libjava/include/jvm.h

   1 // jvm.h - Header file for private implementation information. -*- c++ -*-
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001  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 /* Extract a character from a Java-style Utf8 string.
 115  * PTR points to the current character.
 116  * LIMIT points to the end of the Utf8 string.
 117  * PTR is incremented to point after the character thta gets returns.
 118  * On an error, -1 is returned. */
 119 #define UTF8_GET(PTR, LIMIT) \
 120   ((PTR) >= (LIMIT) ? -1 \
 121    : *(PTR) < 128 ? *(PTR)++ \
 122    : (*(PTR)&0xE0) == 0xC0 && ((PTR)+=2)<=(LIMIT) && ((PTR)[-1]&0xC0) == 0x80 \
 123    ? (((PTR)[-2] & 0x1F) << 6) + ((PTR)[-1] & 0x3F) \
 124    : (*(PTR) & 0xF0) == 0xE0 && ((PTR) += 3) <= (LIMIT) \
 125    && ((PTR)[-2] & 0xC0) == 0x80 && ((PTR)[-1] & 0xC0) == 0x80 \
 126    ? (((PTR)[-3]&0x0F) << 12) + (((PTR)[-2]&0x3F) << 6) + ((PTR)[-1]&0x3F) \
 127    : ((PTR)++, -1))
 128
 129 extern int _Jv_strLengthUtf8(char* str, int len);
 130
 131 typedef struct _Jv_Utf8Const Utf8Const;
 132 _Jv_Utf8Const *_Jv_makeUtf8Const (char *s, int len);
 133 _Jv_Utf8Const *_Jv_makeUtf8Const (jstring string);
 134 extern jboolean _Jv_equalUtf8Consts (_Jv_Utf8Const *, _Jv_Utf8Const *);
 135 extern jboolean _Jv_equal (_Jv_Utf8Const *, jstring, jint);
 136 extern jboolean _Jv_equaln (_Jv_Utf8Const *, jstring, jint);
 137
 138 // FIXME: remove this define.
 139 #define StringClass java::lang::String::class$
 140
 141 namespace gcj
 142 {
 143   /* Some constants used during lookup of special class methods.  */
 144   extern _Jv_Utf8Const *void_signature; /* "()V" */
 145   extern _Jv_Utf8Const *clinit_name;    /* "<clinit>" */
 146   extern _Jv_Utf8Const *init_name;      /* "<init>" */
 147   extern _Jv_Utf8Const *finit_name;     /* "finit$", */
 148
 149   /* Set to true by _Jv_CreateJavaVM. */
 150   extern bool runtimeInitialized;
 151 };
 152
 153 /* Type of pointer used as finalizer.  */
 154 typedef void _Jv_FinalizerFunc (jobject);
 155
 156 /* Allocate space for a new Java object.  */
 157 void *_Jv_AllocObj (jsize size, jclass cl) __attribute__((__malloc__));
 158 /* Allocate space for a potentially uninitialized pointer-free object.
 159    Interesting only with JV_HASH_SYNCHRONIZATION.  */
 160 void *_Jv_AllocPtrFreeObj (jsize size, jclass cl) __attribute__((__malloc__));
 161 /* Allocate space for an array of Java objects.  */
 162 void *_Jv_AllocArray (jsize size, jclass cl) __attribute__((__malloc__));
 163 /* Allocate space that is known to be pointer-free.  */
 164 void *_Jv_AllocBytes (jsize size) __attribute__((__malloc__));
 165 /* Allocate space for a new non-Java object, which does not have the usual
 166    Java object header but may contain pointers to other GC'ed objects.  */
 167 void *_Jv_AllocRawObj (jsize size) __attribute__((__malloc__));
 168 /* Explicitly throw an out-of-memory exception. */
 169 void _Jv_ThrowNoMemory() __attribute__((__noreturn__));
 170 /* Allocate an object with a single pointer.  The first word is reserved
 171    for the GC, and the second word is the traced pointer.  */
 172 void *_Jv_AllocTraceOne (jsize size /* incl. reserved slot */);
 173 /* Ditto, but for two traced pointers.                     */
 174 void *_Jv_AllocTraceTwo (jsize size /* incl. reserved slot */);
 175 /* Initialize the GC.  */
 176 void _Jv_InitGC (void);
 177 /* Register a finalizer.  */
 178 void _Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *method);
 179 /* Compute the GC descriptor for a class */
 180 void * _Jv_BuildGCDescr(jclass);
 181
 182 /* Allocate some unscanned, unmoveable memory.  Return NULL if out of
 183    memory.  */
 184 void *_Jv_MallocUnchecked (jsize size) __attribute__((__malloc__));
 185
 186 /* Initialize finalizers.  The argument is a function to be called
 187    when a finalizer is ready to be run.  */
 188 void _Jv_GCInitializeFinalizers (void (*notifier) (void));
 189 /* Run finalizers for objects ready to be finalized..  */
 190 void _Jv_RunFinalizers (void);
 191 /* Run all finalizers.  Should be called only before exit.  */
 192 void _Jv_RunAllFinalizers (void);
 193 /* Perform a GC.  */
 194 void _Jv_RunGC (void);
 195 /* Disable and enable GC.  */
 196 void _Jv_DisableGC (void);
 197 void _Jv_EnableGC (void);
 198 /* Register a disappearing link.  This is a field F which should be
 199    cleared when *F is found to be inaccessible.  This is used in the
 200    implementation of java.lang.ref.Reference.  */
 201 void _Jv_GCRegisterDisappearingLink (jobject *objp);
 202 /* Return true if OBJECT should be reclaimed.  This is used to
 203    implement soft references.  */
 204 jboolean _Jv_GCCanReclaimSoftReference (jobject obj);
 205
 206 /* Return approximation of total size of heap.  */
 207 long _Jv_GCTotalMemory (void);
 208 /* Return approximation of total free memory.  */
 209 long _Jv_GCFreeMemory (void);
 210
 211 /* Set initial heap size.  If SIZE==0, ignore.  Should be run before
 212    _Jv_InitGC.  Not required to have any actual effect.  */
 213 void _Jv_GCSetInitialHeapSize (size_t size);
 214
 215 /* Set maximum heap size.  If SIZE==0, unbounded.  Should be run
 216    before _Jv_InitGC.  Not required to have any actual effect.  */
 217 void _Jv_GCSetMaximumHeapSize (size_t size);
 218
 219 /* External interface to setting the heap size.  Parses ARG (a number
 220    which can optionally have "k" or "m" appended and calls
 221    _Jv_GCSetInitialHeapSize.  */
 222 void _Jv_SetInitialHeapSize (const char *arg);
 223
 224 /* External interface to setting the maximum heap size.  Parses ARG (a
 225    number which can optionally have "k" or "m" appended and calls
 226    _Jv_GCSetMaximumHeapSize.  */
 227 void _Jv_SetMaximumHeapSize (const char *arg);
 228
 229 extern "C" void JvRunMain (jclass klass, int argc, const char **argv);
 230 void _Jv_RunMain (jclass klass, const char *name, int argc, const char **argv,
 231                   bool is_jar);
 232
 233 // Delayed until after _Jv_AllocBytes is declared.
 234 //
 235 // Note that we allocate this as unscanned memory -- the vtables
 236 // are handled specially by the GC.
 237
 238 inline _Jv_VTable *
 239 _Jv_VTable::new_vtable (int count)
 240 {
 241   size_t size = sizeof(_Jv_VTable) + (count - 1) * vtable_elt_size ();
 242   return (_Jv_VTable *) _Jv_AllocBytes (size);
 243 }
 244
 245 // This function is used to determine the hash code of an object.
 246 inline jint
 247 _Jv_HashCode (jobject obj)
 248 {
 249   // This was chosen to yield relatively well distributed results on
 250   // both 32- and 64-bit architectures.  Note 0x7fffffff is prime.
 251   // FIXME: we assume sizeof(long) == sizeof(void *).
 252   return (jint) ((unsigned long) obj % 0x7fffffff);
 253 }
 254
 255 // Return a raw pointer to the elements of an array given the array
 256 // and its element type.  You might think we could just pick a single
 257 // array type and use elements() on it, but we can't because we must
 258 // account for alignment of the element type.  When ARRAY is null, we
 259 // obtain the number of bytes taken by the base part of the array.
 260 inline char *
 261 _Jv_GetArrayElementFromElementType (jobject array,
 262                                     jclass element_type)
 263 {
 264   char *elts;
 265   if (element_type == JvPrimClass (byte))
 266     elts = (char *) elements ((jbyteArray) array);
 267   else if (element_type == JvPrimClass (short))
 268     elts = (char *) elements ((jshortArray) array);
 269   else if (element_type == JvPrimClass (int))
 270     elts = (char *) elements ((jintArray) array);
 271   else if (element_type == JvPrimClass (long))
 272     elts = (char *) elements ((jlongArray) array);
 273   else if (element_type == JvPrimClass (boolean))
 274     elts = (char *) elements ((jbooleanArray) array);
 275   else if (element_type == JvPrimClass (char))
 276     elts = (char *) elements ((jcharArray) array);
 277   else if (element_type == JvPrimClass (float))
 278     elts = (char *) elements ((jfloatArray) array);
 279   else if (element_type == JvPrimClass (double))
 280     elts = (char *) elements ((jdoubleArray) array);
 281   else
 282     elts = (char *) elements ((jobjectArray) array);
 283   return elts;
 284 }
 285
 286 extern "C" void _Jv_ThrowBadArrayIndex (jint bad_index);
 287 extern "C" void _Jv_ThrowNullPointerException (void);
 288 extern "C" jobject _Jv_NewArray (jint type, jint size)
 289   __attribute__((__malloc__));
 290 extern "C" jobject _Jv_NewMultiArray (jclass klass, jint dims, ...)
 291   __attribute__((__malloc__));
 292 extern "C" void *_Jv_CheckCast (jclass klass, jobject obj);
 293 extern "C" void *_Jv_LookupInterfaceMethod (jclass klass, Utf8Const *name,
 294                                            Utf8Const *signature);
 295 extern "C" void *_Jv_LookupInterfaceMethodIdx (jclass klass, jclass iface,
 296                                                int meth_idx);
 297 extern "C" void _Jv_CheckArrayStore (jobject array, jobject obj);
 298 extern "C" void _Jv_RegisterClass (jclass klass);
 299 extern "C" void _Jv_RegisterClasses (jclass *classes);
 300 extern "C" void _Jv_RegisterResource (void *vptr);
 301 extern void _Jv_UnregisterClass (_Jv_Utf8Const*, java::lang::ClassLoader*);
 302 extern void _Jv_ResolveField (_Jv_Field *, java::lang::ClassLoader*);
 303
 304 extern jclass _Jv_FindClass (_Jv_Utf8Const *name,
 305                              java::lang::ClassLoader *loader);
 306 extern jclass _Jv_FindClassFromSignature (char *,
 307                                           java::lang::ClassLoader *loader);
 308 extern void _Jv_GetTypesFromSignature (jmethodID method,
 309                                        jclass declaringClass,
 310                                        JArray<jclass> **arg_types_out,
 311                                        jclass *return_type_out);
 312
 313 extern jobject _Jv_CallAnyMethodA (jobject obj, jclass return_type,
 314                                    jmethodID meth, jboolean is_constructor,
 315                                    JArray<jclass> *parameter_types,
 316                                    jobjectArray args);
 317
 318 union jvalue;
 319 extern jthrowable _Jv_CallAnyMethodA (jobject obj,
 320                                       jclass return_type,
 321                                       jmethodID meth,
 322                                       jboolean is_constructor,
 323                                       JArray<jclass> *parameter_types,
 324                                       jvalue *args,
 325                                       jvalue *result);
 326
 327 extern jobject _Jv_NewMultiArray (jclass, jint ndims, jint* dims)
 328   __attribute__((__malloc__));
 329
 330 /* Checked divide subroutines. */
 331 extern "C"
 332 {
 333   jint _Jv_divI (jint, jint);
 334   jint _Jv_remI (jint, jint);
 335   jlong _Jv_divJ (jlong, jlong);
 336   jlong _Jv_remJ (jlong, jlong);
 337 }
 338
 339 /* get/set the name of the running executable. */
 340 extern char *_Jv_ThisExecutable (void);
 341 extern void _Jv_ThisExecutable (const char *);
 342
 343 /* Return a pointer to a symbol in executable or loaded library.  */
 344 void *_Jv_FindSymbolInExecutable (const char *);
 345
 346 /* Initialize JNI.  */
 347 extern void _Jv_JNI_Init (void);
 348
 349 /* Get or set the per-thread JNIEnv used by the invocation API.  */
 350 _Jv_JNIEnv *_Jv_GetCurrentJNIEnv ();
 351 void _Jv_SetCurrentJNIEnv (_Jv_JNIEnv *);
 352
 353 struct _Jv_JavaVM;
 354 _Jv_JavaVM *_Jv_GetJavaVM ();
 355
 356 // Some verification functions from defineclass.cc.
 357 bool _Jv_VerifyFieldSignature (_Jv_Utf8Const*sig);
 358 bool _Jv_VerifyMethodSignature (_Jv_Utf8Const*sig);
 359 bool _Jv_VerifyClassName (unsigned char* ptr, _Jv_ushort length);
 360 bool _Jv_VerifyClassName (_Jv_Utf8Const *name);
 361 bool _Jv_VerifyIdentifier (_Jv_Utf8Const *);
 362 bool _Jv_ClassNameSamePackage (_Jv_Utf8Const *name1, _Jv_Utf8Const *name2);
 363
 364 #ifdef ENABLE_JVMPI
 365
 366 #include "jvmpi.h"
 367
 368 extern void (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (JVMPI_Event *event);
 369 extern void (*_Jv_JVMPI_Notify_THREAD_START) (JVMPI_Event *event);
 370 extern void (*_Jv_JVMPI_Notify_THREAD_END) (JVMPI_Event *event);
 371 #endif
 372
 373 #endif /* __JAVA_JVM_H__ */