diff options
| -rw-r--r-- | aio-posix.c | 105 | ||||
| -rw-r--r-- | aio-win32.c | 15 | ||||
| -rw-r--r-- | include/block/aio.h | 20 |
3 files changed, 125 insertions, 15 deletions
diff --git a/aio-posix.c b/aio-posix.c index c6adddbd82..5216d82290 100644 --- a/aio-posix.c +++ b/aio-posix.c @@ -30,6 +30,8 @@ struct AioHandler IOHandler *io_read; IOHandler *io_write; AioPollFn *io_poll; + IOHandler *io_poll_begin; + IOHandler *io_poll_end; int deleted; void *opaque; bool is_external; @@ -270,6 +272,20 @@ void aio_set_fd_handler(AioContext *ctx, } } +void aio_set_fd_poll(AioContext *ctx, int fd, + IOHandler *io_poll_begin, + IOHandler *io_poll_end) +{ + AioHandler *node = find_aio_handler(ctx, fd); + + if (!node) { + return; + } + + node->io_poll_begin = io_poll_begin; + node->io_poll_end = io_poll_end; +} + void aio_set_event_notifier(AioContext *ctx, EventNotifier *notifier, bool is_external, @@ -280,8 +296,53 @@ void aio_set_event_notifier(AioContext *ctx, (IOHandler *)io_read, NULL, io_poll, notifier); } +void aio_set_event_notifier_poll(AioContext *ctx, + EventNotifier *notifier, + EventNotifierHandler *io_poll_begin, + EventNotifierHandler *io_poll_end) +{ + aio_set_fd_poll(ctx, event_notifier_get_fd(notifier), + (IOHandler *)io_poll_begin, + (IOHandler *)io_poll_end); +} + +static void poll_set_started(AioContext *ctx, bool started) +{ + AioHandler *node; + + if (started == ctx->poll_started) { + return; + } + + ctx->poll_started = started; + + ctx->walking_handlers++; + QLIST_FOREACH(node, &ctx->aio_handlers, node) { + IOHandler *fn; + + if (node->deleted) { + continue; + } + + if (started) { + fn = node->io_poll_begin; + } else { + fn = node->io_poll_end; + } + + if (fn) { + fn(node->opaque); + } + } + ctx->walking_handlers--; +} + + bool aio_prepare(AioContext *ctx) { + /* Poll mode cannot be used with glib's event loop, disable it. */ + poll_set_started(ctx, false); + return false; } @@ -422,6 +483,23 @@ static void add_pollfd(AioHandler *node) npfd++; } +static bool run_poll_handlers_once(AioContext *ctx) +{ + bool progress = false; + AioHandler *node; + + QLIST_FOREACH(node, &ctx->aio_handlers, node) { + if (!node->deleted && node->io_poll && + node->io_poll(node->opaque)) { + progress = true; + } + + /* Caller handles freeing deleted nodes. Don't do it here. */ + } + + return progress; +} + /* run_poll_handlers: * @ctx: the AioContext * @max_ns: maximum time to poll for, in nanoseconds @@ -437,7 +515,7 @@ static void add_pollfd(AioHandler *node) */ static bool run_poll_handlers(AioContext *ctx, int64_t max_ns) { - bool progress = false; + bool progress; int64_t end_time; assert(ctx->notify_me); @@ -449,16 +527,7 @@ static bool run_poll_handlers(AioContext *ctx, int64_t max_ns) end_time = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + max_ns; do { - AioHandler *node; - - QLIST_FOREACH(node, &ctx->aio_handlers, node) { - if (!node->deleted && node->io_poll && - node->io_poll(node->opaque)) { - progress = true; - } - - /* Caller handles freeing deleted nodes. Don't do it here. */ - } + progress = run_poll_handlers_once(ctx); } while (!progress && qemu_clock_get_ns(QEMU_CLOCK_REALTIME) < end_time); trace_run_poll_handlers_end(ctx, progress); @@ -468,10 +537,9 @@ static bool run_poll_handlers(AioContext *ctx, int64_t max_ns) /* try_poll_mode: * @ctx: the AioContext - * @blocking: polling is only attempted when blocking is true + * @blocking: busy polling is only attempted when blocking is true * - * If blocking is true then ctx->notify_me must be non-zero so this function - * can detect aio_notify(). + * ctx->notify_me must be non-zero so this function can detect aio_notify(). * * Note that the caller must have incremented ctx->walking_handlers. * @@ -485,13 +553,20 @@ static bool try_poll_mode(AioContext *ctx, bool blocking) (uint64_t)ctx->poll_max_ns); if (max_ns) { + poll_set_started(ctx, true); + if (run_poll_handlers(ctx, max_ns)) { return true; } } } - return false; + poll_set_started(ctx, false); + + /* Even if we don't run busy polling, try polling once in case it can make + * progress and the caller will be able to avoid ppoll(2)/epoll_wait(2). + */ + return run_poll_handlers_once(ctx); } bool aio_poll(AioContext *ctx, bool blocking) diff --git a/aio-win32.c b/aio-win32.c index 0a6e91b0c3..d0e40a854c 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -102,6 +102,13 @@ void aio_set_fd_handler(AioContext *ctx, aio_notify(ctx); } +void aio_set_fd_poll(AioContext *ctx, int fd, + IOHandler *io_poll_begin, + IOHandler *io_poll_end) +{ + /* Not implemented */ +} + void aio_set_event_notifier(AioContext *ctx, EventNotifier *e, bool is_external, @@ -153,6 +160,14 @@ void aio_set_event_notifier(AioContext *ctx, aio_notify(ctx); } +void aio_set_event_notifier_poll(AioContext *ctx, + EventNotifier *notifier, + EventNotifierHandler *io_poll_begin, + EventNotifierHandler *io_poll_end) +{ + /* Not implemented */ +} + bool aio_prepare(AioContext *ctx) { static struct timeval tv0; diff --git a/include/block/aio.h b/include/block/aio.h index 349143f6d9..3817d179fd 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -137,6 +137,9 @@ struct AioContext { /* Maximum polling time in nanoseconds */ int64_t poll_max_ns; + /* Are we in polling mode or monitoring file descriptors? */ + bool poll_started; + /* epoll(7) state used when built with CONFIG_EPOLL */ int epollfd; bool epoll_enabled; @@ -339,6 +342,14 @@ void aio_set_fd_handler(AioContext *ctx, AioPollFn *io_poll, void *opaque); +/* Set polling begin/end callbacks for a file descriptor that has already been + * registered with aio_set_fd_handler. Do nothing if the file descriptor is + * not registered. + */ +void aio_set_fd_poll(AioContext *ctx, int fd, + IOHandler *io_poll_begin, + IOHandler *io_poll_end); + /* Register an event notifier and associated callbacks. Behaves very similarly * to event_notifier_set_handler. Unlike event_notifier_set_handler, these callbacks * will be invoked when using aio_poll(). @@ -352,6 +363,15 @@ void aio_set_event_notifier(AioContext *ctx, EventNotifierHandler *io_read, AioPollFn *io_poll); +/* Set polling begin/end callbacks for an event notifier that has already been + * registered with aio_set_event_notifier. Do nothing if the event notifier is + * not registered. + */ +void aio_set_event_notifier_poll(AioContext *ctx, + EventNotifier *notifier, + EventNotifierHandler *io_poll_begin, + EventNotifierHandler *io_poll_end); + /* Return a GSource that lets the main loop poll the file descriptors attached * to this AioContext. */ |