qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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char-io.c (4397B)

      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/osdep.h"
     25 #include "chardev/char-io.h"
     26 
     27 typedef struct IOWatchPoll {
     28     GSource parent;
     29 
     30     QIOChannel *ioc;
     31     GSource *src;
     32 
     33     IOCanReadHandler *fd_can_read;
     34     GSourceFunc fd_read;
     35     void *opaque;
     36 } IOWatchPoll;
     37 
     38 static IOWatchPoll *io_watch_poll_from_source(GSource *source)
     39 {
     40     return container_of(source, IOWatchPoll, parent);
     41 }
     42 
     43 static gboolean io_watch_poll_prepare(GSource *source,
     44                                       gint *timeout)
     45 {
     46     IOWatchPoll *iwp = io_watch_poll_from_source(source);
     47     bool now_active = iwp->fd_can_read(iwp->opaque) > 0;
     48     bool was_active = iwp->src != NULL;
     49     if (was_active == now_active) {
     50         return FALSE;
     51     }
     52 
     53     if (now_active) {
     54         iwp->src = qio_channel_create_watch(
     55             iwp->ioc, G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);
     56         g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);
     57         g_source_add_child_source(source, iwp->src);
     58         g_source_unref(iwp->src);
     59     } else {
     60         g_source_remove_child_source(source, iwp->src);
     61         iwp->src = NULL;
     62     }
     63     return FALSE;
     64 }
     65 
     66 static gboolean io_watch_poll_dispatch(GSource *source, GSourceFunc callback,
     67                                        gpointer user_data)
     68 {
     69     return G_SOURCE_CONTINUE;
     70 }
     71 
     72 static GSourceFuncs io_watch_poll_funcs = {
     73     .prepare = io_watch_poll_prepare,
     74     .dispatch = io_watch_poll_dispatch,
     75 };
     76 
     77 GSource *io_add_watch_poll(Chardev *chr,
     78                         QIOChannel *ioc,
     79                         IOCanReadHandler *fd_can_read,
     80                         QIOChannelFunc fd_read,
     81                         gpointer user_data,
     82                         GMainContext *context)
     83 {
     84     IOWatchPoll *iwp;
     85     char *name;
     86 
     87     iwp = (IOWatchPoll *) g_source_new(&io_watch_poll_funcs,
     88                                        sizeof(IOWatchPoll));
     89     iwp->fd_can_read = fd_can_read;
     90     iwp->opaque = user_data;
     91     iwp->ioc = ioc;
     92     iwp->fd_read = (GSourceFunc) fd_read;
     93     iwp->src = NULL;
     94 
     95     name = g_strdup_printf("chardev-iowatch-%s", chr->label);
     96     g_source_set_name((GSource *)iwp, name);
     97     g_free(name);
     98 
     99     g_source_attach(&iwp->parent, context);
    100     g_source_unref(&iwp->parent);
    101     return (GSource *)iwp;
    102 }
    103 
    104 void remove_fd_in_watch(Chardev *chr)
    105 {
    106     if (chr->gsource) {
    107         g_source_destroy(chr->gsource);
    108         chr->gsource = NULL;
    109     }
    110 }
    111 
    112 int io_channel_send_full(QIOChannel *ioc,
    113                          const void *buf, size_t len,
    114                          int *fds, size_t nfds)
    115 {
    116     size_t offset = 0;
    117 
    118     while (offset < len) {
    119         ssize_t ret = 0;
    120         struct iovec iov = { .iov_base = (char *)buf + offset,
    121                              .iov_len = len - offset };
    122 
    123         ret = qio_channel_writev_full(
    124             ioc, &iov, 1,
    125             fds, nfds, 0, NULL);
    126         if (ret == QIO_CHANNEL_ERR_BLOCK) {
    127             if (offset) {
    128                 return offset;
    129             }
    130 
    131             errno = EAGAIN;
    132             return -1;
    133         } else if (ret < 0) {
    134             errno = EINVAL;
    135             return -1;
    136         }
    137 
    138         offset += ret;
    139     }
    140 
    141     return offset;
    142 }
    143 
    144 int io_channel_send(QIOChannel *ioc, const void *buf, size_t len)
    145 {
    146     return io_channel_send_full(ioc, buf, len, NULL, 0);
    147 }