diff options
Diffstat (limited to 'aio.c')
| -rw-r--r-- | aio.c | 172 |
1 files changed, 67 insertions, 105 deletions
@@ -35,7 +35,6 @@ struct AioHandler IOHandler *io_read; IOHandler *io_write; AioFlushHandler *io_flush; - AioProcessQueue *io_process_queue; int deleted; void *opaque; QLIST_ENTRY(AioHandler) node; @@ -58,7 +57,6 @@ int qemu_aio_set_fd_handler(int fd, IOHandler *io_read, IOHandler *io_write, AioFlushHandler *io_flush, - AioProcessQueue *io_process_queue, void *opaque) { AioHandler *node; @@ -91,7 +89,6 @@ int qemu_aio_set_fd_handler(int fd, node->io_read = io_read; node->io_write = io_write; node->io_flush = io_flush; - node->io_process_queue = io_process_queue; node->opaque = opaque; } @@ -102,131 +99,96 @@ int qemu_aio_set_fd_handler(int fd, void qemu_aio_flush(void) { - AioHandler *node; - int ret; - - do { - ret = 0; - - /* - * If there are pending emulated aio start them now so flush - * will be able to return 1. - */ - qemu_aio_wait(); - - QLIST_FOREACH(node, &aio_handlers, node) { - if (node->io_flush) { - ret |= node->io_flush(node->opaque); - } - } - } while (qemu_bh_poll() || ret > 0); + while (qemu_aio_wait()); } -int qemu_aio_process_queue(void) +bool qemu_aio_wait(void) { AioHandler *node; - int ret = 0; + fd_set rdfds, wrfds; + int max_fd = -1; + int ret; + bool busy; + + /* + * If there are callbacks left that have been queued, we need to call then. + * Do not call select in this case, because it is possible that the caller + * does not need a complete flush (as is the case for qemu_aio_wait loops). + */ + if (qemu_bh_poll()) { + return true; + } walking_handlers = 1; + FD_ZERO(&rdfds); + FD_ZERO(&wrfds); + + /* fill fd sets */ + busy = false; QLIST_FOREACH(node, &aio_handlers, node) { - if (node->io_process_queue) { - if (node->io_process_queue(node->opaque)) { - ret = 1; + /* If there aren't pending AIO operations, don't invoke callbacks. + * Otherwise, if there are no AIO requests, qemu_aio_wait() would + * wait indefinitely. + */ + if (node->io_flush) { + if (node->io_flush(node->opaque) == 0) { + continue; } + busy = true; + } + if (!node->deleted && node->io_read) { + FD_SET(node->fd, &rdfds); + max_fd = MAX(max_fd, node->fd + 1); + } + if (!node->deleted && node->io_write) { + FD_SET(node->fd, &wrfds); + max_fd = MAX(max_fd, node->fd + 1); } } walking_handlers = 0; - return ret; -} - -void qemu_aio_wait(void) -{ - int ret; - - if (qemu_bh_poll()) - return; - - /* - * If there are callbacks left that have been queued, we need to call then. - * Return afterwards to avoid waiting needlessly in select(). - */ - if (qemu_aio_process_queue()) - return; + /* No AIO operations? Get us out of here */ + if (!busy) { + return false; + } - do { - AioHandler *node; - fd_set rdfds, wrfds; - int max_fd = -1; + /* wait until next event */ + ret = select(max_fd, &rdfds, &wrfds, NULL, NULL); + /* if we have any readable fds, dispatch event */ + if (ret > 0) { walking_handlers = 1; - FD_ZERO(&rdfds); - FD_ZERO(&wrfds); + /* we have to walk very carefully in case + * qemu_aio_set_fd_handler is called while we're walking */ + node = QLIST_FIRST(&aio_handlers); + while (node) { + AioHandler *tmp; - /* fill fd sets */ - QLIST_FOREACH(node, &aio_handlers, node) { - /* If there aren't pending AIO operations, don't invoke callbacks. - * Otherwise, if there are no AIO requests, qemu_aio_wait() would - * wait indefinitely. - */ - if (node->io_flush && node->io_flush(node->opaque) == 0) - continue; - - if (!node->deleted && node->io_read) { - FD_SET(node->fd, &rdfds); - max_fd = MAX(max_fd, node->fd + 1); + if (!node->deleted && + FD_ISSET(node->fd, &rdfds) && + node->io_read) { + node->io_read(node->opaque); } - if (!node->deleted && node->io_write) { - FD_SET(node->fd, &wrfds); - max_fd = MAX(max_fd, node->fd + 1); + if (!node->deleted && + FD_ISSET(node->fd, &wrfds) && + node->io_write) { + node->io_write(node->opaque); } - } - walking_handlers = 0; + tmp = node; + node = QLIST_NEXT(node, node); - /* No AIO operations? Get us out of here */ - if (max_fd == -1) - break; - - /* wait until next event */ - ret = select(max_fd, &rdfds, &wrfds, NULL, NULL); - if (ret == -1 && errno == EINTR) - continue; - - /* if we have any readable fds, dispatch event */ - if (ret > 0) { - walking_handlers = 1; - - /* we have to walk very carefully in case - * qemu_aio_set_fd_handler is called while we're walking */ - node = QLIST_FIRST(&aio_handlers); - while (node) { - AioHandler *tmp; - - if (!node->deleted && - FD_ISSET(node->fd, &rdfds) && - node->io_read) { - node->io_read(node->opaque); - } - if (!node->deleted && - FD_ISSET(node->fd, &wrfds) && - node->io_write) { - node->io_write(node->opaque); - } - - tmp = node; - node = QLIST_NEXT(node, node); - - if (tmp->deleted) { - QLIST_REMOVE(tmp, node); - g_free(tmp); - } + if (tmp->deleted) { + QLIST_REMOVE(tmp, node); + g_free(tmp); } - - walking_handlers = 0; } - } while (ret == 0); + + walking_handlers = 0; + } + + return true; } |