[qemu.git] / main-loop.c

/*
 * QEMU System Emulator
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu-common.h"
#include "qemu-timer.h"
#include "slirp/slirp.h"
#include "main-loop.h"

#ifndef _WIN32

#include "compatfd.h"

static int io_thread_fd = -1;

void qemu_notify_event(void)
{
    /* Write 8 bytes to be compatible with eventfd.  */
    static const uint64_t val = 1;
    ssize_t ret;

    if (io_thread_fd == -1) {
        return;
    }
    do {
        ret = write(io_thread_fd, &val, sizeof(val));
    } while (ret < 0 && errno == EINTR);

    /* EAGAIN is fine, a read must be pending.  */
    if (ret < 0 && errno != EAGAIN) {
        fprintf(stderr, "qemu_notify_event: write() failed: %s\n",
                strerror(errno));
        exit(1);
    }
}

static void qemu_event_read(void *opaque)
{
    int fd = (intptr_t)opaque;
    ssize_t len;
    char buffer[512];

    /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
    do {
        len = read(fd, buffer, sizeof(buffer));
    } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
}

static int qemu_event_init(void)
{
    int err;
    int fds[2];

    err = qemu_eventfd(fds);
    if (err == -1) {
        return -errno;
    }
    err = fcntl_setfl(fds[0], O_NONBLOCK);
    if (err < 0) {
        goto fail;
    }
    err = fcntl_setfl(fds[1], O_NONBLOCK);
    if (err < 0) {
        goto fail;
    }
    qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
                         (void *)(intptr_t)fds[0]);

    io_thread_fd = fds[1];
    return 0;

fail:
    close(fds[0]);
    close(fds[1]);
    return err;
}

/* If we have signalfd, we mask out the signals we want to handle and then
 * use signalfd to listen for them.  We rely on whatever the current signal
 * handler is to dispatch the signals when we receive them.
 */
static void sigfd_handler(void *opaque)
{
    int fd = (intptr_t)opaque;
    struct qemu_signalfd_siginfo info;
    struct sigaction action;
    ssize_t len;

    while (1) {
        do {
            len = read(fd, &info, sizeof(info));
        } while (len == -1 && errno == EINTR);

        if (len == -1 && errno == EAGAIN) {
            break;
        }

        if (len != sizeof(info)) {
            printf("read from sigfd returned %zd: %m\n", len);
            return;
        }

        sigaction(info.ssi_signo, NULL, &action);
        if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
            action.sa_sigaction(info.ssi_signo,
                                (siginfo_t *)&info, NULL);
        } else if (action.sa_handler) {
            action.sa_handler(info.ssi_signo);
        }
    }
}

static int qemu_signal_init(void)
{
    int sigfd;
    sigset_t set;

    /*
     * SIG_IPI must be blocked in the main thread and must not be caught
     * by sigwait() in the signal thread. Otherwise, the cpu thread will
     * not catch it reliably.
     */
    sigemptyset(&set);
    sigaddset(&set, SIG_IPI);
    sigaddset(&set, SIGIO);
    sigaddset(&set, SIGALRM);
    sigaddset(&set, SIGBUS);
    pthread_sigmask(SIG_BLOCK, &set, NULL);

    sigdelset(&set, SIG_IPI);
    sigfd = qemu_signalfd(&set);
    if (sigfd == -1) {
        fprintf(stderr, "failed to create signalfd\n");
        return -errno;
    }

    fcntl_setfl(sigfd, O_NONBLOCK);

    qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
                         (void *)(intptr_t)sigfd);

    return 0;
}

#else /* _WIN32 */

HANDLE qemu_event_handle;

static void dummy_event_handler(void *opaque)
{
}

static int qemu_event_init(void)
{
    qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (!qemu_event_handle) {
        fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
        return -1;
    }
    qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
    return 0;
}

void qemu_notify_event(void)
{
    if (!SetEvent(qemu_event_handle)) {
        fprintf(stderr, "qemu_notify_event: SetEvent failed: %ld\n",
                GetLastError());
        exit(1);
    }
}

static int qemu_signal_init(void)
{
    return 0;
}
#endif

int qemu_init_main_loop(void)
{
    int ret;

    qemu_mutex_lock_iothread();
    ret = qemu_signal_init();
    if (ret) {
        return ret;
    }

    /* Note eventfd must be drained before signalfd handlers run */
    ret = qemu_event_init();
    if (ret) {
        return ret;
    }

    return 0;
}


static GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
static int n_poll_fds;
static int max_priority;

static void glib_select_fill(int *max_fd, fd_set *rfds, fd_set *wfds,
                             fd_set *xfds, struct timeval *tv)
{
    GMainContext *context = g_main_context_default();
    int i;
    int timeout = 0, cur_timeout;

    g_main_context_prepare(context, &max_priority);

    n_poll_fds = g_main_context_query(context, max_priority, &timeout,
                                      poll_fds, ARRAY_SIZE(poll_fds));
    g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));

    for (i = 0; i < n_poll_fds; i++) {
        GPollFD *p = &poll_fds[i];

        if ((p->events & G_IO_IN)) {
            FD_SET(p->fd, rfds);
            *max_fd = MAX(*max_fd, p->fd);
        }
        if ((p->events & G_IO_OUT)) {
            FD_SET(p->fd, wfds);
            *max_fd = MAX(*max_fd, p->fd);
        }
        if ((p->events & G_IO_ERR)) {
            FD_SET(p->fd, xfds);
            *max_fd = MAX(*max_fd, p->fd);
        }
    }

    cur_timeout = (tv->tv_sec * 1000) + ((tv->tv_usec + 500) / 1000);
    if (timeout >= 0 && timeout < cur_timeout) {
        tv->tv_sec = timeout / 1000;
        tv->tv_usec = (timeout % 1000) * 1000;
    }
}

static void glib_select_poll(fd_set *rfds, fd_set *wfds, fd_set *xfds,
                             bool err)
{
    GMainContext *context = g_main_context_default();

    if (!err) {
        int i;

        for (i = 0; i < n_poll_fds; i++) {
            GPollFD *p = &poll_fds[i];

            if ((p->events & G_IO_IN) && FD_ISSET(p->fd, rfds)) {
                p->revents |= G_IO_IN;
            }
            if ((p->events & G_IO_OUT) && FD_ISSET(p->fd, wfds)) {
                p->revents |= G_IO_OUT;
            }
            if ((p->events & G_IO_ERR) && FD_ISSET(p->fd, xfds)) {
                p->revents |= G_IO_ERR;
            }
        }
    }

    if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
        g_main_context_dispatch(context);
    }
}

#ifdef _WIN32
/***********************************************************/
/* Polling handling */

typedef struct PollingEntry {
    PollingFunc *func;
    void *opaque;
    struct PollingEntry *next;
} PollingEntry;

static PollingEntry *first_polling_entry;

int qemu_add_polling_cb(PollingFunc *func, void *opaque)
{
    PollingEntry **ppe, *pe;
    pe = g_malloc0(sizeof(PollingEntry));
    pe->func = func;
    pe->opaque = opaque;
    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
    *ppe = pe;
    return 0;
}

void qemu_del_polling_cb(PollingFunc *func, void *opaque)
{
    PollingEntry **ppe, *pe;
    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
        pe = *ppe;
        if (pe->func == func && pe->opaque == opaque) {
            *ppe = pe->next;
            g_free(pe);
            break;
        }
    }
}

/***********************************************************/
/* Wait objects support */
typedef struct WaitObjects {
    int num;
    HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
    WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
    void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
} WaitObjects;

static WaitObjects wait_objects = {0};

int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
{
    WaitObjects *w = &wait_objects;
    if (w->num >= MAXIMUM_WAIT_OBJECTS) {
        return -1;
    }
    w->events[w->num] = handle;
    w->func[w->num] = func;
    w->opaque[w->num] = opaque;
    w->num++;
    return 0;
}

void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
{
    int i, found;
    WaitObjects *w = &wait_objects;

    found = 0;
    for (i = 0; i < w->num; i++) {
        if (w->events[i] == handle) {
            found = 1;
        }
        if (found) {
            w->events[i] = w->events[i + 1];
            w->func[i] = w->func[i + 1];
            w->opaque[i] = w->opaque[i + 1];
        }
    }
    if (found) {
        w->num--;
    }
}

static void os_host_main_loop_wait(int *timeout)
{
    int ret, ret2, i;
    PollingEntry *pe;

    /* XXX: need to suppress polling by better using win32 events */
    ret = 0;
    for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
        ret |= pe->func(pe->opaque);
    }
    if (ret == 0) {
        int err;
        WaitObjects *w = &wait_objects;

        qemu_mutex_unlock_iothread();
        ret = WaitForMultipleObjects(w->num, w->events, FALSE, *timeout);
        qemu_mutex_lock_iothread();
        if (WAIT_OBJECT_0 + 0 <= ret && ret <= WAIT_OBJECT_0 + w->num - 1) {
            if (w->func[ret - WAIT_OBJECT_0]) {
                w->func[ret - WAIT_OBJECT_0](w->opaque[ret - WAIT_OBJECT_0]);
            }

            /* Check for additional signaled events */
            for (i = (ret - WAIT_OBJECT_0 + 1); i < w->num; i++) {
                /* Check if event is signaled */
                ret2 = WaitForSingleObject(w->events[i], 0);
                if (ret2 == WAIT_OBJECT_0) {
                    if (w->func[i]) {
                        w->func[i](w->opaque[i]);
                    }
                } else if (ret2 != WAIT_TIMEOUT) {
                    err = GetLastError();
                    fprintf(stderr, "WaitForSingleObject error %d %d\n", i, err);
                }
            }
        } else if (ret != WAIT_TIMEOUT) {
            err = GetLastError();
            fprintf(stderr, "WaitForMultipleObjects error %d %d\n", ret, err);
        }
    }

    *timeout = 0;
}
#else
static inline void os_host_main_loop_wait(int *timeout)
{
}
#endif

int main_loop_wait(int nonblocking)
{
    fd_set rfds, wfds, xfds;
    int ret, nfds;
    struct timeval tv;
    int timeout;

    if (nonblocking) {
        timeout = 0;
    } else {
        timeout = qemu_calculate_timeout();
        qemu_bh_update_timeout(&timeout);
    }

    os_host_main_loop_wait(&timeout);

    tv.tv_sec = timeout / 1000;
    tv.tv_usec = (timeout % 1000) * 1000;

    /* poll any events */
    /* XXX: separate device handlers from system ones */
    nfds = -1;
    FD_ZERO(&rfds);
    FD_ZERO(&wfds);
    FD_ZERO(&xfds);

#ifdef CONFIG_SLIRP
    slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
#endif
    qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
    glib_select_fill(&nfds, &rfds, &wfds, &xfds, &tv);

    if (timeout > 0) {
        qemu_mutex_unlock_iothread();
    }

    ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);

    if (timeout > 0) {
        qemu_mutex_lock_iothread();
    }

    glib_select_poll(&rfds, &wfds, &xfds, (ret < 0));
    qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
#ifdef CONFIG_SLIRP
    slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
#endif

    qemu_run_all_timers();

    /* Check bottom-halves last in case any of the earlier events triggered
       them.  */
    qemu_bh_poll();

    return ret;
}
Commit	Line	Data
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"
0ec024f6 SW	28	#include "main-loop.h"
d3b12f5d PB	29
	30	#ifndef _WIN32
	31
0ec024f6 SW	32	#include "compatfd.h"
0ec024f6 SW	33
d3b12f5d PB	34	static int io_thread_fd = -1;
	35
	36	void 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
	57	static 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
	69	static 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
	92	fail:
	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	*/
102	static 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
133	static 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
	167	HANDLE qemu_event_handle;
	168
	169	static void dummy_event_handler(void *opaque)
	170	{
	171	}
	172
	173	static 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
	184	void qemu_notify_event(void)
	185	{
	186	if (!SetEvent(qemu_event_handle)) {
	187	fprintf(stderr, "qemu_notify_event: SetEvent failed: %ld\n",
	188	GetLastError());
	189	exit(1);
	190	}
	191	}
	192
	193	static int qemu_signal_init(void)
	194	{
	195	return 0;
	196	}
	197	#endif
	198
	199	int qemu_init_main_loop(void)
	200	{
	201	int ret;
	202
	203	qemu_mutex_lock_iothread();
	204	ret = qemu_signal_init();
	205	if (ret) {
	206	return ret;
	207	}
	208
	209	/* Note eventfd must be drained before signalfd handlers run */
	210	ret = qemu_event_init();
	211	if (ret) {
	212	return ret;
	213	}
	214
215	return 0;
216	}
217
218
219	static GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
220	static int n_poll_fds;
221	static int max_priority;
222
223	static void glib_select_fill(int max_fd, fd_set rfds, fd_set *wfds,
224	fd_set xfds, struct timeval tv)
225	{
226	GMainContext *context = g_main_context_default();
227	int i;
228	int timeout = 0, cur_timeout;
229
230	g_main_context_prepare(context, &max_priority);
231
232	n_poll_fds = g_main_context_query(context, max_priority, &timeout,
233	poll_fds, ARRAY_SIZE(poll_fds));
234	g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
235
236	for (i = 0; i < n_poll_fds; i++) {
237	GPollFD *p = &poll_fds[i];
238
239	if ((p->events & G_IO_IN)) {
240	FD_SET(p->fd, rfds);
241	max_fd = MAX(max_fd, p->fd);
242	}
243	if ((p->events & G_IO_OUT)) {
244	FD_SET(p->fd, wfds);
245	max_fd = MAX(max_fd, p->fd);
246	}
247	if ((p->events & G_IO_ERR)) {
248	FD_SET(p->fd, xfds);
249	max_fd = MAX(max_fd, p->fd);
250	}
251	}
252
253	cur_timeout = (tv->tv_sec * 1000) + ((tv->tv_usec + 500) / 1000);
254	if (timeout >= 0 && timeout < cur_timeout) {
255	tv->tv_sec = timeout / 1000;
256	tv->tv_usec = (timeout % 1000) * 1000;
257	}
258	}
259
260	static void glib_select_poll(fd_set rfds, fd_set wfds, fd_set *xfds,
261	bool err)
262	{
263	GMainContext *context = g_main_context_default();
264
265	if (!err) {
266	int i;
267
268	for (i = 0; i < n_poll_fds; i++) {
269	GPollFD *p = &poll_fds[i];
270
271	if ((p->events & G_IO_IN) && FD_ISSET(p->fd, rfds)) {
272	p->revents \|= G_IO_IN;
273	}
274	if ((p->events & G_IO_OUT) && FD_ISSET(p->fd, wfds)) {
275	p->revents \|= G_IO_OUT;
276	}
277	if ((p->events & G_IO_ERR) && FD_ISSET(p->fd, xfds)) {
278	p->revents \|= G_IO_ERR;
279	}
280	}
281	}
282
283	if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
284	g_main_context_dispatch(context);
285	}
286	}
287
288	#ifdef _WIN32
289	/***********************************************************/
290	/* Polling handling */
291
292	typedef struct PollingEntry {
293	PollingFunc *func;
294	void *opaque;
295	struct PollingEntry *next;
296	} PollingEntry;
297
298	static PollingEntry *first_polling_entry;
299
300	int qemu_add_polling_cb(PollingFunc func, void opaque)
301	{
302	PollingEntry *ppe, pe;
303	pe = g_malloc0(sizeof(PollingEntry));
304	pe->func = func;
305	pe->opaque = opaque;
306	for(ppe = &first_polling_entry; ppe != NULL; ppe = &(ppe)->next);
307	*ppe = pe;
308	return 0;
309	}
310
311	void qemu_del_polling_cb(PollingFunc func, void opaque)
312	{
313	PollingEntry *ppe, pe;
314	for(ppe = &first_polling_entry; ppe != NULL; ppe = &(ppe)->next) {
315	pe = *ppe;
316	if (pe->func == func && pe->opaque == opaque) {
317	*ppe = pe->next;
318	g_free(pe);
319	break;
320	}
321	}
322	}
323
324	/***********************************************************/
325	/* Wait objects support */
326	typedef struct WaitObjects {
327	int num;
328	HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
329	WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
330	void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
331	} WaitObjects;
332
333	static WaitObjects wait_objects = {0};
334
335	int qemu_add_wait_object(HANDLE handle, WaitObjectFunc func, void opaque)
336	{
337	WaitObjects *w = &wait_objects;
338	if (w->num >= MAXIMUM_WAIT_OBJECTS) {
339	return -1;
340	}
341	w->events[w->num] = handle;
342	w->func[w->num] = func;
343	w->opaque[w->num] = opaque;
344	w->num++;
345	return 0;
346	}
347
348	void qemu_del_wait_object(HANDLE handle, WaitObjectFunc func, void opaque)
349	{
350	int i, found;
351	WaitObjects *w = &wait_objects;
352
353	found = 0;
354	for (i = 0; i < w->num; i++) {
355	if (w->events[i] == handle) {
356	found = 1;
357	}
358	if (found) {
359	w->events[i] = w->events[i + 1];
360	w->func[i] = w->func[i + 1];
361	w->opaque[i] = w->opaque[i + 1];
362	}
363	}
364	if (found) {
365	w->num--;
366	}
367	}
368
369	static void os_host_main_loop_wait(int *timeout)
370	{
371	int ret, ret2, i;
372	PollingEntry *pe;
373
374	/* XXX: need to suppress polling by better using win32 events */
375	ret = 0;
376	for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
377	ret \|= pe->func(pe->opaque);
378	}
379	if (ret == 0) {
380	int err;
381	WaitObjects *w = &wait_objects;
382
383	qemu_mutex_unlock_iothread();
384	ret = WaitForMultipleObjects(w->num, w->events, FALSE, *timeout);
385	qemu_mutex_lock_iothread();
386	if (WAIT_OBJECT_0 + 0 <= ret && ret <= WAIT_OBJECT_0 + w->num - 1) {
387	if (w->func[ret - WAIT_OBJECT_0]) {
388	w->func[ret - WAIT_OBJECT_0](w->opaque[ret - WAIT_OBJECT_0]);
389	}
390
391	/* Check for additional signaled events */
392	for (i = (ret - WAIT_OBJECT_0 + 1); i < w->num; i++) {
393	/* Check if event is signaled */
394	ret2 = WaitForSingleObject(w->events[i], 0);
395	if (ret2 == WAIT_OBJECT_0) {
396	if (w->func[i]) {
397	w->func[i](w->opaque[i]);
398	}
399	} else if (ret2 != WAIT_TIMEOUT) {
400	err = GetLastError();
401	fprintf(stderr, "WaitForSingleObject error %d %d\n", i, err);
402	}
403	}
404	} else if (ret != WAIT_TIMEOUT) {
405	err = GetLastError();
406	fprintf(stderr, "WaitForMultipleObjects error %d %d\n", ret, err);
407	}
408	}
409
410	*timeout = 0;
411	}
412	#else
413	static inline void os_host_main_loop_wait(int *timeout)
414	{
415	}
416	#endif
417
418	int main_loop_wait(int nonblocking)
419	{
420	fd_set rfds, wfds, xfds;
421	int ret, nfds;
422	struct timeval tv;
423	int timeout;
424
425	if (nonblocking) {
426	timeout = 0;
427	} else {
428	timeout = qemu_calculate_timeout();
429	qemu_bh_update_timeout(&timeout);
430	}
431
432	os_host_main_loop_wait(&timeout);
433
434	tv.tv_sec = timeout / 1000;
435	tv.tv_usec = (timeout % 1000) * 1000;
436
437	/* poll any events */
438	/* XXX: separate device handlers from system ones */
439	nfds = -1;
440	FD_ZERO(&rfds);
441	FD_ZERO(&wfds);
442	FD_ZERO(&xfds);
443
444	#ifdef CONFIG_SLIRP
445	slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
446	#endif
447	qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
448	glib_select_fill(&nfds, &rfds, &wfds, &xfds, &tv);
449
450	if (timeout > 0) {
451	qemu_mutex_unlock_iothread();
452	}
453
454	ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
455
456	if (timeout > 0) {
457	qemu_mutex_lock_iothread();
458	}
459
460	glib_select_poll(&rfds, &wfds, &xfds, (ret < 0));
461	qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
462	#ifdef CONFIG_SLIRP
463	slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
464	#endif
465
466	qemu_run_all_timers();
467
468	/* Check bottom-halves last in case any of the earlier events triggered
469	them. */
470	qemu_bh_poll();
471
472	return ret;
473	}