aio-posix: partially inline aio_dispatch into aio_poll
This patch prepares for the removal of unnecessary lockcnt inc/dec pairs.
Extract the dispatching loop for file descriptor handlers into a new
function aio_dispatch_handlers, and then inline aio_dispatch into
aio_poll.
aio_dispatch can now become void.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-17-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/util/aio-posix.c b/util/aio-posix.c
index 84cee43..2173378 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -386,12 +386,6 @@
AioHandler *node, *tmp;
bool progress = false;
- /*
- * We have to walk very carefully in case aio_set_fd_handler is
- * called while we're walking.
- */
- qemu_lockcnt_inc(&ctx->list_lock);
-
QLIST_FOREACH_SAFE_RCU(node, &ctx->aio_handlers, node, tmp) {
int revents;
@@ -426,33 +420,18 @@
}
}
- qemu_lockcnt_dec(&ctx->list_lock);
return progress;
}
-/*
- * Note that dispatch_fds == false has the side-effect of post-poning the
- * freeing of deleted handlers.
- */
-bool aio_dispatch(AioContext *ctx, bool dispatch_fds)
+void aio_dispatch(AioContext *ctx)
{
- bool progress;
+ aio_bh_poll(ctx);
- /*
- * If there are callbacks left that have been queued, we need to call them.
- * 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 aio_poll loops).
- */
- progress = aio_bh_poll(ctx);
+ qemu_lockcnt_inc(&ctx->list_lock);
+ aio_dispatch_handlers(ctx);
+ qemu_lockcnt_dec(&ctx->list_lock);
- if (dispatch_fds) {
- progress |= aio_dispatch_handlers(ctx);
- }
-
- /* Run our timers */
- progress |= timerlistgroup_run_timers(&ctx->tlg);
-
- return progress;
+ timerlistgroup_run_timers(&ctx->tlg);
}
/* These thread-local variables are used only in a small part of aio_poll
@@ -702,11 +681,16 @@
npfd = 0;
qemu_lockcnt_dec(&ctx->list_lock);
- /* Run dispatch even if there were no readable fds to run timers */
- if (aio_dispatch(ctx, ret > 0)) {
- progress = true;
+ progress |= aio_bh_poll(ctx);
+
+ if (ret > 0) {
+ qemu_lockcnt_inc(&ctx->list_lock);
+ progress |= aio_dispatch_handlers(ctx);
+ qemu_lockcnt_dec(&ctx->list_lock);
}
+ progress |= timerlistgroup_run_timers(&ctx->tlg);
+
return progress;
}
