kolibrios/kernel/branches/kolibri-process/network/queue.inc

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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2004-2010. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License ;;
;; ;;
;; queue.inc ;;
;; ;;
;; Written by hidnplayr@kolibrios.org ;;
;; ;;
;; GNU GENERAL PUBLIC LICENSE ;;
;; Version 2, June 1991 ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
$Revision: 4850 $
; The Queues implemented by these macros form a ring-buffer.
; The data to these queue's always looks like this:
;
; At top, you have the queue struct, wich has the size (number of currently queued packets, read and write pointers.
; This struct is followed by a number of slots wich you can read and write to using the macros.
; How these slots look like is up to you to chose, normally they should have at least a pointer to where the real data is.
; (you can see some examples below)
struct queue
size dd ? ; number of queued packets in this queue
w_ptr dd ? ; current writing pointer in queue
r_ptr dd ? ; current reading pointer
ends
; The following macros share these inputs:
; ptr = pointer to where the queue data is located
; size = number of slots/entrys in the queue
; entry_size = size of one slot, in bytes
; failaddr = the address where macro will jump to when there is no data in the queue
; additionally, add_to_queue requires you to set esi to the data wich you want to queue
; get_from_queue on the other hand will return a pointer in esi, to the entry you're interessed in
; PS: macros WILL destroy ecx and edi
macro add_to_queue ptr, size, entry_size, failaddr {
local .ok, .no_wrap
spin_lock_irqsave
cmp [ptr + queue.size], size ; Check if queue isnt full
jb .ok
spin_unlock_irqrestore
jmp failaddr
.ok:
inc [ptr + queue.size] ; if not full, queue one more
mov edi, [ptr + queue.w_ptr] ; Current write pointer (FIFO!)
mov ecx, entry_size/4 ; Write the queue entry
rep movsd ;
lea ecx, [size*entry_size+ptr+sizeof.queue]
cmp edi, ecx ; entry size
jb .no_wrap
sub edi, size*entry_size
.no_wrap:
mov [ptr + queue.w_ptr], edi
spin_unlock_irqrestore
}
macro get_from_queue ptr, size, entry_size, failaddr {
local .ok, .no_wrap
spin_lock_irqsave
cmp [ptr + queue.size], 0 ; any packets queued?
ja .ok
spin_unlock_irqrestore
jmp failaddr
.ok:
dec [ptr + queue.size] ; if so, dequeue one
mov esi, [ptr + queue.r_ptr]
push esi
add esi, entry_size
lea ecx, [size*entry_size+ptr+sizeof.queue]
cmp esi, ecx ; entry size
jb .no_wrap
sub esi, size*entry_size
.no_wrap:
mov dword [ptr + queue.r_ptr], esi
pop esi
spin_unlock_irqrestore
}
macro init_queue ptr {
mov [ptr + queue.size] , 0
lea edi, [ptr + sizeof.queue]
mov [ptr + queue.w_ptr], edi
mov [ptr + queue.r_ptr], edi
}