root / qemu-coroutine-io.c @ 8cfd0495
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1 | 8c5135f9 | Paolo Bonzini | /*
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2 | 8c5135f9 | Paolo Bonzini | * Coroutine-aware I/O functions
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3 | 8c5135f9 | Paolo Bonzini | *
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4 | 8c5135f9 | Paolo Bonzini | * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
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5 | 8c5135f9 | Paolo Bonzini | * Copyright (c) 2011, Red Hat, Inc.
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6 | 8c5135f9 | Paolo Bonzini | *
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7 | 8c5135f9 | Paolo Bonzini | * Permission is hereby granted, free of charge, to any person obtaining a copy
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8 | 8c5135f9 | Paolo Bonzini | * of this software and associated documentation files (the "Software"), to deal
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9 | 8c5135f9 | Paolo Bonzini | * in the Software without restriction, including without limitation the rights
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10 | 8c5135f9 | Paolo Bonzini | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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11 | 8c5135f9 | Paolo Bonzini | * copies of the Software, and to permit persons to whom the Software is
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12 | 8c5135f9 | Paolo Bonzini | * furnished to do so, subject to the following conditions:
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13 | 8c5135f9 | Paolo Bonzini | *
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14 | 8c5135f9 | Paolo Bonzini | * The above copyright notice and this permission notice shall be included in
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15 | 8c5135f9 | Paolo Bonzini | * all copies or substantial portions of the Software.
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16 | 8c5135f9 | Paolo Bonzini | *
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17 | 8c5135f9 | Paolo Bonzini | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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18 | 8c5135f9 | Paolo Bonzini | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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19 | 8c5135f9 | Paolo Bonzini | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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20 | 8c5135f9 | Paolo Bonzini | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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21 | 8c5135f9 | Paolo Bonzini | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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22 | 8c5135f9 | Paolo Bonzini | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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23 | 8c5135f9 | Paolo Bonzini | * THE SOFTWARE.
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24 | 8c5135f9 | Paolo Bonzini | */
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25 | 8c5135f9 | Paolo Bonzini | #include "qemu-common.h" |
26 | 1de7afc9 | Paolo Bonzini | #include "qemu/sockets.h" |
27 | 737e150e | Paolo Bonzini | #include "block/coroutine.h" |
28 | 1de7afc9 | Paolo Bonzini | #include "qemu/iov.h" |
29 | 6a1751b7 | Alex Bligh | #include "qemu/main-loop.h" |
30 | 8c5135f9 | Paolo Bonzini | |
31 | 2fc8ae1d | Michael Tokarev | ssize_t coroutine_fn |
32 | 2fc8ae1d | Michael Tokarev | qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt, |
33 | 2fc8ae1d | Michael Tokarev | size_t offset, size_t bytes, bool do_send)
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34 | 8c5135f9 | Paolo Bonzini | { |
35 | 2fc8ae1d | Michael Tokarev | size_t done = 0;
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36 | 2fc8ae1d | Michael Tokarev | ssize_t ret; |
37 | 2fc8ae1d | Michael Tokarev | while (done < bytes) {
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38 | 25e5e4c7 | Michael Tokarev | ret = iov_send_recv(sockfd, iov, iov_cnt, |
39 | 2fc8ae1d | Michael Tokarev | offset + done, bytes - done, do_send); |
40 | 2fc8ae1d | Michael Tokarev | if (ret > 0) { |
41 | 2fc8ae1d | Michael Tokarev | done += ret; |
42 | 2fc8ae1d | Michael Tokarev | } else if (ret < 0) { |
43 | 8c5135f9 | Paolo Bonzini | if (errno == EAGAIN) {
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44 | 8c5135f9 | Paolo Bonzini | qemu_coroutine_yield(); |
45 | 2fc8ae1d | Michael Tokarev | } else if (done == 0) { |
46 | 2fc8ae1d | Michael Tokarev | return -1; |
47 | 2fc8ae1d | Michael Tokarev | } else {
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48 | 2fc8ae1d | Michael Tokarev | break;
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49 | 8c5135f9 | Paolo Bonzini | } |
50 | 2fc8ae1d | Michael Tokarev | } else if (ret == 0 && !do_send) { |
51 | 2fc8ae1d | Michael Tokarev | /* write (send) should never return 0.
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52 | 2fc8ae1d | Michael Tokarev | * read (recv) returns 0 for end-of-file (-data).
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53 | 2fc8ae1d | Michael Tokarev | * In both cases there's little point retrying,
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54 | 2fc8ae1d | Michael Tokarev | * but we do for write anyway, just in case */
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55 | 8c5135f9 | Paolo Bonzini | break;
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56 | 8c5135f9 | Paolo Bonzini | } |
57 | 8c5135f9 | Paolo Bonzini | } |
58 | 2fc8ae1d | Michael Tokarev | return done;
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59 | 8c5135f9 | Paolo Bonzini | } |
60 | 8c5135f9 | Paolo Bonzini | |
61 | 2fc8ae1d | Michael Tokarev | ssize_t coroutine_fn |
62 | 2fc8ae1d | Michael Tokarev | qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send) |
63 | 8c5135f9 | Paolo Bonzini | { |
64 | 2fc8ae1d | Michael Tokarev | struct iovec iov = { .iov_base = buf, .iov_len = bytes };
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65 | 2fc8ae1d | Michael Tokarev | return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send); |
66 | 8c5135f9 | Paolo Bonzini | } |
67 | 9f05d0c3 | Michael R. Hines | |
68 | 9f05d0c3 | Michael R. Hines | typedef struct { |
69 | 9f05d0c3 | Michael R. Hines | Coroutine *co; |
70 | 9f05d0c3 | Michael R. Hines | int fd;
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71 | 9f05d0c3 | Michael R. Hines | } FDYieldUntilData; |
72 | 9f05d0c3 | Michael R. Hines | |
73 | 9f05d0c3 | Michael R. Hines | static void fd_coroutine_enter(void *opaque) |
74 | 9f05d0c3 | Michael R. Hines | { |
75 | 9f05d0c3 | Michael R. Hines | FDYieldUntilData *data = opaque; |
76 | 9f05d0c3 | Michael R. Hines | qemu_set_fd_handler(data->fd, NULL, NULL, NULL); |
77 | 9f05d0c3 | Michael R. Hines | qemu_coroutine_enter(data->co, NULL);
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78 | 9f05d0c3 | Michael R. Hines | } |
79 | 9f05d0c3 | Michael R. Hines | |
80 | 9f05d0c3 | Michael R. Hines | void coroutine_fn yield_until_fd_readable(int fd) |
81 | 9f05d0c3 | Michael R. Hines | { |
82 | 9f05d0c3 | Michael R. Hines | FDYieldUntilData data; |
83 | 9f05d0c3 | Michael R. Hines | |
84 | 9f05d0c3 | Michael R. Hines | assert(qemu_in_coroutine()); |
85 | 9f05d0c3 | Michael R. Hines | data.co = qemu_coroutine_self(); |
86 | 9f05d0c3 | Michael R. Hines | data.fd = fd; |
87 | 9f05d0c3 | Michael R. Hines | qemu_set_fd_handler(fd, fd_coroutine_enter, NULL, &data);
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88 | 9f05d0c3 | Michael R. Hines | qemu_coroutine_yield(); |
89 | 9f05d0c3 | Michael R. Hines | } |