Initial import into SourceForge CVS

git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14685 87f5fb63-7c3d-0410-a384-fd976d0f7a62

library/stdlib_realloc.c

@@ -0,0 +1,210 @@
+/*
+ * $Id: stdlib_realloc.c,v 1.1.1.1 2004-07-26 16:32:03 obarthel Exp $
+ *
+ * :ts=4
+ *
+ * Portable ISO 'C' (1994) runtime library for the Amiga computer
+ * Copyright (c) 2002-2004 by Olaf Barthel <olsen@sourcery.han.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Neither the name of Olaf Barthel nor the names of contributors
+ *     may be used to endorse or promote products derived from this
+ *     software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _STDLIB_MEM_DEBUG_H
+#include "stdlib_mem_debug.h"
+#endif /* _STDLIB_MEM_DEBUG_H */
+
+/****************************************************************************/
+
+#ifndef _STDLIB_HEADERS_H
+#include "stdlib_headers.h"
+#endif /* _STDLIB_HEADERS_H */
+
+/****************************************************************************/
+
+#undef realloc
+
+/****************************************************************************/
+
+void *
+__realloc(void *ptr,size_t size,const char * file,int line)
+{
+	void * result = NULL;
+
+	ENTER();
+
+	SHOWPOINTER(ptr);
+	SHOWVALUE(size);
+
+	assert( (int)size >= 0 );
+
+	if(ptr == NULL)
+	{
+		D(("calling malloc(%ld)",size));
+
+		result = __malloc(size,file,line);
+	}
+	else if (size == 0)
+	{
+		D(("calling free(0x%08lx)",ptr));
+
+		__free(ptr,file,line);
+	}
+	else
+	{
+		struct MemoryNode * mn;
+		BOOL reallocate;
+
+		assert( ptr != NULL && size > 0 );
+
+		/* Try to find the allocation in the list. */
+		mn = __find_memory_node(ptr);
+
+		#ifdef __MEM_DEBUG
+		{
+			/* If we managed to find the memory allocation,
+			 * reallocate it.
+			 */
+			if(mn == NULL)
+			{
+				SHOWMSG("allocation not found");
+
+				kprintf("[%s] %s:%ld:Address for realloc(0x%08lx,%ld) not known.\n",__program_name,file,line,ptr,size);
+
+				/* Apparently, the address did not qualify for
+				 * reallocation.
+				 */
+				errno = ENOMEM;
+				goto out;
+			}
+		}
+		#else
+		{
+			assert( mn != NULL );
+		}
+		#endif /* __MEM_DEBUG */
+
+		if(mn == NULL || mn->mn_NeverFree)
+		{
+			SHOWMSG("cannot free this chunk");
+
+			errno = ENOMEM;
+			goto out;
+		}
+
+		/* Don't do anything unless the size of the allocation has really
+		 * changed.
+		 */
+		#if defined(__MEM_DEBUG)
+		{
+			reallocate = (mn->mn_Size != size);
+		}
+		#else
+		{
+			if(size > mn->mn_Size)
+			{
+				/* Allocation size should grow. */
+				reallocate = TRUE;
+			}
+			else
+			{
+				size_t rounded_allocation_size;
+
+				/* Round the total allocation size to the operating system
+				 * granularity.
+				 */
+				rounded_allocation_size = __get_allocation_size(size);
+
+				assert( rounded_allocation_size >= size );
+
+				/* Optimization: If the block size shrinks by less than half the
+				 *               original allocation size, do not reallocate the
+				 *               block and do not copy over the contents of the old
+				 *               allocation. We also take into account that the
+				 *               actual size of the allocation is affected by a
+				 *               certain operating system imposed granularity.
+				 */
+				reallocate = (rounded_allocation_size < mn->mn_Size && rounded_allocation_size <= mn->mn_Size / 2);
+			}
+		}
+		#endif /* __MEM_DEBUG */
+
+		if(reallocate)
+		{
+			void * new_ptr;
+
+			D(("realloc() size has changed; old=%ld, new=%ld",mn->mn_Size,size));
+
+			/* We allocate the new memory chunk before we
+			   attempt to replace the old. */
+			new_ptr = __malloc(size,file,line);
+			if(new_ptr == NULL)
+			{
+				SHOWMSG("could not reallocate memory");
+
+				errno = ENOMEM;
+				goto out;
+			}
+
+			/* Copy the contents of the old allocation to the new buffer. */
+			if(size > mn->mn_Size)
+				size = mn->mn_Size;
+
+			memmove(new_ptr,ptr,size);
+
+			/* Free the old allocation. Since we already know which memory
+			   node is associated with it, we don't call __free() here. */
+			__free_memory_node(mn,file,line);
+
+			result = new_ptr;
+		}
+		else
+		{
+			D(("size didn't actually change that much (%ld -> %ld); returning memory block as is.",mn->mn_Size,size));
+
+			/* No change in size. */
+			result = ptr;
+		}
+	}
+
+ out:
+
+	if(result == NULL)
+		SHOWMSG("ouch! realloc failed");
+
+	RETURN(result);
+	return(result);
+}
+
+/****************************************************************************/
+
+void *
+realloc(void *ptr,size_t size)
+{
+	void * result;
+
+	result = __realloc(ptr,size,NULL,0);
+
+	return(result);
+}