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/*
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* QEMU System Emulator
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*
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* Copyright (c) 2003-2008 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
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#include "qemu/timer.h" |
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#include "slirp/slirp.h" |
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#include "qemu/main-loop.h" |
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#include "block/aio.h" |
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#ifndef _WIN32
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#include "qemu/compatfd.h" |
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/* If we have signalfd, we mask out the signals we want to handle and then
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* use signalfd to listen for them. We rely on whatever the current signal
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* handler is to dispatch the signals when we receive them.
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*/
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static void sigfd_handler(void *opaque) |
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{ |
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int fd = (intptr_t)opaque;
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struct qemu_signalfd_siginfo info;
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struct sigaction action;
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ssize_t len; |
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while (1) { |
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do {
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len = read(fd, &info, sizeof(info));
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} while (len == -1 && errno == EINTR); |
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if (len == -1 && errno == EAGAIN) { |
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break;
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} |
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if (len != sizeof(info)) { |
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printf("read from sigfd returned %zd: %m\n", len);
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return;
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} |
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sigaction(info.ssi_signo, NULL, &action);
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if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
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action.sa_sigaction(info.ssi_signo, |
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(siginfo_t *)&info, NULL);
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} else if (action.sa_handler) { |
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action.sa_handler(info.ssi_signo); |
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} |
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} |
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} |
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static int qemu_signal_init(void) |
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{ |
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int sigfd;
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sigset_t set; |
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/*
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* SIG_IPI must be blocked in the main thread and must not be caught
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* by sigwait() in the signal thread. Otherwise, the cpu thread will
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* not catch it reliably.
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*/
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sigemptyset(&set); |
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sigaddset(&set, SIG_IPI); |
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sigaddset(&set, SIGIO); |
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sigaddset(&set, SIGALRM); |
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sigaddset(&set, SIGBUS); |
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pthread_sigmask(SIG_BLOCK, &set, NULL);
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sigdelset(&set, SIG_IPI); |
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sigfd = qemu_signalfd(&set); |
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if (sigfd == -1) { |
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fprintf(stderr, "failed to create signalfd\n");
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return -errno;
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} |
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fcntl_setfl(sigfd, O_NONBLOCK); |
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qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL, |
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(void *)(intptr_t)sigfd);
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return 0; |
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} |
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#else /* _WIN32 */ |
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static int qemu_signal_init(void) |
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{ |
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return 0; |
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} |
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#endif
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static AioContext *qemu_aio_context;
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void qemu_notify_event(void) |
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{ |
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if (!qemu_aio_context) {
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return;
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} |
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aio_notify(qemu_aio_context); |
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} |
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static GArray *gpollfds;
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int qemu_init_main_loop(void) |
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{ |
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int ret;
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GSource *src; |
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init_clocks(); |
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if (init_timer_alarm() < 0) { |
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fprintf(stderr, "could not initialize alarm timer\n");
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exit(1);
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} |
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ret = qemu_signal_init(); |
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if (ret) {
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return ret;
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} |
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gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
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qemu_aio_context = aio_context_new(); |
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src = aio_get_g_source(qemu_aio_context); |
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g_source_attach(src, NULL);
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g_source_unref(src); |
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return 0; |
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} |
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static fd_set rfds, wfds, xfds;
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static int nfds; |
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static int max_priority; |
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/* Load rfds/wfds/xfds into gpollfds. Will be removed a few commits later. */
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static void gpollfds_from_select(void) |
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{ |
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int fd;
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for (fd = 0; fd <= nfds; fd++) { |
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int events = 0; |
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if (FD_ISSET(fd, &rfds)) {
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events |= G_IO_IN | G_IO_HUP | G_IO_ERR; |
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} |
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if (FD_ISSET(fd, &wfds)) {
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events |= G_IO_OUT | G_IO_ERR; |
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} |
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if (FD_ISSET(fd, &xfds)) {
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events |= G_IO_PRI; |
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} |
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if (events) {
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GPollFD pfd = { |
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.fd = fd, |
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.events = events, |
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}; |
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g_array_append_val(gpollfds, pfd); |
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} |
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} |
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} |
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/* Store gpollfds revents into rfds/wfds/xfds. Will be removed a few commits
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* later.
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*/
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static void gpollfds_to_select(int ret) |
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{ |
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int i;
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FD_ZERO(&rfds); |
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FD_ZERO(&wfds); |
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FD_ZERO(&xfds); |
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if (ret <= 0) { |
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return;
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} |
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for (i = 0; i < gpollfds->len; i++) { |
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int fd = g_array_index(gpollfds, GPollFD, i).fd;
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int revents = g_array_index(gpollfds, GPollFD, i).revents;
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if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) {
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FD_SET(fd, &rfds); |
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} |
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if (revents & (G_IO_OUT | G_IO_ERR)) {
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FD_SET(fd, &wfds); |
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} |
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if (revents & G_IO_PRI) {
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FD_SET(fd, &xfds); |
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} |
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} |
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} |
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#ifndef _WIN32
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static int glib_pollfds_idx; |
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static int glib_n_poll_fds; |
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static void glib_pollfds_fill(uint32_t *cur_timeout) |
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{ |
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GMainContext *context = g_main_context_default(); |
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int timeout = 0; |
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int n;
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g_main_context_prepare(context, &max_priority); |
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glib_pollfds_idx = gpollfds->len; |
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n = glib_n_poll_fds; |
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do {
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GPollFD *pfds; |
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glib_n_poll_fds = n; |
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g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds); |
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pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx); |
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n = g_main_context_query(context, max_priority, &timeout, pfds, |
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glib_n_poll_fds); |
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} while (n != glib_n_poll_fds);
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if (timeout >= 0 && timeout < *cur_timeout) { |
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*cur_timeout = timeout; |
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} |
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} |
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static void glib_pollfds_poll(void) |
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{ |
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GMainContext *context = g_main_context_default(); |
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GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx); |
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if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
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g_main_context_dispatch(context); |
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} |
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} |
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static int os_host_main_loop_wait(uint32_t timeout) |
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{ |
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int ret;
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glib_pollfds_fill(&timeout); |
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if (timeout > 0) { |
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qemu_mutex_unlock_iothread(); |
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} |
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/* We'll eventually drop fd_set completely. But for now we still have
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* *_fill() and *_poll() functions that use rfds/wfds/xfds.
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*/
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gpollfds_from_select(); |
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ret = g_poll((GPollFD *)gpollfds->data, gpollfds->len, timeout); |
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gpollfds_to_select(ret); |
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if (timeout > 0) { |
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qemu_mutex_lock_iothread(); |
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} |
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glib_pollfds_poll(); |
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return ret;
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} |
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#else
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/***********************************************************/
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/* Polling handling */
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typedef struct PollingEntry { |
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PollingFunc *func; |
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void *opaque;
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struct PollingEntry *next;
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} PollingEntry; |
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static PollingEntry *first_polling_entry;
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int qemu_add_polling_cb(PollingFunc *func, void *opaque) |
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{ |
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PollingEntry **ppe, *pe; |
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pe = g_malloc0(sizeof(PollingEntry));
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pe->func = func; |
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pe->opaque = opaque; |
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for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next); |
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*ppe = pe; |
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return 0; |
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} |
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void qemu_del_polling_cb(PollingFunc *func, void *opaque) |
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{ |
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PollingEntry **ppe, *pe; |
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for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) { |
297 |
pe = *ppe; |
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if (pe->func == func && pe->opaque == opaque) {
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*ppe = pe->next; |
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g_free(pe); |
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break;
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} |
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} |
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} |
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/***********************************************************/
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/* Wait objects support */
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typedef struct WaitObjects { |
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int num;
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int revents[MAXIMUM_WAIT_OBJECTS + 1]; |
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HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
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WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
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void *opaque[MAXIMUM_WAIT_OBJECTS + 1]; |
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} WaitObjects; |
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static WaitObjects wait_objects = {0}; |
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int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque) |
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{ |
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WaitObjects *w = &wait_objects; |
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if (w->num >= MAXIMUM_WAIT_OBJECTS) {
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return -1; |
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} |
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w->events[w->num] = handle; |
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w->func[w->num] = func; |
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w->opaque[w->num] = opaque; |
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w->revents[w->num] = 0;
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w->num++; |
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return 0; |
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} |
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void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque) |
333 |
{ |
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int i, found;
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WaitObjects *w = &wait_objects; |
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found = 0;
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for (i = 0; i < w->num; i++) { |
339 |
if (w->events[i] == handle) {
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found = 1;
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} |
342 |
if (found) {
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w->events[i] = w->events[i + 1];
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w->func[i] = w->func[i + 1];
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w->opaque[i] = w->opaque[i + 1];
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w->revents[i] = w->revents[i + 1];
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} |
348 |
} |
349 |
if (found) {
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w->num--; |
351 |
} |
352 |
} |
353 |
|
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void qemu_fd_register(int fd) |
355 |
{ |
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WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier), |
357 |
FD_READ | FD_ACCEPT | FD_CLOSE | |
358 |
FD_CONNECT | FD_WRITE | FD_OOB); |
359 |
} |
360 |
|
361 |
static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds, |
362 |
fd_set *xfds) |
363 |
{ |
364 |
int nfds = -1; |
365 |
int i;
|
366 |
|
367 |
for (i = 0; i < pollfds->len; i++) { |
368 |
GPollFD *pfd = &g_array_index(pollfds, GPollFD, i); |
369 |
int fd = pfd->fd;
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int events = pfd->events;
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371 |
if (events & (G_IO_IN | G_IO_HUP | G_IO_ERR)) {
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FD_SET(fd, rfds); |
373 |
nfds = MAX(nfds, fd); |
374 |
} |
375 |
if (events & (G_IO_OUT | G_IO_ERR)) {
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376 |
FD_SET(fd, wfds); |
377 |
nfds = MAX(nfds, fd); |
378 |
} |
379 |
if (events & G_IO_PRI) {
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380 |
FD_SET(fd, xfds); |
381 |
nfds = MAX(nfds, fd); |
382 |
} |
383 |
} |
384 |
return nfds;
|
385 |
} |
386 |
|
387 |
static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds, |
388 |
fd_set *wfds, fd_set *xfds) |
389 |
{ |
390 |
int i;
|
391 |
|
392 |
for (i = 0; i < pollfds->len; i++) { |
393 |
GPollFD *pfd = &g_array_index(pollfds, GPollFD, i); |
394 |
int fd = pfd->fd;
|
395 |
int revents = 0; |
396 |
|
397 |
if (FD_ISSET(fd, rfds)) {
|
398 |
revents |= G_IO_IN | G_IO_HUP | G_IO_ERR; |
399 |
} |
400 |
if (FD_ISSET(fd, wfds)) {
|
401 |
revents |= G_IO_OUT | G_IO_ERR; |
402 |
} |
403 |
if (FD_ISSET(fd, xfds)) {
|
404 |
revents |= G_IO_PRI; |
405 |
} |
406 |
pfd->revents = revents & pfd->events; |
407 |
} |
408 |
} |
409 |
|
410 |
static int os_host_main_loop_wait(uint32_t timeout) |
411 |
{ |
412 |
GMainContext *context = g_main_context_default(); |
413 |
GPollFD poll_fds[1024 * 2]; /* this is probably overkill */ |
414 |
int select_ret = 0; |
415 |
int g_poll_ret, ret, i, n_poll_fds;
|
416 |
PollingEntry *pe; |
417 |
WaitObjects *w = &wait_objects; |
418 |
gint poll_timeout; |
419 |
static struct timeval tv0; |
420 |
|
421 |
/* XXX: need to suppress polling by better using win32 events */
|
422 |
ret = 0;
|
423 |
for (pe = first_polling_entry; pe != NULL; pe = pe->next) { |
424 |
ret |= pe->func(pe->opaque); |
425 |
} |
426 |
if (ret != 0) { |
427 |
return ret;
|
428 |
} |
429 |
|
430 |
g_main_context_prepare(context, &max_priority); |
431 |
n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout, |
432 |
poll_fds, ARRAY_SIZE(poll_fds)); |
433 |
g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds)); |
434 |
|
435 |
for (i = 0; i < w->num; i++) { |
436 |
poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i]; |
437 |
poll_fds[n_poll_fds + i].events = G_IO_IN; |
438 |
} |
439 |
|
440 |
if (poll_timeout < 0 || timeout < poll_timeout) { |
441 |
poll_timeout = timeout; |
442 |
} |
443 |
|
444 |
qemu_mutex_unlock_iothread(); |
445 |
g_poll_ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout); |
446 |
qemu_mutex_lock_iothread(); |
447 |
if (g_poll_ret > 0) { |
448 |
for (i = 0; i < w->num; i++) { |
449 |
w->revents[i] = poll_fds[n_poll_fds + i].revents; |
450 |
} |
451 |
for (i = 0; i < w->num; i++) { |
452 |
if (w->revents[i] && w->func[i]) {
|
453 |
w->func[i](w->opaque[i]); |
454 |
} |
455 |
} |
456 |
} |
457 |
|
458 |
if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
|
459 |
g_main_context_dispatch(context); |
460 |
} |
461 |
|
462 |
/* Call select after g_poll to avoid a useless iteration and therefore
|
463 |
* improve socket latency.
|
464 |
*/
|
465 |
|
466 |
/* This back-and-forth between GPollFDs and select(2) is temporary. We'll
|
467 |
* drop it in a couple of patches, I promise :).
|
468 |
*/
|
469 |
gpollfds_from_select(); |
470 |
FD_ZERO(&rfds); |
471 |
FD_ZERO(&wfds); |
472 |
FD_ZERO(&xfds); |
473 |
nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds); |
474 |
if (nfds >= 0) { |
475 |
select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
|
476 |
if (select_ret != 0) { |
477 |
timeout = 0;
|
478 |
} |
479 |
if (select_ret > 0) { |
480 |
pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds); |
481 |
} |
482 |
} |
483 |
gpollfds_to_select(select_ret); |
484 |
|
485 |
return select_ret || g_poll_ret;
|
486 |
} |
487 |
#endif
|
488 |
|
489 |
int main_loop_wait(int nonblocking) |
490 |
{ |
491 |
int ret;
|
492 |
uint32_t timeout = UINT32_MAX; |
493 |
|
494 |
if (nonblocking) {
|
495 |
timeout = 0;
|
496 |
} |
497 |
|
498 |
/* poll any events */
|
499 |
g_array_set_size(gpollfds, 0); /* reset for new iteration */ |
500 |
/* XXX: separate device handlers from system ones */
|
501 |
nfds = -1;
|
502 |
FD_ZERO(&rfds); |
503 |
FD_ZERO(&wfds); |
504 |
FD_ZERO(&xfds); |
505 |
|
506 |
#ifdef CONFIG_SLIRP
|
507 |
slirp_update_timeout(&timeout); |
508 |
slirp_select_fill(&nfds, &rfds, &wfds, &xfds); |
509 |
#endif
|
510 |
qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds); |
511 |
ret = os_host_main_loop_wait(timeout); |
512 |
qemu_iohandler_poll(&rfds, &wfds, &xfds, ret); |
513 |
#ifdef CONFIG_SLIRP
|
514 |
slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
|
515 |
#endif
|
516 |
|
517 |
qemu_run_all_timers(); |
518 |
|
519 |
return ret;
|
520 |
} |
521 |
|
522 |
/* Functions to operate on the main QEMU AioContext. */
|
523 |
|
524 |
QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
|
525 |
{ |
526 |
return aio_bh_new(qemu_aio_context, cb, opaque);
|
527 |
} |
528 |
|
529 |
bool qemu_aio_wait(void) |
530 |
{ |
531 |
return aio_poll(qemu_aio_context, true); |
532 |
} |
533 |
|
534 |
#ifdef CONFIG_POSIX
|
535 |
void qemu_aio_set_fd_handler(int fd, |
536 |
IOHandler *io_read, |
537 |
IOHandler *io_write, |
538 |
AioFlushHandler *io_flush, |
539 |
void *opaque)
|
540 |
{ |
541 |
aio_set_fd_handler(qemu_aio_context, fd, io_read, io_write, io_flush, |
542 |
opaque); |
543 |
} |
544 |
#endif
|
545 |
|
546 |
void qemu_aio_set_event_notifier(EventNotifier *notifier,
|
547 |
EventNotifierHandler *io_read, |
548 |
AioFlushEventNotifierHandler *io_flush) |
549 |
{ |
550 |
aio_set_event_notifier(qemu_aio_context, notifier, io_read, io_flush); |
551 |
} |