func NewBIO(dev BlockDevice, N int, BSize uint64) (bio *BIO) {
if (PAGESIZE % BSize) != 0 {
f**k("BIO with non-divisors of the PAGESIZE not implemented")
}
bio = new(BIO)
bio.BSize = BSize
bio.BlockDevice = dev
bio.free = make(chan *Buf, N)
bio.all = make([]Buf, N)
virt, phys := runtime.AlignAlloc(uint64(N) * BSize)
for k := range bio.all {
h := (*runtime.SliceHeader)(unsafe.Pointer(&bio.all[k].Data))
h.Data, bio.all[k].Phys = virt, phys
virt += uintptr(BSize)
phys += BSize
h.Len = int(BSize)
h.Cap = int(BSize)
bio.all[k].Done = make(chan bool)
bio.all[k].Want = make(chan bool)
bio.all[k].BIO = bio
bio.all[k].Block = ^uint64(0)
bio.free <- &bio.all[k]
}
return
}
// This produces (pseudo-) buffers for actually unbuffered I/O
// DON'T use those with the buffer functions, use DoEet
// DON'T use it in a large scale
// You have been warned
func MakeBuf(size uint64, dev BlockDevice) (b *Buf) {
b = new(Buf)
b.Done = make(chan bool)
virt, phys := runtime.AlignAlloc(size)
h := (*runtime.SliceHeader)(unsafe.Pointer(&b.Data))
h.Data, b.Phys = virt, phys
h.Len, h.Cap = int(size), int(size)
b.BIO = new(BIO)
b.BIO.BlockDevice = dev
return
}
