| 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/osdep.h" |
| 26 | #include "qemu/sockets.h" |
| 27 | #include "qemu/coroutine.h" |
| 28 | #include "qemu/iov.h" |
| 29 | #include "qemu/main-loop.h" |
| 30 | |
| 31 | ssize_t coroutine_fn |
| 32 | qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt, |
| 33 | size_t offset, size_t bytes, bool do_send) |
| 34 | { |
| 35 | size_t done = 0; |
| 36 | ssize_t ret; |
| 37 | while (done < bytes) { |
| 38 | ret = iov_send_recv(sockfd, iov, iov_cnt, |
| 39 | offset + done, bytes - done, do_send); |
| 40 | if (ret > 0) { |
| 41 | done += ret; |
| 42 | } else if (ret < 0) { |
| 43 | if (errno == EAGAIN || errno == EWOULDBLOCK) { |
| 44 | qemu_coroutine_yield(); |
| 45 | } else if (done == 0) { |
| 46 | return -errno; |
| 47 | } else { |
| 48 | break; |
| 49 | } |
| 50 | } else if (ret == 0 && !do_send) { |
| 51 | /* write (send) should never return 0. |
| 52 | * read (recv) returns 0 for end-of-file (-data). |
| 53 | * In both cases there's little point retrying, |
| 54 | * but we do for write anyway, just in case */ |
| 55 | break; |
| 56 | } |
| 57 | } |
| 58 | return done; |
| 59 | } |
| 60 | |
| 61 | ssize_t coroutine_fn |
| 62 | qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send) |
| 63 | { |
| 64 | struct iovec iov = { .iov_base = buf, .iov_len = bytes }; |
| 65 | return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send); |
| 66 | } |
| 67 | |
| 68 | typedef struct { |
| 69 | AioContext *ctx; |
| 70 | Coroutine *co; |
| 71 | int fd; |
| 72 | } FDYieldUntilData; |
| 73 | |
| 74 | static void fd_coroutine_enter(void *opaque) |
| 75 | { |
| 76 | FDYieldUntilData *data = opaque; |
| 77 | aio_set_fd_handler(data->ctx, data->fd, NULL, NULL, NULL, NULL, NULL); |
| 78 | qemu_coroutine_enter(data->co); |
| 79 | } |
| 80 | |
| 81 | void coroutine_fn yield_until_fd_readable(int fd) |
| 82 | { |
| 83 | FDYieldUntilData data; |
| 84 | |
| 85 | assert(qemu_in_coroutine()); |
| 86 | data.ctx = qemu_get_current_aio_context(); |
| 87 | data.co = qemu_coroutine_self(); |
| 88 | data.fd = fd; |
| 89 | aio_set_fd_handler(data.ctx, fd, fd_coroutine_enter, NULL, NULL, NULL, |
| 90 | &data); |
| 91 | qemu_coroutine_yield(); |
| 92 | } |