From patchwork Wed Aug 29 11:05:47 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wayne Xia X-Patchwork-Id: 180684 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E7C002C0336 for ; Wed, 29 Aug 2012 21:06:10 +1000 (EST) Received: from localhost ([::1]:59379 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T6g65-0007Pu-09 for incoming@patchwork.ozlabs.org; Wed, 29 Aug 2012 07:06:09 -0400 Received: from eggs.gnu.org ([208.118.235.92]:37275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T6g5x-0007Jg-3z for qemu-devel@nongnu.org; Wed, 29 Aug 2012 07:06:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T6g5r-0007n6-5V for qemu-devel@nongnu.org; Wed, 29 Aug 2012 07:06:01 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:54707) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T6g5q-0007mt-Ip for qemu-devel@nongnu.org; Wed, 29 Aug 2012 07:05:55 -0400 Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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X-Received-From: 202.81.31.144 Cc: kwolf@redhat.com, aliguori@us.ibm.com, stefanha@gmail.com, Wenchao Xia , blauwirbel@gmail.com, pbonzini@redhat.com, eblake@redhat.com, afaerber@suse.de Subject: [Qemu-devel] [PATCH v3 4/5] [RFC] libqblock, implemention minor X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Simply exposed a block.c API, and added a AIO check function. Signed-off-by: Wenchao Xia --- aio.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ block.c | 2 +- block.h | 1 + qemu-aio.h | 1 + 4 files changed, 98 insertions(+), 1 deletions(-) diff --git a/aio.c b/aio.c index 0a9eb10..dbe0f6f 100644 --- a/aio.c +++ b/aio.c @@ -192,3 +192,98 @@ bool qemu_aio_wait(void) return true; } + + +bool qemu_aio_check(void) +{ + AioHandler *node; + fd_set rdfds, wrfds; + int max_fd = -1; + int ret; + bool busy; + struct timeval tv; + + walking_handlers = 1; + + FD_ZERO(&rdfds); + FD_ZERO(&wrfds); + + /* fill fd sets */ + busy = false; + 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) { + 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; + + /* No AIO operations? Get us out of here */ + if (!busy) { + return false; + } + + tv.tv_sec = 0; + tv.tv_usec = 0; + /* wait until next event */ + ret = select(max_fd, &rdfds, &wrfds, NULL, &tv); + + /* 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); + } + } + + walking_handlers = 0; + } + + /* + * 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; + } + + return true; +} diff --git a/block.c b/block.c index b38940b..d30f363 100644 --- a/block.c +++ b/block.c @@ -196,7 +196,7 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs, } /* check if the path starts with ":" */ -static int path_has_protocol(const char *path) +int path_has_protocol(const char *path) { const char *p; diff --git a/block.h b/block.h index c89590d..3aca2fd 100644 --- a/block.h +++ b/block.h @@ -403,4 +403,5 @@ typedef enum { #define BLKDBG_EVENT(bs, evt) bdrv_debug_event(bs, evt) void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event); +int path_has_protocol(const char *path); #endif diff --git a/qemu-aio.h b/qemu-aio.h index bfdd35f..b34eb16 100644 --- a/qemu-aio.h +++ b/qemu-aio.h @@ -66,4 +66,5 @@ int qemu_aio_set_fd_handler(int fd, AioFlushHandler *io_flush, void *opaque); +bool qemu_aio_check(void); #endif