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25#include "qemu/osdep.h"
26#include "qapi/error.h"
27#include "qemu/cutils.h"
28#include "qemu/timer.h"
29#include "qemu/sockets.h"
30#include "sysemu/qtest.h"
31#include "sysemu/cpus.h"
32#include "slirp/libslirp.h"
33#include "qemu/main-loop.h"
34#include "block/aio.h"
35#include "qemu/error-report.h"
36
37#ifndef _WIN32
38
39
40
41
42
43static void sigfd_handler(void *opaque)
44{
45 int fd = (intptr_t)opaque;
46 struct qemu_signalfd_siginfo info;
47 struct sigaction action;
48 ssize_t len;
49
50 while (1) {
51 do {
52 len = read(fd, &info, sizeof(info));
53 } while (len == -1 && errno == EINTR);
54
55 if (len == -1 && errno == EAGAIN) {
56 break;
57 }
58
59 if (len != sizeof(info)) {
60 printf("read from sigfd returned %zd: %m\n", len);
61 return;
62 }
63
64 sigaction(info.ssi_signo, NULL, &action);
65 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
66 sigaction_invoke(&action, &info);
67 } else if (action.sa_handler) {
68 action.sa_handler(info.ssi_signo);
69 }
70 }
71}
72
73static int qemu_signal_init(void)
74{
75 int sigfd;
76 sigset_t set;
77
78
79
80
81
82
83 sigemptyset(&set);
84 sigaddset(&set, SIG_IPI);
85 sigaddset(&set, SIGIO);
86 sigaddset(&set, SIGALRM);
87 sigaddset(&set, SIGBUS);
88
89
90
91
92
93 pthread_sigmask(SIG_BLOCK, &set, NULL);
94
95 sigdelset(&set, SIG_IPI);
96 sigfd = qemu_signalfd(&set);
97 if (sigfd == -1) {
98 fprintf(stderr, "failed to create signalfd\n");
99 return -errno;
100 }
101
102 fcntl_setfl(sigfd, O_NONBLOCK);
103
104 qemu_set_fd_handler(sigfd, sigfd_handler, NULL, (void *)(intptr_t)sigfd);
105
106 return 0;
107}
108
109#else
110
111static int qemu_signal_init(void)
112{
113 return 0;
114}
115#endif
116
117static AioContext *qemu_aio_context;
118static QEMUBH *qemu_notify_bh;
119
120static void notify_event_cb(void *opaque)
121{
122
123
124
125}
126
127AioContext *qemu_get_aio_context(void)
128{
129 return qemu_aio_context;
130}
131
132void qemu_notify_event(void)
133{
134 if (!qemu_aio_context) {
135 return;
136 }
137 qemu_bh_schedule(qemu_notify_bh);
138}
139
140static GArray *gpollfds;
141
142int qemu_init_main_loop(Error **errp)
143{
144 int ret;
145 GSource *src;
146 Error *local_error = NULL;
147
148 init_clocks(qemu_timer_notify_cb);
149
150 ret = qemu_signal_init();
151 if (ret) {
152 return ret;
153 }
154
155 qemu_aio_context = aio_context_new(&local_error);
156 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
157 if (!qemu_aio_context) {
158 error_propagate(errp, local_error);
159 return -EMFILE;
160 }
161 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
162 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
163 src = aio_get_g_source(qemu_aio_context);
164 g_source_set_name(src, "aio-context");
165 g_source_attach(src, NULL);
166 g_source_unref(src);
167 src = iohandler_get_g_source();
168 g_source_set_name(src, "io-handler");
169 g_source_attach(src, NULL);
170 g_source_unref(src);
171 return 0;
172}
173
174static int max_priority;
175
176#ifndef _WIN32
177static int glib_pollfds_idx;
178static int glib_n_poll_fds;
179
180static void glib_pollfds_fill(int64_t *cur_timeout)
181{
182 GMainContext *context = g_main_context_default();
183 int timeout = 0;
184 int64_t timeout_ns;
185 int n;
186
187 g_main_context_prepare(context, &max_priority);
188
189 glib_pollfds_idx = gpollfds->len;
190 n = glib_n_poll_fds;
191 do {
192 GPollFD *pfds;
193 glib_n_poll_fds = n;
194 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
195 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
196 n = g_main_context_query(context, max_priority, &timeout, pfds,
197 glib_n_poll_fds);
198 } while (n != glib_n_poll_fds);
199
200 if (timeout < 0) {
201 timeout_ns = -1;
202 } else {
203 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
204 }
205
206 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
207}
208
209static void glib_pollfds_poll(void)
210{
211 GMainContext *context = g_main_context_default();
212 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
213
214 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
215 g_main_context_dispatch(context);
216 }
217}
218
219#define MAX_MAIN_LOOP_SPIN (1000)
220
221static int os_host_main_loop_wait(int64_t timeout)
222{
223 GMainContext *context = g_main_context_default();
224 int ret;
225 static int spin_counter;
226
227 g_main_context_acquire(context);
228
229 glib_pollfds_fill(&timeout);
230
231
232
233
234
235
236
237 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
238 static bool notified;
239
240 if (!notified && !qtest_enabled() && !qtest_driver()) {
241 warn_report("I/O thread spun for %d iterations",
242 MAX_MAIN_LOOP_SPIN);
243 notified = true;
244 }
245
246 timeout = SCALE_MS;
247 }
248
249 if (timeout) {
250 spin_counter = 0;
251 qemu_mutex_unlock_iothread();
252 } else {
253 spin_counter++;
254 }
255
256 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
257
258 if (timeout) {
259 qemu_mutex_lock_iothread();
260 }
261
262 glib_pollfds_poll();
263
264 g_main_context_release(context);
265
266 return ret;
267}
268#else
269
270
271
272typedef struct PollingEntry {
273 PollingFunc *func;
274 void *opaque;
275 struct PollingEntry *next;
276} PollingEntry;
277
278static PollingEntry *first_polling_entry;
279
280int qemu_add_polling_cb(PollingFunc *func, void *opaque)
281{
282 PollingEntry **ppe, *pe;
283 pe = g_malloc0(sizeof(PollingEntry));
284 pe->func = func;
285 pe->opaque = opaque;
286 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
287 *ppe = pe;
288 return 0;
289}
290
291void qemu_del_polling_cb(PollingFunc *func, void *opaque)
292{
293 PollingEntry **ppe, *pe;
294 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
295 pe = *ppe;
296 if (pe->func == func && pe->opaque == opaque) {
297 *ppe = pe->next;
298 g_free(pe);
299 break;
300 }
301 }
302}
303
304
305
306typedef struct WaitObjects {
307 int num;
308 int revents[MAXIMUM_WAIT_OBJECTS + 1];
309 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
310 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
311 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
312} WaitObjects;
313
314static WaitObjects wait_objects = {0};
315
316int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
317{
318 WaitObjects *w = &wait_objects;
319 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
320 return -1;
321 }
322 w->events[w->num] = handle;
323 w->func[w->num] = func;
324 w->opaque[w->num] = opaque;
325 w->revents[w->num] = 0;
326 w->num++;
327 return 0;
328}
329
330void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
331{
332 int i, found;
333 WaitObjects *w = &wait_objects;
334
335 found = 0;
336 for (i = 0; i < w->num; i++) {
337 if (w->events[i] == handle) {
338 found = 1;
339 }
340 if (found) {
341 w->events[i] = w->events[i + 1];
342 w->func[i] = w->func[i + 1];
343 w->opaque[i] = w->opaque[i + 1];
344 w->revents[i] = w->revents[i + 1];
345 }
346 }
347 if (found) {
348 w->num--;
349 }
350}
351
352void qemu_fd_register(int fd)
353{
354 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
355 FD_READ | FD_ACCEPT | FD_CLOSE |
356 FD_CONNECT | FD_WRITE | FD_OOB);
357}
358
359static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
360 fd_set *xfds)
361{
362 int nfds = -1;
363 int i;
364
365 for (i = 0; i < pollfds->len; i++) {
366 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
367 int fd = pfd->fd;
368 int events = pfd->events;
369 if (events & G_IO_IN) {
370 FD_SET(fd, rfds);
371 nfds = MAX(nfds, fd);
372 }
373 if (events & G_IO_OUT) {
374 FD_SET(fd, wfds);
375 nfds = MAX(nfds, fd);
376 }
377 if (events & G_IO_PRI) {
378 FD_SET(fd, xfds);
379 nfds = MAX(nfds, fd);
380 }
381 }
382 return nfds;
383}
384
385static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
386 fd_set *wfds, fd_set *xfds)
387{
388 int i;
389
390 for (i = 0; i < pollfds->len; i++) {
391 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
392 int fd = pfd->fd;
393 int revents = 0;
394
395 if (FD_ISSET(fd, rfds)) {
396 revents |= G_IO_IN;
397 }
398 if (FD_ISSET(fd, wfds)) {
399 revents |= G_IO_OUT;
400 }
401 if (FD_ISSET(fd, xfds)) {
402 revents |= G_IO_PRI;
403 }
404 pfd->revents = revents & pfd->events;
405 }
406}
407
408static int os_host_main_loop_wait(int64_t timeout)
409{
410 GMainContext *context = g_main_context_default();
411 GPollFD poll_fds[1024 * 2];
412 int select_ret = 0;
413 int g_poll_ret, ret, i, n_poll_fds;
414 PollingEntry *pe;
415 WaitObjects *w = &wait_objects;
416 gint poll_timeout;
417 int64_t poll_timeout_ns;
418 static struct timeval tv0;
419 fd_set rfds, wfds, xfds;
420 int nfds;
421
422 g_main_context_acquire(context);
423
424
425 ret = 0;
426 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
427 ret |= pe->func(pe->opaque);
428 }
429 if (ret != 0) {
430 g_main_context_release(context);
431 return ret;
432 }
433
434 FD_ZERO(&rfds);
435 FD_ZERO(&wfds);
436 FD_ZERO(&xfds);
437 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
438 if (nfds >= 0) {
439 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
440 if (select_ret != 0) {
441 timeout = 0;
442 }
443 if (select_ret > 0) {
444 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
445 }
446 }
447
448 g_main_context_prepare(context, &max_priority);
449 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
450 poll_fds, ARRAY_SIZE(poll_fds));
451 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
452
453 for (i = 0; i < w->num; i++) {
454 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
455 poll_fds[n_poll_fds + i].events = G_IO_IN;
456 }
457
458 if (poll_timeout < 0) {
459 poll_timeout_ns = -1;
460 } else {
461 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
462 }
463
464 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
465
466 qemu_mutex_unlock_iothread();
467 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
468
469 qemu_mutex_lock_iothread();
470 if (g_poll_ret > 0) {
471 for (i = 0; i < w->num; i++) {
472 w->revents[i] = poll_fds[n_poll_fds + i].revents;
473 }
474 for (i = 0; i < w->num; i++) {
475 if (w->revents[i] && w->func[i]) {
476 w->func[i](w->opaque[i]);
477 }
478 }
479 }
480
481 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
482 g_main_context_dispatch(context);
483 }
484
485 g_main_context_release(context);
486
487 return select_ret || g_poll_ret;
488}
489#endif
490
491void main_loop_wait(int nonblocking)
492{
493 int ret;
494 uint32_t timeout = UINT32_MAX;
495 int64_t timeout_ns;
496
497 if (nonblocking) {
498 timeout = 0;
499 }
500
501
502 g_array_set_size(gpollfds, 0);
503
504 slirp_pollfds_fill(gpollfds, &timeout);
505
506 if (timeout == UINT32_MAX) {
507 timeout_ns = -1;
508 } else {
509 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
510 }
511
512 timeout_ns = qemu_soonest_timeout(timeout_ns,
513 timerlistgroup_deadline_ns(
514 &main_loop_tlg));
515
516 ret = os_host_main_loop_wait(timeout_ns);
517 slirp_pollfds_poll(gpollfds, (ret < 0));
518
519
520
521 qemu_start_warp_timer();
522 qemu_clock_run_all_timers();
523}
524
525
526
527QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
528{
529 return aio_bh_new(qemu_aio_context, cb, opaque);
530}
531