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