gcc/libjava/java/lang/natObject.cc

// natObject.cc - Implementation of the Object class.

/* Copyright (C) 1998, 1999  Cygnus Solutions

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

#include <config.h>

#include <string.h>

#pragma implementation "Object.h"

#include <gcj/cni.h>
#include <jvm.h>
#include <java/lang/Object.h>
#include <java-threads.h>
#include <java/lang/CloneNotSupportedException.h>
#include <java/lang/IllegalArgumentException.h>
#include <java/lang/IllegalMonitorStateException.h>
#include <java/lang/InterruptedException.h>
#include <java/lang/NullPointerException.h>
#include <java/lang/Class.h>
#include <java/lang/Cloneable.h>
#include <java/lang/Thread.h>

#define CloneableClass _CL_Q34java4lang9Cloneable
extern java::lang::Class CloneableClass;



// This is used to represent synchronization information.
struct _Jv_SyncInfo
{
#if defined (_Jv_HaveCondDestroy) || defined (_Jv_HaveMutexDestroy)
  // We only need to keep track of initialization state if we can
  // possibly finalize this object.
  bool init;
#endif
  _Jv_ConditionVariable_t condition;
  _Jv_Mutex_t mutex;
};



jclass
java::lang::Object::getClass (void)
{
  _Jv_VTable **dt = (_Jv_VTable **) this;
  return (*dt)->clas;
}

jint
java::lang::Object::hashCode (void)
{
  return _Jv_HashCode (this);
}

jobject
java::lang::Object::clone (void)
{
  jclass klass = getClass ();
  jobject r;
  jint size;

  // We also clone arrays here.  If we put the array code into
  // __JArray, then we'd have to figure out a way to find the array
  // vtbl when creating a new array class.  This is easier, if uglier.
  if (klass->isArray())
    {
      __JArray *array = (__JArray *) this;
      jclass comp = getClass()->getComponentType();
      jint eltsize;
      if (comp->isPrimitive())
	{
	  r = _Jv_NewPrimArray (comp, array->length);
	  eltsize = comp->size();
	}
      else
	{
	  r = _Jv_NewObjectArray (array->length, comp, NULL);
	  eltsize = sizeof (jobject);
	}
      // We can't use sizeof on __JArray because we must account for
      // alignment of the element type.
      size = (_Jv_GetArrayElementFromElementType (array, comp) - (char *) array
	      + array->length * eltsize);
    }
  else
    {
      if (! CloneableClass.isAssignableFrom(klass))
	JvThrow (new CloneNotSupportedException);

      size = klass->size();
      r = JvAllocObject (klass, size);
    }

  memcpy ((void *) r, (void *) this, size);
  return r;
}


//
// Synchronization code.
//

// This global is used to make sure that only one thread sets an
// object's `sync_info' field.
static _Jv_Mutex_t sync_mutex;

// This macro is used to see if synchronization initialization is
// needed.
#if defined (_Jv_HaveCondDestroy) || defined (_Jv_HaveMutexDestroy)
#  define INIT_NEEDED(Obj) (! (Obj)->sync_info \
			    || ! ((_Jv_SyncInfo *) ((Obj)->sync_info))->init)
#else
#  define INIT_NEEDED(Obj) (! (Obj)->sync_info)
#endif

#if defined (_Jv_HaveCondDestroy) || defined (_Jv_HaveMutexDestroy)
// If we have to run a destructor for a sync_info member, then this
// function is registered as a finalizer for the sync_info.
static void
finalize_sync_info (jobject obj)
{
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) obj;
#if defined (_Jv_HaveCondDestroy)
  _Jv_CondDestroy (&si->condition);
#endif
#if defined (_Jv_HaveMutexDestroy)
  _Jv_MutexDestroy (&si->mutex);
#endif
  si->init = false;
}
#endif

// This is called to initialize the sync_info element of an object.
void
java::lang::Object::sync_init (void)
{
  _Jv_MutexLock (&sync_mutex);
  // Check again to see if initialization is needed now that we have
  // the lock.
  if (INIT_NEEDED (this))
    {
      // We assume there are no pointers in the sync_info
      // representation.
      _Jv_SyncInfo *si;
      // We always create a new sync_info, even if there is already
      // one available.  Any given object can only be finalized once.
      // If we get here and sync_info is not null, then it has already
      // been finalized.  So if we just reinitialize the old one,
      // we'll never be able to (re-)destroy the mutex and/or
      // condition variable.
      si = (_Jv_SyncInfo *) _Jv_AllocBytesChecked (sizeof (_Jv_SyncInfo));
      _Jv_MutexInit (&si->mutex);
      _Jv_CondInit (&si->condition);
#if defined (_Jv_HaveCondDestroy) || defined (_Jv_HaveMutexDestroy)
      // Register a finalizer.
      si->init = true;
      _Jv_RegisterFinalizer (si, finalize_sync_info);
#endif
      sync_info = (jobject) si;
    }
  _Jv_MutexUnlock (&sync_mutex);
}

void
java::lang::Object::notify (void)
{
  if (INIT_NEEDED (this))
    sync_init ();
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) sync_info;
  if (_Jv_CondNotify (&si->condition, &si->mutex))
    JvThrow (new IllegalMonitorStateException(JvNewStringLatin1 
                                              ("current thread not owner")));
}

void
java::lang::Object::notifyAll (void)
{
  if (INIT_NEEDED (this))
    sync_init ();
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) sync_info;
  if (_Jv_CondNotifyAll (&si->condition, &si->mutex))
    JvThrow (new IllegalMonitorStateException(JvNewStringLatin1 
                                              ("current thread not owner")));
}

void
java::lang::Object::wait (jlong timeout, jint nanos)
{
  if (INIT_NEEDED (this))
    sync_init ();
  if (timeout < 0 || nanos < 0 || nanos > 999999)
    JvThrow (new IllegalArgumentException);
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) sync_info;
  if (_Jv_CondWait (&si->condition, &si->mutex, timeout, nanos))
    JvThrow (new IllegalMonitorStateException(JvNewStringLatin1 
                                              ("current thread not owner")));
  if (Thread::interrupted())
    JvThrow (new InterruptedException);
}

//
// Some runtime code.
//

// This function is called at system startup to initialize the
// `sync_mutex'.
void
_Jv_InitializeSyncMutex (void)
{
  _Jv_MutexInit (&sync_mutex);
}

jint
_Jv_MonitorEnter (jobject obj)
{
  if (! obj)
    JvThrow (new java::lang::NullPointerException);
  if (INIT_NEEDED (obj))
    obj->sync_init ();
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) obj->sync_info;
  return _Jv_MutexLock (&si->mutex);
}

jint
_Jv_MonitorExit (jobject obj)
{
  JvAssert (obj);
  JvAssert (! INIT_NEEDED (obj));
  _Jv_SyncInfo *si = (_Jv_SyncInfo *) obj->sync_info;
  if (_Jv_MutexUnlock (&si->mutex))
    JvThrow (new java::lang::IllegalMonitorStateException);
  return 0;
}

void
_Jv_FinalizeObject (jobject obj)
{
  java::lang::Object::hack12_6(obj);
}