/// <summary>
/// Gets the amount of available (free) memory on the system.
/// </summary>
/// <returns>
/// Amount of available (free) memory on the system in bytes.
/// </returns>
public static ulong GetAvailableMemory()
{
uint hostInfoCount = HOST_VM_INFO_COUNT;
var vmstat = new vm_statistics_data_t();
uint host_priv = mach_host_self();
PInvokeUtils.Try(() => host_statistics(host_priv, HostStatsType.HOST_VM_INFO, ref vmstat, ref hostInfoCount), result => result == KERN_SUCCESS);
ulong physicalMemory = GetPhysicalMemory();
double pagesTotal = vmstat.wire_count + vmstat.active_count + vmstat.inactive_count + vmstat.free_count;
double pagesFreePct = vmstat.free_count / pagesTotal;
double bytesFree = pagesFreePct * physicalMemory;
return((ulong)bytesFree);
}
static extern int host_statistics(
[In] uint host_priv,
[In][MarshalAs(UnmanagedType.SysUInt)] HostStatsType flavor,
[In, Out] ref vm_statistics_data_t host_info,
[In, Out] ref uint host_info_count
);