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qemu-timer: make initialization functions idempotent
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CommitLineData
d3b12f5d
PB
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 */
d3b12f5d 24
0ec024f6 25#include "qemu-common.h"
d3b12f5d 26#include "qemu-timer.h"
0ec024f6
SW
27#include "slirp/slirp.h"
28#include "main-loop.h"
d3b12f5d
PB
29
30#ifndef _WIN32
31
0ec024f6
SW
32#include "compatfd.h"
33
d3b12f5d
PB
34static int io_thread_fd = -1;
35
36void qemu_notify_event(void)
37{
38 /* Write 8 bytes to be compatible with eventfd. */
39 static const uint64_t val = 1;
40 ssize_t ret;
41
42 if (io_thread_fd == -1) {
43 return;
44 }
45 do {
46 ret = write(io_thread_fd, &val, sizeof(val));
47 } while (ret < 0 && errno == EINTR);
48
49 /* EAGAIN is fine, a read must be pending. */
50 if (ret < 0 && errno != EAGAIN) {
51 fprintf(stderr, "qemu_notify_event: write() failed: %s\n",
52 strerror(errno));
53 exit(1);
54 }
55}
56
57static void qemu_event_read(void *opaque)
58{
59 int fd = (intptr_t)opaque;
60 ssize_t len;
61 char buffer[512];
62
63 /* Drain the notify pipe. For eventfd, only 8 bytes will be read. */
64 do {
65 len = read(fd, buffer, sizeof(buffer));
66 } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
67}
68
69static int qemu_event_init(void)
70{
71 int err;
72 int fds[2];
73
74 err = qemu_eventfd(fds);
75 if (err == -1) {
76 return -errno;
77 }
78 err = fcntl_setfl(fds[0], O_NONBLOCK);
79 if (err < 0) {
80 goto fail;
81 }
82 err = fcntl_setfl(fds[1], O_NONBLOCK);
83 if (err < 0) {
84 goto fail;
85 }
86 qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
87 (void *)(intptr_t)fds[0]);
88
89 io_thread_fd = fds[1];
90 return 0;
91
92fail:
93 close(fds[0]);
94 close(fds[1]);
95 return err;
96}
97
98/* If we have signalfd, we mask out the signals we want to handle and then
99 * use signalfd to listen for them. We rely on whatever the current signal
100 * handler is to dispatch the signals when we receive them.
101 */
102static void sigfd_handler(void *opaque)
103{
104 int fd = (intptr_t)opaque;
105 struct qemu_signalfd_siginfo info;
106 struct sigaction action;
107 ssize_t len;
108
109 while (1) {
110 do {
111 len = read(fd, &info, sizeof(info));
112 } while (len == -1 && errno == EINTR);
113
114 if (len == -1 && errno == EAGAIN) {
115 break;
116 }
117
118 if (len != sizeof(info)) {
119 printf("read from sigfd returned %zd: %m\n", len);
120 return;
121 }
122
123 sigaction(info.ssi_signo, NULL, &action);
124 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
125 action.sa_sigaction(info.ssi_signo,
126 (siginfo_t *)&info, NULL);
127 } else if (action.sa_handler) {
128 action.sa_handler(info.ssi_signo);
129 }
130 }
131}
132
133static int qemu_signal_init(void)
134{
135 int sigfd;
136 sigset_t set;
137
138 /*
139 * SIG_IPI must be blocked in the main thread and must not be caught
140 * by sigwait() in the signal thread. Otherwise, the cpu thread will
141 * not catch it reliably.
142 */
143 sigemptyset(&set);
144 sigaddset(&set, SIG_IPI);
d3b12f5d
PB
145 sigaddset(&set, SIGIO);
146 sigaddset(&set, SIGALRM);
147 sigaddset(&set, SIGBUS);
148 pthread_sigmask(SIG_BLOCK, &set, NULL);
149
4aa7534d 150 sigdelset(&set, SIG_IPI);
d3b12f5d
PB
151 sigfd = qemu_signalfd(&set);
152 if (sigfd == -1) {
153 fprintf(stderr, "failed to create signalfd\n");
154 return -errno;
155 }
156
157 fcntl_setfl(sigfd, O_NONBLOCK);
158
159 qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
160 (void *)(intptr_t)sigfd);
161
162 return 0;
163}
164
165#else /* _WIN32 */
166
a92433af 167static HANDLE qemu_event_handle = NULL;
d3b12f5d
PB
168
169static void dummy_event_handler(void *opaque)
170{
171}
172
173static int qemu_event_init(void)
174{
175 qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
176 if (!qemu_event_handle) {
177 fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
178 return -1;
179 }
180 qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
181 return 0;
182}
183
184void qemu_notify_event(void)
185{
ee77dfb2
MR
186 if (!qemu_event_handle) {
187 return;
188 }
d3b12f5d
PB
189 if (!SetEvent(qemu_event_handle)) {
190 fprintf(stderr, "qemu_notify_event: SetEvent failed: %ld\n",
191 GetLastError());
192 exit(1);
193 }
194}
195
196static int qemu_signal_init(void)
197{
198 return 0;
199}
200#endif
201
d34e8f6e 202int main_loop_init(void)
d3b12f5d
PB
203{
204 int ret;
205
206 qemu_mutex_lock_iothread();
207 ret = qemu_signal_init();
208 if (ret) {
209 return ret;
210 }
211
212 /* Note eventfd must be drained before signalfd handlers run */
213 ret = qemu_event_init();
214 if (ret) {
215 return ret;
216 }
217
218 return 0;
219}
220
15455536
PB
221static fd_set rfds, wfds, xfds;
222static int nfds;
06ac7d49 223static GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
d3b12f5d
PB
224static int n_poll_fds;
225static int max_priority;
226
ea26ce76 227#ifndef _WIN32
d3b12f5d 228static void glib_select_fill(int *max_fd, fd_set *rfds, fd_set *wfds,
7c7db755 229 fd_set *xfds, uint32_t *cur_timeout)
d3b12f5d
PB
230{
231 GMainContext *context = g_main_context_default();
232 int i;
4dae83ae 233 int timeout = 0;
d3b12f5d
PB
234
235 g_main_context_prepare(context, &max_priority);
236
237 n_poll_fds = g_main_context_query(context, max_priority, &timeout,
238 poll_fds, ARRAY_SIZE(poll_fds));
239 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
240
241 for (i = 0; i < n_poll_fds; i++) {
242 GPollFD *p = &poll_fds[i];
243
244 if ((p->events & G_IO_IN)) {
245 FD_SET(p->fd, rfds);
246 *max_fd = MAX(*max_fd, p->fd);
247 }
248 if ((p->events & G_IO_OUT)) {
249 FD_SET(p->fd, wfds);
250 *max_fd = MAX(*max_fd, p->fd);
251 }
252 if ((p->events & G_IO_ERR)) {
253 FD_SET(p->fd, xfds);
254 *max_fd = MAX(*max_fd, p->fd);
255 }
256 }
257
4dae83ae
PB
258 if (timeout >= 0 && timeout < *cur_timeout) {
259 *cur_timeout = timeout;
d3b12f5d
PB
260 }
261}
262
263static void glib_select_poll(fd_set *rfds, fd_set *wfds, fd_set *xfds,
264 bool err)
265{
266 GMainContext *context = g_main_context_default();
267
268 if (!err) {
269 int i;
270
271 for (i = 0; i < n_poll_fds; i++) {
272 GPollFD *p = &poll_fds[i];
273
274 if ((p->events & G_IO_IN) && FD_ISSET(p->fd, rfds)) {
275 p->revents |= G_IO_IN;
276 }
277 if ((p->events & G_IO_OUT) && FD_ISSET(p->fd, wfds)) {
278 p->revents |= G_IO_OUT;
279 }
280 if ((p->events & G_IO_ERR) && FD_ISSET(p->fd, xfds)) {
281 p->revents |= G_IO_ERR;
282 }
283 }
284 }
285
286 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
287 g_main_context_dispatch(context);
288 }
289}
290
7c7db755 291static int os_host_main_loop_wait(uint32_t timeout)
15455536 292{
7c7db755 293 struct timeval tv, *tvarg = NULL;
15455536
PB
294 int ret;
295
296 glib_select_fill(&nfds, &rfds, &wfds, &xfds, &timeout);
297
7c7db755
SS
298 if (timeout < UINT32_MAX) {
299 tvarg = &tv;
300 tv.tv_sec = timeout / 1000;
301 tv.tv_usec = (timeout % 1000) * 1000;
302 }
303
15455536
PB
304 if (timeout > 0) {
305 qemu_mutex_unlock_iothread();
306 }
307
7c7db755 308 ret = select(nfds + 1, &rfds, &wfds, &xfds, tvarg);
15455536
PB
309
310 if (timeout > 0) {
311 qemu_mutex_lock_iothread();
312 }
313
314 glib_select_poll(&rfds, &wfds, &xfds, (ret < 0));
315 return ret;
316}
317#else
d3b12f5d
PB
318/***********************************************************/
319/* Polling handling */
320
321typedef struct PollingEntry {
322 PollingFunc *func;
323 void *opaque;
324 struct PollingEntry *next;
325} PollingEntry;
326
327static PollingEntry *first_polling_entry;
328
329int qemu_add_polling_cb(PollingFunc *func, void *opaque)
330{
331 PollingEntry **ppe, *pe;
332 pe = g_malloc0(sizeof(PollingEntry));
333 pe->func = func;
334 pe->opaque = opaque;
335 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
336 *ppe = pe;
337 return 0;
338}
339
340void qemu_del_polling_cb(PollingFunc *func, void *opaque)
341{
342 PollingEntry **ppe, *pe;
343 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
344 pe = *ppe;
345 if (pe->func == func && pe->opaque == opaque) {
346 *ppe = pe->next;
347 g_free(pe);
348 break;
349 }
350 }
351}
352
353/***********************************************************/
354/* Wait objects support */
355typedef struct WaitObjects {
356 int num;
06ac7d49 357 int revents[MAXIMUM_WAIT_OBJECTS + 1];
d3b12f5d
PB
358 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
359 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
360 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
361} WaitObjects;
362
363static WaitObjects wait_objects = {0};
364
365int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
366{
367 WaitObjects *w = &wait_objects;
368 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
369 return -1;
370 }
371 w->events[w->num] = handle;
372 w->func[w->num] = func;
373 w->opaque[w->num] = opaque;
06ac7d49 374 w->revents[w->num] = 0;
d3b12f5d
PB
375 w->num++;
376 return 0;
377}
378
379void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
380{
381 int i, found;
382 WaitObjects *w = &wait_objects;
383
384 found = 0;
385 for (i = 0; i < w->num; i++) {
386 if (w->events[i] == handle) {
387 found = 1;
388 }
389 if (found) {
390 w->events[i] = w->events[i + 1];
391 w->func[i] = w->func[i + 1];
392 w->opaque[i] = w->opaque[i + 1];
06ac7d49 393 w->revents[i] = w->revents[i + 1];
d3b12f5d
PB
394 }
395 }
396 if (found) {
397 w->num--;
398 }
399}
400
d3385eb4
PB
401void qemu_fd_register(int fd)
402{
403 WSAEventSelect(fd, qemu_event_handle, FD_READ | FD_ACCEPT | FD_CLOSE |
404 FD_CONNECT | FD_WRITE | FD_OOB);
405}
406
7c7db755 407static int os_host_main_loop_wait(uint32_t timeout)
d3b12f5d 408{
ea26ce76 409 GMainContext *context = g_main_context_default();
06ac7d49 410 int ret, i;
d3b12f5d 411 PollingEntry *pe;
d3385eb4 412 WaitObjects *w = &wait_objects;
42fe1c24 413 gint poll_timeout;
15455536 414 static struct timeval tv0;
d3b12f5d
PB
415
416 /* XXX: need to suppress polling by better using win32 events */
417 ret = 0;
418 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
419 ret |= pe->func(pe->opaque);
420 }
d3385eb4
PB
421 if (ret != 0) {
422 return ret;
423 }
d3b12f5d 424
d3385eb4
PB
425 if (nfds >= 0) {
426 ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
427 if (ret != 0) {
3239ad04 428 timeout = 0;
d3385eb4
PB
429 }
430 }
d3b12f5d 431
ea26ce76 432 g_main_context_prepare(context, &max_priority);
42fe1c24 433 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
ea26ce76
PB
434 poll_fds, ARRAY_SIZE(poll_fds));
435 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
436
06ac7d49 437 for (i = 0; i < w->num; i++) {
58b9630d 438 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
ea26ce76 439 poll_fds[n_poll_fds + i].events = G_IO_IN;
06ac7d49
PB
440 }
441
3239ad04
SW
442 if (poll_timeout < 0 || timeout < poll_timeout) {
443 poll_timeout = timeout;
444 }
445
d3385eb4 446 qemu_mutex_unlock_iothread();
42fe1c24 447 ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout);
d3385eb4 448 qemu_mutex_lock_iothread();
06ac7d49
PB
449 if (ret > 0) {
450 for (i = 0; i < w->num; i++) {
ea26ce76 451 w->revents[i] = poll_fds[n_poll_fds + i].revents;
d3385eb4 452 }
06ac7d49
PB
453 for (i = 0; i < w->num; i++) {
454 if (w->revents[i] && w->func[i]) {
455 w->func[i](w->opaque[i]);
d3b12f5d 456 }
d3b12f5d
PB
457 }
458 }
459
ea26ce76
PB
460 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
461 g_main_context_dispatch(context);
462 }
463
d3385eb4
PB
464 /* If an edge-triggered socket event occurred, select will return a
465 * positive result on the next iteration. We do not need to do anything
466 * here.
467 */
468
15455536 469 return ret;
d3b12f5d
PB
470}
471#endif
472
473int main_loop_wait(int nonblocking)
474{
7c7db755
SS
475 int ret;
476 uint32_t timeout = UINT32_MAX;
d3b12f5d
PB
477
478 if (nonblocking) {
479 timeout = 0;
480 } else {
d3b12f5d
PB
481 qemu_bh_update_timeout(&timeout);
482 }
483
d3b12f5d
PB
484 /* poll any events */
485 /* XXX: separate device handlers from system ones */
486 nfds = -1;
487 FD_ZERO(&rfds);
488 FD_ZERO(&wfds);
489 FD_ZERO(&xfds);
490
491#ifdef CONFIG_SLIRP
7c7db755 492 slirp_update_timeout(&timeout);
d3b12f5d
PB
493 slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
494#endif
495 qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
15455536 496 ret = os_host_main_loop_wait(timeout);
d3b12f5d
PB
497 qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
498#ifdef CONFIG_SLIRP
499 slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
500#endif
501
502 qemu_run_all_timers();
503
504 /* Check bottom-halves last in case any of the earlier events triggered
505 them. */
506 qemu_bh_poll();
507
508 return ret;
509}