[Qemu-devel] [PULL 21/71] aio-posix: Assert that aio_poll() is always called in home thread

Kevin Wolf posted 71 patches 6 years, 2 months ago
Maintainers: Eric Blake <eblake@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Ronnie Sahlberg <ronniesahlberg@gmail.com>, Alberto Garcia <berto@igalia.com>, Kevin Wolf <kwolf@redhat.com>, Cleber Rosa <crosa@redhat.com>, Peter Lieven <pl@kamp.de>, Wen Congyang <wencongyang2@huawei.com>, Jeff Cody <codyprime@gmail.com>, Xie Changlong <xiechanglong.d@gmail.com>, Markus Armbruster <armbru@redhat.com>, Liu Yuan <namei.unix@gmail.com>, "Daniel P. Berrangé" <berrange@redhat.com>, John Snow <jsnow@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, "Michael S. Tsirkin" <mst@redhat.com>, Ari Sundholm <ari@tuxera.com>, "Richard W.M. Jones" <rjones@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Max Reitz <mreitz@redhat.com>, Josh Durgin <jdurgin@redhat.com>
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[Qemu-devel] [PULL 21/71] aio-posix: Assert that aio_poll() is always called in home thread
Posted by Kevin Wolf 6 years, 2 months ago
aio_poll() has an existing assertion that the function is only called
from the AioContext's home thread if blocking is allowed.

This is not enough, some handlers make assumptions about the thread they
run in. Extend the assertion to non-blocking calls, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 util/aio-posix.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/util/aio-posix.c b/util/aio-posix.c
index 8640dfde9f..6fbfa7924f 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -613,6 +613,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
     int64_t timeout;
     int64_t start = 0;
 
+    assert(in_aio_context_home_thread(ctx));
+
     /* aio_notify can avoid the expensive event_notifier_set if
      * everything (file descriptors, bottom halves, timers) will
      * be re-evaluated before the next blocking poll().  This is
@@ -621,7 +623,6 @@ bool aio_poll(AioContext *ctx, bool blocking)
      * so disable the optimization now.
      */
     if (blocking) {
-        assert(in_aio_context_home_thread(ctx));
         atomic_add(&ctx->notify_me, 2);
     }
 
-- 
2.20.1