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