module runtime

import os

[typedef]
struct C.SYSTEM_INFO {
    dwNumberOfProcessors u32
}

[typedef]
struct C.MEMORYSTATUS {
    dwTotalPhys usize
    dwAvailPhys usize
}

fn C.GetSystemInfo(&C.SYSTEM_INFO)
fn C.GlobalMemoryStatus(&C.MEMORYSTATUS)

// nr_cpus returns the number of virtual CPU cores found on the system.
pub fn nr_cpus() int {
    sinfo := C.SYSTEM_INFO{}
    C.GetSystemInfo(&sinfo)
    mut nr := int(sinfo.dwNumberOfProcessors)
    if nr == 0 {
        nr = os.getenv('NUMBER_OF_PROCESSORS').int()
    }
    return nr
}

// total_memory returns total physical memory found on the system.
pub fn total_memory() usize {
    memory_status := C.MEMORYSTATUS{}
    C.GlobalMemoryStatus(&memory_status)
    return memory_status.dwTotalPhys
}

// free_memory returns free physical memory found on the system.
pub fn free_memory() usize {
    memory_status := C.MEMORYSTATUS{}
    C.GlobalMemoryStatus(&memory_status)
    return memory_status.dwAvailPhys
}