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-rw-r--r--MAINTAINERS2
-rw-r--r--include/block/aio.h36
-rw-r--r--util/Makefile.objs2
-rw-r--r--util/aio-posix.c286
-rw-r--r--util/aio-posix.h61
-rw-r--r--util/fdmon-epoll.c151
-rw-r--r--util/fdmon-poll.c104
7 files changed, 366 insertions, 276 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 36d0c6887a..66f46fa41a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1885,6 +1885,8 @@ L: qemu-block@nongnu.org
S: Supported
F: util/async.c
F: util/aio-*.c
+F: util/aio-*.h
+F: util/fdmon-*.c
F: block/io.c
F: migration/block*
F: include/block/aio.h
diff --git a/include/block/aio.h b/include/block/aio.h
index 9dd61cee7e..90e07d7507 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -52,6 +52,38 @@ struct ThreadPool;
struct LinuxAioState;
struct LuringState;
+/* Callbacks for file descriptor monitoring implementations */
+typedef struct {
+ /*
+ * update:
+ * @ctx: the AioContext
+ * @node: the handler
+ * @is_new: is the file descriptor already being monitored?
+ *
+ * Add/remove/modify a monitored file descriptor. There are three cases:
+ * 1. node->pfd.events == 0 means remove the file descriptor.
+ * 2. !is_new means modify an already monitored file descriptor.
+ * 3. is_new means add a new file descriptor.
+ *
+ * Called with ctx->list_lock acquired.
+ */
+ void (*update)(AioContext *ctx, AioHandler *node, bool is_new);
+
+ /*
+ * wait:
+ * @ctx: the AioContext
+ * @ready_list: list for handlers that become ready
+ * @timeout: maximum duration to wait, in nanoseconds
+ *
+ * Wait for file descriptors to become ready and place them on ready_list.
+ *
+ * Called with ctx->list_lock incremented but not locked.
+ *
+ * Returns: number of ready file descriptors.
+ */
+ int (*wait)(AioContext *ctx, AioHandlerList *ready_list, int64_t timeout);
+} FDMonOps;
+
/*
* Each aio_bh_poll() call carves off a slice of the BH list, so that newly
* scheduled BHs are not processed until the next aio_bh_poll() call. All
@@ -173,8 +205,8 @@ struct AioContext {
/* epoll(7) state used when built with CONFIG_EPOLL */
int epollfd;
- bool epoll_enabled;
- bool epoll_available;
+
+ const FDMonOps *fdmon_ops;
};
/**
diff --git a/util/Makefile.objs b/util/Makefile.objs
index 6b38b67cf1..6439077a68 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -5,6 +5,8 @@ util-obj-y += aiocb.o async.o aio-wait.o thread-pool.o qemu-timer.o
util-obj-y += main-loop.o
util-obj-$(call lnot,$(CONFIG_ATOMIC64)) += atomic64.o
util-obj-$(CONFIG_POSIX) += aio-posix.o
+util-obj-$(CONFIG_POSIX) += fdmon-poll.o
+util-obj-$(CONFIG_EPOLL_CREATE1) += fdmon-epoll.o
util-obj-$(CONFIG_POSIX) += compatfd.o
util-obj-$(CONFIG_POSIX) += event_notifier-posix.o
util-obj-$(CONFIG_POSIX) += mmap-alloc.o
diff --git a/util/aio-posix.c b/util/aio-posix.c
index 11a4971955..bc0b86547c 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -20,191 +20,17 @@
#include "qemu/sockets.h"
#include "qemu/cutils.h"
#include "trace.h"
-#ifdef CONFIG_EPOLL_CREATE1
-#include <sys/epoll.h>
-#endif
+#include "aio-posix.h"
-struct AioHandler
-{
- GPollFD pfd;
- IOHandler *io_read;
- IOHandler *io_write;
- AioPollFn *io_poll;
- IOHandler *io_poll_begin;
- IOHandler *io_poll_end;
- void *opaque;
- bool is_external;
- QLIST_ENTRY(AioHandler) node;
- QLIST_ENTRY(AioHandler) node_ready; /* only used during aio_poll() */
- QLIST_ENTRY(AioHandler) node_deleted;
-};
-
-/* Add a handler to a ready list */
-static void add_ready_handler(AioHandlerList *ready_list,
- AioHandler *node,
- int revents)
+void aio_add_ready_handler(AioHandlerList *ready_list,
+ AioHandler *node,
+ int revents)
{
QLIST_SAFE_REMOVE(node, node_ready); /* remove from nested parent's list */
node->pfd.revents = revents;
QLIST_INSERT_HEAD(ready_list, node, node_ready);
}
-#ifdef CONFIG_EPOLL_CREATE1
-
-/* The fd number threshold to switch to epoll */
-#define EPOLL_ENABLE_THRESHOLD 64
-
-static void aio_epoll_disable(AioContext *ctx)
-{
- ctx->epoll_enabled = false;
- if (!ctx->epoll_available) {
- return;
- }
- ctx->epoll_available = false;
- close(ctx->epollfd);
-}
-
-static inline int epoll_events_from_pfd(int pfd_events)
-{
- return (pfd_events & G_IO_IN ? EPOLLIN : 0) |
- (pfd_events & G_IO_OUT ? EPOLLOUT : 0) |
- (pfd_events & G_IO_HUP ? EPOLLHUP : 0) |
- (pfd_events & G_IO_ERR ? EPOLLERR : 0);
-}
-
-static bool aio_epoll_try_enable(AioContext *ctx)
-{
- AioHandler *node;
- struct epoll_event event;
-
- QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
- int r;
- if (QLIST_IS_INSERTED(node, node_deleted) || !node->pfd.events) {
- continue;
- }
- event.events = epoll_events_from_pfd(node->pfd.events);
- event.data.ptr = node;
- r = epoll_ctl(ctx->epollfd, EPOLL_CTL_ADD, node->pfd.fd, &event);
- if (r) {
- return false;
- }
- }
- ctx->epoll_enabled = true;
- return true;
-}
-
-static void aio_epoll_update(AioContext *ctx, AioHandler *node, bool is_new)
-{
- struct epoll_event event;
- int r;
- int ctl;
-
- if (!ctx->epoll_enabled) {
- return;
- }
- if (!node->pfd.events) {
- ctl = EPOLL_CTL_DEL;
- } else {
- event.data.ptr = node;
- event.events = epoll_events_from_pfd(node->pfd.events);
- ctl = is_new ? EPOLL_CTL_ADD : EPOLL_CTL_MOD;
- }
-
- r = epoll_ctl(ctx->epollfd, ctl, node->pfd.fd, &event);
- if (r) {
- aio_epoll_disable(ctx);
- }
-}
-
-static int aio_epoll(AioContext *ctx, AioHandlerList *ready_list,
- int64_t timeout)
-{
- GPollFD pfd = {
- .fd = ctx->epollfd,
- .events = G_IO_IN | G_IO_OUT | G_IO_HUP | G_IO_ERR,
- };
- AioHandler *node;
- int i, ret = 0;
- struct epoll_event events[128];
-
- if (timeout > 0) {
- ret = qemu_poll_ns(&pfd, 1, timeout);
- if (ret > 0) {
- timeout = 0;
- }
- }
- if (timeout <= 0 || ret > 0) {
- ret = epoll_wait(ctx->epollfd, events,
- ARRAY_SIZE(events),
- timeout);
- if (ret <= 0) {
- goto out;
- }
- for (i = 0; i < ret; i++) {
- int ev = events[i].events;
- int revents = (ev & EPOLLIN ? G_IO_IN : 0) |
- (ev & EPOLLOUT ? G_IO_OUT : 0) |
- (ev & EPOLLHUP ? G_IO_HUP : 0) |
- (ev & EPOLLERR ? G_IO_ERR : 0);
-
- node = events[i].data.ptr;
- add_ready_handler(ready_list, node, revents);
- }
- }
-out:
- return ret;
-}
-
-static bool aio_epoll_enabled(AioContext *ctx)
-{
- /* Fall back to ppoll when external clients are disabled. */
- return !aio_external_disabled(ctx) && ctx->epoll_enabled;
-}
-
-static bool aio_epoll_check_poll(AioContext *ctx, GPollFD *pfds,
- unsigned npfd, int64_t timeout)
-{
- if (!ctx->epoll_available) {
- return false;
- }
- if (aio_epoll_enabled(ctx)) {
- return true;
- }
- if (npfd >= EPOLL_ENABLE_THRESHOLD) {
- if (aio_epoll_try_enable(ctx)) {
- return true;
- } else {
- aio_epoll_disable(ctx);
- }
- }
- return false;
-}
-
-#else
-
-static void aio_epoll_update(AioContext *ctx, AioHandler *node, bool is_new)
-{
-}
-
-static int aio_epoll(AioContext *ctx, AioHandlerList *ready_list,
- int64_t timeout)
-{
- assert(false);
-}
-
-static bool aio_epoll_enabled(AioContext *ctx)
-{
- return false;
-}
-
-static bool aio_epoll_check_poll(AioContext *ctx, GPollFD *pfds,
- unsigned npfd, int64_t timeout)
-{
- return false;
-}
-
-#endif
-
static AioHandler *find_aio_handler(AioContext *ctx, int fd)
{
AioHandler *node;
@@ -314,10 +140,10 @@ void aio_set_fd_handler(AioContext *ctx,
atomic_read(&ctx->poll_disable_cnt) + poll_disable_change);
if (new_node) {
- aio_epoll_update(ctx, new_node, is_new);
+ ctx->fdmon_ops->update(ctx, new_node, is_new);
} else if (node) {
/* Unregister deleted fd_handler */
- aio_epoll_update(ctx, node, false);
+ ctx->fdmon_ops->update(ctx, node, false);
}
qemu_lockcnt_unlock(&ctx->list_lock);
aio_notify(ctx);
@@ -532,52 +358,6 @@ void aio_dispatch(AioContext *ctx)
timerlistgroup_run_timers(&ctx->tlg);
}
-/* These thread-local variables are used only in a small part of aio_poll
- * around the call to the poll() system call. In particular they are not
- * used while aio_poll is performing callbacks, which makes it much easier
- * to think about reentrancy!
- *
- * Stack-allocated arrays would be perfect but they have size limitations;
- * heap allocation is expensive enough that we want to reuse arrays across
- * calls to aio_poll(). And because poll() has to be called without holding
- * any lock, the arrays cannot be stored in AioContext. Thread-local data
- * has none of the disadvantages of these three options.
- */
-static __thread GPollFD *pollfds;
-static __thread AioHandler **nodes;
-static __thread unsigned npfd, nalloc;
-static __thread Notifier pollfds_cleanup_notifier;
-
-static void pollfds_cleanup(Notifier *n, void *unused)
-{
- g_assert(npfd == 0);
- g_free(pollfds);
- g_free(nodes);
- nalloc = 0;
-}
-
-static void add_pollfd(AioHandler *node)
-{
- if (npfd == nalloc) {
- if (nalloc == 0) {
- pollfds_cleanup_notifier.notify = pollfds_cleanup;
- qemu_thread_atexit_add(&pollfds_cleanup_notifier);
- nalloc = 8;
- } else {
- g_assert(nalloc <= INT_MAX);
- nalloc *= 2;
- }
- pollfds = g_renew(GPollFD, pollfds, nalloc);
- nodes = g_renew(AioHandler *, nodes, nalloc);
- }
- nodes[npfd] = node;
- pollfds[npfd] = (GPollFD) {
- .fd = node->pfd.fd,
- .events = node->pfd.events,
- };
- npfd++;
-}
-
static bool run_poll_handlers_once(AioContext *ctx, int64_t *timeout)
{
bool progress = false;
@@ -689,8 +469,6 @@ static bool try_poll_mode(AioContext *ctx, int64_t *timeout)
bool aio_poll(AioContext *ctx, bool blocking)
{
AioHandlerList ready_list = QLIST_HEAD_INITIALIZER(ready_list);
- AioHandler *node;
- int i;
int ret = 0;
bool progress;
int64_t timeout;
@@ -723,26 +501,7 @@ bool aio_poll(AioContext *ctx, bool blocking)
* system call---a single round of run_poll_handlers_once suffices.
*/
if (timeout || atomic_read(&ctx->poll_disable_cnt)) {
- assert(npfd == 0);
-
- /* fill pollfds */
-
- if (!aio_epoll_enabled(ctx)) {
- QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
- if (!QLIST_IS_INSERTED(node, node_deleted) && node->pfd.events
- && aio_node_check(ctx, node->is_external)) {
- add_pollfd(node);
- }
- }
- }
-
- /* wait until next event */
- if (aio_epoll_check_poll(ctx, pollfds, npfd, timeout)) {
- npfd = 0; /* pollfds[] is not being used */
- ret = aio_epoll(ctx, &ready_list, timeout);
- } else {
- ret = qemu_poll_ns(pollfds, npfd, timeout);
- }
+ ret = ctx->fdmon_ops->wait(ctx, &ready_list, timeout);
}
if (blocking) {
@@ -791,19 +550,6 @@ bool aio_poll(AioContext *ctx, bool blocking)
}
}
- /* if we have any readable fds, dispatch event */
- if (ret > 0) {
- for (i = 0; i < npfd; i++) {
- int revents = pollfds[i].revents;
-
- if (revents) {
- add_ready_handler(&ready_list, nodes[i], revents);
- }
- }
- }
-
- npfd = 0;
-
progress |= aio_bh_poll(ctx);
if (ret > 0) {
@@ -821,23 +567,15 @@ bool aio_poll(AioContext *ctx, bool blocking)
void aio_context_setup(AioContext *ctx)
{
-#ifdef CONFIG_EPOLL_CREATE1
- assert(!ctx->epollfd);
- ctx->epollfd = epoll_create1(EPOLL_CLOEXEC);
- if (ctx->epollfd == -1) {
- fprintf(stderr, "Failed to create epoll instance: %s", strerror(errno));
- ctx->epoll_available = false;
- } else {
- ctx->epoll_available = true;
- }
-#endif
+ ctx->fdmon_ops = &fdmon_poll_ops;
+ ctx->epollfd = -1;
+
+ fdmon_epoll_setup(ctx);
}
void aio_context_destroy(AioContext *ctx)
{
-#ifdef CONFIG_EPOLL_CREATE1
- aio_epoll_disable(ctx);
-#endif
+ fdmon_epoll_disable(ctx);
}
void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
diff --git a/util/aio-posix.h b/util/aio-posix.h
new file mode 100644
index 0000000000..97899d0fbc
--- /dev/null
+++ b/util/aio-posix.h
@@ -0,0 +1,61 @@
+/*
+ * AioContext POSIX event loop implementation internal APIs
+ *
+ * Copyright IBM, Corp. 2008
+ * Copyright Red Hat, Inc. 2020
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#ifndef AIO_POSIX_H
+#define AIO_POSIX_H
+
+#include "block/aio.h"
+
+struct AioHandler {
+ GPollFD pfd;
+ IOHandler *io_read;
+ IOHandler *io_write;
+ AioPollFn *io_poll;
+ IOHandler *io_poll_begin;
+ IOHandler *io_poll_end;
+ void *opaque;
+ bool is_external;
+ QLIST_ENTRY(AioHandler) node;
+ QLIST_ENTRY(AioHandler) node_ready; /* only used during aio_poll() */
+ QLIST_ENTRY(AioHandler) node_deleted;
+};
+
+/* Add a handler to a ready list */
+void aio_add_ready_handler(AioHandlerList *ready_list, AioHandler *node,
+ int revents);
+
+extern const FDMonOps fdmon_poll_ops;
+
+#ifdef CONFIG_EPOLL_CREATE1
+bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd);
+void fdmon_epoll_setup(AioContext *ctx);
+void fdmon_epoll_disable(AioContext *ctx);
+#else
+static inline bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd)
+{
+ return false;
+}
+
+static inline void fdmon_epoll_setup(AioContext *ctx)
+{
+}
+
+static inline void fdmon_epoll_disable(AioContext *ctx)
+{
+}
+#endif /* !CONFIG_EPOLL_CREATE1 */
+
+#endif /* AIO_POSIX_H */
diff --git a/util/fdmon-epoll.c b/util/fdmon-epoll.c
new file mode 100644
index 0000000000..29c1454469
--- /dev/null
+++ b/util/fdmon-epoll.c
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * epoll(7) file descriptor monitoring
+ */
+
+#include "qemu/osdep.h"
+#include <sys/epoll.h>
+#include "qemu/rcu_queue.h"
+#include "aio-posix.h"
+
+/* The fd number threshold to switch to epoll */
+#define EPOLL_ENABLE_THRESHOLD 64
+
+void fdmon_epoll_disable(AioContext *ctx)
+{
+ if (ctx->epollfd >= 0) {
+ close(ctx->epollfd);
+ ctx->epollfd = -1;
+ }
+
+ /* Switch back */
+ ctx->fdmon_ops = &fdmon_poll_ops;
+}
+
+static inline int epoll_events_from_pfd(int pfd_events)
+{
+ return (pfd_events & G_IO_IN ? EPOLLIN : 0) |
+ (pfd_events & G_IO_OUT ? EPOLLOUT : 0) |
+ (pfd_events & G_IO_HUP ? EPOLLHUP : 0) |
+ (pfd_events & G_IO_ERR ? EPOLLERR : 0);
+}
+
+static void fdmon_epoll_update(AioContext *ctx, AioHandler *node, bool is_new)
+{
+ struct epoll_event event;
+ int r;
+ int ctl;
+
+ if (!node->pfd.events) {
+ ctl = EPOLL_CTL_DEL;
+ } else {
+ event.data.ptr = node;
+ event.events = epoll_events_from_pfd(node->pfd.events);
+ ctl = is_new ? EPOLL_CTL_ADD : EPOLL_CTL_MOD;
+ }
+
+ r = epoll_ctl(ctx->epollfd, ctl, node->pfd.fd, &event);
+ if (r) {
+ fdmon_epoll_disable(ctx);
+ }
+}
+
+static int fdmon_epoll_wait(AioContext *ctx, AioHandlerList *ready_list,
+ int64_t timeout)
+{
+ GPollFD pfd = {
+ .fd = ctx->epollfd,
+ .events = G_IO_IN | G_IO_OUT | G_IO_HUP | G_IO_ERR,
+ };
+ AioHandler *node;
+ int i, ret = 0;
+ struct epoll_event events[128];
+
+ /* Fall back while external clients are disabled */
+ if (atomic_read(&ctx->external_disable_cnt)) {
+ return fdmon_poll_ops.wait(ctx, ready_list, timeout);
+ }
+
+ if (timeout > 0) {
+ ret = qemu_poll_ns(&pfd, 1, timeout);
+ if (ret > 0) {
+ timeout = 0;
+ }
+ }
+ if (timeout <= 0 || ret > 0) {
+ ret = epoll_wait(ctx->epollfd, events,
+ ARRAY_SIZE(events),
+ timeout);
+ if (ret <= 0) {
+ goto out;
+ }
+ for (i = 0; i < ret; i++) {
+ int ev = events[i].events;
+ int revents = (ev & EPOLLIN ? G_IO_IN : 0) |
+ (ev & EPOLLOUT ? G_IO_OUT : 0) |
+ (ev & EPOLLHUP ? G_IO_HUP : 0) |
+ (ev & EPOLLERR ? G_IO_ERR : 0);
+
+ node = events[i].data.ptr;
+ aio_add_ready_handler(ready_list, node, revents);
+ }
+ }
+out:
+ return ret;
+}
+
+static const FDMonOps fdmon_epoll_ops = {
+ .update = fdmon_epoll_update,
+ .wait = fdmon_epoll_wait,
+};
+
+static bool fdmon_epoll_try_enable(AioContext *ctx)
+{
+ AioHandler *node;
+ struct epoll_event event;
+
+ QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
+ int r;
+ if (QLIST_IS_INSERTED(node, node_deleted) || !node->pfd.events) {
+ continue;
+ }
+ event.events = epoll_events_from_pfd(node->pfd.events);
+ event.data.ptr = node;
+ r = epoll_ctl(ctx->epollfd, EPOLL_CTL_ADD, node->pfd.fd, &event);
+ if (r) {
+ return false;
+ }
+ }
+
+ ctx->fdmon_ops = &fdmon_epoll_ops;
+ return true;
+}
+
+bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd)
+{
+ if (ctx->epollfd < 0) {
+ return false;
+ }
+
+ /* Do not upgrade while external clients are disabled */
+ if (atomic_read(&ctx->external_disable_cnt)) {
+ return false;
+ }
+
+ if (npfd >= EPOLL_ENABLE_THRESHOLD) {
+ if (fdmon_epoll_try_enable(ctx)) {
+ return true;
+ } else {
+ fdmon_epoll_disable(ctx);
+ }
+ }
+ return false;
+}
+
+void fdmon_epoll_setup(AioContext *ctx)
+{
+ ctx->epollfd = epoll_create1(EPOLL_CLOEXEC);
+ if (ctx->epollfd == -1) {
+ fprintf(stderr, "Failed to create epoll instance: %s", strerror(errno));
+ }
+}
diff --git a/util/fdmon-poll.c b/util/fdmon-poll.c
new file mode 100644
index 0000000000..67992116b8
--- /dev/null
+++ b/util/fdmon-poll.c
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * poll(2) file descriptor monitoring
+ *
+ * Uses ppoll(2) when available, g_poll() otherwise.
+ */
+
+#include "qemu/osdep.h"
+#include "aio-posix.h"
+#include "qemu/rcu_queue.h"
+
+/*
+ * These thread-local variables are used only in fdmon_poll_wait() around the
+ * call to the poll() system call. In particular they are not used while
+ * aio_poll is performing callbacks, which makes it much easier to think about
+ * reentrancy!
+ *
+ * Stack-allocated arrays would be perfect but they have size limitations;
+ * heap allocation is expensive enough that we want to reuse arrays across
+ * calls to aio_poll(). And because poll() has to be called without holding
+ * any lock, the arrays cannot be stored in AioContext. Thread-local data
+ * has none of the disadvantages of these three options.
+ */
+static __thread GPollFD *pollfds;
+static __thread AioHandler **nodes;
+static __thread unsigned npfd, nalloc;
+static __thread Notifier pollfds_cleanup_notifier;
+
+static void pollfds_cleanup(Notifier *n, void *unused)
+{
+ g_assert(npfd == 0);
+ g_free(pollfds);
+ g_free(nodes);
+ nalloc = 0;
+}
+
+static void add_pollfd(AioHandler *node)
+{
+ if (npfd == nalloc) {
+ if (nalloc == 0) {
+ pollfds_cleanup_notifier.notify = pollfds_cleanup;
+ qemu_thread_atexit_add(&pollfds_cleanup_notifier);
+ nalloc = 8;
+ } else {
+ g_assert(nalloc <= INT_MAX);
+ nalloc *= 2;
+ }
+ pollfds = g_renew(GPollFD, pollfds, nalloc);
+ nodes = g_renew(AioHandler *, nodes, nalloc);
+ }
+ nodes[npfd] = node;
+ pollfds[npfd] = (GPollFD) {
+ .fd = node->pfd.fd,
+ .events = node->pfd.events,
+ };
+ npfd++;
+}
+
+static int fdmon_poll_wait(AioContext *ctx, AioHandlerList *ready_list,
+ int64_t timeout)
+{
+ AioHandler *node;
+ int ret;
+
+ assert(npfd == 0);
+
+ QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
+ if (!QLIST_IS_INSERTED(node, node_deleted) && node->pfd.events
+ && aio_node_check(ctx, node->is_external)) {
+ add_pollfd(node);
+ }
+ }
+
+ /* epoll(7) is faster above a certain number of fds */
+ if (fdmon_epoll_try_upgrade(ctx, npfd)) {
+ return ctx->fdmon_ops->wait(ctx, ready_list, timeout);
+ }
+
+ ret = qemu_poll_ns(pollfds, npfd, timeout);
+ if (ret > 0) {
+ int i;
+
+ for (i = 0; i < npfd; i++) {
+ int revents = pollfds[i].revents;
+
+ if (revents) {
+ aio_add_ready_handler(ready_list, nodes[i], revents);
+ }
+ }
+ }
+
+ npfd = 0;
+ return ret;
+}
+
+static void fdmon_poll_update(AioContext *ctx, AioHandler *node, bool is_new)
+{
+ /* Do nothing, AioHandler already contains the state we'll need */
+}
+
+const FDMonOps fdmon_poll_ops = {
+ .update = fdmon_poll_update,
+ .wait = fdmon_poll_wait,
+};
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-11-21 17:34:40 +0100