qemu-ioh.c

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu-ioh.h"
  25 #include "qlist.h"
  26
  27 /* XXX: fd_read_poll should be suppressed, but an API change is
  28    necessary in the character devices to suppress fd_can_read(). */
  29 int qemu_set_fd_handler3(void *ioh_record_list,
  30                          int fd,
  31                          IOCanReadHandler *fd_read_poll,
  32                          IOHandler *fd_read,
  33                          IOHandler *fd_write,
  34                          void *opaque)
  35 {
  36     QLIST_HEAD(, IOHandlerRecord) *io_handlers_ptr = ioh_record_list;
  37     IOHandlerRecord *ioh;
  38
  39     if (!fd_read && !fd_write) {
  40         QLIST_FOREACH(ioh, io_handlers_ptr, next) {
  41             if (ioh->fd == fd) {
  42                 ioh->deleted = 1;
  43                 break;
  44             }
  45         }
  46     } else {
  47         QLIST_FOREACH(ioh, io_handlers_ptr, next) {
  48             if (ioh->fd == fd)
  49                 goto found;
  50         }
  51         ioh = qemu_mallocz(sizeof(IOHandlerRecord));
  52         QLIST_INSERT_HEAD(io_handlers_ptr, ioh, next);
  53     found:
  54         ioh->fd = fd;
  55         ioh->fd_read_poll = fd_read_poll;
  56         ioh->fd_read = fd_read;
  57         ioh->fd_write = fd_write;
  58         ioh->opaque = opaque;
  59         ioh->deleted = 0;
  60     }
  61     return 0;
  62 }
  63
  64 /* add entries from ioh record list to fd sets. nfds and fd sets
  65  * should be cleared/reset by caller if desired. set a particular
  66  * fdset to NULL to ignore fd events of that type
  67  */
  68 void qemu_get_fdset2(void *ioh_record_list, int *nfds, fd_set *rfds,
  69                      fd_set *wfds, fd_set *xfds)
  70 {
  71     QLIST_HEAD(, IOHandlerRecord) *io_handlers = ioh_record_list;
  72     IOHandlerRecord *ioh;
  73
  74     QLIST_FOREACH(ioh, io_handlers, next) {
  75         if (ioh->deleted)
  76             continue;
  77         if ((rfds != NULL && ioh->fd_read) &&
  78             (!ioh->fd_read_poll ||
  79              ioh->fd_read_poll(ioh->opaque) != 0)) {
  80             FD_SET(ioh->fd, rfds);
  81             if (ioh->fd > *nfds)
  82                 *nfds = ioh->fd;
  83         }
  84         if (wfds != NULL && ioh->fd_write) {
  85             FD_SET(ioh->fd, wfds);
  86             if (ioh->fd > *nfds)
  87                 *nfds = ioh->fd;
  88         }
  89     }
  90 }
  91
  92 /* execute registered handlers for r/w events in the provided fdsets. unset
  93  * handlers are cleaned up here as well
  94  */
  95 void qemu_process_fd_handlers2(void *ioh_record_list, const fd_set *rfds,
  96                                const fd_set *wfds, const fd_set *xfds)
  97 {
  98     QLIST_HEAD(, IOHandlerRecord) *io_handlers = ioh_record_list;
  99     IOHandlerRecord *ioh, *pioh;
 100
 101     QLIST_FOREACH_SAFE(ioh, io_handlers, next, pioh) {
 102         if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, rfds)) {
 103             ioh->fd_read(ioh->opaque);
 104         }
 105         if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, wfds)) {
 106             ioh->fd_write(ioh->opaque);
 107         }
 108
 109         /* Do this last in case read/write handlers marked it for deletion */
 110         if (ioh->deleted) {
 111             QLIST_REMOVE(ioh, next);
 112             qemu_free(ioh);
 113         }
 114     }
 115 }