libjava/include/jvm.h

   1 // jvm.h - Header file for private implementation information. -*- c++ -*-
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 #ifndef __JAVA_JVM_H__
  12 #define __JAVA_JVM_H__
  13
  14 // Define this before including jni.h.
  15 // jni.h is included by jvmpi.h, which might be included.  We define
  16 // this unconditionally because it is convenient and it lets other
  17 // files include jni.h without difficulty.
  18 #define __GCJ_JNI_IMPL__
  19
  20 #include <gcj/javaprims.h>
  21
  22 #include <java-assert.h>
  23 #include <java-threads.h>
  24 // Must include java-gc.h before Object.h for the implementation.
  25 #include <java-gc.h>
  26
  27 #include <java/lang/Object.h>
  28
  29 // Include cni.h before field.h to enable all definitions.  FIXME.
  30 #include <gcj/cni.h>
  31 #include <gcj/field.h>
  32
  33 /* Macro for possible unused arguments.  */
  34 #define MAYBE_UNUSED __attribute__((__unused__))
  35
  36 /* Structure of the virtual table.  */
  37 struct _Jv_VTable
  38 {
  39 #ifdef __ia64__
  40   typedef struct { void *pc, *gp; } vtable_elt;
  41 #else
  42   typedef void *vtable_elt;
  43 #endif
  44   jclass clas;
  45   void *gc_descr;
  46
  47   // This must be last, as derived classes "extend" this by
  48   // adding new data members.
  49   vtable_elt method[1];
  50
  51 #ifdef __ia64__
  52   void *get_method(int i) { return &method[i]; }
  53   void set_method(int i, void *fptr) { method[i] = *(vtable_elt *)fptr; }
  54   void *get_finalizer()
  55   {
  56     // We know that get_finalizer is only used for checking whether
  57     // this object needs to have a finalizer registered.  So it is
  58     // safe to simply return just the PC component of the vtable
  59     // slot.
  60     return ((vtable_elt *)(get_method(0)))->pc;
  61   }
  62 #else
  63   void *get_method(int i) { return method[i]; }
  64   void set_method(int i, void *fptr) { method[i] = fptr; }
  65   void *get_finalizer() { return get_method(0); }
  66 #endif
  67
  68   static size_t vtable_elt_size() { return sizeof(vtable_elt); }
  69
  70   // Given a method index, return byte offset from the vtable pointer.
  71   static jint idx_to_offset (int index)
  72   {
  73     return (2 * sizeof (void *)) + (index * vtable_elt_size ());
  74   }
  75   static _Jv_VTable *new_vtable (int count);
  76 };
  77
  78 // Number of virtual methods on object.  FIXME: it sucks that we have
  79 // to keep this up to date by hand.
  80 #define NUM_OBJECT_METHODS 5
  81
  82 union _Jv_word
  83 {
  84   jobject o;
  85   jint i;                       // Also stores smaller integral types.
  86   jfloat f;
  87   jint ia[1];                   // Half of _Jv_word2.
  88   void* p;
  89
  90 #if SIZEOF_VOID_P == 8
  91   // We can safely put a long or a double in here without increasing
  92   // the size of _Jv_Word; we take advantage of this in the interpreter.
  93   jlong l;
  94   jdouble d;
  95 #endif
  96
  97   jclass                     clazz;
  98   jstring                    string;
  99   struct _Jv_Field          *field;
 100   struct _Jv_Utf8Const      *utf8;
 101   struct _Jv_ResolvedMethod *rmethod;
 102 };
 103
 104 union _Jv_word2
 105 {
 106   jint ia[2];
 107   jlong l;
 108   jdouble d;
 109 };
 110
 111 union _Jv_value
 112 {
 113   jbyte byte_value;
 114   jshort short_value;
 115   jchar char_value;
 116   jint int_value;
 117   jlong long_value;
 118   jfloat float_value;
 119   jdouble double_value;
 120   jobject object_value;
 121 };
 122
 123 // An instance of this type is used to represent a single frame in a
 124 // backtrace.  If the interpreter has been built, we also include
 125 // information about the interpreted method.
 126 struct _Jv_frame_info
 127 {
 128   // PC value.
 129   void *addr;
 130 #ifdef INTERPRETER
 131   // Actually a _Jv_InterpMethod, but we don't want to include
 132   // java-interp.h everywhere.
 133   void *interp;
 134 #endif // INTERPRETER
 135 };
 136
 137 /* Extract a character from a Java-style Utf8 string.
 138  * PTR points to the current character.
 139  * LIMIT points to the end of the Utf8 string.
 140  * PTR is incremented to point after the character thta gets returns.
 141  * On an error, -1 is returned. */
 142 #define UTF8_GET(PTR, LIMIT) \
 143   ((PTR) >= (LIMIT) ? -1 \
 144    : *(PTR) < 128 ? *(PTR)++ \
 145    : (*(PTR)&0xE0) == 0xC0 && ((PTR)+=2)<=(LIMIT) && ((PTR)[-1]&0xC0) == 0x80 \
 146    ? (((PTR)[-2] & 0x1F) << 6) + ((PTR)[-1] & 0x3F) \
 147    : (*(PTR) & 0xF0) == 0xE0 && ((PTR) += 3) <= (LIMIT) \
 148    && ((PTR)[-2] & 0xC0) == 0x80 && ((PTR)[-1] & 0xC0) == 0x80 \
 149    ? (((PTR)[-3]&0x0F) << 12) + (((PTR)[-2]&0x3F) << 6) + ((PTR)[-1]&0x3F) \
 150    : ((PTR)++, -1))
 151
 152 extern int _Jv_strLengthUtf8(char* str, int len);
 153
 154 typedef struct _Jv_Utf8Const Utf8Const;
 155 _Jv_Utf8Const *_Jv_makeUtf8Const (char *s, int len);
 156 _Jv_Utf8Const *_Jv_makeUtf8Const (jstring string);
 157 extern jboolean _Jv_equalUtf8Consts (const _Jv_Utf8Const *, const _Jv_Utf8Const *);
 158 extern jboolean _Jv_equal (_Jv_Utf8Const *, jstring, jint);
 159 extern jboolean _Jv_equaln (_Jv_Utf8Const *, jstring, jint);
 160
 161 /* Helper class which converts a jstring to a temporary char*.
 162    Uses the supplied buffer, if non-null. Otherwise, allocates
 163    the buffer on the heap. Use the JV_TEMP_UTF_STRING macro,
 164    which follows, to automatically allocate a stack buffer if
 165    the string is small enough. */
 166 class _Jv_TempUTFString
 167 {
 168 public:
 169   _Jv_TempUTFString(jstring jstr, char* buf=0);
 170   ~_Jv_TempUTFString();
 171
 172 // Accessors
 173   operator const char*() const
 174   {
 175     return buf_;
 176   }
 177   const char* buf() const
 178   {
 179     return buf_;
 180   }
 181   char* buf()
 182   {
 183     return buf_;
 184   }
 185
 186 private:
 187   char* buf_;
 188   bool heapAllocated_;
 189 };
 190
 191 inline _Jv_TempUTFString::_Jv_TempUTFString (jstring jstr, char* buf)
 192   : buf_(0), heapAllocated_(false)
 193 {
 194   if (!jstr) return;
 195   jsize len = JvGetStringUTFLength (jstr);
 196   if (buf)
 197     buf_ = buf;
 198   else
 199     {
 200       buf_ = (char*) _Jv_Malloc (len+1);
 201       heapAllocated_ = true;
 202     }
 203
 204   JvGetStringUTFRegion (jstr, 0, jstr->length(), buf_);
 205   buf_[len] = '\0';
 206 }
 207
 208 inline _Jv_TempUTFString::~_Jv_TempUTFString ()
 209 {
 210   if (heapAllocated_)
 211     _Jv_Free (buf_);
 212 }
 213
 214 /* Macro which uses _Jv_TempUTFString. Allocates a stack-based
 215    buffer if the string and its null terminator are <= 256
 216    characters in length. Otherwise, a heap-based buffer is
 217    used. The parameters to this macro are the variable name
 218    which is an instance of _Jv_TempUTFString (above) and a
 219    jstring.
 220
 221    Sample Usage:
 222
 223    jstring jstr = getAJString();
 224    JV_TEMP_UTF_STRING(utfstr, jstr);
 225    printf("The string is: %s\n", utfstr.buf());
 226
 227  */
 228 #define JV_TEMP_UTF_STRING(utfstr, jstr) \
 229   jstring utfstr##thejstr = (jstr); \
 230   jsize utfstr##_len = utfstr##thejstr ? JvGetStringUTFLength (utfstr##thejstr) + 1 : 0; \
 231   char utfstr##_buf[utfstr##_len <= 256 ? utfstr##_len : 0]; \
 232   _Jv_TempUTFString utfstr(utfstr##thejstr, sizeof(utfstr##_buf)==0 ? 0 : utfstr##_buf)
 233
 234 // FIXME: remove this define.
 235 #define StringClass java::lang::String::class$
 236
 237 namespace gcj
 238 {
 239   /* Some constants used during lookup of special class methods.  */
 240   extern _Jv_Utf8Const *void_signature; /* "()V" */
 241   extern _Jv_Utf8Const *clinit_name;    /* "<clinit>" */
 242   extern _Jv_Utf8Const *init_name;      /* "<init>" */
 243   extern _Jv_Utf8Const *finit_name;     /* "finit$", */
 244
 245   /* Set to true by _Jv_CreateJavaVM. */
 246   extern bool runtimeInitialized;
 247
 248   /* Print out class names as they are initialized. */
 249   extern bool verbose_class_flag;
 250 }
 251
 252 /* Type of pointer used as finalizer.  */
 253 typedef void _Jv_FinalizerFunc (jobject);
 254
 255 /* Allocate space for a new Java object.  */
 256 void *_Jv_AllocObj (jsize size, jclass cl) __attribute__((__malloc__));
 257 /* Allocate space for a potentially uninitialized pointer-free object.
 258    Interesting only with JV_HASH_SYNCHRONIZATION.  */
 259 void *_Jv_AllocPtrFreeObj (jsize size, jclass cl) __attribute__((__malloc__));
 260 /* Allocate space for an array of Java objects.  */
 261 void *_Jv_AllocArray (jsize size, jclass cl) __attribute__((__malloc__));
 262 /* Allocate space that is known to be pointer-free.  */
 263 void *_Jv_AllocBytes (jsize size) __attribute__((__malloc__));
 264 /* Allocate space for a new non-Java object, which does not have the usual
 265    Java object header but may contain pointers to other GC'ed objects.  */
 266 void *_Jv_AllocRawObj (jsize size) __attribute__((__malloc__));
 267 /* Explicitly throw an out-of-memory exception. */
 268 void _Jv_ThrowNoMemory() __attribute__((__noreturn__));
 269 /* Allocate an object with a single pointer.  The first word is reserved
 270    for the GC, and the second word is the traced pointer.  */
 271 void *_Jv_AllocTraceOne (jsize size /* incl. reserved slot */);
 272 /* Ditto, but for two traced pointers.                     */
 273 void *_Jv_AllocTraceTwo (jsize size /* incl. reserved slot */);
 274 /* Initialize the GC.  */
 275 void _Jv_InitGC (void);
 276 /* Register a finalizer.  */
 277 void _Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *method);
 278 /* Compute the GC descriptor for a class */
 279 void * _Jv_BuildGCDescr(jclass);
 280
 281 /* Allocate some unscanned, unmoveable memory.  Return NULL if out of
 282    memory.  */
 283 void *_Jv_MallocUnchecked (jsize size) __attribute__((__malloc__));
 284
 285 /* Initialize finalizers.  The argument is a function to be called
 286    when a finalizer is ready to be run.  */
 287 void _Jv_GCInitializeFinalizers (void (*notifier) (void));
 288 /* Run finalizers for objects ready to be finalized..  */
 289 void _Jv_RunFinalizers (void);
 290 /* Run all finalizers.  Should be called only before exit.  */
 291 void _Jv_RunAllFinalizers (void);
 292 /* Perform a GC.  */
 293 void _Jv_RunGC (void);
 294 /* Disable and enable GC.  */
 295 void _Jv_DisableGC (void);
 296 void _Jv_EnableGC (void);
 297 /* Register a disappearing link.  This is a field F which should be
 298    cleared when *F is found to be inaccessible.  This is used in the
 299    implementation of java.lang.ref.Reference.  */
 300 void _Jv_GCRegisterDisappearingLink (jobject *objp);
 301 /* Return true if OBJECT should be reclaimed.  This is used to
 302    implement soft references.  */
 303 jboolean _Jv_GCCanReclaimSoftReference (jobject obj);
 304
 305 /* Register a finalizer for a String object.  This is only used by
 306    the intern() implementation.  */
 307 void _Jv_RegisterStringFinalizer (jobject str);
 308 /* This is called to actually finalize a possibly-intern()d String.  */
 309 void _Jv_FinalizeString (jobject str);
 310
 311 /* Return approximation of total size of heap.  */
 312 long _Jv_GCTotalMemory (void);
 313 /* Return approximation of total free memory.  */
 314 long _Jv_GCFreeMemory (void);
 315
 316 /* Set initial heap size.  If SIZE==0, ignore.  Should be run before
 317    _Jv_InitGC.  Not required to have any actual effect.  */
 318 void _Jv_GCSetInitialHeapSize (size_t size);
 319
 320 /* Set maximum heap size.  If SIZE==0, unbounded.  Should be run
 321    before _Jv_InitGC.  Not required to have any actual effect.  */
 322 void _Jv_GCSetMaximumHeapSize (size_t size);
 323
 324 /* External interface to setting the heap size.  Parses ARG (a number
 325    which can optionally have "k" or "m" appended and calls
 326    _Jv_GCSetInitialHeapSize.  */
 327 void _Jv_SetInitialHeapSize (const char *arg);
 328
 329 /* External interface to setting the maximum heap size.  Parses ARG (a
 330    number which can optionally have "k" or "m" appended and calls
 331    _Jv_GCSetMaximumHeapSize.  */
 332 void _Jv_SetMaximumHeapSize (const char *arg);
 333
 334 extern "C" void JvRunMain (jclass klass, int argc, const char **argv);
 335 void _Jv_RunMain (jclass klass, const char *name, int argc, const char **argv,
 336                   bool is_jar);
 337
 338 // Delayed until after _Jv_AllocBytes is declared.
 339 //
 340 // Note that we allocate this as unscanned memory -- the vtables
 341 // are handled specially by the GC.
 342
 343 inline _Jv_VTable *
 344 _Jv_VTable::new_vtable (int count)
 345 {
 346   size_t size = sizeof(_Jv_VTable) + (count - 1) * vtable_elt_size ();
 347   return (_Jv_VTable *) _Jv_AllocBytes (size);
 348 }
 349
 350 // Determine if METH gets an entry in a VTable.
 351 static inline jboolean _Jv_isVirtualMethod (_Jv_Method *meth)
 352 {
 353   using namespace java::lang::reflect;
 354   return (((meth->accflags & (Modifier::STATIC | Modifier::PRIVATE)) == 0)
 355           && meth->name->first() != '<');
 356 }
 357
 358 // This function is used to determine the hash code of an object.
 359 inline jint
 360 _Jv_HashCode (jobject obj)
 361 {
 362   // This was chosen to yield relatively well distributed results on
 363   // both 32- and 64-bit architectures.  Note 0x7fffffff is prime.
 364   // FIXME: we assume sizeof(long) == sizeof(void *).
 365   return (jint) ((unsigned long) obj % 0x7fffffff);
 366 }
 367
 368 // Return a raw pointer to the elements of an array given the array
 369 // and its element type.  You might think we could just pick a single
 370 // array type and use elements() on it, but we can't because we must
 371 // account for alignment of the element type.  When ARRAY is null, we
 372 // obtain the number of bytes taken by the base part of the array.
 373 inline char *
 374 _Jv_GetArrayElementFromElementType (jobject array,
 375                                     jclass element_type)
 376 {
 377   char *elts;
 378   if (element_type == JvPrimClass (byte))
 379     elts = (char *) elements ((jbyteArray) array);
 380   else if (element_type == JvPrimClass (short))
 381     elts = (char *) elements ((jshortArray) array);
 382   else if (element_type == JvPrimClass (int))
 383     elts = (char *) elements ((jintArray) array);
 384   else if (element_type == JvPrimClass (long))
 385     elts = (char *) elements ((jlongArray) array);
 386   else if (element_type == JvPrimClass (boolean))
 387     elts = (char *) elements ((jbooleanArray) array);
 388   else if (element_type == JvPrimClass (char))
 389     elts = (char *) elements ((jcharArray) array);
 390   else if (element_type == JvPrimClass (float))
 391     elts = (char *) elements ((jfloatArray) array);
 392   else if (element_type == JvPrimClass (double))
 393     elts = (char *) elements ((jdoubleArray) array);
 394   else
 395     elts = (char *) elements ((jobjectArray) array);
 396   return elts;
 397 }
 398
 399 extern "C" void _Jv_ThrowBadArrayIndex (jint bad_index)
 400   __attribute__((noreturn));
 401 extern "C" void _Jv_ThrowNullPointerException (void)
 402   __attribute__((noreturn));
 403 extern "C" jobject _Jv_NewArray (jint type, jint size)
 404   __attribute__((__malloc__));
 405 extern "C" jobject _Jv_NewMultiArray (jclass klass, jint dims, ...)
 406   __attribute__((__malloc__));
 407 extern "C" void *_Jv_CheckCast (jclass klass, jobject obj);
 408 extern "C" void *_Jv_LookupInterfaceMethod (jclass klass, Utf8Const *name,
 409                                            Utf8Const *signature);
 410 extern "C" void *_Jv_LookupInterfaceMethodIdx (jclass klass, jclass iface,
 411                                                int meth_idx);
 412 extern "C" void _Jv_CheckArrayStore (jobject array, jobject obj);
 413 extern "C" void _Jv_RegisterClass (jclass klass);
 414 extern "C" void _Jv_RegisterClasses (jclass *classes);
 415 extern "C" void _Jv_RegisterResource (void *vptr);
 416 extern void _Jv_UnregisterClass (_Jv_Utf8Const*, java::lang::ClassLoader*);
 417 extern void _Jv_ResolveField (_Jv_Field *, java::lang::ClassLoader*);
 418
 419 extern jclass _Jv_FindClass (_Jv_Utf8Const *name,
 420                              java::lang::ClassLoader *loader);
 421 extern jclass _Jv_FindClassFromSignature (char *,
 422                                           java::lang::ClassLoader *loader);
 423 extern void _Jv_GetTypesFromSignature (jmethodID method,
 424                                        jclass declaringClass,
 425                                        JArray<jclass> **arg_types_out,
 426                                        jclass *return_type_out);
 427
 428 extern jboolean _Jv_CheckAccess (jclass self_klass, jclass other_klass,
 429                                  jint flags);
 430
 431 extern jobject _Jv_CallAnyMethodA (jobject obj, jclass return_type,
 432                                    jmethodID meth, jboolean is_constructor,
 433                                    JArray<jclass> *parameter_types,
 434                                    jobjectArray args,
 435                                    jclass iface = NULL);
 436
 437 union jvalue;
 438 extern void _Jv_CallAnyMethodA (jobject obj,
 439                                 jclass return_type,
 440                                 jmethodID meth,
 441                                 jboolean is_constructor,
 442                                 jboolean is_virtual_call,
 443                                 JArray<jclass> *parameter_types,
 444                                 jvalue *args,
 445                                 jvalue *result,
 446                                 jboolean is_jni_call = true,
 447                                 jclass iface = NULL);
 448
 449 extern jobject _Jv_NewMultiArray (jclass, jint ndims, jint* dims)
 450   __attribute__((__malloc__));
 451
 452 /* Checked divide subroutines. */
 453 extern "C"
 454 {
 455   jint _Jv_divI (jint, jint);
 456   jint _Jv_remI (jint, jint);
 457   jlong _Jv_divJ (jlong, jlong);
 458   jlong _Jv_remJ (jlong, jlong);
 459 }
 460
 461 /* Get the number of arguments (cf. argc) or 0 if our argument
 462    list was never initialized.  */
 463 extern int _Jv_GetNbArgs (void);
 464
 465 /* Get the specified argument (cf. argv[index]) or "" if either
 466    our argument list was never initialized or the specified index
 467    is out of bounds.  */
 468 extern const char * _Jv_GetSafeArg (int index);
 469
 470 /* Sets our argument list. Can be used by programs with non-standard
 471    entry points.  */
 472 extern void _Jv_SetArgs (int argc, const char **argv);
 473
 474 /* Get the name of the running executable.  */
 475 extern const char *_Jv_ThisExecutable (void);
 476
 477 /* Return a pointer to a symbol in executable or loaded library.  */
 478 void *_Jv_FindSymbolInExecutable (const char *);
 479
 480 /* Initialize JNI.  */
 481 extern void _Jv_JNI_Init (void);
 482
 483 /* Get or set the per-thread JNIEnv used by the invocation API.  */
 484 _Jv_JNIEnv *_Jv_GetCurrentJNIEnv ();
 485 void _Jv_SetCurrentJNIEnv (_Jv_JNIEnv *);
 486
 487 struct _Jv_JavaVM;
 488 _Jv_JavaVM *_Jv_GetJavaVM ();
 489
 490 // Some verification functions from defineclass.cc.
 491 bool _Jv_VerifyFieldSignature (_Jv_Utf8Const*sig);
 492 bool _Jv_VerifyMethodSignature (_Jv_Utf8Const*sig);
 493 bool _Jv_VerifyClassName (unsigned char* ptr, _Jv_ushort length);
 494 bool _Jv_VerifyClassName (_Jv_Utf8Const *name);
 495 bool _Jv_VerifyIdentifier (_Jv_Utf8Const *);
 496 bool _Jv_ClassNameSamePackage (_Jv_Utf8Const *name1, _Jv_Utf8Const *name2);
 497
 498 struct _Jv_core_chain
 499 {
 500   int name_length;
 501   const char *name;
 502   int data_length;
 503   const void *data;
 504
 505   struct _Jv_core_chain *next;
 506 };
 507
 508 // This is called when new core data is loaded.
 509 extern void (*_Jv_RegisterCoreHook) (_Jv_core_chain *);
 510
 511 _Jv_core_chain *_Jv_FindCore (_Jv_core_chain *node, jstring name);
 512 void _Jv_FreeCoreChain (_Jv_core_chain *chain);
 513
 514 #ifdef ENABLE_JVMPI
 515
 516 #include "jvmpi.h"
 517
 518 extern void (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (JVMPI_Event *event);
 519 extern void (*_Jv_JVMPI_Notify_THREAD_START) (JVMPI_Event *event);
 520 extern void (*_Jv_JVMPI_Notify_THREAD_END) (JVMPI_Event *event);
 521 #endif
 522
 523 #endif /* __JAVA_JVM_H__ */