search for: read_verifi

On 8/13/19 5:36 PM, Richard W.M. Jones wrote: > Change the way that we deal with freeing closures in language > bindings: > > * The valid_flag is removed (mostly reverting > commit 2d9b98e96772e282d51dafac07f16387dadc8afa). > > * An extra ‘free’ parameter is added to all callback structures. This > is called by the library whenever the closure won't be called

On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

On Wed, Jul 24, 2019 at 12:21:37PM -0500, Eric Blake wrote: > On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > > Previously closures had a crude flag which tells if they are > > persistent or transient. Transient closures (flag = false) last for > > the lifetime of the currently called libnbd function. Persistent > > closures had an indefinite lifetime which could last

On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

On Wed, Jul 24, 2019 at 10:18:20AM -0500, Eric Blake wrote: > On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > > +=head2 Callback lifetimes > > + > > +All callbacks have an C<int valid_flag> parameter which is used to > > +help with the lifetime of the callback. C<valid_flag> contains the > > +I<logical or> of: > > Again, worth mentioning

Demonstrate a use of the new nbd_pread_structured_verify API by writing a strict validation that a server's structured replies comply with the specification (well, 99% strict, as I did not check that the server does not return an error at the same offset twice). I was able to test that qemu-nbd is compliant. An example run: $ qemu-img create -f qcow2 file 32m $ for i in `seq 32`; do

On 7/25/19 8:07 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

Change the way that we deal with freeing closures in language bindings: * The valid_flag is removed (mostly reverting commit 2d9b98e96772e282d51dafac07f16387dadc8afa). * An extra ‘free’ parameter is added to all callback structures. This is called by the library whenever the closure won't be called again (so the user_data can be freed). This is analogous to valid_flag ==

Patches 1 & 2 are rather complex, but the end result is that we pass closures + user_data + free function in single struct parameters as I described previously in this email: https://www.redhat.com/archives/libguestfs/2019-August/msg00210.html Patch 3 adds a convenient FREE_CALLBACK macro which seems a worthwhile simplification if you buy into 1 & 2. Patch 4 adds another macro which is

I think I've addressed everything that was raised in review. Some of the highlights: - Callbacks should be freed reliably along all exit paths. - There's a simple test of closure lifetimes. - I've tried to use VALID|FREE in all the places where I'm confident that it's safe and correct to do. There may be more places. Note this is an optimization and shouldn't

Existing practice tends to prefer the void* closure argument for C callbacks to occur after the function pointer (POSIX: pthread_create; glibc: qsort_r; glib: g_thread_new; libvirt: virConnectDomainEventRegisterAny; etc.). It's also handy to think that calling 'myfunc(cb, arg)' will eventually result in a call to 'cb(arg)'. While I couldn't quickly find any style guide

As discussed in this thread, the parameter is an invitation to write code with race conditions: https://www.redhat.com/archives/libguestfs/2019-July/thread.html#00309 --- docs/libnbd.pod | 6 +- examples/glib-main-loop.c | 10 ++-- examples/strict-structured-reads.c | 2 +- generator/generator | 57

The freeing feature can now be done by associating a free callback with a closure's user_data, so having the valid_flag is no longer necessary and it can be completely removed. This mostly reverts commit 2d9b98e96772e282d51dafac07f16387dadc8afa. --- TODO | 2 - docs/libnbd.pod | 64 ++-------------- examples/glib-main-loop.c |

This implements most of what I wrote here: https://www.redhat.com/archives/libguestfs/2019-July/msg00213.html

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

The original nbd_aio_* (non-callback) functions are removed and replaced with the renamed callback variants. This is a simple mechanical change to the API: (1) Any existing call to nbd_aio_*_callback can simply be renamed to nbd_aio_* (2) Any existing call to nbd_aio_* must have two extra NULL parameters added before the final flags parameter. In non-C languages, only change (1) is

Convert the S_<FOO> symbolic permissions to their octal equivalents as using octal and not symbolic permissions is preferred by many as more readable. see: https://lkml.org/lkml/2016/8/2/1945 Done with automated conversion via: $ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...> Miscellanea: o Wrapped modified multi-line calls to a single line where

Convert the S_<FOO> symbolic permissions to their octal equivalents as using octal and not symbolic permissions is preferred by many as more readable. see: https://lkml.org/lkml/2016/8/2/1945 Done with automated conversion via: $ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...> Miscellanea: o Wrapped modified multi-line calls to a single line where

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to