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2012-10-30aio: add Win32 implementationPaolo Bonzini
The Win32 implementation will only accept EventNotifiers, thus a few drivers are disabled under Windows. EventNotifiers are a good match for the GSource implementation, too, because the Win32 port of glib allows to place their HANDLEs in a GPollFD. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: prepare for introducing GSource-based dispatchPaolo Bonzini
This adds a GPollFD to each AioHandler. It will then be possible to attach these GPollFDs to a GSource, and from there to the main loop. aio_wait examines the GPollFDs and avoids calling select() if any is set (similar to what it does if bottom halves are available). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: add non-blocking variant of aio_waitPaolo Bonzini
This will be used when polling the GSource attached to an AioContext. Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: test node->deleted before calling io_flushPaolo Bonzini
Otherwise, there could be a case where io_flush accesses freed memory because it should not have been called. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: add I/O handlers to the AioContext interfacePaolo Bonzini
With this patch, I/O handlers (including event notifier handlers) can be attached to a single AioContext. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: introduce AioContext, move bottom halves therePaolo Bonzini
Start introducing AioContext, which will let us remove globals from aio.c/async.c, and introduce multiple I/O threads. The bottom half functions now take an additional AioContext argument. A bottom half is created with a specific AioContext that remains the same throughout the lifetime. qemu_bh_new is just a wrapper that uses a global context. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: provide platform-independent APIPaolo Bonzini
This adds to aio.c a platform-independent API based on EventNotifiers, that can be used by both POSIX and Win32. Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-30aio: change qemu_aio_set_fd_handler to return voidPaolo Bonzini
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-28aio: Another fix to the walking_handlers logicPaolo Bonzini
The AIO dispatch loop will call QLIST_REMOVE and g_free even if there are other pending calls to qemu_aio_wait outside the current one. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28aio: Fix qemu_aio_wait() to maintain correct walking_handlers countPaolo Bonzini
Fix qemu_aio_wait() to ensure that registered aio handlers don't get deleted when they are still active. This is ensured by maintaning the right count of walking_handlers. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19aio: simplify qemu_aio_waitPaolo Bonzini
The do...while loop can never loop, because select will just not return 0 when invoked with infinite timeout. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19aio: return "AIO in progress" state from qemu_aio_waitPaolo Bonzini
The definition of when qemu_aio_flush should loop is much simpler than it looks. It just has to call qemu_aio_wait until it makes no progress and all flush callbacks return false. qemu_aio_wait is the logical place to tell the caller about this. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19aio: remove process_queue callback and qemu_aio_process_queuePaolo Bonzini
Both unused after the previous patch. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-13prepare for future GPLv2+ relicensingPaolo Bonzini
All files under GPLv2 will get GPLv2+ changes starting tomorrow. event_notifier.c and exec-obsolete.h were only ever touched by Red Hat employees and can be relicensed now. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-05-21block: fix aio_flush segfaults for read-only protocols (e.g. curl)Avi Kivity
Not all block format drivers expose an io_flush method (reasonable for read-only protocols), so calling io_flush there will immediately segfault. Fix by checking for the method's existence before calling it. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-10-27Add qemu_aio_process_queue()Kevin Wolf
We'll leave some AIO completions unhandled when we can't call the callback. qemu_aio_process_queue() is used later to run any callbacks that are left and can be run then. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-12Fix sys-queue.h conflict for goodBlue Swirl
Problem: Our file sys-queue.h is a copy of the BSD file, but there are some additions and it's not entirely compatible. Because of that, there have been conflicts with system headers on BSD systems. Some hacks have been introduced in the commits 15cc9235840a22c289edbe064a9b3c19c5f49896, f40d753718c72693c5f520f0d9899f6e50395e94, 96555a96d724016e13190b28cffa3bc929ac60dc and 3990d09adf4463eca200ad964cc55643c33feb50 but the fixes were fragile. Solution: Avoid the conflict entirely by renaming the functions and the file. Revert the previous hacks. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-07-22Handle BH's queued by AIO completions in qemu_aio_flush()Nolan
Without this, the call to qemu_aio_flush during migration doesn't actually flush all in-flight SCSI IOs. Signed-off-by: Nolan Leake <nolan <at> sigbus.net> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-15fix qemu_aio_flushAndrea Arcangeli
qemu_aio_wait by invoking the bh or one of the aio completion callbacks, could end up submitting new pending aio, breaking the invariant that qemu_aio_flush returns only when no pending aio is outstanding (possibly a problem for migration as such). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Kevin Wolf <kwolf@redhat.com>
2009-05-08AIO deletion race fixAlexander Graf
When deleting an fd event there is a chance the object doesn't get deleted, but only ->deleted set positive and deleted somewhere later. Now, if we create a handler for the fd again before the actual deletion occurs, we end up writing data into an object that has ->deleted set, which is obviously wrong. I see two ways to fix this: 1. Don't return ->deleted objects in the search 2. Unset ->deleted in the search This patch implements 1. which feels safer to do. It fixes AIO issues I've seen with curl, as libcurl unsets fd event listeners pretty frequently. Signed-off-by: Alexander Graf <alex@csgraf.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-02-05toplevel: remove error handling from qemu_malloc() callers (Avi Kivity)aliguori
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6531 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-12Make sure to initialize fd_sets in aio.caliguori
This was spotted by valgrind. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5470 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-22Refactor AIO to allow multiple AIO implementationsaliguori
This patch refactors the AIO layer to allow multiple AIO implementations. It's only possible because of the recent signalfd() patch. Right now, the AIO infrastructure is pretty specific to the block raw backend. For other block devices to implement AIO, the qemu_aio_wait function must support registration. This patch introduces a new function, qemu_aio_set_fd_handler, which can be used to register a file descriptor to be called back. qemu_aio_wait() now polls a set of file descriptors registered with this function until one becomes readable or writable. This patch should allow the implementation of alternative AIO backends (via a thread pool or linux-aio) and AIO backends in non-traditional block devices (like NBD). Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5297 c046a42c-6fe2-441c-8c8c-71466251a162