Use signalfd() to work around signal/select race

This patch introduces signalfd() to work around the signal/select race in
checking for AIO completions.  For platforms that don't support signalfd(), we
emulate it with threads.

There was a long discussion about this approach.  I don't believe there are any
fundamental problems with this approach and I believe eliminating the use of
signals is a good thing.

I've tested Windows and Linux using Windows and Linux guests.  I've also checked
for disk IO performance regressions.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5187 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 0 insertions, 3 deletions

diff --git a/block.h b/block.h
index fa741b55a5..044358539f 100644
--- a/block.h
+++ b/block.h
@@ -90,11 +90,8 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
 void bdrv_aio_cancel(BlockDriverAIOCB *acb);
 
 void qemu_aio_init(void);
-void qemu_aio_poll(void);
 void qemu_aio_flush(void);
-void qemu_aio_wait_start(void);
 void qemu_aio_wait(void);
-void qemu_aio_wait_end(void);
 
 int qemu_key_check(BlockDriverState *bs, const char *name);