Re: [Xen-devel] Re: [PATCH] libxenlight: fix multiple xenstore watches problem

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

I will apply Stefano's patches now, then you can see what bits you need to
re-send. Stefano or Vincent will want to ack/nack your patches before I try
to apply them anyway.

 -- Keir

On 02/12/2009 18:08, "Andres Lagar-Cavilla" <andres@xxxxxxxxxxxxxxxx> wrote:

> mmm,
> most likely the first two patches in my latest resend clash against
> this. Yikes
> Andres
>> Message: 3
>> Date: Wed, 2 Dec 2009 15:01:32 +0000
>> From: Stefano Stabellini<stefano.stabellini@xxxxxxxxxxxxx>
>> Subject: [Xen-devel] [PATCH] libxenlight: fix multiple xenstore
>> watches problem
>> To: xen-devel@xxxxxxxxxxxxxxxxxxx
>> Message-ID:<alpine.DEB.2.00.0912021455450.26846@kaball-desktop>
>> Content-Type: text/plain; charset="US-ASCII"
>> 
>> Hi all,
>> this patch fixes the multiple xenstore watches problem in libxenlight
>> opening a new xenstore connection to set and read temporary watches on
>> the device state nodes.
>> This way they don't interfere with other long running watches.
>> 
>> Signed-off-by: Stefano Stabellini<stefano.stabellini@xxxxxxxxxxxxx>
>> 
>> ---
>> 
>> diff -r 96a9740f4f33 tools/libxl/libxl_device.c
>> --- a/tools/libxl/libxl_device.c Wed Dec 02 14:29:24 2009 +0000
>> +++ b/tools/libxl/libxl_device.c Wed Dec 02 14:43:06 2009 +0000
>> @@ -212,47 +212,50 @@
>>       fd_set rfds;
>>       struct timeval tv;
>>       flexarray_t *toremove;
>> +    struct libxl_ctx clone = *ctx;
>> 
>> +    clone.xsh = xs_daemon_open();
>>       toremove = flexarray_make(16, 1);
>> -    path = libxl_sprintf(ctx, "/local/domain/%d/device", domid);
>> -    l1 = libxl_xs_directory(ctx, XBT_NULL, path,&num1);
>> +    path = libxl_sprintf(&clone, "/local/domain/%d/device", domid);
>> +    l1 = libxl_xs_directory(&clone, XBT_NULL, path,&num1);
>>       if (!l1) {
>> -        XL_LOG(ctx, XL_LOG_ERROR, "%s is empty", path);
>> +        XL_LOG(&clone, XL_LOG_ERROR, "%s is empty", path);
>> +        xs_daemon_close(clone.xsh);
>>           return -1;
>>       }
>>       for (i = 0; i<  num1; i++) {
>> -        path = libxl_sprintf(ctx, "/local/domain/%d/device/%s", domid,
>> l1[i]);
>> -        l2 = libxl_xs_directory(ctx, XBT_NULL, path,&num2);
>> +        path = libxl_sprintf(&clone, "/local/domain/%d/device/%s", domid,
>> l1[i]);
>> +        l2 = libxl_xs_directory(&clone, XBT_NULL, path,&num2);
>>           if (!l2)
>>               continue;
>>           for (j = 0; j<  num2; j++) {
>> -            fe_path = libxl_sprintf(ctx, "/local/domain/%d/device/%s/%s",
>> domid, l1[i], l2[j]);
>> -            be_path = libxl_xs_read(ctx, XBT_NULL, libxl_sprintf(ctx,
>> "%s/backend", fe_path));
>> +            fe_path = libxl_sprintf(&clone, "/local/domain/%d/device/%s/%s",
>> domid, l1[i], l2[j]);
>> +            be_path = libxl_xs_read(&clone, XBT_NULL, libxl_sprintf(&clone,
>> "%s/backend", fe_path));
>>               if (be_path != NULL) {
>> -                if (libxl_device_destroy(ctx, be_path, force)>  0)
>> +                if (libxl_device_destroy(&clone, be_path, force)>  0)
>>                       n_watches++;
>> -                flexarray_set(toremove, n++, libxl_dirname(ctx, be_path));
>> +                flexarray_set(toremove, n++, libxl_dirname(&clone,
>> be_path));
>>               } else {
>> -                xs_rm(ctx->xsh, XBT_NULL, path);
>> +                xs_rm(clone.xsh, XBT_NULL, path);
>>               }
>>           }
>>       }
>>       if (!force) {
>> -        nfds = xs_fileno(ctx->xsh) + 1;
>> +        nfds = xs_fileno(clone.xsh) + 1;
>>           /* Linux-ism */
>>           tv.tv_sec = LIBXL_DESTROY_TIMEOUT;
>>           tv.tv_usec = 0;
>>           while (n_watches>  0&&  tv.tv_sec>  0) {
>>               FD_ZERO(&rfds);
>> -            FD_SET(xs_fileno(ctx->xsh),&rfds);
>> +            FD_SET(xs_fileno(clone.xsh),&rfds);
>>               if (select(nfds,&rfds, NULL, NULL,&tv)>  0) {
>> -                l1 = xs_read_watch(ctx->xsh,&num1);
>> +                l1 = xs_read_watch(clone.xsh,&num1);
>>                   if (l1 != NULL) {
>> -                    char *state = libxl_xs_read(ctx, XBT_NULL, l1[0]);
>> +                    char *state = libxl_xs_read(&clone, XBT_NULL, l1[0]);
>>                       if (!state || atoi(state) == 6) {
>> -                        xs_unwatch(ctx->xsh, l1[0], l1[1]);
>> -                        xs_rm(ctx->xsh, XBT_NULL, l1[1]);
>> -                        XL_LOG(ctx, XL_LOG_DEBUG, "Destroyed device backend
>> at %s", l1[1]);
>> +                        xs_unwatch(clone.xsh, l1[0], l1[1]);
>> +                        xs_rm(clone.xsh, XBT_NULL, l1[1]);
>> +                        XL_LOG(&clone, XL_LOG_DEBUG, "Destroyed device
>> backend at %s", l1[1]);
>>                           n_watches--;
>>                       }
>>                       free(l1);
>> @@ -263,9 +266,10 @@
>>       }
>>       for (i = 0; i<  n; i++) {
>>           flexarray_get(toremove, i, (void**)&path);
>> -        xs_rm(ctx->xsh, XBT_NULL, path);
>> +        xs_rm(clone.xsh, XBT_NULL, path);
>>       }
>>       flexarray_free(toremove);
>> +    xs_daemon_close(clone.xsh);
>>       return 0;
>>   }
>> 
>>    
> 
> 
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