search for: asynch

...Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + +import select +import nbd + +disk_size = 512 * 1024 * 1024 +bs = 65536 +max_reads_in_flight = 16 +bytes_read = 0 +bytes_written = 0 + +def asynch_copy (src, dst): + size = src.get_size () + + # This is our reading position in the source. + soff = 0 + + # This callback is called when any pread from the source + # has completed. + writes = [] + def read_completed (buf, offset, error): + global bytes_read + by...

On Jun 14, 2011, at 10:27 AM, Duncan Sands wrote: > Hi Chris, I've CC'd Eric Botcazou in the hope that he will clear up just what > the Ada front-end needs from the rest of the compiler as far as asynchronous > exceptions are concerned. > >>> gcc Ada turns signals into exceptions. As far as I know it does this >>> completely asynchronously, and the fact that LLVM doesn't support this >>> is rather bad as far as Ada is concerned. That said, the Ada front-end...

Hi all, I have created a linear mixed-effects model using lmer. My dependent variable is comp.score and my main independent variable is delay.type, a repeated-measures within-subject variable (2 levels: Synch and Asynch, order counter-balanced across participants). I had a series of covariates that were included in the initial model and used a step-wise process to produce the most parsimonious model (two covariates age and PLE). The final model was: disem<-lmer(comp.score~delay.type+age+PLE+(1|id), data=Disem...

Hi Chris, I've CC'd Eric Botcazou in the hope that he will clear up just what the Ada front-end needs from the rest of the compiler as far as asynchronous exceptions are concerned. >> gcc Ada turns signals into exceptions. As far as I know it does this >> completely asynchronously, and the fact that LLVM doesn't support this >> is rather bad as far as Ada is concerned. That said, the Ada front-end > > You're s...

...guestfs/2019-August/msg00103.html In v2 I've made several changes: - Fix Python callbacks so if they don't return something which is int-like, we assume they mean to return 0. - Add nbd.Buffer free() method. Read commit message in patch 2 to see what this is about. - Fixed the asynch copy test to deal with the unbelievably braindead behaviour of Python closures. It took me many hours this morning to work out what was going on. It turns out that Python closures aren't closed (yeah, the clue is in the name, Python developers). Rich.

...ub.com/nertpinx/v2v-conversion-host/commit/0bb2efdcacd975a2cae7380080991ac7fc238d2b The first 4 patches are fairly uncontroversial miscellaneous cleanups. Patch 5 is the interesting one. (Note it doesn't quite work yet, so it's for discussion only.) Patch 5 converts the inner loop to use asynchronous libnbd calls. performance improves quite a bit for me -- about 13 minutes down to 5 minutes for an "initial" run on a moderate sized Linux VM. We do this by changing the read call from nbd.pread to nbd.aio_pread and moving the writing code into a completion callback which runs when...

...k). If we are using synchronous API, this is not a problem (we never have more than one request in flight at once, which implies there are no outstanding replies from the server when we send a request, so we always get the needed POLLIN when the server's next reply begins); but if we are using asynch API and have more than one message in flight, it is conceivable that the server flushes its complete reply queue (two or more replies) contained within a single encrypted network packet, but where our state machine reads only the first reply and then waits for a POLLIN kick before reading again. F...

...ece /db/dumps/TR1_1/rmanbackup/TR1_88_1 ORA-19502: write error on file "/db/devices/db1/PR2/pr2_1/pr2.data1", blockno 1409 (blocksize=8192) ORA-27061: waiting for async I/Os failed Linux-x86_64 Error: 5: Input/output error Tried various Oracle init parameters for filesystem i/o SETALL, ASYNCH, DIRECT and also disk_asynch_io settings. After this failure tried to used a non ocfs2 filesytem (ext3) for the source RMAN backup files, however the error still occurred. For testing purposes specified a non ocfs2 filesystem ( ext3 ) as restore target filesystem and the RMAN restore completed s...

I was wondering if the disk I/O in OpenSSH is synchronous or asynchronous. If its not asynchronous is there any reason why doing at least asynch writes would be a bad idea? I'm just wondering if I'm over looking some obvious problem. Thanks for the clue Chris

On Jun 13, 2011, at 2:23 PM, Andrew Trick wrote: >> There is really no alternative to putting EH edges on basic blocks if you're going to support preemptive asynchronous exceptions — some random multiply that gets hoisted out of a loop has to change exception handlers just in case that's where the PC lands during a signal. There isn't much point in complaining that doing so muddies the CFG, which is really just an inherent fact of handling asynchrono...

On Jun 14, 2011, at 2:11 AM, Duncan Sands wrote: > gcc Ada turns signals into exceptions. As far as I know it does this > completely asynchronously, and the fact that LLVM doesn't support this > is rather bad as far as Ada is concerned. That said, the Ada front-end You're saying that it turns asynch signals like SIGHUP (which can occur on any machine instruction) into signals? -Chris

...e of a prologue > or epilogue, at which point having more fine-grained directives can > help. In practice there's no real reason to do that so people don't > emit directives for it (at least not as a high priority). > > Cheers. > > Tim. OpenVMS' EH model is for full asynchronous prologue/epilogue EH.  We do more than just program-level EH, but have to deal with OS events (timers going off, asynch I/O completion, mailboxes filled with data, etc.) which could result in an unwind occurring.   We're just about finished with our proposal for extending the x86 compact...

...l(2): https://github.com/libguestfs/libnbd/blob/a5fe64ab5323d649d348e61c9126ef7e7234c145/examples/batched-read-write.c#L69 It currently works from golang too, but it seems likely that synchronous calls like nbd_pread are blocking the golang main loop (because we make our own call to poll(2)). The asynch stuff also works (see libnbd_590_aio_copy_test.go in the attached patch) but it's rather awkward. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from...

...qmp_capabilities (all other commands are ignored until you do this). It's unclear how capabilities negotiation is supposed to work, since there are currently no capabilities. -> { "execute": "qmp_capabilities" } <- {"return": {}} At shut down QMP sends an asynch event: <- {"timestamp": {"seconds": 1301057475, "microseconds": 2615}, "event": "SHUTDOWN"} It appears asynch events can arrive at any time. Other commands can be run (after capabilities "negotiation" see above): -> { "execu...

Hi John, On 13/06/11 23:27, John McCall wrote: > On Jun 13, 2011, at 2:12 PM, Andrew Trick wrote: >> Although I believe asynchronous signals are also best handled by the runtime. They can be converted into cooperative exceptions. I have to say I can't see the value in resuming from an interrupt at literally any instruction address. > > For what it's worth, SEH (which inspires a lot of this) allows blocks of c...

On 19 Jan 2018, at 14:48, John Reagan via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > OpenVMS' EH model is for full asynchronous prologue/epilogue EH. We do more > than just program-level EH, but have to deal with OS events (timers going off, > asynch I/O completion, mailboxes filled with data, etc.) which could result in > an unwind occurring. > > We're just about finished with our proposal fo...

This doesn't yet work. However it does make me more convinced than ever that we really need to sort out persistent buffer lifetimes in the library (similar to what we did for closures). Rich.

In order to get more information on IO performance problems I created the script below: #!/usr/sbin/dtrace -s #pragma D option flowindent syscall::*write*:entry /pid == $1 && guard++ == 0/ { self -> ts = timestamp; self->traceme = 1; printf("fd: %d", arg0); } fbt::: /self->traceme/ { /* elapsd =timestamp - self -> ts; printf("

Hi all, Is there some documentation or some example on how to interpret the arg0 .. arg<n> for the aioread, aiowrite, aiowait syscalls? The system call name for all three seems to be "kaio". Michael === Michael Mueller ================== Tel. + 49 8171 63600 Fax. + 49 8171 63615 Web: http://www.michael-mueller-it.de ======================================

I think it's valuable to have precise / asynchronous unwind information without adding support for non-call exceptions. Profilers and debuggers need to be able to unwind the stack from arbitrary instruction boundaries, but they don't need to run exception handlers. We can still declare that outside the model. Speaking of which, barring bugs...