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2009-02-21Properly handle pthread_cond_timedwait timing outmalc1-1/+1
pthread_cond_timedwait is allowed to both consume the signal and return with the value indicating the timeout, hence predicate should always be (re)checked before taking an action git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6634 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-21Cosmeticsmalc1-11/+13
Avoid repeated creation/initalization/destruction of attr and calls to getpid git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6633 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-21Avoid thundering herd problemmalc1-4/+4
Broadcast was used so that the I/O threads would wakeup, reset their ts values and all but one go to sleep, in other words an optimization to prevent threads from exiting in presence of continuing I/O activity. Spurious wakeups make the looping around cond_timedwait with ever reinitialized ts potentially unsafe and as such ts in no longer reinitilized inside the loop, hence switch to signal is warranted and this benefits of this particlaur optimization are lost. (It's worth noting that timed variants of pthread calls use realtime clock by default, and therefore can hang "forever" should the host time be changed. Unfortunatelly not all host systems QEMU runs on support CLOCK_MONOTONIC and/or pthread_condattr_setclock with this value) git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6632 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-21Avoid infinite loop around timed condition variablemalc1-6/+7
This can happen due to spurious wakeups git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6631 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-21Error checkingmalc1-24/+72
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6630 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-24Rename sigev_signo to avoid FreeBSD problems (Juergen Lock)blueswir11-1/+1
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6414 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-17Use kill instead of sigqueue: re-enables AIO on OpenBSDblueswir11-3/+1
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6360 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-13Fix race in POSIX AIO emulation (Jan Kiszka)aliguori1-7/+2
When we cancel an AIO request that is already being processed by aio_thread, qemu_paio_cancel should return QEMU_PAIO_NOTCANCELED as long as aio_thread isn't done with this request. But as the latter currently updates aiocb->ret after every block of the request, we may report QEMU_PAIO_ALLDONE too early. Futhermore, in case some zero-length request should have been queued, aiocb->ret is never set to != -EINPROGRESS and callers like raw_aio_cancel could get stuck in an endless loop. Fix those issues by updating aiocb->ret _after_ the request has been fully processed. This also simplifies the locking. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6278 c046a42c-6fe2-441c-8c8c-71466251a162
2008-12-13Remove unnecessary trailing newlinesblueswir11-1/+0
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6000 c046a42c-6fe2-441c-8c8c-71466251a162
2008-12-12Replace posix-aio with custom thread poolaliguori1-0/+202
glibc implements posix-aio as a thread pool and imposes a number of limitations. 1) it limits one request per-file descriptor. we hack around this by dup()'ing file descriptors which is hideously ugly 2) it's impossible to add new interfaces and we need a vectored read/write operation to properly support a zero-copy API. What has been suggested to me by glibc folks, is to implement whatever new interfaces we want and then it can eventually be proposed for standardization. This requires that we implement our own posix-aio implementation though. This patch implements posix-aio using pthreads. It immediately eliminates the need for fd pooling. It performs at least as well as the current posix-aio code (in some circumstances, even better). Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5996 c046a42c-6fe2-441c-8c8c-71466251a162