diff options
Diffstat (limited to 'main-loop.c')
| -rw-r--r-- | main-loop.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/main-loop.c b/main-loop.c new file mode 100644 index 0000000000..bfecdb7769 --- /dev/null +++ b/main-loop.c @@ -0,0 +1,495 @@ +/* + * 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 "config-host.h" +#include <unistd.h> +#include <signal.h> +#include <time.h> +#include <errno.h> +#include <sys/time.h> +#include <stdbool.h> + +#ifdef _WIN32 +#include <windows.h> +#include <winsock2.h> +#include <ws2tcpip.h> +#else +#include <sys/socket.h> +#include <netinet/in.h> +#include <net/if.h> +#include <arpa/inet.h> +#include <sys/select.h> +#include <sys/stat.h> +#include "compatfd.h" +#endif + +#include <glib.h> + +#include "main-loop.h" +#include "qemu-timer.h" +#include "slirp/libslirp.h" + +#ifndef _WIN32 + +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); + pthread_sigmask(SIG_BLOCK, &set, NULL); + + sigemptyset(&set); + sigaddset(&set, SIGIO); + sigaddset(&set, SIGALRM); + sigaddset(&set, SIGBUS); + pthread_sigmask(SIG_BLOCK, &set, NULL); + + 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; +} |