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author | Peter Maydell <peter.maydell@linaro.org> | 2019-01-15 17:24:00 +0000 |
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committer | Peter Maydell <peter.maydell@linaro.org> | 2019-01-15 17:24:00 +0000 |
commit | 4b9f0b0f7c84eea2dfb0d5be3e0254bc91319dbc (patch) | |
tree | 6dad0111547ebebcd2bb5e5ac412ba2b4f052883 /util | |
parent | 44ba6010635641a538c9b9b1f377dfa288751906 (diff) | |
parent | fef1660132b0f25bf2d275d7f986ddcfe19a4426 (diff) | |
download | qemu-4b9f0b0f7c84eea2dfb0d5be3e0254bc91319dbc.zip qemu-4b9f0b0f7c84eea2dfb0d5be3e0254bc91319dbc.tar.gz qemu-4b9f0b0f7c84eea2dfb0d5be3e0254bc91319dbc.tar.bz2 |
Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging
Pull request
No user-visible changes.
# gpg: Signature made Mon 14 Jan 2019 16:32:19 GMT
# gpg: using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha/tags/block-pull-request:
aio-posix: Fix concurrent aio_poll/set_fd_handler.
aio-posix: Unregister fd from ctx epoll when removing fd_handler.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'util')
-rw-r--r-- | util/aio-posix.c | 90 | ||||
-rw-r--r-- | util/aio-win32.c | 67 |
2 files changed, 84 insertions, 73 deletions
diff --git a/util/aio-posix.c b/util/aio-posix.c index 51c41ed..8640dfd 100644 --- a/util/aio-posix.c +++ b/util/aio-posix.c @@ -200,6 +200,31 @@ static AioHandler *find_aio_handler(AioContext *ctx, int fd) return NULL; } +static bool aio_remove_fd_handler(AioContext *ctx, AioHandler *node) +{ + /* If the GSource is in the process of being destroyed then + * g_source_remove_poll() causes an assertion failure. Skip + * removal in that case, because glib cleans up its state during + * destruction anyway. + */ + if (!g_source_is_destroyed(&ctx->source)) { + g_source_remove_poll(&ctx->source, &node->pfd); + } + + /* If a read is in progress, just mark the node as deleted */ + if (qemu_lockcnt_count(&ctx->list_lock)) { + node->deleted = 1; + node->pfd.revents = 0; + return false; + } + /* Otherwise, delete it for real. We can't just mark it as + * deleted because deleted nodes are only cleaned up while + * no one is walking the handlers list. + */ + QLIST_REMOVE(node, node); + return true; +} + void aio_set_fd_handler(AioContext *ctx, int fd, bool is_external, @@ -209,6 +234,7 @@ void aio_set_fd_handler(AioContext *ctx, void *opaque) { AioHandler *node; + AioHandler *new_node = NULL; bool is_new = false; bool deleted = false; int poll_disable_change; @@ -223,50 +249,39 @@ void aio_set_fd_handler(AioContext *ctx, qemu_lockcnt_unlock(&ctx->list_lock); return; } + /* Clean events in order to unregister fd from the ctx epoll. */ + node->pfd.events = 0; - /* If the GSource is in the process of being destroyed then - * g_source_remove_poll() causes an assertion failure. Skip - * removal in that case, because glib cleans up its state during - * destruction anyway. - */ - if (!g_source_is_destroyed(&ctx->source)) { - g_source_remove_poll(&ctx->source, &node->pfd); - } - - /* If a read is in progress, just mark the node as deleted */ - if (qemu_lockcnt_count(&ctx->list_lock)) { - node->deleted = 1; - node->pfd.revents = 0; - } else { - /* Otherwise, delete it for real. We can't just mark it as - * deleted because deleted nodes are only cleaned up while - * no one is walking the handlers list. - */ - QLIST_REMOVE(node, node); - deleted = true; - } poll_disable_change = -!node->io_poll; } else { poll_disable_change = !io_poll - (node && !node->io_poll); if (node == NULL) { - /* Alloc and insert if it's not already there */ - node = g_new0(AioHandler, 1); - node->pfd.fd = fd; - QLIST_INSERT_HEAD_RCU(&ctx->aio_handlers, node, node); - - g_source_add_poll(&ctx->source, &node->pfd); is_new = true; } + /* Alloc and insert if it's not already there */ + new_node = g_new0(AioHandler, 1); /* Update handler with latest information */ - node->io_read = io_read; - node->io_write = io_write; - node->io_poll = io_poll; - node->opaque = opaque; - node->is_external = is_external; + new_node->io_read = io_read; + new_node->io_write = io_write; + new_node->io_poll = io_poll; + new_node->opaque = opaque; + new_node->is_external = is_external; + + if (is_new) { + new_node->pfd.fd = fd; + } else { + new_node->pfd = node->pfd; + } + g_source_add_poll(&ctx->source, &new_node->pfd); + + new_node->pfd.events = (io_read ? G_IO_IN | G_IO_HUP | G_IO_ERR : 0); + new_node->pfd.events |= (io_write ? G_IO_OUT | G_IO_ERR : 0); - node->pfd.events = (io_read ? G_IO_IN | G_IO_HUP | G_IO_ERR : 0); - node->pfd.events |= (io_write ? G_IO_OUT | G_IO_ERR : 0); + QLIST_INSERT_HEAD_RCU(&ctx->aio_handlers, new_node, node); + } + if (node) { + deleted = aio_remove_fd_handler(ctx, node); } /* No need to order poll_disable_cnt writes against other updates; @@ -278,7 +293,12 @@ void aio_set_fd_handler(AioContext *ctx, atomic_set(&ctx->poll_disable_cnt, atomic_read(&ctx->poll_disable_cnt) + poll_disable_change); - aio_epoll_update(ctx, node, is_new); + if (new_node) { + aio_epoll_update(ctx, new_node, is_new); + } else if (node) { + /* Unregister deleted fd_handler */ + aio_epoll_update(ctx, node, false); + } qemu_lockcnt_unlock(&ctx->list_lock); aio_notify(ctx); diff --git a/util/aio-win32.c b/util/aio-win32.c index c58957c..a23b9c3 100644 --- a/util/aio-win32.c +++ b/util/aio-win32.c @@ -35,6 +35,22 @@ struct AioHandler { QLIST_ENTRY(AioHandler) node; }; +static void aio_remove_fd_handler(AioContext *ctx, AioHandler *node) +{ + /* If aio_poll is in progress, just mark the node as deleted */ + if (qemu_lockcnt_count(&ctx->list_lock)) { + node->deleted = 1; + node->pfd.revents = 0; + } else { + /* Otherwise, delete it for real. We can't just mark it as + * deleted because deleted nodes are only cleaned up after + * releasing the list_lock. + */ + QLIST_REMOVE(node, node); + g_free(node); + } +} + void aio_set_fd_handler(AioContext *ctx, int fd, bool is_external, @@ -44,41 +60,23 @@ void aio_set_fd_handler(AioContext *ctx, void *opaque) { /* fd is a SOCKET in our case */ - AioHandler *node; + AioHandler *old_node; + AioHandler *node = NULL; qemu_lockcnt_lock(&ctx->list_lock); - QLIST_FOREACH(node, &ctx->aio_handlers, node) { - if (node->pfd.fd == fd && !node->deleted) { + QLIST_FOREACH(old_node, &ctx->aio_handlers, node) { + if (old_node->pfd.fd == fd && !old_node->deleted) { break; } } - /* Are we deleting the fd handler? */ - if (!io_read && !io_write) { - if (node) { - /* If aio_poll is in progress, just mark the node as deleted */ - if (qemu_lockcnt_count(&ctx->list_lock)) { - node->deleted = 1; - node->pfd.revents = 0; - } else { - /* Otherwise, delete it for real. We can't just mark it as - * deleted because deleted nodes are only cleaned up after - * releasing the list_lock. - */ - QLIST_REMOVE(node, node); - g_free(node); - } - } - } else { + if (io_read || io_write) { HANDLE event; long bitmask = 0; - if (node == NULL) { - /* Alloc and insert if it's not already there */ - node = g_new0(AioHandler, 1); - node->pfd.fd = fd; - QLIST_INSERT_HEAD_RCU(&ctx->aio_handlers, node, node); - } + /* Alloc and insert if it's not already there */ + node = g_new0(AioHandler, 1); + node->pfd.fd = fd; node->pfd.events = 0; if (node->io_read) { @@ -104,9 +102,13 @@ void aio_set_fd_handler(AioContext *ctx, bitmask |= FD_WRITE | FD_CONNECT; } + QLIST_INSERT_HEAD_RCU(&ctx->aio_handlers, node, node); event = event_notifier_get_handle(&ctx->notifier); WSAEventSelect(node->pfd.fd, event, bitmask); } + if (old_node) { + aio_remove_fd_handler(ctx, old_node); + } qemu_lockcnt_unlock(&ctx->list_lock); aio_notify(ctx); @@ -139,18 +141,7 @@ void aio_set_event_notifier(AioContext *ctx, if (node) { g_source_remove_poll(&ctx->source, &node->pfd); - /* aio_poll is in progress, just mark the node as deleted */ - if (qemu_lockcnt_count(&ctx->list_lock)) { - node->deleted = 1; - node->pfd.revents = 0; - } else { - /* Otherwise, delete it for real. We can't just mark it as - * deleted because deleted nodes are only cleaned up after - * releasing the list_lock. - */ - QLIST_REMOVE(node, node); - g_free(node); - } + aio_remove_fd_handler(ctx, node); } } else { if (node == NULL) { |