1 // natClassLoader.cc - Implementation of java.lang.ClassLoader native methods.
3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation
5 This file is part of libgcj.
7 This software is copyrighted work licensed under the terms of the
8 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
11 /* Author: Kresten Krab Thorup <krab@gnu.org> */
22 #include <java-threads.h>
23 #include <java-interp.h>
25 #include <java/lang/Character.h>
26 #include <java/lang/Thread.h>
27 #include <java/lang/ClassLoader.h>
28 #include <gnu/gcj/runtime/VMClassLoader.h>
29 #include <java/lang/InternalError.h>
30 #include <java/lang/IllegalAccessError.h>
31 #include <java/lang/LinkageError.h>
32 #include <java/lang/NoClassDefFoundError.h>
33 #include <java/lang/ClassNotFoundException.h>
34 #include <java/lang/ClassCircularityError.h>
35 #include <java/lang/IncompatibleClassChangeError.h>
36 #include <java/lang/VirtualMachineError.h>
37 #include <java/lang/VMClassLoader.h>
38 #include <java/lang/reflect/Modifier.h>
39 #include <java/lang/Runtime.h>
40 #include <java/lang/StringBuffer.h>
41 #include <java/io/Serializable.h>
42 #include <java/lang/Cloneable.h>
45 _Jv_WaitForState (jclass klass, int state)
47 if (klass->state >= state)
50 _Jv_MonitorEnter (klass) ;
52 if (klass->state == JV_STATE_COMPILED)
54 klass->state = JV_STATE_LOADED;
55 if (gcj::verbose_class_flag)
56 fprintf (stderr, "[Loaded (pre-compiled) %s]\n", klass->name->chars());
58 if (state == JV_STATE_LINKED)
60 // Must call _Jv_PrepareCompiledClass while holding the class
63 if (_Jv_IsInterpretedClass (klass))
64 _Jv_PrepareClass (klass);
66 _Jv_PrepareCompiledClass (klass);
67 _Jv_MonitorExit (klass);
71 java::lang::Thread *self = java::lang::Thread::currentThread();
73 // this is similar to the strategy for class initialization.
74 // if we already hold the lock, just leave.
75 while (klass->state <= state
77 && klass->thread != self)
80 _Jv_MonitorExit (klass);
82 if (klass->state == JV_STATE_ERROR)
83 throw new java::lang::LinkageError;
86 typedef unsigned int uaddr __attribute__ ((mode (pointer)));
88 /** This function does class-preparation for compiled classes.
89 NOTE: It contains replicated functionality from
90 _Jv_ResolvePoolEntry, and this is intentional, since that function
91 lives in resolve.cc which is entirely conditionally compiled.
94 _Jv_PrepareCompiledClass (jclass klass)
96 jint state = klass->state;
97 if (state >= JV_STATE_LINKED)
100 // Short-circuit, so that mutually dependent classes are ok.
101 klass->state = JV_STATE_LINKED;
103 _Jv_Constants *pool = &klass->constants;
105 // Resolve class constants first, since other constant pool
106 // entries may rely on these.
107 for (int index = 1; index < pool->size; ++index)
109 if (pool->tags[index] == JV_CONSTANT_Class)
111 _Jv_Utf8Const *name = pool->data[index].utf8;
114 if (name->first() == '[')
115 found = _Jv_FindClassFromSignature (name->chars(),
118 found = _Jv_FindClass (name, klass->loader);
122 jstring str = name->toString();
123 throw new java::lang::NoClassDefFoundError (str);
126 pool->data[index].clazz = found;
127 pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
131 // If superclass looks like a constant pool entry,
133 if ((uaddr) klass->superclass < pool->size)
134 klass->superclass = pool->data[(uaddr) klass->superclass].clazz;
136 // Likewise for interfaces.
137 for (int i = 0; i < klass->interface_count; i++)
138 if ((uaddr) klass->interfaces[i] < pool->size)
139 klass->interfaces[i] = pool->data[(uaddr) klass->interfaces[i]].clazz;
141 // Resolve the remaining constant pool entries.
142 for (int index = 1; index < pool->size; ++index)
144 if (pool->tags[index] == JV_CONSTANT_String)
148 str = _Jv_NewStringUtf8Const (pool->data[index].utf8);
149 pool->data[index].o = str;
150 pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
155 // FIXME: although the comment up top says that this function is
156 // only called for compiled classes, it is actually called for every
158 if (! _Jv_IsInterpretedClass (klass))
160 #endif /* INTERPRETER */
161 jfieldID f = JvGetFirstStaticField (klass);
162 for (int n = JvNumStaticFields (klass); n > 0; --n)
164 int mod = f->getModifiers ();
165 // If we have a static String field with a non-null initial
166 // value, we know it points to a Utf8Const.
167 _Jv_ResolveField(f, klass->loader);
168 if (f->getClass () == &java::lang::String::class$
169 && java::lang::reflect::Modifier::isStatic (mod))
171 jstring *strp = (jstring *) f->u.addr;
173 *strp = _Jv_NewStringUtf8Const ((_Jv_Utf8Const *) *strp);
175 f = f->getNextField ();
179 #endif /* INTERPRETER */
181 if (klass->isInterface ())
182 _Jv_LayoutInterfaceMethods (klass);
184 if (state == JV_STATE_COMPILED && gcj::verbose_class_flag)
185 fprintf (stderr, "[Loaded (pre-compiled) %s]\n",
186 klass->name->chars());
190 _Jv_PushClass (klass);
195 // A single class can have many "initiating" class loaders,
196 // and a single "defining" class loader. The Defining
197 // class loader is what is returned from Class.getClassLoader()
198 // and is used when loading dependent classes during resolution.
199 // The set of initiating class loaders are used to ensure
200 // safety of linking, and is maintained in the hash table
201 // "initiated_classes". A defining classloader is by definition also
202 // initiating, so we only store classes in this table if they have more
203 // than one class loader associated.
207 // Size of local hash table.
208 #define HASH_LEN 1013
210 // Hash function for Utf8Consts.
211 #define HASH_UTF(Utf) ((Utf)->hash16() % HASH_LEN)
213 struct _Jv_LoaderInfo
215 _Jv_LoaderInfo *next;
216 java::lang::Class *klass;
217 java::lang::ClassLoader *loader;
220 static _Jv_LoaderInfo *initiated_classes[HASH_LEN];
221 static jclass loaded_classes[HASH_LEN];
223 // This is the root of a linked list of classes
228 _Jv_FindClassInCache (_Jv_Utf8Const *name, java::lang::ClassLoader *loader)
230 JvSynchronize sync (&java::lang::Class::class$);
231 jint hash = HASH_UTF (name);
233 if (loader && loader == java::lang::ClassLoader::getSystemClassLoader())
236 // first, if LOADER is a defining loader, then it is also initiating
238 for (klass = loaded_classes[hash]; klass; klass = klass->next)
240 if (loader == klass->loader && _Jv_equalUtf8Consts (name, klass->name))
244 // otherwise, it may be that the class in question was defined
245 // by some other loader, but that the loading was initiated by
246 // the loader in question.
249 _Jv_LoaderInfo *info;
250 for (info = initiated_classes[hash]; info; info = info->next)
252 if (loader == info->loader
253 && _Jv_equalUtf8Consts (name, info->klass->name))
265 _Jv_UnregisterClass (jclass the_class)
267 JvSynchronize sync (&java::lang::Class::class$);
268 jint hash = HASH_UTF(the_class->name);
270 jclass *klass = &(loaded_classes[hash]);
271 for ( ; *klass; klass = &((*klass)->next))
273 if (*klass == the_class)
275 *klass = (*klass)->next;
280 _Jv_LoaderInfo **info = &(initiated_classes[hash]);
281 for ( ; ; info = &((*info)->next))
283 while (*info && (*info)->klass == the_class)
285 _Jv_LoaderInfo *old = *info;
286 *info = (*info)->next;
296 _Jv_RegisterInitiatingLoader (jclass klass, java::lang::ClassLoader *loader)
298 if (loader && loader == java::lang::ClassLoader::getSystemClassLoader())
301 // This information can't be visible to the GC.
303 = (_Jv_LoaderInfo *) _Jv_Malloc (sizeof(_Jv_LoaderInfo));
304 jint hash = HASH_UTF(klass->name);
306 JvSynchronize sync (&java::lang::Class::class$);
307 info->loader = loader;
309 info->next = initiated_classes[hash];
310 initiated_classes[hash] = info;
313 // This function is called many times during startup, before main() is
314 // run. At that point in time we know for certain we are running
315 // single-threaded, so we don't need to lock when adding classes to the
316 // class chain. At all other times, the caller should synchronize on
319 _Jv_RegisterClasses (const jclass *classes)
321 for (; *classes; ++classes)
323 jclass klass = *classes;
325 (*_Jv_RegisterClassHook) (klass);
327 // registering a compiled class causes
328 // it to be immediately "prepared".
329 if (klass->state == JV_STATE_NOTHING)
330 klass->state = JV_STATE_COMPILED;
334 // This is a version of _Jv_RegisterClasses that takes a count.
336 _Jv_RegisterClasses_Counted (const jclass * classes, size_t count)
339 for (i = 0; i < count; i++)
341 jclass klass = classes[i];
343 (*_Jv_RegisterClassHook) (klass);
345 // registering a compiled class causes
346 // it to be immediately "prepared".
347 if (klass->state == JV_STATE_NOTHING)
348 klass->state = JV_STATE_COMPILED;
353 _Jv_RegisterClassHookDefault (jclass klass)
355 jint hash = HASH_UTF (klass->name);
357 jclass check_class = loaded_classes[hash];
359 // If the class is already registered, don't re-register it.
360 while (check_class != NULL)
362 if (check_class == klass)
364 // If you get this, it means you have the same class in two
365 // different libraries.
366 #define TEXT "Duplicate class registration: "
367 // We size-limit MESSAGE so that you can't trash the stack.
369 strcpy (message, TEXT);
370 strncpy (message + sizeof (TEXT) - 1, klass->name->chars(),
371 sizeof (message) - sizeof (TEXT));
372 message[sizeof (message) - 1] = '\0';
373 if (! gcj::runtimeInitialized)
377 java::lang::String *str = JvNewStringLatin1 (message);
378 throw new java::lang::VirtualMachineError (str);
382 check_class = check_class->next;
385 klass->next = loaded_classes[hash];
386 loaded_classes[hash] = klass;
389 // A pointer to a function that actually registers a class.
390 // Normally _Jv_RegisterClassHookDefault, but could be some other function
391 // that registers the class in e.g. a ClassLoader-local table.
392 // Should synchronize on Class:class$ while setting/restore this variable.
394 void (*_Jv_RegisterClassHook) (jclass cl) = _Jv_RegisterClassHookDefault;
397 _Jv_RegisterClass (jclass klass)
402 _Jv_RegisterClasses (classes);
406 _Jv_FindClass (_Jv_Utf8Const *name, java::lang::ClassLoader *loader)
408 jclass klass = _Jv_FindClassInCache (name, loader);
412 jstring sname = name->toString();
414 java::lang::ClassLoader *sys
415 = java::lang::ClassLoader::getSystemClassLoader ();
419 // Load using a user-defined loader, jvmspec 5.3.2
420 klass = loader->loadClass(sname, false);
422 // If "loader" delegated the loadClass operation to another
423 // loader, explicitly register that it is also an initiating
424 // loader of the given class.
425 java::lang::ClassLoader *delegate = (loader == sys
428 if (klass && klass->getClassLoaderInternal () != delegate)
429 _Jv_RegisterInitiatingLoader (klass, loader);
433 // Load using the bootstrap loader jvmspec 5.3.1.
434 klass = sys->loadClass (sname, false);
436 // Register that we're an initiating loader.
438 _Jv_RegisterInitiatingLoader (klass, 0);
443 // we need classes to be in the hash while
444 // we're loading, so that they can refer to themselves.
445 _Jv_WaitForState (klass, JV_STATE_LOADED);
452 _Jv_NewClass (_Jv_Utf8Const *name, jclass superclass,
453 java::lang::ClassLoader *loader)
455 jclass ret = (jclass) _Jv_AllocObject (&java::lang::Class::class$);
457 ret->superclass = superclass;
458 ret->loader = loader;
460 _Jv_RegisterClass (ret);
465 static _Jv_IDispatchTable *array_idt = NULL;
466 static jshort array_depth = 0;
467 static jclass *array_ancestors = NULL;
469 // Create a class representing an array of ELEMENT and store a pointer to it
470 // in element->arrayclass. LOADER is the ClassLoader which _initiated_ the
471 // instantiation of this array. ARRAY_VTABLE is the vtable to use for the new
472 // array class. This parameter is optional.
474 _Jv_NewArrayClass (jclass element, java::lang::ClassLoader *loader,
475 _Jv_VTable *array_vtable)
477 JvSynchronize sync (element);
479 _Jv_Utf8Const *array_name;
482 if (element->arrayclass)
485 if (element->isPrimitive())
487 if (element == JvPrimClass (void))
488 throw new java::lang::ClassNotFoundException ();
492 len = element->name->len() + 5;
497 signature[index++] = '[';
498 // Compute name of array class.
499 if (element->isPrimitive())
501 signature[index++] = (char) element->method_count;
505 size_t length = element->name->len();
506 const char *const name = element->name->chars();
508 signature[index++] = 'L';
509 memcpy (&signature[index], name, length);
512 signature[index++] = ';';
514 array_name = _Jv_makeUtf8Const (signature, index);
517 // Create new array class.
518 jclass array_class = _Jv_NewClass (array_name, &java::lang::Object::class$,
521 // Note that `vtable_method_count' doesn't include the initial
523 JvAssert (java::lang::Object::class$.vtable_method_count
524 == NUM_OBJECT_METHODS);
525 int dm_count = java::lang::Object::class$.vtable_method_count;
527 // Create a new vtable by copying Object's vtable.
530 vtable = array_vtable;
532 vtable = _Jv_VTable::new_vtable (dm_count);
533 vtable->clas = array_class;
534 vtable->gc_descr = java::lang::Object::class$.vtable->gc_descr;
535 for (int i = 0; i < dm_count; ++i)
536 vtable->set_method (i, java::lang::Object::class$.vtable->get_method (i));
538 array_class->vtable = vtable;
539 array_class->vtable_method_count
540 = java::lang::Object::class$.vtable_method_count;
542 // Stash the pointer to the element type.
543 array_class->methods = (_Jv_Method *) element;
545 // Register our interfaces.
546 static jclass interfaces[] =
548 &java::lang::Cloneable::class$,
549 &java::io::Serializable::class$
551 array_class->interfaces = interfaces;
552 array_class->interface_count = sizeof interfaces / sizeof interfaces[0];
554 // Since all array classes have the same interface dispatch table, we can
555 // cache one and reuse it. It is not necessary to synchronize this.
558 _Jv_PrepareConstantTimeTables (array_class);
559 array_idt = array_class->idt;
560 array_depth = array_class->depth;
561 array_ancestors = array_class->ancestors;
565 array_class->idt = array_idt;
566 array_class->depth = array_depth;
567 array_class->ancestors = array_ancestors;
570 using namespace java::lang::reflect;
572 // Array classes are "abstract final"...
573 _Jv_ushort accflags = Modifier::FINAL | Modifier::ABSTRACT;
574 // ... and inherit accessibility from element type, per vmspec 5.3.3.2
575 accflags |= (element->accflags & Modifier::PUBLIC);
576 accflags |= (element->accflags & Modifier::PROTECTED);
577 accflags |= (element->accflags & Modifier::PRIVATE);
578 array_class->accflags = accflags;
581 // An array class has no visible instance fields. "length" is invisible to
584 // say this class is initialized and ready to go!
585 array_class->state = JV_STATE_DONE;
587 // vmspec, section 5.3.3 describes this
588 if (element->loader != loader)
589 _Jv_RegisterInitiatingLoader (array_class, loader);
591 element->arrayclass = array_class;
594 static jclass stack_head;
596 // These two functions form a stack of classes. When a class is loaded
597 // it is pushed onto the stack by the class loader; this is so that
598 // StackTrace can quickly determine which classes have been loaded.
603 JvSynchronize sync (&java::lang::Class::class$);
606 jclass tmp = stack_head;
607 stack_head = tmp->chain;
614 _Jv_PushClass (jclass k)
616 JvSynchronize sync (&java::lang::Class::class$);
617 jclass tmp = stack_head;