mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			242 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			242 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
| /* java_nio_MappedByteBufferImpl.c - Native methods for MappedByteBufferImpl
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|    Copyright (C) 2004, 2005, 2006  Free Software Foundation, Inc.
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| 
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| This file is part of GNU Classpath.
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| 
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| GNU Classpath is free software; you can redistribute it and/or modify
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| it under the terms of the GNU General Public License as published by
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| the Free Software Foundation; either version 2, or (at your option)
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| any later version.
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| 
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| GNU Classpath is distributed in the hope that it will be useful, but
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| WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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| General Public License for more details.
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| 
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| You should have received a copy of the GNU General Public License
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| along with GNU Classpath; see the file COPYING.  If not, write to the
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| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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| 02110-1301 USA.
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| 
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| Linking this library statically or dynamically with other modules is
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| making a combined work based on this library.  Thus, the terms and
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| conditions of the GNU General Public License cover the whole
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| combination.
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| 
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| As a special exception, the copyright holders of this library give you
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| permission to link this library with independent modules to produce an
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| executable, regardless of the license terms of these independent
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| modules, and to copy and distribute the resulting executable under
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| terms of your choice, provided that you also meet, for each linked
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| independent module, the terms and conditions of the license of that
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| module.  An independent module is a module which is not derived from
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| or based on this library.  If you modify this library, you may extend
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| this exception to your version of the library, but you are not
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| obligated to do so.  If you do not wish to do so, delete this
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| exception statement from your version. */
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| 
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| #include <config.h>
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| #include <errno.h>
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| 
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| #include <jni.h>
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| #include <jcl.h>
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| 
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| #include "java_nio_MappedByteBufferImpl.h"
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| 
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| #include <string.h>
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| #include <stdlib.h>
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| #ifdef HAVE_UNISTD_H
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| #include <unistd.h>
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| #endif /* HAVE_UNISTD_H */
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| #ifdef HAVE_SYS_MMAN_H
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| #include <sys/mman.h>
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| #endif /* HAVE_SYS_MMAN_H */
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| 
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| #define IO_EXCEPTION "java/io/IOException"
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| 
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| /* FIXME these are defined in gnu_java_nio_channels_FileChannelImpl
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|    too; should be someplace common. */
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| #define ALIGN_DOWN(p,s) ((jpointer)(p) - ((jpointer)(p) % (s)))
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| #define ALIGN_UP(p,s) ((jpointer)(p) + ((s) - ((jpointer)(p) % (s))))
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| 
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| /**
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|  * Returns the memory page size of this platform.
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|  *
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|  * \return The page size.
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|  */
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| static long
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| get_pagesize (void)
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| {
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|   /* FIXME can we just try HAVE_SYSCONF? */
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| #if defined(HAVE_GETPAGESIZE)
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|   return getpagesize ();
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| #elif defined (HAVE_SYSCONF)
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|   return sysconf (_SC_PAGESIZE);
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| #endif /* HAVE_GETPAGESIZE / HAVE_SYSCONF */
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| }
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| 
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| /**
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|  * Retrieve the 'address' and 'cap' (the mapped size) fields of this
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|  * buffer.
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|  *
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|  * This function will align the address down to the nearest page
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|  * boundary, and the size up to the nearest page boundary. Thus, it is
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|  * safe to use these values in 'mman' functions.
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|  *
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|  * \param env The JNI environment pointer.
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|  * \param this The MappedByteBufferImpl instance.
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|  * \param address A pointer to where the actual pointer should be
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|  * stored.
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|  * \param size A pointer to where the mapped region's size should be
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|  * stored
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|  */
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| static void
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| get_raw_values (JNIEnv *env, jobject this, void **address, size_t *size)
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| {
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|   const long pagesize = get_pagesize ();
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|   jfieldID MappedByteBufferImpl_address;
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|   jfieldID MappedByteBufferImpl_size;
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|   jobject MappedByteBufferImpl_address_value = NULL;
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| 
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|   *address = NULL;
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|   /* 'address' is declared in java.nio.Buffer */
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|   MappedByteBufferImpl_address
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|     = (*env)->GetFieldID (env, (*env)->GetObjectClass (env, this),
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| 			  "address", "Lgnu/classpath/Pointer;");
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|   /* 'cap' -- likewise, the capacity */
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|   MappedByteBufferImpl_size
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|     = (*env)->GetFieldID (env, (*env)->GetObjectClass (env, this),
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| 			  "cap", "I");
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|   if (MappedByteBufferImpl_address != NULL)
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|     {
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|       MappedByteBufferImpl_address_value =
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| 	(*env)->GetObjectField (env, this, MappedByteBufferImpl_address);
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|     }
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|   if ((*env)->ExceptionOccurred (env))
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|     return;
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|   if (MappedByteBufferImpl_address_value == NULL)
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|     {
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|       JCL_ThrowException (env, "java/lang/NullPointerException",
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|                           "mapped address is NULL");
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|       return;
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|     }
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| 
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|   *address = (void *)
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|     ALIGN_DOWN (JCL_GetRawData (env, MappedByteBufferImpl_address_value), pagesize);
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|   *size = (size_t)
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|     ALIGN_UP ((*env)->GetIntField (env, this, MappedByteBufferImpl_size),
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| 	      pagesize);
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| }
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| 
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| JNIEXPORT void JNICALL
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| Java_java_nio_MappedByteBufferImpl_unmapImpl (JNIEnv *env, jobject this)
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| {
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| #ifdef HAVE_MUNMAP
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|   void *address;
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|   size_t size;
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| 
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|   get_raw_values (env, this, &address, &size);
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| 
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|   if (address == NULL)
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|     return;
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| 
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|   if (munmap (address, size) != 0)
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|     {
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|       JCL_ThrowException (env, IO_EXCEPTION, strerror (errno));
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|       return;
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|     }
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| #else
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|   JCL_ThrowException (env, IO_EXCEPTION,
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| 		      "unmapping files not implemented");
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| #endif /* HAVE_MUNMAP */
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| }
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| 
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| JNIEXPORT jboolean JNICALL
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| Java_java_nio_MappedByteBufferImpl_isLoadedImpl (JNIEnv * env, jobject this)
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| {
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| #ifdef HAVE_MINCORE
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|   void *address;
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|   size_t size;
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|   char *vec;
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|   size_t count, i;
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|   const long pagesize = get_pagesize ();
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| 
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|   /*
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|    * FIXME on Darwin this does not work if the mapped region is
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|    * exactly one page long; i.e., 'mincore' tells us it isn't loaded.
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|    */
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|   get_raw_values (env, this, &address, &size);
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|   if (address == NULL)
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|     return JNI_FALSE;
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|   count = (size_t) ((size + pagesize - 1) / pagesize);
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|   vec = (char *) malloc (count * sizeof (unsigned char));
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| 
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|   /*
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|    * Darwin (and BSD?) define argument 3 of 'mincore' to be 'char *',
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|    * while GNU libc defines it to be 'unsigned char *'. Casting the
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|    * argument to 'void *' fixes this, but not with C++. So you might
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|    * be SOL if you compile this with g++ (!) on GNU with -Werror.
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|    */
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| #ifdef __cplusplus
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|   if (mincore (address, size, vec) != 0)
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| #else
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|   if (mincore (address, size, (void *) vec) != 0)
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| #endif /* __cplusplus */
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|     {
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|       free (vec);
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|       JCL_ThrowException (env, IO_EXCEPTION, strerror (errno));
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|       return JNI_FALSE;
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|     }
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| 
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|   for (i = 0; i < count; i++)
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|     {
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|       if ((vec[i] & 1) == 0)
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|         return JNI_FALSE;
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|     }
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|   return JNI_TRUE;
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| #else
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|   return JNI_FALSE;
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| #endif
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| }
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| 
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| JNIEXPORT void JNICALL
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| Java_java_nio_MappedByteBufferImpl_loadImpl (JNIEnv *env, jobject this)
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| {
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| #ifdef HAVE_MADVISE
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|   void *address;
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|   size_t size;
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| 
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|   get_raw_values (env, this, &address, &size);
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|   if (address == NULL)
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|     return;
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| 
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|   madvise (address, size, MADV_WILLNEED);
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| #else
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|   JCL_ThrowException (env, IO_EXCEPTION,
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|                       "forcing mapped files into core not implemented");
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| #endif /* HAVE_MADVISE */
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| }
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| 
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| JNIEXPORT void JNICALL
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| Java_java_nio_MappedByteBufferImpl_forceImpl (JNIEnv *env, jobject this)
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| {
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| #ifdef HAVE_MSYNC
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|   void *address;
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|   size_t size;
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| 
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|   get_raw_values (env, this, &address, &size);
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| 
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|   if (address == NULL)
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|     return;
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| 
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|   /* FIXME: is using MS_SYNC ok? Should we use MS_INVALIDATE? */
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|   if (msync (address, size, MS_SYNC) != 0)
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|     {
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|       JCL_ThrowException (env, IO_EXCEPTION, strerror (errno));
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|     }
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| #else
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|   JCL_ThrowException (env, IO_EXCEPTION,
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| 		      "forcing mapped files to disk not implemented");
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| #endif /* HAVE_MSYNC */
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| }
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