1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 * Permission is hereby granted, free of charge, to any person obtaining a copy
3 * of this software and associated documentation files (the "Software"), to
4 * deal in the Software without restriction, including without limitation the
5 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
6 * sell copies of the Software, and to permit persons to whom the Software is
7 * furnished to do so, subject to the following conditions:
8 *
9 * The above copyright notice and this permission notice shall be included in
10 * all copies or substantial portions of the Software.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
15 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
16 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
17 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
18 * IN THE SOFTWARE.
19 */
20
21 /* This file contains both the uv__async internal infrastructure and the
22 * user-facing uv_async_t functions.
23 */
24
25 #include "uv.h"
26 #include "internal.h"
27 #include "uv_log.h"
28
29 #include <errno.h>
30 #include <stdatomic.h>
31 #include <stdio.h> /* snprintf() */
32 #include <assert.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 #include <sched.h> /* sched_yield() */
37
38 #ifdef __linux__
39 #include <sys/eventfd.h>
40 #endif
41
42 #ifdef USE_FFRT
43 #include "ffrt.h"
44 #include "c/executor_task.h"
45 #endif
46
47 static void uv__async_send(uv_async_t* handle);
48 static int uv__async_start(uv_loop_t* loop);
49
50
uv_async_init(uv_loop_t * loop,uv_async_t * handle,uv_async_cb async_cb)51 int uv_async_init(uv_loop_t* loop, uv_async_t* handle, uv_async_cb async_cb) {
52 int err;
53
54 #if defined(USE_OHOS_DFX) && defined(__aarch64__)
55 uv__multi_thread_check_unify(loop, __func__);
56 #endif
57 err = uv__async_start(loop);
58 if (err)
59 return err;
60
61 uv__handle_init(loop, (uv_handle_t*)handle, UV_ASYNC);
62 handle->async_cb = async_cb;
63 handle->pending = 0;
64
65 uv__queue_insert_tail(&loop->async_handles, &handle->queue);
66 uv__handle_start(handle);
67
68 return 0;
69 }
70
71
uv_async_send(uv_async_t * handle)72 int uv_async_send(uv_async_t* handle) {
73 _Atomic int* pending;
74
75 #ifdef USE_OHOS_DFX
76 if (handle == NULL) {
77 UV_LOGF("handle is NULL");
78 return -1;
79 }
80 #endif
81
82 pending = (_Atomic int*) &handle->pending;
83
84
85 /* Do a cheap read first. */
86 if (atomic_load_explicit(pending, memory_order_relaxed) != 0)
87 return 0;
88
89 /* Wake up the other thread's event loop. */
90 if (atomic_exchange(pending, 1) != 0)
91 return 0;
92
93 /* Wake up the other thread's event loop. */
94 uv__async_send(handle);
95 return 0;
96 }
97
98
99
uv__async_close(uv_async_t * handle)100 void uv__async_close(uv_async_t* handle) {
101 atomic_exchange((_Atomic int*) &handle->pending, 0);
102 uv__queue_remove(&handle->queue);
103 uv__handle_stop(handle);
104 }
105
106
uv__async_io(uv_loop_t * loop,uv__io_t * w,unsigned int events)107 static void uv__async_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
108 char buf[1024];
109 ssize_t r;
110 struct uv__queue queue;
111 struct uv__queue* q;
112 uv_async_t* h;
113 _Atomic int *pending;
114
115 assert(w == &loop->async_io_watcher);
116
117 for (;;) {
118 r = read(w->fd, buf, sizeof(buf));
119
120 if (r == sizeof(buf))
121 continue;
122
123 if (r != -1)
124 break;
125
126 if (errno == EAGAIN || errno == EWOULDBLOCK)
127 break;
128
129 if (errno == EINTR)
130 continue;
131
132 #ifdef USE_OHOS_DFX
133 UV_ERRNO_ABORT("errno is %d, loop addr is %zu, fd is %d (%s:%s:%d)",
134 errno, (size_t)loop, w->fd, __FILE__, __func__, __LINE__);
135 #else
136 abort();
137 #endif
138 }
139
140 uv__queue_move(&loop->async_handles, &queue);
141 while (!uv__queue_empty(&queue)) {
142 q = uv__queue_head(&queue);
143 h = uv__queue_data(q, uv_async_t, queue);
144
145 uv__queue_remove(q);
146 uv__queue_insert_tail(&loop->async_handles, q);
147
148 /* Atomically fetch and clear pending flag */
149 pending = (_Atomic int*) &h->pending;
150 if (atomic_exchange(pending, 0) == 0)
151 continue;
152
153 if (h->async_cb == NULL)
154 continue;
155
156 h->async_cb(h);
157 }
158 }
159
160
uv__async_send(uv_async_t * handle)161 static void uv__async_send(uv_async_t* handle) {
162 const void* buf;
163 ssize_t len;
164 int fd;
165 int r;
166
167 uv_loop_t* loop = handle->loop;
168 if (loop == NULL) {
169 UV_LOGF("loop is NULL");
170 return;
171 }
172
173 buf = "";
174 len = 1;
175 fd = loop->async_wfd;
176
177 #if defined(__linux__)
178 if (fd == -1) {
179 static const uint64_t val = 1;
180 buf = &val;
181 len = sizeof(val);
182 fd = loop->async_io_watcher.fd; /* eventfd */
183 }
184 #endif
185
186 do
187 r = write(fd, buf, len);
188 while (r == -1 && errno == EINTR && atomic_load_explicit((_Atomic int*) &handle->pending, memory_order_relaxed) == 1);
189
190 if (r == len)
191 return;
192
193 if (r == -1)
194 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
195 return;
196
197 #ifdef USE_OHOS_DFX
198 UV_ERRNO_ABORT("errno is %d, loop addr is %zu, fd is %d (%s:%s:%d)",
199 errno, (size_t)loop, fd, __FILE__, __func__, __LINE__);
200 #else
201 abort();
202 #endif
203 }
204
205
uv__async_start(uv_loop_t * loop)206 static int uv__async_start(uv_loop_t* loop) {
207 int pipefd[2];
208 int err;
209
210 if (loop->async_io_watcher.fd != -1)
211 return 0;
212
213 #ifdef __linux__
214 err = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
215 if (err < 0)
216 return UV__ERR(errno);
217
218 pipefd[0] = err;
219 pipefd[1] = -1;
220 #ifdef USE_OHOS_DFX
221 fdsan_exchange_owner_tag(pipefd[0], 0, uv__get_addr_tag((void *)&loop->async_io_watcher));
222 #endif
223 #else
224 err = uv__make_pipe(pipefd, UV_NONBLOCK_PIPE);
225 if (err < 0)
226 return err;
227 #endif
228
229 uv__io_init(&loop->async_io_watcher, uv__async_io, pipefd[0]);
230 uv__io_start(loop, &loop->async_io_watcher, POLLIN);
231 loop->async_wfd = pipefd[1];
232 UV_LOGI("open:%{public}zu, pipefd[0]:%{public}d", (size_t)loop, pipefd[0]);
233 return 0;
234 }
235
236
uv__async_fork(uv_loop_t * loop)237 int uv__async_fork(uv_loop_t* loop) {
238 if (loop->async_io_watcher.fd == -1) /* never started */
239 return 0;
240
241 uv__async_stop(loop);
242
243 return uv__async_start(loop);
244 }
245
246
uv__async_stop(uv_loop_t * loop)247 void uv__async_stop(uv_loop_t* loop) {
248 if (loop->async_io_watcher.fd == -1)
249 return;
250
251 if (loop->async_wfd != -1) {
252 if (loop->async_wfd != loop->async_io_watcher.fd) {
253 UV_LOGI("close:%{public}zu, async_wfd:%{public}d", (size_t)loop, loop->async_wfd);
254 uv__close(loop->async_wfd);
255 }
256 loop->async_wfd = -1;
257 }
258
259 uv__io_stop(loop, &loop->async_io_watcher, POLLIN);
260 #ifdef USE_FFRT
261 if (ffrt_get_cur_task() != NULL) {
262 uv__epoll_ctl(loop->backend_fd, EPOLL_CTL_DEL, loop->async_io_watcher.fd, NULL);
263 }
264 #endif
265
266 #if defined(__linux__) && defined(USE_OHOS_DFX)
267 fdsan_close_with_tag(loop->async_io_watcher.fd, uv__get_addr_tag((void *)&loop->async_io_watcher));
268 #else
269 uv__close(loop->async_io_watcher.fd);
270 #endif
271 UV_LOGI("close:%{public}zu, async_io_wfd:%{public}d", (size_t)loop, loop->async_io_watcher.fd);
272 loop->async_io_watcher.fd = -1;
273 }
274
275