+++ /dev/null
-/* void * malloc( size_t )
-
- This file is part of the Public Domain C Library (PDCLib).
- Permission is granted to use, modify, and / or redistribute at will.
-*/
-
-#include <stdlib.h>
-#include <stdint.h>
-#include <stdbool.h>
-
-#ifndef REGTEST
-#include <_PDCLIB_glue.h>
-
-/* TODO: Primitive placeholder. Much room for improvement. */
-
-/* Keeping pointers to the first and the last element of the free list. */
-struct _PDCLIB_headnode_t _PDCLIB_memlist = { NULL, NULL };
-
-void * malloc( size_t size )
-{
- if ( size == 0 )
- {
- return NULL;
- }
- if ( size < _PDCLIB_MINALLOC )
- {
- size = _PDCLIB_MINALLOC;
- }
- {
- struct _PDCLIB_memnode_t * current = _PDCLIB_memlist.first;
- struct _PDCLIB_memnode_t * previous = NULL;
- struct _PDCLIB_memnode_t * firstfit = NULL;
- struct _PDCLIB_memnode_t * firstfit_previous = NULL;
- /* Trying exact fit */
- while ( current != NULL )
- {
- if ( current->size == size )
- {
- /* Found exact fit, allocate node */
- if ( previous != NULL )
- {
- /* Node in the middle of the list */
- previous->next = current->next;
- }
- else
- {
- /* Node is first in list */
- _PDCLIB_memlist.first = current->next;
- }
- if ( _PDCLIB_memlist.last == current )
- {
- /* Node is last in list */
- _PDCLIB_memlist.last = previous;
- }
- return (char *)current + sizeof( struct _PDCLIB_memnode_t );
- }
- else if ( current->size > size && ( firstfit == NULL || current->size < firstfit->size ) )
- {
- /* Remember previous node in case we do not get an exact fit.
- Note that this is the node *pointing to* the first fit,
- as we need that for allocating (i.e., changing next pointer).
- */
- firstfit_previous = previous;
- firstfit = current;
- }
- /* Skip to next node */
- previous = current;
- current = current->next;
- }
- /* No exact fit; go for first fit */
- if ( firstfit != NULL )
- {
- bool node_split = false;
- if ( ( firstfit->size - size ) > ( _PDCLIB_MINALLOC + sizeof( struct _PDCLIB_memnode_t ) ) )
- {
- /* Oversized - split into two nodes */
- struct _PDCLIB_memnode_t * newnode = (struct _PDCLIB_memnode_t *)( (char *)firstfit + sizeof( struct _PDCLIB_memnode_t ) + size );
- newnode->size = firstfit->size - size - sizeof( struct _PDCLIB_memnode_t );
- newnode->next = firstfit->next;
- firstfit->next = newnode;
- firstfit->size = firstfit->size - newnode->size - sizeof( struct _PDCLIB_memnode_t );
- node_split = true;
- }
- if ( firstfit_previous != NULL )
- {
- /* Node in the middle of the list */
- firstfit_previous->next = firstfit->next;
- }
- else
- {
- /* Node is first in list */
- _PDCLIB_memlist.first = firstfit->next;
- }
- if ( _PDCLIB_memlist.last == firstfit )
- {
- /* Node is last in list */
- if ( node_split )
- {
- _PDCLIB_memlist.last = firstfit->next;
- }
- else
- {
- _PDCLIB_memlist.last = firstfit_previous;
- }
- }
- return (char *)firstfit + sizeof( struct _PDCLIB_memnode_t );
- }
- }
- {
- /* No fit possible; how many additional pages do we need? */
- size_t pages = ( ( size + sizeof( struct _PDCLIB_memnode_t ) - 1 ) / _PDCLIB_PAGESIZE ) + 1;
- /* Allocate more pages */
- struct _PDCLIB_memnode_t * newnode = (struct _PDCLIB_memnode_t *)_PDCLIB_allocpages( (int)pages );
- if ( newnode != NULL )
- {
- newnode->next = NULL;
- newnode->size = pages * _PDCLIB_PAGESIZE - sizeof( struct _PDCLIB_memnode_t );
- if ( ( newnode->size - size ) > ( _PDCLIB_MINALLOC + sizeof( struct _PDCLIB_memnode_t ) ) )
- {
- /* Oversized - split into two nodes */
- struct _PDCLIB_memnode_t * splitnode = (struct _PDCLIB_memnode_t *)( (char *)newnode + sizeof( struct _PDCLIB_memnode_t ) + size );
- splitnode->size = newnode->size - size - sizeof( struct _PDCLIB_memnode_t );
- newnode->size = size;
- /* Add splitted node as last element to free node list */
- if ( _PDCLIB_memlist.last == NULL )
- {
- _PDCLIB_memlist.first = splitnode;
- }
- else
- {
- _PDCLIB_memlist.last->next = splitnode;
- }
- splitnode->next = NULL; /* TODO: This is bug #7, uncovered by testdriver yet. */
- _PDCLIB_memlist.last = splitnode;
- }
- return (char *)newnode + sizeof( struct _PDCLIB_memnode_t );
- }
- }
- /* No fit, heap extension not possible - out of memory */
- return NULL;
-}
-
-#endif
-
-
-#ifdef TEST
-#include <_PDCLIB_test.h>
-#include <string.h>
-#include <stdarg.h>
-#include <stdio.h>
-
-
-#ifndef REGTEST
-
-/* Effective page size, i.e. how many bytes can be allocated and still be on
- one page of memory.
-*/
-#define EFFECTIVE _PDCLIB_PAGESIZE - sizeof( struct _PDCLIB_memnode_t )
-#define MEMTEST( ptr, size ) ( ( ptr = malloc( size ) ) != NULL ) && ( memset( ptr, 0, size ) == ptr )
-
-char * pages_start = 0;
-int test_nodes( char const * const, int, ... );
-void PRINT( char const * const, ... );
-
-/* This can be enabled to give a dump of node information */
-#if 0
-void PRINT( char const * const format, ... )
-{
- va_list( ap );
- va_start( ap, format );
- vprintf( format, ap );
-}
-#else
-void PRINT( char const * const format, ... )
-{
- /* EMPTY */
-}
-#endif
-
-/* Helper function checking number of allocated memory pages and the nodes
- in the free memory list against expectations.
-*/
-int test_nodes( char const * const action, int expected_pages, ... )
-{
- static int count = 1;
- int result = 1;
- PRINT( action );
- /* Determining the amount of allocated pages */
- int allocated_pages = ( (intptr_t)_PDCLIB_allocpages( 0 ) - (intptr_t)pages_start ) / _PDCLIB_PAGESIZE;
- PRINT( "Test #%2d, %d allocated pages", count++, allocated_pages );
- if ( allocated_pages != expected_pages )
- {
- PRINT( " - MISMATCH, expected\n %d pages\n", expected_pages );
- result = 0;
- }
- else
- {
- PRINT( "\n" );
- }
- /* Now moving through the free nodes list */
- va_list( ap );
- va_start( ap, expected_pages );
- struct _PDCLIB_memnode_t * tracer = _PDCLIB_memlist.first;
- int firstnode = 0;
- int lastnode = 0;
- while ( tracer != NULL )
- {
- /* Data from node */
- size_t node_location = (char *)tracer - (char *)pages_start;
- PRINT( " - node %.4p, size %#.4x", node_location, tracer->size );
- /* Expected data */
- size_t expected_location = va_arg( ap, size_t );
- if ( expected_location == 0 )
- {
- PRINT( " - UNEXPECTED NODE\n" );
- result = 0;
- continue;
- }
- /* Memorizing first and last expected node for later comparison. */
- if ( firstnode == 0 )
- {
- firstnode = expected_location;
- }
- lastnode = expected_location;
- /* Comparing expected node against current node */
- size_t expected_size = va_arg( ap, size_t );
- if ( ( node_location != expected_location ) || ( tracer->size != expected_size ) )
- {
- PRINT( " - MISMATCH, expected values\n %.4p %#.4p\n", expected_location, expected_size );
- result = 0;
- }
- else
- {
- PRINT( "\n" );
- }
- tracer = tracer->next;
- }
- /* Comparing first and last node in memlist against expectations. */
- PRINT( " - memlist first: %#.4x - last: %#.4x",
- ( _PDCLIB_memlist.first == NULL ) ? NULL : (char *)_PDCLIB_memlist.first - (char *)pages_start,
- ( _PDCLIB_memlist.last == NULL ) ? NULL : (char *)_PDCLIB_memlist.last - (char *)pages_start );
- if ( ( firstnode != 0 ) &&
- ( ( ( (char *)_PDCLIB_memlist.first - (char *)pages_start ) != firstnode )
- || ( ( (char *)_PDCLIB_memlist.last - (char *)pages_start ) != lastnode ) ) )
- {
- PRINT( " - MISMATCH, expected values\n %#.4x - last: %#.4x\n", firstnode, lastnode );
- result = 0;
- }
- else
- {
- PRINT( "\n" );
- }
- PRINT( "\n" );
- return result;
-}
-
-#endif
-
-/* Note that this test driver heavily tests *internals* of the implementation
- above (and of free() and realloc(), too). That means that changes in the
- implementation must be accompanied with appropriate changes of the test
- driver. It does *not* make a good regression tester for the implementation,
- I am afraid, and thus there is no REGTEST equivalent.
-*/
-
-int main( void )
-{
-#ifndef REGTEST
- void * ptr1, * ptr2, * ptr3, * ptr4, * ptr5, * ptr6, * ptr7, * ptr8, * ptr9, * ptrA, * ptrB, * ptrC;
-
- pages_start = _PDCLIB_allocpages( 0 );
- PRINT( "\nEffective is: %#.4x\nsizeof( memnode ) is: %#.2x\n\n", EFFECTIVE, sizeof( struct _PDCLIB_memnode_t ) );
-
- /* Allocating 10 bytes; expecting one page allocation and a node split */
- TESTCASE( MEMTEST( ptr1, 10 ) );
- TESTCASE( test_nodes( "Allocating 10 bytes.", 1,
- sizeof( struct _PDCLIB_memnode_t ) + 10, EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - 10,
- 0 ) );
-
- /* Allocating the rest of the page; expecting no page allocation and assignment of the remaining node */
- TESTCASE( MEMTEST( ptr2, EFFECTIVE - 10 - sizeof( struct _PDCLIB_memnode_t ) ) );
- TESTCASE( test_nodes( "Allocating the rest of the page.", 1,
- 0 ) );
-
- /* Allocating a full page; expecting one page allocation, no node split */
- TESTCASE( MEMTEST( ptr3, EFFECTIVE ) );
- TESTCASE( test_nodes( "Allocating a full page.", 2,
- 0 ) );
-
- /* Allocating *almost* a full page; expecting one page allocation, no node split */
- TESTCASE( MEMTEST( ptr4, EFFECTIVE - 4 ) );
- TESTCASE( test_nodes( "Allocating *almost* a full page.", 3,
- 0 ) );
-
- /* Freeing and re-allocating the "almost" full page; expecting no page allocation, no node split */
- free( ptr4 );
- TESTCASE( MEMTEST( ptr5, EFFECTIVE - 4 ) );
- TESTCASE( ptr4 == ptr5 );
- TESTCASE( test_nodes( "Freeing and re-allocating the \"almost\" full page.", 3 ) );
-
- /* Freeing the full page from test #3; expecting a full-sized free node. */
- free( ptr3 );
- TESTCASE( test_nodes( "Freeing the full page from test #3.", 3,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Allocating two full pages; expecting two page allocations, no node split */
- TESTCASE( MEMTEST( ptr3, EFFECTIVE + _PDCLIB_PAGESIZE ) );
- TESTCASE( test_nodes( "Allocating two full pages.", 5,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Re-allocating to size of 10 bytes; expecting no page allocation, no node split */
- /* TODO: Shouldn't realloc() split the now much-too-large node? */
- TESTCASE( realloc( ptr3, 10 ) == ptr3 );
- TESTCASE( test_nodes( "Re-allocating to size of 10 bytes.", 5,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Re-allocating to size of two full pages; expecting no page allocation, no node split */
- TESTCASE( realloc( ptr3, EFFECTIVE + _PDCLIB_PAGESIZE ) == ptr3 );
- TESTCASE( test_nodes( "Re-allocating to size of two full pages.", 5,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Re-allocating to size of three full pages; expecting three page allocation, freeing of two-page node */
- TESTCASE( realloc( ptr3, EFFECTIVE + _PDCLIB_PAGESIZE * 2 ) != ptr3 );
- TESTCASE( test_nodes( "Re-allocating to size of three full pages.", 8,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- _PDCLIB_PAGESIZE * 3, EFFECTIVE + _PDCLIB_PAGESIZE,
- 0 ) );
-
- /* Allocating two full pages; expecting allocation of the available two-page node */
- TESTCASE( MEMTEST( ptr4, EFFECTIVE + _PDCLIB_PAGESIZE ) );
- TESTCASE( test_nodes( "Allocating two full pages.", 8,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Allocating zero bytes; expecting no change */
- TESTCASE( ! MEMTEST( ptr6, 0 ) );
- TESTCASE( test_nodes( "Allocating zero bytes.", 8,
- _PDCLIB_PAGESIZE * 1, EFFECTIVE,
- 0 ) );
-
- /* Allocating 4 bytes; expecting upsizing of requestupsizing of size, node split */
- TESTCASE( MEMTEST( ptr7, 4 ) );
- TESTCASE( test_nodes( "Allocating 4 bytes.", 8,
- _PDCLIB_PAGESIZE * 1 + _PDCLIB_MINALLOC + sizeof( struct _PDCLIB_memnode_t ),
- EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ),
- 0 ) );
-
- /* Allocating the rest of the page; expecting no page allocation and assignment of the remaining node */
- TESTCASE( MEMTEST( ptr8, EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ) ) );
- TESTCASE( test_nodes( "Allocating the rest of the page.", 8, 0 ) );
-
- /* Freeing the node from the previous test; expecting node to re-appear in free list */
- free( ptr8 );
- TESTCASE( test_nodes( "Freeing the node from the previous test.", 8,
- _PDCLIB_PAGESIZE * 1 + _PDCLIB_MINALLOC + sizeof( struct _PDCLIB_memnode_t ),
- EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ),
- 0 ) );
-
- /* Allocating one byte more than available in free node; expecting page allocation */
- TESTCASE( MEMTEST( ptr8, EFFECTIVE + 1 - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ) ) );
- TESTCASE( test_nodes( "Allocating one byte more than available in free node.", 9,
- _PDCLIB_PAGESIZE * 1 + _PDCLIB_MINALLOC + sizeof( struct _PDCLIB_memnode_t ),
- EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ),
- 0 ) );
-
- /* Re-allocating with NULL pointer; expecting no page allocation, no node split */
- ptr9 = realloc( NULL, EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ) );
- TESTCASE( ptr9 != NULL );
- TESTCASE( memset( ptr9, 0, EFFECTIVE - _PDCLIB_MINALLOC - sizeof( struct _PDCLIB_memnode_t ) ) == ptr9 );
- TESTCASE( test_nodes( "Re-allocating with NULL pointer.", 9, 0 ) );
-
- /* Allocating a bit more than half a page; expecting page allocation, node split */
-#define TESTSIZE 3000
- TESTCASE( MEMTEST( ptrA, TESTSIZE ) );
- TESTCASE( test_nodes( "Allocating a bit more than half a page.", 10,
- _PDCLIB_PAGESIZE * 9 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- 0 ) );
-
- /* Allocating a bit more than half a page; expecting page allocation, node split */
- TESTCASE( MEMTEST( ptrB, TESTSIZE ) );
- TESTCASE( test_nodes( "Allocating a bit more than half a page.", 11,
- _PDCLIB_PAGESIZE * 9 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 10 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- 0 ) );
-
- /* Allocating a bit more than half a page; expecting page allocation, node split */
- TESTCASE( MEMTEST( ptrC, TESTSIZE ) );
- TESTCASE( test_nodes( "Allocating a bit more than half a page.", 12,
- _PDCLIB_PAGESIZE * 9 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 10 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 11 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- 0 ) );
-
- /* Freeing the middle node */
- free( ptrB );
- TESTCASE( test_nodes( "Freeing the middle node.", 12,
- _PDCLIB_PAGESIZE * 9 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 10 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 11 + sizeof( struct _PDCLIB_memnode_t ) + TESTSIZE,
- EFFECTIVE - sizeof( struct _PDCLIB_memnode_t ) - TESTSIZE,
- _PDCLIB_PAGESIZE * 10,
- TESTSIZE,
- 0 ) );
-
-#else
- puts( " NOTEST malloc() test driver is PDCLib-specific." );
-#endif
- return TEST_RESULTS;
-}
-
-#endif