static ClassPathEntry* _last_entry;
	// Hash table used to keep track of loaded packages
	static PackageHashtable* _package_hash_table;
	static const char* _shared_archive;

	// Hash function
	static unsigned int hash(const char *s, int n);
	// Returns the package file name corresponding to the specified package
	// or class name, or null if not found.
	static PackageInfo* lookup_package(const char *pkgname);
	// Adds a new package entry for the specified class or package name and
	// corresponding directory or jar file name.
	static bool add_package(const char *pkgname, int classpath_index, TRAPS);

	// Initialization
	static void setup_meta_index();
	static void setup_bootstrap_search_path();
	static void load_zip_library();
	static void create_class_path_entry(char path, struct stat st, ClassPathEntry *new_entry, bool lazy);

	// Canonicalizes path names, so strcmp will work properly. This is mainly
	// to avoid confusing the zip library
	static bool get_canonical_path(char* orig, char* out, int len);
	public:
	// Used by the kernel jvm.
	static void update_class_path_entry_list(const char *path,
	bool check_for_duplicates);
	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_verify_time() { return _perf_class_verify_time; }
	static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
	static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }

	// 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;
	}

	// Load individual .class file
	static instanceKlassHandle load_classfile(symbolHandle h_name, 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 create_package_info_table();
	static void create_package_info_table(HashtableBucket *t, int length,
	int number_of_entries);
	static int compute_Object_vtable();

	static ClassPathEntry* classpath_entry(int n) {
	ClassPathEntry* e = ClassLoader::_first_entry;
	while (--n >= 0) {
	assert(e != NULL, "Not that many classpath entries.");
	e = e->next();
	}
	return e;
	}

	// Sharing dump and restore
	static void copy_package_info_buckets(char** top, char* end);
	static void copy_package_info_table(char** top, char* end);

	// 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();

	// indicates if class path already contains a entry (exact match by name)
	static bool contains_entry(ClassPathEntry* entry);

	// 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);

	// Debugging
	static void verify() PRODUCT_RETURN;

	// Force compilation of all methods in all classes in bootstrap class path (stress test)
	#ifndef PRODUCT
	private:
	static int _compile_the_world_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_counter; }
	#endif //PRODUCT
	};