trap signals for "-serial mon:stdio"
[qemu.git] / qemu-coroutine-io.c
1 /*
2 * Coroutine-aware I/O functions
3 *
4 * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
5 * Copyright (c) 2011, Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25 #include "qemu-common.h"
26 #include "qemu/sockets.h"
27 #include "block/coroutine.h"
28 #include "qemu/iov.h"
29
30 ssize_t coroutine_fn
31 qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt,
32 size_t offset, size_t bytes, bool do_send)
33 {
34 size_t done = 0;
35 ssize_t ret;
36 while (done < bytes) {
37 ret = iov_send_recv(sockfd, iov, iov_cnt,
38 offset + done, bytes - done, do_send);
39 if (ret > 0) {
40 done += ret;
41 } else if (ret < 0) {
42 if (errno == EAGAIN) {
43 qemu_coroutine_yield();
44 } else if (done == 0) {
45 return -1;
46 } else {
47 break;
48 }
49 } else if (ret == 0 && !do_send) {
50 /* write (send) should never return 0.
51 * read (recv) returns 0 for end-of-file (-data).
52 * In both cases there's little point retrying,
53 * but we do for write anyway, just in case */
54 break;
55 }
56 }
57 return done;
58 }
59
60 ssize_t coroutine_fn
61 qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
62 {
63 struct iovec iov = { .iov_base = buf, .iov_len = bytes };
64 return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
65 }
66
67 typedef struct {
68 Coroutine *co;
69 int fd;
70 } FDYieldUntilData;
71
72 static void fd_coroutine_enter(void *opaque)
73 {
74 FDYieldUntilData *data = opaque;
75 qemu_set_fd_handler(data->fd, NULL, NULL, NULL);
76 qemu_coroutine_enter(data->co, NULL);
77 }
78
79 void coroutine_fn yield_until_fd_readable(int fd)
80 {
81 FDYieldUntilData data;
82
83 assert(qemu_in_coroutine());
84 data.co = qemu_coroutine_self();
85 data.fd = fd;
86 qemu_set_fd_handler(fd, fd_coroutine_enter, NULL, &data);
87 qemu_coroutine_yield();
88 }