Utilities for getting memory allocation & free amounts (works on Mac & iPhone).

Memory.c

/*
 *  Memory.c
 *  Outpost
 *
 *  Created by Jim Dovey on 23/04/09.
 *  Copyright 2009 Morfunk, LLC. All rights reserved.
 *
 *  Copyright (c) 2009, Jim Dovey
 *  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.
 *  
 *  Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *  
 *  Neither the name of this project's author nor the names of its
 *  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
 *  HOLDER 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.
 *
 */

#import <mach/mach_host.h>
#import <mach/task.h>
#import <mach/task_info.h>
#import <mach/vm_types.h>
#import <mach/vm_statistics.h>
#import <mach/machine/vm_param.h>

mach_vm_size_t GetFreeMemory( void )
{
    mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
    vm_statistics_data_t vmstat;
    if ( host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vmstat, &count) != KERN_SUCCESS )
        return ( 0 );
    
    return ( vmstat.free_count * vm_page_size );
}

mach_vm_size_t GetProcessMemoryUsage( void )
{
    task_basic_info_data_t info;
    mach_msg_type_number_t count = TASK_BASIC_INFO_COUNT;
    if ( task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &count) != KERN_SUCCESS )
        return ( 0 );
    
    return ( info.resident_size );
}

Memory.h

/*
 *  Memory.h
 *  Outpost
 *
 *  Created by Jim Dovey on 23/04/09.
 *  Copyright 2009 Morfunk, LLC. All rights reserved.
 *
 *  Copyright (c) 2009, Jim Dovey
 *  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.
 *  
 *  Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *  
 *  Neither the name of this project's author nor the names of its
 *  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
 *  HOLDER 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 __OUTPOST_MEMORY_H__
#define __OUTPOST_MEMORY_H__

#include <mach/vm_types.h>

mach_vm_size_t GetFreeMemory( void );
mach_vm_size_t GetProcessMemoryUsage( void );

#endif  /* __OUTPOST_MEMORY_H__ */