configure: Drop CONFIG_ATFILE test
[qemu/ar7.git] / main-loop.c
blobcf36645af482cf1d60799c107dc5fab02701b8aa
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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.
25 #include "qemu-common.h"
26 #include "qemu/timer.h"
27 #include "slirp/slirp.h"
28 #include "qemu/main-loop.h"
29 #include "block/aio.h"
31 #ifndef _WIN32
33 #include "qemu/compatfd.h"
35 /* If we have signalfd, we mask out the signals we want to handle and then
36 * use signalfd to listen for them. We rely on whatever the current signal
37 * handler is to dispatch the signals when we receive them.
39 static void sigfd_handler(void *opaque)
41 int fd = (intptr_t)opaque;
42 struct qemu_signalfd_siginfo info;
43 struct sigaction action;
44 ssize_t len;
46 while (1) {
47 do {
48 len = read(fd, &info, sizeof(info));
49 } while (len == -1 && errno == EINTR);
51 if (len == -1 && errno == EAGAIN) {
52 break;
55 if (len != sizeof(info)) {
56 printf("read from sigfd returned %zd: %m\n", len);
57 return;
60 sigaction(info.ssi_signo, NULL, &action);
61 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
62 action.sa_sigaction(info.ssi_signo,
63 (siginfo_t *)&info, NULL);
64 } else if (action.sa_handler) {
65 action.sa_handler(info.ssi_signo);
70 static int qemu_signal_init(void)
72 int sigfd;
73 sigset_t set;
76 * SIG_IPI must be blocked in the main thread and must not be caught
77 * by sigwait() in the signal thread. Otherwise, the cpu thread will
78 * not catch it reliably.
80 sigemptyset(&set);
81 sigaddset(&set, SIG_IPI);
82 sigaddset(&set, SIGIO);
83 sigaddset(&set, SIGALRM);
84 sigaddset(&set, SIGBUS);
85 pthread_sigmask(SIG_BLOCK, &set, NULL);
87 sigdelset(&set, SIG_IPI);
88 sigfd = qemu_signalfd(&set);
89 if (sigfd == -1) {
90 fprintf(stderr, "failed to create signalfd\n");
91 return -errno;
94 fcntl_setfl(sigfd, O_NONBLOCK);
96 qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
97 (void *)(intptr_t)sigfd);
99 return 0;
102 #else /* _WIN32 */
104 static int qemu_signal_init(void)
106 return 0;
108 #endif
110 static AioContext *qemu_aio_context;
112 AioContext *qemu_get_aio_context(void)
114 return qemu_aio_context;
117 void qemu_notify_event(void)
119 if (!qemu_aio_context) {
120 return;
122 aio_notify(qemu_aio_context);
125 static GArray *gpollfds;
127 int qemu_init_main_loop(void)
129 int ret;
130 GSource *src;
132 init_clocks();
133 if (init_timer_alarm() < 0) {
134 fprintf(stderr, "could not initialize alarm timer\n");
135 exit(1);
138 ret = qemu_signal_init();
139 if (ret) {
140 return ret;
143 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
144 qemu_aio_context = aio_context_new();
145 src = aio_get_g_source(qemu_aio_context);
146 g_source_attach(src, NULL);
147 g_source_unref(src);
148 return 0;
151 static int max_priority;
153 #ifndef _WIN32
154 static int glib_pollfds_idx;
155 static int glib_n_poll_fds;
157 static void glib_pollfds_fill(uint32_t *cur_timeout)
159 GMainContext *context = g_main_context_default();
160 int timeout = 0;
161 int n;
163 g_main_context_prepare(context, &max_priority);
165 glib_pollfds_idx = gpollfds->len;
166 n = glib_n_poll_fds;
167 do {
168 GPollFD *pfds;
169 glib_n_poll_fds = n;
170 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
171 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
172 n = g_main_context_query(context, max_priority, &timeout, pfds,
173 glib_n_poll_fds);
174 } while (n != glib_n_poll_fds);
176 if (timeout >= 0 && timeout < *cur_timeout) {
177 *cur_timeout = timeout;
181 static void glib_pollfds_poll(void)
183 GMainContext *context = g_main_context_default();
184 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
186 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
187 g_main_context_dispatch(context);
191 #define MAX_MAIN_LOOP_SPIN (1000)
193 static int os_host_main_loop_wait(uint32_t timeout)
195 int ret;
196 static int spin_counter;
198 glib_pollfds_fill(&timeout);
200 /* If the I/O thread is very busy or we are incorrectly busy waiting in
201 * the I/O thread, this can lead to starvation of the BQL such that the
202 * VCPU threads never run. To make sure we can detect the later case,
203 * print a message to the screen. If we run into this condition, create
204 * a fake timeout in order to give the VCPU threads a chance to run.
206 if (spin_counter > MAX_MAIN_LOOP_SPIN) {
207 static bool notified;
209 if (!notified) {
210 fprintf(stderr,
211 "main-loop: WARNING: I/O thread spun for %d iterations\n",
212 MAX_MAIN_LOOP_SPIN);
213 notified = true;
216 timeout = 1;
219 if (timeout > 0) {
220 spin_counter = 0;
221 qemu_mutex_unlock_iothread();
222 } else {
223 spin_counter++;
226 ret = g_poll((GPollFD *)gpollfds->data, gpollfds->len, timeout);
228 if (timeout > 0) {
229 qemu_mutex_lock_iothread();
232 glib_pollfds_poll();
233 return ret;
235 #else
236 /***********************************************************/
237 /* Polling handling */
239 typedef struct PollingEntry {
240 PollingFunc *func;
241 void *opaque;
242 struct PollingEntry *next;
243 } PollingEntry;
245 static PollingEntry *first_polling_entry;
247 int qemu_add_polling_cb(PollingFunc *func, void *opaque)
249 PollingEntry **ppe, *pe;
250 pe = g_malloc0(sizeof(PollingEntry));
251 pe->func = func;
252 pe->opaque = opaque;
253 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
254 *ppe = pe;
255 return 0;
258 void qemu_del_polling_cb(PollingFunc *func, void *opaque)
260 PollingEntry **ppe, *pe;
261 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
262 pe = *ppe;
263 if (pe->func == func && pe->opaque == opaque) {
264 *ppe = pe->next;
265 g_free(pe);
266 break;
271 /***********************************************************/
272 /* Wait objects support */
273 typedef struct WaitObjects {
274 int num;
275 int revents[MAXIMUM_WAIT_OBJECTS + 1];
276 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
277 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
278 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
279 } WaitObjects;
281 static WaitObjects wait_objects = {0};
283 int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
285 WaitObjects *w = &wait_objects;
286 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
287 return -1;
289 w->events[w->num] = handle;
290 w->func[w->num] = func;
291 w->opaque[w->num] = opaque;
292 w->revents[w->num] = 0;
293 w->num++;
294 return 0;
297 void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
299 int i, found;
300 WaitObjects *w = &wait_objects;
302 found = 0;
303 for (i = 0; i < w->num; i++) {
304 if (w->events[i] == handle) {
305 found = 1;
307 if (found) {
308 w->events[i] = w->events[i + 1];
309 w->func[i] = w->func[i + 1];
310 w->opaque[i] = w->opaque[i + 1];
311 w->revents[i] = w->revents[i + 1];
314 if (found) {
315 w->num--;
319 void qemu_fd_register(int fd)
321 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
322 FD_READ | FD_ACCEPT | FD_CLOSE |
323 FD_CONNECT | FD_WRITE | FD_OOB);
326 static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
327 fd_set *xfds)
329 int nfds = -1;
330 int i;
332 for (i = 0; i < pollfds->len; i++) {
333 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
334 int fd = pfd->fd;
335 int events = pfd->events;
336 if (events & G_IO_IN) {
337 FD_SET(fd, rfds);
338 nfds = MAX(nfds, fd);
340 if (events & G_IO_OUT) {
341 FD_SET(fd, wfds);
342 nfds = MAX(nfds, fd);
344 if (events & G_IO_PRI) {
345 FD_SET(fd, xfds);
346 nfds = MAX(nfds, fd);
349 return nfds;
352 static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
353 fd_set *wfds, fd_set *xfds)
355 int i;
357 for (i = 0; i < pollfds->len; i++) {
358 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
359 int fd = pfd->fd;
360 int revents = 0;
362 if (FD_ISSET(fd, rfds)) {
363 revents |= G_IO_IN;
365 if (FD_ISSET(fd, wfds)) {
366 revents |= G_IO_OUT;
368 if (FD_ISSET(fd, xfds)) {
369 revents |= G_IO_PRI;
371 pfd->revents = revents & pfd->events;
375 static int os_host_main_loop_wait(uint32_t timeout)
377 GMainContext *context = g_main_context_default();
378 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
379 int select_ret = 0;
380 int g_poll_ret, ret, i, n_poll_fds;
381 PollingEntry *pe;
382 WaitObjects *w = &wait_objects;
383 gint poll_timeout;
384 static struct timeval tv0;
385 fd_set rfds, wfds, xfds;
386 int nfds;
388 /* XXX: need to suppress polling by better using win32 events */
389 ret = 0;
390 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
391 ret |= pe->func(pe->opaque);
393 if (ret != 0) {
394 return ret;
397 FD_ZERO(&rfds);
398 FD_ZERO(&wfds);
399 FD_ZERO(&xfds);
400 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
401 if (nfds >= 0) {
402 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
403 if (select_ret != 0) {
404 timeout = 0;
406 if (select_ret > 0) {
407 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
411 g_main_context_prepare(context, &max_priority);
412 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
413 poll_fds, ARRAY_SIZE(poll_fds));
414 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
416 for (i = 0; i < w->num; i++) {
417 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
418 poll_fds[n_poll_fds + i].events = G_IO_IN;
421 if (poll_timeout < 0 || timeout < poll_timeout) {
422 poll_timeout = timeout;
425 qemu_mutex_unlock_iothread();
426 g_poll_ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout);
427 qemu_mutex_lock_iothread();
428 if (g_poll_ret > 0) {
429 for (i = 0; i < w->num; i++) {
430 w->revents[i] = poll_fds[n_poll_fds + i].revents;
432 for (i = 0; i < w->num; i++) {
433 if (w->revents[i] && w->func[i]) {
434 w->func[i](w->opaque[i]);
439 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
440 g_main_context_dispatch(context);
443 return select_ret || g_poll_ret;
445 #endif
447 int main_loop_wait(int nonblocking)
449 int ret;
450 uint32_t timeout = UINT32_MAX;
452 if (nonblocking) {
453 timeout = 0;
456 /* poll any events */
457 g_array_set_size(gpollfds, 0); /* reset for new iteration */
458 /* XXX: separate device handlers from system ones */
459 #ifdef CONFIG_SLIRP
460 slirp_update_timeout(&timeout);
461 slirp_pollfds_fill(gpollfds);
462 #endif
463 qemu_iohandler_fill(gpollfds);
464 ret = os_host_main_loop_wait(timeout);
465 qemu_iohandler_poll(gpollfds, ret);
466 #ifdef CONFIG_SLIRP
467 slirp_pollfds_poll(gpollfds, (ret < 0));
468 #endif
470 qemu_run_all_timers();
472 return ret;
475 /* Functions to operate on the main QEMU AioContext. */
477 QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
479 return aio_bh_new(qemu_aio_context, cb, opaque);
482 bool qemu_aio_wait(void)
484 return aio_poll(qemu_aio_context, true);
487 #ifdef CONFIG_POSIX
488 void qemu_aio_set_fd_handler(int fd,
489 IOHandler *io_read,
490 IOHandler *io_write,
491 AioFlushHandler *io_flush,
492 void *opaque)
494 aio_set_fd_handler(qemu_aio_context, fd, io_read, io_write, io_flush,
495 opaque);
497 #endif
499 void qemu_aio_set_event_notifier(EventNotifier *notifier,
500 EventNotifierHandler *io_read,
501 AioFlushEventNotifierHandler *io_flush)
503 aio_set_event_notifier(qemu_aio_context, notifier, io_read, io_flush);