diff options
Diffstat (limited to 'devio/window.c')
| -rw-r--r-- | devio/window.c | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/devio/window.c b/devio/window.c deleted file mode 100644 index f7df045d..00000000 --- a/devio/window.c +++ /dev/null @@ -1,171 +0,0 @@ -/* Window management routines for buffered I/O using VM. - - Copyright (C) 1995 Free Software Foundation, Inc. - - Written by Miles Bader <miles@gnu.ai.mit.edu> - - This program is free software; you can redistribute it and/or - modify it under the terms of the GNU General Public License as - published by the Free Software Foundation; either version 2, or (at - your option) any later version. - - This program is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - -#include <hurd.h> - -#include "window.h" -#include "mem.h" - -/* ---------------------------------------------------------------- */ - -/* Create a VM window onto the memory object MEMOBJ, and return it in WIN. - MIN_SIZE and MAX_SIZE are the minimum and maximum sizes that the window - will shrink/grow to (a value of 0 will use some default). */ -error_t -window_create(mach_port_t memobj, vm_offset_t max_pos, - vm_size_t min_size, vm_size_t max_size, int read_only, - struct window **win) -{ - *win = malloc(sizeof(struct window)); - if (*win == NULL) - return ENOMEM; - - if (min_size < max_size) - min_size = max_size; - - (*win)->pos = 0; - (*win)->max_pos = max_pos; - (*win)->size = 0; - (*win)->memobj = memobj; - (*win)->min_size = (min_size < vm_page_size ? vm_page_size : min_size); - (*win)->max_size = (max_size < vm_page_size ? vm_page_size : max_size); - (*win)->read_only = read_only; - - return 0; -} - -/* Free WIN and any resources it holds. */ -void -window_free(struct window *win) -{ - if (win->size > 0) - vm_deallocate(mach_task_self(), win->buffer, win->size); - mach_port_destroy(mach_task_self(), win->memobj); - free(win); -} - -/* ---------------------------------------------------------------- */ - -/* Makes sure that WIN's memory window contains at least positions POS - through POS + LEN on the device WIN's mapping. If an error occurs in the - process, the error code is returned (and WIN may not map the desired - locations), otherwise 0. WIN is assumed to already be locked when this is - called. */ -static error_t -position(struct window *win, vm_offset_t pos, vm_size_t len) -{ - vm_offset_t end = pos + len; - vm_offset_t win_beg = win->pos; - vm_offset_t win_end = win_beg + win->size; - - if (pos >= win_beg && end <= win_end) - /* The request is totally satisfied by our current position. */ - return 0; - else -#if 0 /* XXXXXXX */ - if (end < win_beg || pos >= win_end) - /* The desired locations are entirely outside our current window, so just - trash it, and map a new buffer anywhere. */ -#endif - { - int prot = VM_PROT_READ | (win->read_only ? 0 : VM_PROT_WRITE); - - if (win->size > 0) - vm_deallocate(mach_task_self(), win->buffer, win->size); - - win->pos = trunc_page(pos); - win->size = round_page(len + (pos - win->pos)); - win->buffer = 0; - - if (win->size < win->min_size) - win->size = win->min_size; - - if (win->pos + win->size > win->max_pos) - win->size = win->max_pos - win->pos; - - return - vm_map(mach_task_self(), &win->buffer, win->size, 0, 1, - win->memobj, win->pos, 0, prot, prot, VM_INHERIT_NONE); - } - - return 0; -} - -/* ---------------------------------------------------------------- */ - -/* Write up to BUF_LEN bytes from BUF to the device that WIN is a window on, - at offset *OFFS, using memory-mapped buffered I/O. If successful, 0 is - returned, otherwise an error code is returned. *OFFS is incremented by - the amount sucessfully written. */ -error_t -window_write(struct window *win, - vm_address_t buf, vm_size_t buf_len, vm_size_t *amount, - vm_offset_t *offs) -{ - error_t err; - - mutex_lock(&win->lock); - - err = position(win, *offs, buf_len); - if (!err) - { - bcopy((char *)buf, - (char *)win->buffer + (*offs - win->pos), - buf_len); - *amount = buf_len; - *offs += buf_len; - } - - mutex_unlock(&win->lock); - - return err; -} - -/* Read up to AMOUNT bytes from the device that WIN is a window on, at offset - *OFFS, into BUF and BUF_LEN (using the standard mach out-array - conventions), using memory-mapped buffered I/O. If successful, 0 is - returned, otherwise an error code is returned. *OFFS is incremented by - the amount sucessfully written. */ -error_t -window_read(struct window *win, - vm_address_t *buf, vm_size_t *buf_len, - vm_size_t amount, vm_offset_t *offs) -{ - error_t err; - - mutex_lock(&win->lock); - - err = position(win, *offs, amount); - if (!err) - { - err = allocate(buf, buf_len, amount); - if (!err) - { - bcopy((char *)win->buffer + (*offs - win->pos), - (char *)*buf, - amount); - *offs += amount; - } - } - - mutex_unlock(&win->lock); - - return err; -} |