testmalloc.c

对内存的分配、释放和使用进行检查

/* NOT copyright by SoftQuad Inc. -- msb, 1988 */
#ifndef lint
static char *SQ_SccsId = "@(#)mtest3.c	1.2 88/08/25";
#endif
#include <stdio.h>
/*
** looptest.c -- intensive allocator tester 
**
** Usage:  looptest
**
** History:
**	4-Feb-1987 rtech!daveb 
*/

# ifdef SYS5
# define random	rand
# else
# include <sys/vadvise.h>
# endif

# include <stdio.h>
# include <signal.h>
# include <setjmp.h>

# define MAXITER	1000000		/* main loop iterations */
# define MAXOBJS	1000		/* objects in pool */
# define BIGOBJ		90000		/* max size of a big object */
# define TINYOBJ	80		/* max size of a small object */
# define BIGMOD		100		/* 1 in BIGMOD is a BIGOBJ */
# define STATMOD	10000		/* interation interval for status */

main( argc, argv )
int argc;
char **argv;
{
	register int **objs;		/* array of objects */
	register int *sizes;		/* array of object sizes */
	register int n;			/* iteration counter */
	register int i;			/* object index */
	register int size;		/* object size */
	register int r;			/* random number */

	int objmax;			/* max size this iteration */
	int cnt;			/* number of allocated objects */
	int nm = 0;			/* number of mallocs */
	int nre = 0;			/* number of reallocs */
	int nal;			/* number of allocated objects */
	int nfre;			/* number of free list objects */
	long alm;			/* memory in allocated objects */
	long frem;			/* memory in free list */
	long startsize;			/* size at loop start */
	long endsize;			/* size at loop exit */
	long maxiter = 0;		/* real max # iterations */

	extern char end;		/* memory before heap */
	char *calloc();
	char *malloc();
	char *sbrk();
	long atol();

# ifndef SYS5
	/* your milage may vary... */
	vadvise( VA_ANOM );
# endif

	if (argc > 1)
		maxiter = atol (argv[1]);
	if (maxiter <= 0)
		maxiter = MAXITER;

	printf("MAXITER %d MAXOBJS %d ", maxiter, MAXOBJS );
	printf("BIGOBJ %d, TINYOBJ %d, nbig/ntiny 1/%d\n",
	BIGOBJ, TINYOBJ, BIGMOD );
	fflush( stdout );

	if( NULL == (objs = (int **)calloc( MAXOBJS, sizeof( *objs ) ) ) )
	{
		fprintf(stderr, "Can't allocate memory for objs array\n");
		exit(1);
	}

	if( NULL == ( sizes = (int *)calloc( MAXOBJS, sizeof( *sizes ) ) ) )
	{
		fprintf(stderr, "Can't allocate memory for sizes array\n");
		exit(1);
	}

	/* as per recent discussion on net.lang.c, calloc does not 
	** necessarily fill in NULL pointers...
	*/
	for( i = 0; i < MAXOBJS; i++ )
		objs[ i ] = NULL;

	startsize = sbrk(0) - &end;
	printf( "Memory use at start: %d bytes\n", startsize );
	fflush(stdout);

	printf("Starting the test...\n");
	fflush(stdout);
	for( n = 0; n < maxiter ; n++ )
	{
		if( !(n % STATMOD) )
		{
			printf("%d iterations\n", n);
			fflush(stdout);
		}

		/* determine object of interst and it's size */

		r = random();
		objmax = ( r % BIGMOD ) ? TINYOBJ : BIGOBJ;
		size = r % objmax;
		i = r % (MAXOBJS - 1);

		/* either replace the object of get a new one */

		if( objs[ i ] == NULL )
		{
			objs[ i ] = (int *)malloc( size );
			nm++;
		}
		else
		{
			/* don't keep bigger objects around */
			if( size > sizes[ i ] )
			{
				objs[ i ] = (int *)realloc( objs[ i ], size );
				nre++;
			}
			else
			{
				free( objs[ i ] );
				objs[ i ] = (int *)malloc( size );
				nm++;
			}
		}

		sizes[ i ] = size;
		if( objs[ i ] == NULL )
		{
			printf("\nCouldn't allocate %d byte object!\n", 
				size );
			break;
		}
	} /* for() */

	printf( "\n" );
	cnt = 0;
	for( i = 0; i < MAXOBJS; i++ )
		if( objs[ i ] )
			cnt++;

	printf( "Did %d iterations, %d objects, %d mallocs, %d reallocs\n",
		n, cnt, nm, nre );
	printf( "Memory use at end: %d bytes\n", sbrk(0) - &end );
	fflush( stdout );

	/* free all the objects */
	for( i = 0; i < MAXOBJS; i++ )
		if( objs[ i ] != NULL )
			free( objs[ i ] );

	endsize = sbrk(0) - &end;
	printf( "Memory use after free: %d bytes\n", endsize );
	fflush( stdout );

	if( startsize != endsize )
		printf("startsize %d != endsize %d\n", startsize, endsize );

	free( objs );
	free( sizes );

	malloc_dump(2);
	exit( 0 );
}